Nothing too dramatic today. I managed to get out after work and grab my drill with a drum sanding attachment and went to work on my Leading edge jig (its actually more of a support stand than a jig). I sure wish I would have resolved my padding solution before I cut the panels with the jig saw. Sometimes I am so precise with my measurements that they are bit too precise. I had a percect fit for my leading edge ribs, but absolutely no additional space for the .025 inch thick wing skins or the anti scuff material around the edges of the supports. Needless to say there is a lot of sanding dust in the garage now, and since I free handed the additional wood removal with the sanding drum on the drill, I have very uneven gaps along the edges of the supports.
Vans says this is all that is needed since all you are doing is supporting the match drilled leading edge assembly. Problem is that there are a lot of posts from builders who have experienced the difficulties of trying to cleco all the holes in the skins to the ribs. Everyone seems to be able to get one side done relatively easy, and then struggles with the wrap around and clecoeing of the other side. Most builders have reported that a different method than what Vans describes is wht works best, i.e. working from the nose rearward or vices versa. Anyway, as soon as I get the supports widened up a bit more I will tiral fit the skin and the LE ribs and get to see for myself how this will go.Getting ready for one more blast of winter around here for the next couple of days (was 80 degree today - sigh......). Can't wait to get my LE mock up put together so I can finish the gun ports.
Monday, April 29, 2013
Fooled ya!!
For some reason I think that I must have exceeded bloggers memory lmitations when I tried to add a second video to the same post. So here is the second video I eluded to in my previous post inc ase you were wondering where that went. Can't wait to get the full mockup done. I have a rather huge order to place with Aircraft Spruce and Vans. That is one of the problems with attending these SportAir workshops - you come away realizing that there is now a bunch of cool stuff that you need to get so you can try out all the cool things you learned in the class. I now need fiberglass, flox, micro, epoxy resin, peel ply, and so on and so on. Welcome to the expensive world of composite materials! I also need to order a small sheet of .025 alclad aluminum to use as a a leading edge wing skin. I will attach that to the two rib cutouts from my LE wing jig so that I have a test surface upon which to apply my mocked up gun fairings. Happy Monday all! (If there is such a thing...)
Fabrication of Prototype Test Gun Faring
Lots of busy house stuff going on this weekend now that the weather has made a turn for the better, so work on the plane was slow, with most of my attention focused on the fabrication of my fake P-51 style gun port. I also contacted Vans on Friday to discuss this modification with them, based on the fact that this will be an added element to the leading edge of the wing, and I need to make sure that I am not doing anything inherently unsafe.
The last thing I want is for this assembly to get ripped off of the leading edge of the wing during moderate G maneuvers of say 4 Gs or less, so I need to make certain that my "in wing" concept is sound. There are risks of fire nad potential structural failure of the wing at stake here, so again, consider this my disclaimer that if you wish to take on thise sort of thing yourself, you need to do the research, consider the risks, and take the appropriate steps to properly design and test leyour ideas. The EAA and the FAA are gracious enough to allow us to experiment with our designs, and provides several programs that we as builders can take full advantage of to ensure that we are doing so as safely as possible.
After a bunch of rough sketches, notes, and hours of deep thought about how best to design and build the gun farings, I came up with the basis for a prototype design. I plan to use a special reinforced fiberglass material, polystyrene foam, and a combination of various filler and strengthening materials to reinforce the critical areas of the faring that attaches the assembly to the wing. This, combined with some stock and fabricated PVC parts from the local HD aviation supply store, will make up the bulk of the materials.
So here are some more pics:
First is the fabricated gun fairing assembly that houses the bulb base as well as the light bulb.
I tried very hard to find an existing PVC part that had the base flange that I needed, but I can tell you with reasonable assurance that it does not exist. There are parts that I found that are close, but they are designed for much larger electrical and plumbing assemblies with diameters of 3 inches or more, and are much too large for my application, not to mention very expensive. So I had to come up with a way to fabricate my own flange. I settled on a conduit junction box that has walls that are 1/4 inch thick. All of the parts are rough cut only, and are not perfectly symmetrical. Part of the prototyping process involves figuring out the required assembly steps, and I am not after perfectly formed parts at this stage - just enough to get the basic design down.
I used a piece of .032 alclad aluminum from a trim kits I purchased long ago from Vans as a backer plate for the assembly. What you don't see is yet another aluminum plate that I will probably add to the front before it is all done. I thought that I could simply countersink the PVC for the #6 countersunk screws I plan to use, and just encase that in Epoxy and fiberglass for added strength. What I have found is that the PVC I am working with does not counterink very well using manual methods, and it also caused me to question the strength of the PVC. So as a result I will sandwich the PVC flange between two pieces of aluminum and then encase it in fiberglass. This way I can dimple the aluminum on the front for the #6 screws so that they have a solid mounting patform.
Here are the pieces left over from the PVC junction box after cutting some circles on my band saw:
From the rear you will notice that I am using a special nut plate designed to fit in tight corners. This seems to work well and I just need to iron out my match drilling process to ensure that all holes for assembled parts are properly aligned. The whole concept behind this assembly is to make it removeable so that the electrical wires and the light mounting base can be connected/disconnected, inspected, serviced, or replaced as needed. This entire assembly will be mounted to the rest of the fabricated gun port faring on the wing.
I will close this post with a couple of vidoes that prove that this design will work. The first video I got all the way up to connecting the circuit, and of course it did not work! I am having some strange problems with the strobe controller from time to time, but until I have a stable, mounted electrical platform to work with that is on a continuous source of 12 volt power instead of a 9 volt battery, it is hard to say what is causing the problems. IN one case the strobe controller became horribly confused and would not even shut off. I will have a series of switches in the airplane that will control power supplied to the light system, so I don't think I will have any problems shutting it all off whenever I need to, but it is a bit disconcerting to know that the the system may very well develop a mind of its own.
EDITED 5-26-17. The above video only shows my test setup. The lights would not energize for any of the reasons listed in the next paragraph. I ended up tweaking some things (don't remember if it was a new battery or if I discovered some play in the connection between the back plate and the grounding tabs of the light socket, but in the next post at https://bryansrv8project.blogspot.com/2013/04/fooled-ya.html I finally got it working.
ORIGINAL Entry.....See edits above and go to the next post to see it working.
And here is the subsequent video where I managed to get it to come to life. Again, not sure why it decided not to work the first time, but it may have something to do with the forward voltage requirement for such a high powered LED, and the use of a less than fully charged 9 volt battery for testing, or a short in the wires, or a fault in the chip circuitry of the strobe controller, or the alclad coating not providing a good electrical contact, or..... well..... you get the idea. Lots more testing needed on all this.
And finally, if you think what I am doing is kinda cool, I have been sitting here watching an episode on the Smithsonian channel called the incredible flying cars. It is absolutely amazing to see the level and type of technology that is currently being developed and tested in today's world. While I am certainly no engineer in the typical sense, I am still absolutely amazed at what the collective imagination of all those engineers can conjur up.
The last thing I want is for this assembly to get ripped off of the leading edge of the wing during moderate G maneuvers of say 4 Gs or less, so I need to make certain that my "in wing" concept is sound. There are risks of fire nad potential structural failure of the wing at stake here, so again, consider this my disclaimer that if you wish to take on thise sort of thing yourself, you need to do the research, consider the risks, and take the appropriate steps to properly design and test leyour ideas. The EAA and the FAA are gracious enough to allow us to experiment with our designs, and provides several programs that we as builders can take full advantage of to ensure that we are doing so as safely as possible.
After a bunch of rough sketches, notes, and hours of deep thought about how best to design and build the gun farings, I came up with the basis for a prototype design. I plan to use a special reinforced fiberglass material, polystyrene foam, and a combination of various filler and strengthening materials to reinforce the critical areas of the faring that attaches the assembly to the wing. This, combined with some stock and fabricated PVC parts from the local HD aviation supply store, will make up the bulk of the materials.
So here are some more pics:
First is the fabricated gun fairing assembly that houses the bulb base as well as the light bulb.
I tried very hard to find an existing PVC part that had the base flange that I needed, but I can tell you with reasonable assurance that it does not exist. There are parts that I found that are close, but they are designed for much larger electrical and plumbing assemblies with diameters of 3 inches or more, and are much too large for my application, not to mention very expensive. So I had to come up with a way to fabricate my own flange. I settled on a conduit junction box that has walls that are 1/4 inch thick. All of the parts are rough cut only, and are not perfectly symmetrical. Part of the prototyping process involves figuring out the required assembly steps, and I am not after perfectly formed parts at this stage - just enough to get the basic design down.
I used a piece of .032 alclad aluminum from a trim kits I purchased long ago from Vans as a backer plate for the assembly. What you don't see is yet another aluminum plate that I will probably add to the front before it is all done. I thought that I could simply countersink the PVC for the #6 countersunk screws I plan to use, and just encase that in Epoxy and fiberglass for added strength. What I have found is that the PVC I am working with does not counterink very well using manual methods, and it also caused me to question the strength of the PVC. So as a result I will sandwich the PVC flange between two pieces of aluminum and then encase it in fiberglass. This way I can dimple the aluminum on the front for the #6 screws so that they have a solid mounting patform.
Here are the pieces left over from the PVC junction box after cutting some circles on my band saw:
From the rear you will notice that I am using a special nut plate designed to fit in tight corners. This seems to work well and I just need to iron out my match drilling process to ensure that all holes for assembled parts are properly aligned. The whole concept behind this assembly is to make it removeable so that the electrical wires and the light mounting base can be connected/disconnected, inspected, serviced, or replaced as needed. This entire assembly will be mounted to the rest of the fabricated gun port faring on the wing.
I will close this post with a couple of vidoes that prove that this design will work. The first video I got all the way up to connecting the circuit, and of course it did not work! I am having some strange problems with the strobe controller from time to time, but until I have a stable, mounted electrical platform to work with that is on a continuous source of 12 volt power instead of a 9 volt battery, it is hard to say what is causing the problems. IN one case the strobe controller became horribly confused and would not even shut off. I will have a series of switches in the airplane that will control power supplied to the light system, so I don't think I will have any problems shutting it all off whenever I need to, but it is a bit disconcerting to know that the the system may very well develop a mind of its own.
EDITED 5-26-17. The above video only shows my test setup. The lights would not energize for any of the reasons listed in the next paragraph. I ended up tweaking some things (don't remember if it was a new battery or if I discovered some play in the connection between the back plate and the grounding tabs of the light socket, but in the next post at https://bryansrv8project.blogspot.com/2013/04/fooled-ya.html I finally got it working.
ORIGINAL Entry.....See edits above and go to the next post to see it working.
And here is the subsequent video where I managed to get it to come to life. Again, not sure why it decided not to work the first time, but it may have something to do with the forward voltage requirement for such a high powered LED, and the use of a less than fully charged 9 volt battery for testing, or a short in the wires, or a fault in the chip circuitry of the strobe controller, or the alclad coating not providing a good electrical contact, or..... well..... you get the idea. Lots more testing needed on all this.
And finally, if you think what I am doing is kinda cool, I have been sitting here watching an episode on the Smithsonian channel called the incredible flying cars. It is absolutely amazing to see the level and type of technology that is currently being developed and tested in today's world. While I am certainly no engineer in the typical sense, I am still absolutely amazed at what the collective imagination of all those engineers can conjur up.
Sunday, April 21, 2013
An Exhausting Weekend at SportAir Workshop
So comes gthe end of my vacation week. What better way to do that than to attend another weekend SportAir Workshop held by the EAA at RedStone College near KBJC. This is a very well known School for Aircraft Mechanics. This time the class was for Composite Construction techniques, aka fiberglass, carbon fiber, and other materials used in aircraft construction. My main focus for attending this class was to determine what I can use to fabricate the fake machine gun farings for the leading edges of my wings. Many of the others in my class were from the boating or race car genres, and others were building aircraft completely out of composite materials by using plans and not kits.
This class, as with all of the other classes, provides invaluable information, and for the $350.00 price tag you need to soak up as much of it as possible. There are at least 2 or 3 more of these classes I intend to take in the future, including, welding, firewall forward, and maintaining your aircraft. These will come later on, but for now I will add this latest class to my existing list of attended classes, including basic sheet metal, RV construction techniques, and Electrical systems.
While there on Saturday Mike Rettig (attending the electrical class) and I stopped by the hangar where the builds for Bob Markert (RV8) and Sean Thomas wage on. Sean has now passed me up and is working on his fuel tanks. I got to see some Proseal action in progress, so that was good. I learned from him to use a technique where I will use a scale that can read in gram units to measure out the proseal by measuring the correct amounts for each of the two parts of this stuff, then mix together in a separate cup, then take a plastic bag and place the mixture inside it, and then cut abottom corner out the bag, and using it like a cake frosting decorator, squeeze the mixture onto an appropriate syringe, which I will then use to apply the proseal in precisely the areas that I need.
Bob Markert is still wrapping up some wing stuff and working on his fuselage. It is great to see both a completed RV8 (Jim gray), and Bobs fuselage under construction, all in the same hangar. I took some additional photos of Bob's planned parking brake mechanism, ELT mount, access door for back side of the avionics bay, and his static port assembly. One other item that I was not aware that he was going to add was a prefabricated removeable Smoke Tank, which I also intend to install on my aircraft. Jim Gray also has this same tank for his aircraft, so I will have lots of knowledgeable folks to ask questions about all this when the time comes.
First pic is of Bob's Fuel Pump assembly. taken from the front of the firewall looking down from the top. The issue with this little assembly is about the tight space with which to make bends in the fuel lines. Bob spoke about providing bends in the line to provide some flex capability, which apparently does not exist if the lines are left too straight. Not sure I understand all that yet, but in time I will I am sure. Wow, those sure are some tight 90 degree bends.
Next shot is of the parking brake assembly. That is all I know about it at this point, but I plan on putting one on my plane so I will be paying close attention to how Bob does his. This was taken from the front again looking rearward:
And now from the cockpit side:
Next is the smoke tank. There is another version with a smaller tank that I think that Sean said he was going to put in his plane, and I may end up doing the same, but this is a typical full size tank that is used for those that are so inclined.
Next is Bob's Static source plumbing in the back of the fuselage. I ahve the fittings for all this already. Just need a fuselage to mount them on!
the last two pics show the Adel clamps and nuts/bolts used to atach everything to the bulkhead.
NOw on to the sport air composites class. I managed to get a few pics of some of the activity today. We learned how to use a bagging technique for vacuum forming that allows the parts to cure more quickly and also provide a much better finish by extruding all excess epoxy from the parts during the process. THis was very cool to witness, but it does involve some tools and know how in order to do it correctly.
First is instructor Scott Vanderveen getting ready to place some NACA vents fabricated from clay molds under the vacuum. There were about 14 of us in the class, so doing all of these at the same time presented some challenges.
The blue plastic is a self adhesive vacuum bagging vinyl material with some double sided sealing tape applied to the bottom layer. The red stuff on top of each part is a perforated teflon coated release material that allows excess epoxy to be extruded and separated from the parts.
Next is a heat pamp area and our primary working table where we made all are creations come to life. For the class you will make a canard airfoil section with a spar cap and foam core, a polystyrene foam and fiberglass sandwich that later becomes a partial wing spar assembly, and the naca vents shown above.
Next is the modeling clay that is used to form molds. You can apparently get this from Hobby Lobby locally. Sounds like time for a trip to the hobby store.
Next is a pic of what I think is just bed batting material that you can get from Joanns or any fabric store. this is used to help maintain a constant temperature while under the vacuum.
then the top layer of the bag goes down, and theother side of the tape, which actually resembles the clay or caulk, is exposed:
Then some pics of the vacuum pump assembly and process:
And finally the pump turned on the vacuum being applied:
And lastly, once the vacuum started working we had to try to massage the top of the bag around the parts. Mine did not turn out so well because the vaccum did not apply evently around the part and I could not get the wrinkles in the bag totally removed.
what I got most from this class was the confidence to be able to to acquire some supplies and create some mock ups from which I can fabricate my own machine gun composite parts. It will be a lot of fun, albeit time consuming, to fabricate everything and seee how it turns out. Totally worth while and highly recommended if you are even thinking about building an airplane.
To be continued.......
This class, as with all of the other classes, provides invaluable information, and for the $350.00 price tag you need to soak up as much of it as possible. There are at least 2 or 3 more of these classes I intend to take in the future, including, welding, firewall forward, and maintaining your aircraft. These will come later on, but for now I will add this latest class to my existing list of attended classes, including basic sheet metal, RV construction techniques, and Electrical systems.
While there on Saturday Mike Rettig (attending the electrical class) and I stopped by the hangar where the builds for Bob Markert (RV8) and Sean Thomas wage on. Sean has now passed me up and is working on his fuel tanks. I got to see some Proseal action in progress, so that was good. I learned from him to use a technique where I will use a scale that can read in gram units to measure out the proseal by measuring the correct amounts for each of the two parts of this stuff, then mix together in a separate cup, then take a plastic bag and place the mixture inside it, and then cut abottom corner out the bag, and using it like a cake frosting decorator, squeeze the mixture onto an appropriate syringe, which I will then use to apply the proseal in precisely the areas that I need.
Bob Markert is still wrapping up some wing stuff and working on his fuselage. It is great to see both a completed RV8 (Jim gray), and Bobs fuselage under construction, all in the same hangar. I took some additional photos of Bob's planned parking brake mechanism, ELT mount, access door for back side of the avionics bay, and his static port assembly. One other item that I was not aware that he was going to add was a prefabricated removeable Smoke Tank, which I also intend to install on my aircraft. Jim Gray also has this same tank for his aircraft, so I will have lots of knowledgeable folks to ask questions about all this when the time comes.
First pic is of Bob's Fuel Pump assembly. taken from the front of the firewall looking down from the top. The issue with this little assembly is about the tight space with which to make bends in the fuel lines. Bob spoke about providing bends in the line to provide some flex capability, which apparently does not exist if the lines are left too straight. Not sure I understand all that yet, but in time I will I am sure. Wow, those sure are some tight 90 degree bends.
Next shot is of the parking brake assembly. That is all I know about it at this point, but I plan on putting one on my plane so I will be paying close attention to how Bob does his. This was taken from the front again looking rearward:
And now from the cockpit side:
Next is the smoke tank. There is another version with a smaller tank that I think that Sean said he was going to put in his plane, and I may end up doing the same, but this is a typical full size tank that is used for those that are so inclined.
Next is Bob's Static source plumbing in the back of the fuselage. I ahve the fittings for all this already. Just need a fuselage to mount them on!
the last two pics show the Adel clamps and nuts/bolts used to atach everything to the bulkhead.
NOw on to the sport air composites class. I managed to get a few pics of some of the activity today. We learned how to use a bagging technique for vacuum forming that allows the parts to cure more quickly and also provide a much better finish by extruding all excess epoxy from the parts during the process. THis was very cool to witness, but it does involve some tools and know how in order to do it correctly.
First is instructor Scott Vanderveen getting ready to place some NACA vents fabricated from clay molds under the vacuum. There were about 14 of us in the class, so doing all of these at the same time presented some challenges.
The blue plastic is a self adhesive vacuum bagging vinyl material with some double sided sealing tape applied to the bottom layer. The red stuff on top of each part is a perforated teflon coated release material that allows excess epoxy to be extruded and separated from the parts.
Next is a heat pamp area and our primary working table where we made all are creations come to life. For the class you will make a canard airfoil section with a spar cap and foam core, a polystyrene foam and fiberglass sandwich that later becomes a partial wing spar assembly, and the naca vents shown above.
Next is the modeling clay that is used to form molds. You can apparently get this from Hobby Lobby locally. Sounds like time for a trip to the hobby store.
Next is a pic of what I think is just bed batting material that you can get from Joanns or any fabric store. this is used to help maintain a constant temperature while under the vacuum.
then the top layer of the bag goes down, and theother side of the tape, which actually resembles the clay or caulk, is exposed:
Then some pics of the vacuum pump assembly and process:
And finally the pump turned on the vacuum being applied:
And lastly, once the vacuum started working we had to try to massage the top of the bag around the parts. Mine did not turn out so well because the vaccum did not apply evently around the part and I could not get the wrinkles in the bag totally removed.
what I got most from this class was the confidence to be able to to acquire some supplies and create some mock ups from which I can fabricate my own machine gun composite parts. It will be a lot of fun, albeit time consuming, to fabricate everything and seee how it turns out. Totally worth while and highly recommended if you are even thinking about building an airplane.
To be continued.......
Thursday, April 18, 2013
More LED Light Goodies Arrived
In response to a suggestion from a member on the EAA forum related to my LED light project (link in a previous post), I ordered a couple of different versions of an 1156 replacement LED light that is designed to replace the existing front or tail light/turn signal lights in our cars. IN response to an inquirey by me about a proper weather proof solution, the suggestion was to use a 3 watt 1156 replacement LED light that has its own lense cover. I ordered 2 of those in addition to two other 1156 lights without a lense cover that have a total of 45 SMD (Surface mount devices) attached in front and all around the circumferance of that light. The former light with the lense contains a single red LED in the front. Here is pic of both of them wired up to a couple of different connectors that I also purchased:
The non-lensed 45 SMD light is on the top of the above pic, and the bottom one is the lensed single LED version of the 1156. Each one is mounted in a different style base connector that I am also evaluating for my application.
Then next couple of pics came our real blurry so sorry about that, but you can still get the idea:
45 SMD light:
And the Lensed single LED:
And now for the fun part. Here is another short video test of 4 lights all wired up to the strobe controller and ready to "fire." These are all 3 watt lights, and I All I can say is HOLY COW!. These are definitely almost blinding up close, and certainly can be seen from a considerable distance I think (tests pending). The whole thing is wired up to a 9 volt battery, so I can only imagine what a full 12 volt supply will look like. I think that these lights are the winners for my application. At first I thought that the 45 SMD light was putting out a lot more light, but when I wired all 4 of them together they seem to be about the same or fairly close. I still like the 45 SMD better because I can use a reflector of sorts to allow all the sideway light to be redirected back out to the front if I so desire. Having lights on the sides should help with viewing angles on the side of the aircraft.
Either way, with all four of them wired together the effect is just too cool for school!
One last building note. I also recently found what I consider to be a great solution for some padding on my leading edge wing jig. Originally I was just going to use some electrical tape to line the jig to repvent scratches and dings to my leading edge skins, but was not too thrilled about that solution since there was really no cushion effect. Then I found some fiber-type material that I purchased that I thought would work until I opened it and realized that this stuff was about as close to scotch brite pad as you can get without actually being one. So I had a DUH moment, and realized that I certainly did not want to use this stuff to line my jig. then I finally found some latex rubber weather sealant at HD aviation supply, and this stuff looks to be exactly what I was looking for.
I sanded out my cutouts for the jig to leave approximately 1/8 inch gap on either side. this weather strip is 1/8" thick x 3/4" wide if you keep both sides of it attached as it comes in the package. the package dimensions it gives are 1/8" x 3/8", which is exactly one half the width as you see it in the package. Turns out that it is designed to fit into tight spaces so you are supposed to separate the two halves when using it for its intended purpose. For my application I will just leave both sides together, and it will fit nicely inside my 3/4 inch thick jigs to provide jsut enough cushion and abrasion protection as I prep the leading edges and the fuel tanks for assembly.
And finally one last pic of the bayonet mount that I seem to prefer for may application so far:
The non-lensed 45 SMD light is on the top of the above pic, and the bottom one is the lensed single LED version of the 1156. Each one is mounted in a different style base connector that I am also evaluating for my application.
Then next couple of pics came our real blurry so sorry about that, but you can still get the idea:
45 SMD light:
And the Lensed single LED:
And now for the fun part. Here is another short video test of 4 lights all wired up to the strobe controller and ready to "fire." These are all 3 watt lights, and I All I can say is HOLY COW!. These are definitely almost blinding up close, and certainly can be seen from a considerable distance I think (tests pending). The whole thing is wired up to a 9 volt battery, so I can only imagine what a full 12 volt supply will look like. I think that these lights are the winners for my application. At first I thought that the 45 SMD light was putting out a lot more light, but when I wired all 4 of them together they seem to be about the same or fairly close. I still like the 45 SMD better because I can use a reflector of sorts to allow all the sideway light to be redirected back out to the front if I so desire. Having lights on the sides should help with viewing angles on the side of the aircraft.
Either way, with all four of them wired together the effect is just too cool for school!
One last building note. I also recently found what I consider to be a great solution for some padding on my leading edge wing jig. Originally I was just going to use some electrical tape to line the jig to repvent scratches and dings to my leading edge skins, but was not too thrilled about that solution since there was really no cushion effect. Then I found some fiber-type material that I purchased that I thought would work until I opened it and realized that this stuff was about as close to scotch brite pad as you can get without actually being one. So I had a DUH moment, and realized that I certainly did not want to use this stuff to line my jig. then I finally found some latex rubber weather sealant at HD aviation supply, and this stuff looks to be exactly what I was looking for.
I sanded out my cutouts for the jig to leave approximately 1/8 inch gap on either side. this weather strip is 1/8" thick x 3/4" wide if you keep both sides of it attached as it comes in the package. the package dimensions it gives are 1/8" x 3/8", which is exactly one half the width as you see it in the package. Turns out that it is designed to fit into tight spaces so you are supposed to separate the two halves when using it for its intended purpose. For my application I will just leave both sides together, and it will fit nicely inside my 3/4 inch thick jigs to provide jsut enough cushion and abrasion protection as I prep the leading edges and the fuel tanks for assembly.
And finally one last pic of the bayonet mount that I seem to prefer for may application so far:
Tuesday, April 16, 2013
Simulated Machine Gun Testing
One of the most enjotable things about building an experimental airplane is that there are numerous sources for everything from raw materials to electronics to tools, etc. Sometimes you have to "research" things in some less-than-obvious places to come up with solutions to a particular problem. One of the problems I am facing is trying to find a suitable weather proof enclosure for the simulated machine gun lights I mentioned in my previous post. I just happened to visit my local tool rental shop today to get a new propane tank for my backyard grill, and I noticed that they had a whole section of trailer light parts, including many LED assemblies. One of the lights caught my immediate attention. I have absolutey no specs on it yet, since the guy that does all the trailer stuff was out of the office while I was there. Nevertheless, I felt compelled to go ahead and buy one so I could try it out. It is a small round 3/4 inch fully enclosed pre-wired 12 volt dual LED light unit.
It looks like this:
I took it home and wired it up to a strobe controller unit that I have also been testing. I wired up this light and one of the other lights I had already purchased to the strobe controller wires, and then I set both lights about 7 feet apart on the floor, and turned it all on to see what would happen. I ahve to say I was very pleased with the results. While the intensity from these lights may not be very visible from a distance, from a static "on the ramp" perspective these are more than enough to provide some real crowd pleasing WOW factor. The following is short video I took. There is no gun sound (yet). This was strictly a light test.
Both lights appear to deliver about the same intensity, so right now I am guessing that the trailer light I purchased is about 1 watt - similar to the other one. They are both red LEDs, the only major difference being that the one I purchased today was enclosed inside a red lense cover and appeared to be sealed from the elements from both front and back. Hopefully the video has rendered properly on this post, because it really looks cool in all the raw footage. Right now I am planning on 4 lights - two in each wing, in the Leading Edge bay just after the outboard end of the integrated fuel tanks. I will do some mock ups to determine if a 3 gun arrangement in the same Bay will look OK or if that will appear to be too crowded, and decide if I can go with 3 lights per side instead of two after I get a better look at that.
The other light that I wired up was a 1 watt non-polarized wedge base light from Super Brite LEDs, shown here:
The other ones I ordered yesterday might be here tomorrow. I am having way too much fun with all this. True, I am not getting much done on the plane, but this was a big reason why I wanted to build it in the first place, so it's all good. There are many other tests to perform on all this, including adding two more lights to the same strobe controller circuit to see if it handles the load and if the sync between all 4 lights looks realistic or not.
It looks like this:
I took it home and wired it up to a strobe controller unit that I have also been testing. I wired up this light and one of the other lights I had already purchased to the strobe controller wires, and then I set both lights about 7 feet apart on the floor, and turned it all on to see what would happen. I ahve to say I was very pleased with the results. While the intensity from these lights may not be very visible from a distance, from a static "on the ramp" perspective these are more than enough to provide some real crowd pleasing WOW factor. The following is short video I took. There is no gun sound (yet). This was strictly a light test.
Both lights appear to deliver about the same intensity, so right now I am guessing that the trailer light I purchased is about 1 watt - similar to the other one. They are both red LEDs, the only major difference being that the one I purchased today was enclosed inside a red lense cover and appeared to be sealed from the elements from both front and back. Hopefully the video has rendered properly on this post, because it really looks cool in all the raw footage. Right now I am planning on 4 lights - two in each wing, in the Leading Edge bay just after the outboard end of the integrated fuel tanks. I will do some mock ups to determine if a 3 gun arrangement in the same Bay will look OK or if that will appear to be too crowded, and decide if I can go with 3 lights per side instead of two after I get a better look at that.
The other light that I wired up was a 1 watt non-polarized wedge base light from Super Brite LEDs, shown here:
The other ones I ordered yesterday might be here tomorrow. I am having way too much fun with all this. True, I am not getting much done on the plane, but this was a big reason why I wanted to build it in the first place, so it's all good. There are many other tests to perform on all this, including adding two more lights to the same strobe controller circuit to see if it handles the load and if the sync between all 4 lights looks realistic or not.
Monday, April 15, 2013
Special Project - Partially Revealed
I have not posted for a while for a number of reasons. Last week was a busy work week, and I ended up being sick for most of the week. In between all that, I managed to get most of my main rib wire run holes deburred. I then entered into a period of very intense research and development on an idea I have hinted at in various posts for quite some time now. Over the past week and a half I have visited literally hundreds of websites, and read hundreds of posts on various builder forums. I am happy to say that I am very close to making this idea a reality. It will still involve some additional time to fabricate, test, and develop the final solution, but the basic design concepts are laid down, and I have met some new friends at EAA along the way that are helping me make this idea come to life.
So what am I doing? For those that know me it is not hard to figure out. WWII aviation has always been a passion of mine. My finished airplane will also reflect that passion - being painted and fitted as closely as possible to a P-51D Mustang fighter aircraft. For a little fun I plan to add a portable smoke tank that will fit inside my forward baggage compartment, not that I like portraying the fact that I have been shot at and hit by enemy bullets, but everybody loves to see the smoke trails, and they will add to the overall effect.
For even more fun I plan to add "working" machine guns in the wings of my aircraft. Now when I say "working", I mean in an artificial sense, by using a series of very brite LED lights cleverly enclosed in a fabricated gun port that will emulate the actual gun ports on a P-51 Mustang. They will be attached to a strobe controller unit, that will then be tied into a sound system, and everything will ultimately be wired into the trigger switch on my Joysticks. Young Eagles will have a blast shooting enemy planes out of the sky (figuratively speaking of course!)
Originally I had thought that I was doing something unique, and as far as Vans RV aircraft are concerned, perhaps I still am. I see a lot of Military schemed RVs that will either have vinyl machine gun port stickers stuck to their aircraft, or they are cleverly and very realistically painted onto the wing. I just wanted something more I guess.
I found out that I was not as unique in my thinking as first thought when I just happened to venture onto the EAA website, and decided to do a search on the EAA forums. They had restructured the forums a couple of years ago, and this required everyone to establish new account IDs to gain access to the new forum sites. I guess I lost interest at that point, and found myself spending most of my time on the VAF website addressing building questions.
Anyway, just out of the blue one day I decided to go check the EAA forums to see if anyone was as crazy as me. Turns out that literally as of that very same week, someone had posted a new thread on the Homebuilders Corner forum about designing and implementing a fully electronic solution to adding fake machine guns to your experimental warbird aircraft. Before I knew it, I was right in the middle of the discussion, and I could not believe that thre were actually others out there with the same ambition, even if it would be applied to some different airplanes.
This is one of those ironic situations where those that are building WW I replica fighter planes actually had a bit of an easier time implementing this type of solution. In reality, WW I fighters had a very difficult time figuring out how to mount a working machine gun so that it would fire through the propellor blades without destroying the prop or killing the pilot. then came the infamous timing gear that solved all those problems. The WW I guys can retrofit an electronic light solution onto their WWI machine guns a lot easier than the rest of us WWII guys, who have to figure out how to mount them in the Wing. In the end the hardest part of the hole process is designing the proper machine ports and making absolutely sure that they are airworthy and safe for flight (read as - " will not fly off or rip off of the wing during high G maneuvers, etc.). Check out the machine gun thread on the EAA forums.
As a result of all this, the folks that run SuperBriteLEDs are now on my new best friends list. I have ordered a variety of test lights, controllers, and mounting bases, and, after getting some new info n the EAA forum thread, I now have several more lights on order. The challenge is how to make light flash with enough intensity so that a crowd waching the runway would actually see the flashes and here the sound of the guns going off. I am currently working with lights in the 3 watt range, but it may take as much as 5-10 watt powered lights to have a really good effect. My problem, as stated above, is how to get a light with that much power to fit in a relatively small space on the leading edge of the wing. In the end actual flight testing will determine of the flash is brite enough. The process of making multiple guns appear to fire with slightly out of sync timings for realism has already been tested (and works quite well I might add!).
The sound will be another challenge. I need to compile noise data from a lycoming engine at various power and prop settings and airspeeds during a low pass configuration with a crowd standing a certain distance away, to figure out what kind of sound would be needed from machine gun to be heard. That little problem lead me to the discovery of a group of WWI experimental airplane folks back in Kansas City know as the The Dawn Patrol that are even more crazy (or just have more fun) than me. There are a couple of folks there that have designed and are using an inert gas system and electronic trigger mechanism that takes care of the noise issue with no problem. Even provides realistic muzzle blast out of the ends of the guns. Truth is that I think that this is also what the Tora Tora Tora flight team of the Commemorative Air Force (CAF) is using when they re-enact the raid on Pearl Harbor. They will be at Airventure again this year and I can hardly wait.
My ultimate dream is to incorporate that same system in addition to the LED lights in my airplane to get the best of both systems. Now I think it's time for a disclaimer for anyone reading this that may have similar ideas.
The inert gas system is inherently dangerous. If things go wrong it could result in a number of outcomes - most all of which will be very unhealthy for pilot and passengers and perhaps innicent bystanders on the ground. I am approaching the application of both of these systems purely from a safety priority persepective. If I feel I can safely implement both systems then I will most likely do so, but I will start with the light systems first. I am not going about this without very seriously thinking through all of the things that could go wrong first. I will design my application as safely as possible to ensure that I can get maximum fun and minimum trouble with it. If you wish to do something similar, then you need to take the time and do the research to ensure that your application is a safe one as well.
The light testing phase has been fun. I will leave you with a couple of photos of possible light and in-wing gun port solutions that I am currently entertaining:
First is a pic of he first set of LED lights I ordered for testing. Most of these are different configurations of a 1 watt red LED light:
One example of a light mounted inside the gun port:
Much more to come on this. Stay tuned!
So what am I doing? For those that know me it is not hard to figure out. WWII aviation has always been a passion of mine. My finished airplane will also reflect that passion - being painted and fitted as closely as possible to a P-51D Mustang fighter aircraft. For a little fun I plan to add a portable smoke tank that will fit inside my forward baggage compartment, not that I like portraying the fact that I have been shot at and hit by enemy bullets, but everybody loves to see the smoke trails, and they will add to the overall effect.
For even more fun I plan to add "working" machine guns in the wings of my aircraft. Now when I say "working", I mean in an artificial sense, by using a series of very brite LED lights cleverly enclosed in a fabricated gun port that will emulate the actual gun ports on a P-51 Mustang. They will be attached to a strobe controller unit, that will then be tied into a sound system, and everything will ultimately be wired into the trigger switch on my Joysticks. Young Eagles will have a blast shooting enemy planes out of the sky (figuratively speaking of course!)
Originally I had thought that I was doing something unique, and as far as Vans RV aircraft are concerned, perhaps I still am. I see a lot of Military schemed RVs that will either have vinyl machine gun port stickers stuck to their aircraft, or they are cleverly and very realistically painted onto the wing. I just wanted something more I guess.
I found out that I was not as unique in my thinking as first thought when I just happened to venture onto the EAA website, and decided to do a search on the EAA forums. They had restructured the forums a couple of years ago, and this required everyone to establish new account IDs to gain access to the new forum sites. I guess I lost interest at that point, and found myself spending most of my time on the VAF website addressing building questions.
Anyway, just out of the blue one day I decided to go check the EAA forums to see if anyone was as crazy as me. Turns out that literally as of that very same week, someone had posted a new thread on the Homebuilders Corner forum about designing and implementing a fully electronic solution to adding fake machine guns to your experimental warbird aircraft. Before I knew it, I was right in the middle of the discussion, and I could not believe that thre were actually others out there with the same ambition, even if it would be applied to some different airplanes.
This is one of those ironic situations where those that are building WW I replica fighter planes actually had a bit of an easier time implementing this type of solution. In reality, WW I fighters had a very difficult time figuring out how to mount a working machine gun so that it would fire through the propellor blades without destroying the prop or killing the pilot. then came the infamous timing gear that solved all those problems. The WW I guys can retrofit an electronic light solution onto their WWI machine guns a lot easier than the rest of us WWII guys, who have to figure out how to mount them in the Wing. In the end the hardest part of the hole process is designing the proper machine ports and making absolutely sure that they are airworthy and safe for flight (read as - " will not fly off or rip off of the wing during high G maneuvers, etc.). Check out the machine gun thread on the EAA forums.
As a result of all this, the folks that run SuperBriteLEDs are now on my new best friends list. I have ordered a variety of test lights, controllers, and mounting bases, and, after getting some new info n the EAA forum thread, I now have several more lights on order. The challenge is how to make light flash with enough intensity so that a crowd waching the runway would actually see the flashes and here the sound of the guns going off. I am currently working with lights in the 3 watt range, but it may take as much as 5-10 watt powered lights to have a really good effect. My problem, as stated above, is how to get a light with that much power to fit in a relatively small space on the leading edge of the wing. In the end actual flight testing will determine of the flash is brite enough. The process of making multiple guns appear to fire with slightly out of sync timings for realism has already been tested (and works quite well I might add!).
The sound will be another challenge. I need to compile noise data from a lycoming engine at various power and prop settings and airspeeds during a low pass configuration with a crowd standing a certain distance away, to figure out what kind of sound would be needed from machine gun to be heard. That little problem lead me to the discovery of a group of WWI experimental airplane folks back in Kansas City know as the The Dawn Patrol that are even more crazy (or just have more fun) than me. There are a couple of folks there that have designed and are using an inert gas system and electronic trigger mechanism that takes care of the noise issue with no problem. Even provides realistic muzzle blast out of the ends of the guns. Truth is that I think that this is also what the Tora Tora Tora flight team of the Commemorative Air Force (CAF) is using when they re-enact the raid on Pearl Harbor. They will be at Airventure again this year and I can hardly wait.
My ultimate dream is to incorporate that same system in addition to the LED lights in my airplane to get the best of both systems. Now I think it's time for a disclaimer for anyone reading this that may have similar ideas.
The inert gas system is inherently dangerous. If things go wrong it could result in a number of outcomes - most all of which will be very unhealthy for pilot and passengers and perhaps innicent bystanders on the ground. I am approaching the application of both of these systems purely from a safety priority persepective. If I feel I can safely implement both systems then I will most likely do so, but I will start with the light systems first. I am not going about this without very seriously thinking through all of the things that could go wrong first. I will design my application as safely as possible to ensure that I can get maximum fun and minimum trouble with it. If you wish to do something similar, then you need to take the time and do the research to ensure that your application is a safe one as well.
The light testing phase has been fun. I will leave you with a couple of photos of possible light and in-wing gun port solutions that I am currently entertaining:
First is a pic of he first set of LED lights I ordered for testing. Most of these are different configurations of a 1 watt red LED light:
One example of a light mounted inside the gun port:
Much more to come on this. Stay tuned!
Thursday, April 4, 2013
Back to Makin' an Airplane.
To start off, I am in a much better place now than I was a few days ago. My pitot tube woes are behind me and it was time to move on. Besides, the weather is getting downright beautiful around here. For those of you that have checked my profile, you know that a big part of who I am revolves around music. The guitar always goes to Oshkosh with me, and I do manage to find some time to play while I am there. I mention this because I am also sitting here watching the latest episode from Live At Daryl's House on the Palladia channel. I just recently "discovered" this show, even though it has been on since 2007. I am absolutely in love with this program. For those that don't know, it feature Daryl Hall from the old Hall & Oats days. He invites guest artists to his home in Pennsylvania about once a month and they jam to each others tunes - just totally awesome stuff. So if you love music, especially the music from Daryl Hall, you need to check this out. Tonight's guest is Rob Thomas, and it is just magic to my ears.
I also wanted to take a moment to recognize some new folks that are following my blog. I just managed to glance over that way and saw a few more icons in the followers section. Welcome everyone! I also have to mention that last night I had a really nice visit with Mike Rettig over at his place where he is building an RV10. Just as I knew would happen, he is blazing right along with his wings adn he is now leaps and bounds ahead of me as far as general progress goes. He has now entered the realm of proseal and fuel tank construction. Only problem is that he decided he wants to be able to cross the Atlantic Ocean with his RV10 and so he is building a completely integrated auxhiliary tank into his entire leading edge. I got to have a sneak peak at his progress on the first of the two aux tanks. Things are lookin pretty good there Mike. Keep of the great work.
As for me, tonight I managed to get out the garage and remove both tip ribs from the main wing spars so I could debur the last few holes that I had match drilled several days ago. I ahd to take the spars off the stands to finish these up. Then I started drilling the tooling holes in my ribs to 3/8 inches for the snap bushings that will house my RG400 antenna coax and any additional wire runs that I need. I used the step drill as shown in the following sequence of photos. You will notice that I used a sharpee to mark the step just above the one that I need, so I know when to stop drilling. As I mentioned in posts from long ago while using this thing on my empennage, I only use this with a variable speed cordless electric drill, and I clamp everything down when I use it so I can keep both hands on the drill.
First is the trailing edge hole before drilling
And next is the leading edge of the main rib before drilling
One rib does not have the small third hole already drilled, and I am not exactly sure why. Here it is after drilling
and here is the other "after drilling" pics
There are 2 schools of thought for marking the step drill. You either mark the step just above the step that you need to drill down to, or you mark the actual step that you need to drill down to. Either way you choose to do it, the key is go slow when you get close the last step in the drill bit and proceed with caution so that you do not "over step" your bounds, pun intended. In all seriousness though, it is real easy to go too far with this thing so you need to be careful.
The larger hole in the center of one of the above pics is already drilled by Vans to 7/16 inches. This is designed to fit an SB437-4 snap bushing that has an ID of 1/4 inch. The other smaller 3/8 inch holes that I am enlarging will accept an SB375-4 snap bushing, that, as it turns out, also provides a 1/4 inch ID for wires and such. I had already checked the alignment of the exist holes of the aileron pushrod in the rear spar of the wing, and I am satisfied that drilling out the rear-most tooling hole for the antenna wire for my Bob Archer navigation antenna will not interfere with the pushrod at all.
I did not get all the ribs done tonight but should be able to get them done tomorrow. One other thing - There is actually a right way to insert the snap bushings into the holes, but I often see pics on various builders sites that do not do it that way. You are supposed to place in the hole so that the smaller flange area of the bushing will be on the side of the rib that has the flanges, so that it is as out of the way as possible when to start to rivet the wing skins to the ribs. The bushings have to be inserted differently in the ribs depending on if it is a left or a right-flanged rib. The other thing is to remember not to put the bushings in the hole until AFTER you finish priming the ribs.
I got to fly a couple more Young Eagles last Saturday at KFTG - what a blast that always is. It was about 2.5 hours out of my pocket for a rental C-172, but it was worth every penny. KFTG was one of the contract towers that was on the original hit list, but they took it off - thankfully. All this budget crap is a real bummer.
I have a hefty order to place with ACS, Avery, and a few other vendors for various things.
All for now. Oh yeah, Oshkosh isjust a few short months away - make your plans now!
I also wanted to take a moment to recognize some new folks that are following my blog. I just managed to glance over that way and saw a few more icons in the followers section. Welcome everyone! I also have to mention that last night I had a really nice visit with Mike Rettig over at his place where he is building an RV10. Just as I knew would happen, he is blazing right along with his wings adn he is now leaps and bounds ahead of me as far as general progress goes. He has now entered the realm of proseal and fuel tank construction. Only problem is that he decided he wants to be able to cross the Atlantic Ocean with his RV10 and so he is building a completely integrated auxhiliary tank into his entire leading edge. I got to have a sneak peak at his progress on the first of the two aux tanks. Things are lookin pretty good there Mike. Keep of the great work.
As for me, tonight I managed to get out the garage and remove both tip ribs from the main wing spars so I could debur the last few holes that I had match drilled several days ago. I ahd to take the spars off the stands to finish these up. Then I started drilling the tooling holes in my ribs to 3/8 inches for the snap bushings that will house my RG400 antenna coax and any additional wire runs that I need. I used the step drill as shown in the following sequence of photos. You will notice that I used a sharpee to mark the step just above the one that I need, so I know when to stop drilling. As I mentioned in posts from long ago while using this thing on my empennage, I only use this with a variable speed cordless electric drill, and I clamp everything down when I use it so I can keep both hands on the drill.
First is the trailing edge hole before drilling
And next is the leading edge of the main rib before drilling
One rib does not have the small third hole already drilled, and I am not exactly sure why. Here it is after drilling
and here is the other "after drilling" pics
There are 2 schools of thought for marking the step drill. You either mark the step just above the step that you need to drill down to, or you mark the actual step that you need to drill down to. Either way you choose to do it, the key is go slow when you get close the last step in the drill bit and proceed with caution so that you do not "over step" your bounds, pun intended. In all seriousness though, it is real easy to go too far with this thing so you need to be careful.
The larger hole in the center of one of the above pics is already drilled by Vans to 7/16 inches. This is designed to fit an SB437-4 snap bushing that has an ID of 1/4 inch. The other smaller 3/8 inch holes that I am enlarging will accept an SB375-4 snap bushing, that, as it turns out, also provides a 1/4 inch ID for wires and such. I had already checked the alignment of the exist holes of the aileron pushrod in the rear spar of the wing, and I am satisfied that drilling out the rear-most tooling hole for the antenna wire for my Bob Archer navigation antenna will not interfere with the pushrod at all.
I did not get all the ribs done tonight but should be able to get them done tomorrow. One other thing - There is actually a right way to insert the snap bushings into the holes, but I often see pics on various builders sites that do not do it that way. You are supposed to place in the hole so that the smaller flange area of the bushing will be on the side of the rib that has the flanges, so that it is as out of the way as possible when to start to rivet the wing skins to the ribs. The bushings have to be inserted differently in the ribs depending on if it is a left or a right-flanged rib. The other thing is to remember not to put the bushings in the hole until AFTER you finish priming the ribs.
I got to fly a couple more Young Eagles last Saturday at KFTG - what a blast that always is. It was about 2.5 hours out of my pocket for a rental C-172, but it was worth every penny. KFTG was one of the contract towers that was on the original hit list, but they took it off - thankfully. All this budget crap is a real bummer.
I have a hefty order to place with ACS, Avery, and a few other vendors for various things.
All for now. Oh yeah, Oshkosh isjust a few short months away - make your plans now!
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