F-117
10-06-2002, 11:42 PM
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nose
Anther shot after parts are installed.
Hey guys when is Florida jets? If this gal makes it through her maiden flight I think I'm going to take her on a Florida vacation.
David Hudson
Hey guys when is Florida jets? If this gal makes it through her maiden flight I think I'm going to take her on a Florida vacation.
David Hudson
10-10-2002, 01:41 AM
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F-117
I de-molded the verticals today. The pivot rod is chrome-molly and was mounted during layup. The layup is mostly graphite for lightness and strength. Note of interest is the trailing and leading edges are the same length and the surface area of this part has 180 sq."
David Hudson
David Hudson
10-10-2002, 06:41 PM
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F-117
Hey Mr. A10,
I going to keep plugging. I want to take it to FJ so it needs to be up and running sometime around the end or early year.
David Hudson
I going to keep plugging. I want to take it to FJ so it needs to be up and running sometime around the end or early year.
David Hudson
10-14-2002, 01:45 AM
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F-117
Unlike the display model that was created. I wanted the gear doors inner surfaces to have detail. The patterns shown were created by drawing the door inner and outer surfaces. I then created a box around the part. The whole drawing was exported to a cutting program. The upper half of the part was cut , at that point flip the material on the machine and cut the other half. Once the part is cut it is released from the material box.
David Hudson
David Hudson
10-14-2002, 10:25 AM
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F-117
The display model was for a client and the RC model is mainly a personal project. After the prototype has flown and the bugs are out I will sell some. The gear door molds are the last ones to be made. I know this type and size of plane isn't for everyone and I hope no one thinks I'm trying to be a big shot posting this stuff. This is a really fun project for me and I thought I would share some of the design and construction. As for as the exhaust it will be stainless and ceramic. The stainless by Tam and ceramic by David. Work on that segment will soon began. I'm drawing the file for the inlet grid now. We're going to grow a sterolthogrph screen. The shop doesn't have that capably but, I got friends 
Some day I hope to see one at Top gun ether by me or someone.
Thanks
David Hudson
Some day I hope to see one at Top gun ether by me or someone.
Thanks
David Hudson
10-14-2002, 12:57 PM
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F-117
Hi Bob,
Feb. 20 - 23 are the dates. See ya there. ( Thanks )
Where were you Sat.? Metroplex Jets. ( Work got in the way )
Will you do maiden flight at TMS? Let us know, would like to be there.
( yes, OK )
David Hudson
P.S. Must....keep.....moving....................
Feb. 20 - 23 are the dates. See ya there. ( Thanks )
Where were you Sat.? Metroplex Jets. ( Work got in the way )
Will you do maiden flight at TMS? Let us know, would like to be there.
( yes, OK )
David Hudson
P.S. Must....keep.....moving....................
10-15-2002, 03:43 AM
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STL Inlet Screens
David,
Okay, question: when you say you're doing stereolithography inlet screens, what do you mean? Are you planning to use stereo parts on the model, or are you going to use the stereo parts as plugs to make urethane or silicone rubber molds, then mold the parts from another material?
Although stereolithography resins have become stronger in the last few years, I'm not sure they've come to the point where I'd be comfortable using them in this application. If one disintegrated in flight, you'd FOD an engine, pronto. I'd hate to see something like that happen to a project like this--you've spent too much time on it to risk losing it this way.
I ran a stereolithography lab a few years back, so I'm fairly familiar with the processes involved. That was about 5 years ago, though, so there may be newer resins on the market now that address my concerns.
Great project. Good luck.
David Eichstedt
Okay, question: when you say you're doing stereolithography inlet screens, what do you mean? Are you planning to use stereo parts on the model, or are you going to use the stereo parts as plugs to make urethane or silicone rubber molds, then mold the parts from another material?
Although stereolithography resins have become stronger in the last few years, I'm not sure they've come to the point where I'd be comfortable using them in this application. If one disintegrated in flight, you'd FOD an engine, pronto. I'd hate to see something like that happen to a project like this--you've spent too much time on it to risk losing it this way.
I ran a stereolithography lab a few years back, so I'm fairly familiar with the processes involved. That was about 5 years ago, though, so there may be newer resins on the market now that address my concerns.
Great project. Good luck.
David Eichstedt
10-15-2002, 09:51 AM
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Hi Flanker,
Yes, your very right stereo parts in that shape would be delicate.
I was planning the stereo parts to be masters and I was going to cast silicone rubber molds. I don't want to think about machining them, what a nightmare. I'm not sure what to cast them with. I think when the time comes I'll call my resin rep, inform him of the environment the parts are going to be living in and let him tell me what to use.
Do you have any suggestions on a type of casting resin that would be good in this application? You seem to be knowledgeable
in this area.
Another thought would be to have some thin brass strips acid etched. Each strip would have slots so the assembly could be egg crated together and then soldiered. More work but maybe much better.
Thanks
David Hudson
Yes, your very right stereo parts in that shape would be delicate.
I was planning the stereo parts to be masters and I was going to cast silicone rubber molds. I don't want to think about machining them, what a nightmare. I'm not sure what to cast them with. I think when the time comes I'll call my resin rep, inform him of the environment the parts are going to be living in and let him tell me what to use.
Do you have any suggestions on a type of casting resin that would be good in this application? You seem to be knowledgeable
in this area.
Another thought would be to have some thin brass strips acid etched. Each strip would have slots so the assembly could be egg crated together and then soldiered. More work but maybe much better.
Thanks
David Hudson
10-16-2002, 03:08 AM
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STL Inlet Screens
David,
Wow! I'm not sure what to say. I guess since I'm an engineer and I like to make lists, I'll make another one.
1) No ideas here for proper molding material.
2) If pulling a silicone mold, how are you going to separate the two halves between the grids? You can cut a parting line around the outside, but you'll be stuck trying to separate the two silicone mold halves in the checkerboard square regions (or in this case, parallelograms).
3) Maybe you need to do this the same way you do a traditional fiberglass mold--mold one silicone half, let it cure, treat the mating half with release material and mold the other half.
4) Maybe another process would be more appropriate, like investment casting. Or maybe Selective Laser Sintering (SLS). With SLS, you can directly build a glass-filled nylon part. I'll bet glass-filled nylon would be strong enough.
5) Check out www.solidconcepts.com. They're a rapid prototyping service bureau that's just around the corner from 3D Systems (inventors of stereolithography). They may be too expensive for your use, but they might have some information on their web page that could give you some ideas. They also do excellent work.
6) A grid of soldered brass strips may be workable by the average modeller, but they won't look terribly scale and the result would probably be heavy.
7) I envy you. I have so many cool projects I'd like to do, but I just don't have the time and money right now. When I'm done with school, hopefully I'll be able to move on with the important stuff--my model airplane career.
Wow! I'm not sure what to say. I guess since I'm an engineer and I like to make lists, I'll make another one.
1) No ideas here for proper molding material.
2) If pulling a silicone mold, how are you going to separate the two halves between the grids? You can cut a parting line around the outside, but you'll be stuck trying to separate the two silicone mold halves in the checkerboard square regions (or in this case, parallelograms).
3) Maybe you need to do this the same way you do a traditional fiberglass mold--mold one silicone half, let it cure, treat the mating half with release material and mold the other half.
4) Maybe another process would be more appropriate, like investment casting. Or maybe Selective Laser Sintering (SLS). With SLS, you can directly build a glass-filled nylon part. I'll bet glass-filled nylon would be strong enough.
5) Check out www.solidconcepts.com. They're a rapid prototyping service bureau that's just around the corner from 3D Systems (inventors of stereolithography). They may be too expensive for your use, but they might have some information on their web page that could give you some ideas. They also do excellent work.
6) A grid of soldered brass strips may be workable by the average modeller, but they won't look terribly scale and the result would probably be heavy.
7) I envy you. I have so many cool projects I'd like to do, but I just don't have the time and money right now. When I'm done with school, hopefully I'll be able to move on with the important stuff--my model airplane career.
10-16-2002, 03:14 AM
#43
F-117
David,
We'll do some taxi test on our AD F-117 project this coming friday. My customer like to talk to you about your F-117.
Email me your number. So we can call you on friday.
Brg,
Tam
We'll do some taxi test on our AD F-117 project this coming friday. My customer like to talk to you about your F-117.
Email me your number. So we can call you on friday.
Brg,
Tam
10-16-2002, 12:51 PM
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F-117
The stereo. parts would only be patterns for the screen/grids in the F-117 intakes.
Flanker thanks for the input. Lancaster CA. I assume that you work on airplanes. I did my part on the B1, B2. ( Vought ) .
David Hudson
Flanker thanks for the input. Lancaster CA. I assume that you work on airplanes. I did my part on the B1, B2. ( Vought ) .
David Hudson
10-21-2002, 02:18 AM
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I got the two major bulkheads cut and installed. Not totally finished but the gear and engine bays are coming together. I'm going to put all hatches on the bottom so to keep the top skins clean. The engine bay hatches have not been cut in yet.
David Huson
David Huson
10-21-2002, 02:27 AM
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Another shot showing main spar bulkhead and hole lending to those dreaded exhausts. This is a good shot showing the bomb bays.
Each bay door is 30"x5.5".
David Hudson
Each bay door is 30"x5.5".
David Hudson
10-26-2002, 02:25 AM
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The saga continues with the mounting of the verticals. The tails have chrome molly tubes with a brass tube over that. That unit telescopes into a brass tube mounted into the stationary part of the vertical. This gives me a bearing contact surface around 7"long. I chose this setup for it's simplicity and low weight. Weight is a huge issue in the tail area of a aircraft design like this.
David Hudson
David Hudson