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-   -   All Composite 1/7th P-40E Mould Build (http://www.rcuniverse.com/forum/composites-fabrication-repair-97/7289267-all-composite-1-7th-p-40e-mould-build.html)

Slow Low 03-27-2008 12:25 AM

All Composite 1/7th P-40E Mould Build
 
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Hello Everyone - I have to admit to being a quiet observer for some time now, but I've just posted a video on youtube of my ongoing build of an all composite warbird. It's a 1/7th P-40E Warhawk. I don't know how much interest there is for this sort of thing, but you can feel free to watch the video here http://www.youtube.com/watch?v=-ge3yw99b9g You can also search for composite warbird. I know how helpful it can be to see pictures of someone elses methods - so if this helps even one person, it will be worth the typing - nice to meet ya

fokke 03-27-2008 06:53 AM

RE: All Composite 1/7th P-40E Mould Build
 
WOW , very nice mould you have there :) super
What glass you use for moulding :) ?

here is my job

http://www.rcuniverse.com/forum/m_53..._5/key_/tm.htm

Slow Low 03-27-2008 07:33 AM

RE: All Composite 1/7th P-40E Mould Build
 
Nice to meet you fokke - I have to tell you that you have been an inspiration to me on many nights when I thought that I would never see a mould for this project! I must tell you that I especially respect the work that you do with foil on flight skins! In regards to your question, I kept it pretty simple - the typical schedule was

1 coat tooling epoxy
1 X 3/4 Oz/ft^2 biaxial weave to get into the corners
1 X 1-1/2 Oz continuous strand surface veil
1 X 2 Oz biaxial weave
8 X 7-1/2 Oz biaxial weave (surfboard stock from California USA - cheap)

I do apologize for not doing the metric conversions for you, but it's early in the morning here!

soarrich 03-27-2008 07:41 AM

RE: All Composite 1/7th P-40E Mould Build
 
Great job!

fokke 03-27-2008 07:53 AM

RE: All Composite 1/7th P-40E Mould Build
 
""In regards to your question, I kept it pretty simple - the typical schedule was """"

pretty simple but is very good result wiht your mould [sm=thumbs_up.gif]

I cant wait the result from your molud :)

I don't understand Oz ,but I'll - look for more info :)
Nice decision for tail-end of the P 40 ,why you made that way ?

Slow Low 03-27-2008 08:13 AM

RE: All Composite 1/7th P-40E Mould Build
 
I see that you watched the video! Well the Engineer in me wants to say that it was the most efficient use of resources (my labour), but in reality it's because I'm lazy and I only like to do things once![sm=wink_smile.gif] I've done it like everyone else before and made set after set of sheeted foam stabilizers, and frankly I hate it! It's too much work, and I'm too lazy! It does take a little thought and consideration as far as mould sections and removing the finished fuselage, but it's worth the work (once). The other thing is that it adds a whole bunch of time to the build, because each section back there is moulded over the previous one. This usually means a week to finish a section and get it back onto the plug, before you can start the next section. So it's about a month of layup, before you can move away from the horizontal and vertical stabilizer sections. I really like the realism of your finish - do you have one painted up yet?

Slow Low 03-27-2008 08:17 AM

RE: All Composite 1/7th P-40E Mould Build
 
Thanks Soarrich - it's you slope soaring types that got me onto composites in the first place. Props to all you guys that use composites to push the envelope!

jeffk464 03-29-2008 09:46 AM

RE: All Composite 1/7th P-40E Mould Build
 
I was thinking about doing this with a top flite spitfire and a 65" 190 Dora build , so I'm really interested in following this build. I would also be really curious what the flying weight will be.

Slow Low 03-29-2008 10:10 AM

RE: All Composite 1/7th P-40E Mould Build
 
1 Attachment(s)
Hi Jeffk464 - You hit the nail on the head my friend. That's one of the reasons why I decided to sacrifice this kit to a mould project. I know that I've seen some of the kits in this Gold Edition series build heavy, so I initially started to build with flaps, but no retracts. After some initial layup trials (very limited mind you at this point) I've made a decision to incorporate the retracts. So the wing just got wheel bays, and my wing mould timeline just got a little longer! (I hope I got enough draft in there - lol) Here's a photo.

Slow Low 04-01-2008 10:10 AM

RE: All Composite 1/7th P-40E Mould Build
 
Well I woke up early this morning with a kink in my back so I started getting ready to start the second half of the fuse mold. I got the parting board ready to go anyway. Here's another video link for the brave at heart!! http://www.youtube.com/watch?v=_DDN-G0cQ1w

andernamen 04-01-2008 03:20 PM

RE: All Composite 1/7th P-40E Mould Build
 
You may want to re-think the wing regarding the ailerons. Looks like you have it set up for bellcranks. Most people who build this plane put one aileron servo on each side. Gives much better control. I lost one of these recently, partially due to the bellcrank set-up.

Slow Low 04-01-2008 06:05 PM

RE: All Composite 1/7th P-40E Mould Build
 
Ouch Andernamen, I'm sorry to hear that.[sm=cry_smile.gif] I've lost a friend or two along the way myself.
You've brought up a touchy subject for me. In fact, this is the perfect opportunity for me to get some input. Truth is, I haven't decided what I'm going to do with it at this point. Those pushrods will get cut off and stuck under the skin before I glass it and there will be bosses on the outside of the wing instead. I've given this much thought, but you've got me thinking KISS now. Thoughts range from incorporating tube inserts into the mould to allow installation of bellcranks and provide the pushrods somewhere to exit the mould to, ya, two servos in a similar fashion to the flaps. I haven't checked yet, but one concern with the two servo approach is space in the wing that far out along the spar. I put that central bay in the wing so that I could keep moving along without interrupting the critical path as it were, while I made some decisions. I'd be interested in some input for sure!![sm=thumbs_up.gif]

John Sohm 04-01-2008 07:38 PM

RE: All Composite 1/7th P-40E Mould Build
 
Bellcranks, if installed properly, will operate flawlessly for an awful long time. The problem is, most people don't install them the right way. They put the screw thru the mount plate and the bearing and the bellcrank and then tighten it down. When they notice it sticks from being tight, they back off a bit so it moves freely. Over time, it loosens even more and wears away at the mount. I've seen this happen before.
What you should do is put the screw thru the mount and put a nut on and tighten it really well to the mount. That way you have a secure post for mounting the bellcrank. Then you install the bearing/bushing and bellcrank and then screw on another nut, snug it up but just to where it moves freely and then use some loctite or a jam nut to keep it from loosening in the future. Also make sure the pushrods to actuate the bellcrank are stiff enough or have guide holes thru the wingribs that are close enough to prevent flexing. You should have no issues using this method.

Slow Low 04-01-2008 08:46 PM

RE: All Composite 1/7th P-40E Mould Build
 
Thanks for jumping in John[sm=teeth_smile.gif] - you make a very valid point about the little details that we often aren't aware of during construction, that in retrospect we often look back and learn from the hard way. Your installation method is sound and all others should read it carefully and burn it to memory. When you see a bellcrank mounted you should see a squarely mounted, pre-installed and tightened spindle, and then you should see a precision bushing assembly slid over it and not "tightened down" by the nut, but as John said "retained" by the nut. Tightened just enough to keep the bushing assembly from moving up and down. That top nut is not a nut so much as it is an adjustable stop. In order to keep it in place I like to use a dab of epoxy on top of the nut and the first few threads. Be careful not to get epoxy on the bushing so as to prevent its free movement. John also mentioned double nutting or "jam" nutting. This would be the preferred method if you have the extra nut. But be sure to use two wrenches. One to hold the first or bottom nut from spinning any further, while you tighten the top nut down against it.
Assuming Andernamen did not fall into this trap, it's also worth noting that in terms of the mechanical systems of your aircraft, this is a highly stressed area where a very slight deviation from the normal mounting plane will cause bending moments in your wing ribs and could lead to a catastrophic failure in flight. Especially, while rolling out at the bottom of a high speed dive. This area needs to be constructed carefully with prudent forethought to function, patience and attention to detail.
Hmmm...I certainly did go on there didn't I?[sm=confused_smile.gif]

soarrich 04-01-2008 10:32 PM

RE: All Composite 1/7th P-40E Mould Build
 
Viking Models used to make a nice bellcrank. The pivot was a screw big enough that the nylon bellcrank was tapped for the tread, that way there was no slop, and it couldn't come off unless it was turn around 20 times. I really liked them.

Slow Low 04-01-2008 10:37 PM

RE: All Composite 1/7th P-40E Mould Build
 
The KISS approach!

Slow Low 04-03-2008 07:29 PM

RE: All Composite 1/7th P-40E Mould Build
 
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In today's update I get the fuselage assembled into the first half of the mould, and then mount it back into the parting board. It's all clayed up and almost ready to start showing you the layup process in detail.

http://www.youtube.com/user/b1heqh54


Strankon 04-04-2008 06:43 PM

RE: All Composite 1/7th P-40E Mould Build
 
[sm=49_49.gif]Thanks for the update, looking forward to your next installment

Slow Low 04-04-2008 06:50 PM

RE: All Composite 1/7th P-40E Mould Build
 
Thanks for letting me know you're out there! :)

soarrich 04-04-2008 07:25 PM

RE: All Composite 1/7th P-40E Mould Build
 
We're watching you![sm=thumbup.gif]

Slow Low 04-04-2008 07:44 PM

RE: All Composite 1/7th P-40E Mould Build
 
...and I'm watching your 50cc's of thunder videos Rich - everyone should hear this one

http://www.youtube.com/watch?v=m7kdRLzvfPg

SCALECRAFT 04-05-2008 10:39 PM

RE: All Composite 1/7th P-40E Mould Build
 
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Hi

Nice composite project.

For years we have used bellcranks, torque rods, and flexible "golden rod" in our all composite war birds. All without failure. I believe one of the rules should be to always consider the vibration from the gas/glow engines and build with thread lock.

Also, securing control rods with epoxy/glass or epoxy cabosil bonds.

I have begun to use a bead of silicone around some of the wood parts in case they do break loose, they do not break away.

Sluggish control is better than none.

If the pics load: From our molds: My buddies composite Typhoon, (torque rods) my composite corsair ( bellcranks/golden rod), and our composite 109F (torque rods).

Steve

Slow Low 04-05-2008 10:59 PM

RE: All Composite 1/7th P-40E Mould Build
 
Thanks for the silicone tip Steve - you are someone I want to meet! Man that's some nice work there! Where can I see more?

Slow Low 04-05-2008 11:04 PM

RE: All Composite 1/7th P-40E Mould Build
 
I got the thread! c you there

SCALECRAFT 04-06-2008 12:00 PM

RE: All Composite 1/7th P-40E Mould Build
 
Over the years my buddy and I have developed many ways to fabricate composite models. I post tips and try to encourage modelers who have talent and the motivation to create their own top quality stuff.

Its not hard, you need to have what it takes. Patience.

My pics are all over these forms. In composite planes, spinners, and props. I have no "site" since its a form of escape/renewal for me.

Oh. Before you layup the second half, I would grind some "dimples" into your 1st 1/2s parting board o insure perfect alignment.

Your probably going to drill and bolt your mold before you open it to get alignment, thats not the best way for perfect alignment. . Look at some of the molds on here, they show molded in "keyways" placed around the perimeter of the plug before any resin goes on. You'll see what I mean.

Keep it up.

Steve


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