Repairs & Mods: custom cowl, new gear,etc

[Willja67 144]

Ripped all the white foam off, tweaked the blue foam a bit and used the previous white pieces as templates and I'm pretty happy with the lower cowl now. At some point in the near future i'll start plastering it with drywall mud and sand it smooth. Obviously gotta get the top done first. 

I was a little surprised when measuring that the left "nostril" was a little narrower than the right. The size was dictated by the cowling mount portion of the engine mount. I guess that's due to the engine offset. I would have expected though that the center of the prop would have been on the centerline of the plane with the rear endof the engine kicked out not the other way around. 

Got a line on a decent looking wood lathe that I'm going to go look at on Monday and if it's any good I'm going to learn how to use it to make a custom spinner.

[Yamma-Fox 403]

Following this.  Keep posting up your cowl build!  I have some cowl mod to do and this is really helpful.

Edited 22 Oct 2018 by Yamma-Fox

[Willja67 144]

Following this.  Keep posting up your cowl build!  I have some cowl mod to do and this is really helpful.

You may be watching the beginning of an epic fail here as I've never seen anyone build a cowling this way and I've frequented some forums where it's discussed in depth. I don't think it will, but i can tell you that it's not going to be the highest quality you'll ever see. The white foam is a little too flexible to really do some top notch surface finishing. But then again most guys going for a top notch cowl would make a male mold, pull a female mold off it and finish that to perfection, then use that to make a vaccum infused final product. I'm going to smooth this as much as possible in place lay up my fiberglass and then hopefully it'll be good enough to do a little filling and sanding and be the final product. It won't be show quality but hopefully it'll be a 10 footer.

[Yamma-Fox 403]

I have no desire for a show plane either.  Just a nice one.  So I like the way you think!

 

Edited 22 Oct 2018 by Yamma-Fox

[Allen Sutphin 705]

A safe plane beats a show plane every time.

[Willja67 144]

Got a little more done. Its not really visible in the pics but the white foam on the top center section of the cowl isn't holding the curve from behind the spinner to the firewall, it flattens out between the 2 blue foam "stringers". So obviously some more support of some kind is needed, but I'm tired so i'll figure it out later.

[Willja67 144]

Looking good i think!

[Yamma-Fox 403]

Yeah man!

Looking forward to seeing how you finish this up!

[Good old number 29 158]

The previous owner of my Kitfox had performed a similar stunt with the trailer. Fortunately for me, it didn’t damage steel, like your incident. Still, it broke a wood stringer and punched a nice hole in the bottom of the fuselage. 

[Willja67 144]

The previous owner of my Kitfox had performed a similar stunt with the trailer. Fortunately for me, it didn’t damage steel, like your incident. Still, it broke a wood stringer and punched a nice hole in the bottom of the fuselage. 

Does good old number 29 mean the serial number of your aircraft? Ive got kit number 32.

[Buckchop 479]

Ive got KF #0021 flying,

KF #0038 rebuilding now,

KF #0048 not sure what im going to do with it yet 

that cowl will look good, b good to c how it turns out. 

Edited 25 Oct 2018 by Buckchop

[Willja67 144]

Got some sheetrock mud slathered on it

[Willja67 144]

Right side except for the nostril is done! And I'm very pleased with the result

[Yamma-Fox 403]

Thumbs up!

[Willja67 144]

Stace Schrader just sent me a pic of my new gear legs! 

Trying to get fiberglass on the cowling asap  the weather is supposed to turn cold inthe next few days and my garage isn't heated. The foam on the top cowling has some "saddle" areas where it doesn't keep a nice curve so trying to build it up a little with spackle. 

[1avidflyer 1983]

On some of these landing gears, the cabane has had another tube installed that helps tied the top of the cabane together.  That helps to keep if from being pulled down and pulling the sides of the fuselage in.  Some have bent their longerons in hard landings from this.  Lowell Fitt now uses that cross tube.  I still think that if one tied the cabane to the seat truss, it would help as well.  You can see the added cross brace in this picture.  JImChuk

 

[Willja67 144]

Jim, this is more me trying to wrap my head around the dynamics of the 2 designs than doubts about what you're saying. 

The gear I'm getting is a bungee gear as opposed to the spring gear you've got. If you bottom out that spring ie compress it totally and still have more energy to absorb that's going to go into the cabane then the fuselage. 

The bungees get pulled apart and if you exceed their strength i guess they just break and the gear splays out? I guess it's all subject to if the bungees are stronger than the cabane. 

[1avidflyer 1983]

I would imaging there is some stop at the end of your gear/bungee stretch.   Is there not a slotted hole that only allows you to go so far?  Actually, I do like the idea of bungees instead of springs.  Lighter and more adjustable.  More or less wraps.  JImChuk

[Willja67 144]

I would imaging there is some stop at the end of your gear/bungee stretch.   Is there not a slotted hole that only allows you to go so far?  Actually, I do like the idea of bungees instead of springs.  Lighter and more adjustable.  More or less wraps.  JImChuk

At the moment you know as much as i do by looking at that pic. I vaguely remember talk of a safety cable like is used on the stock setup, in which case you're right it's still an issue, but the answer for right now is i don't know. 

[akflyer 1427]

It would be easy to slot the tubes and put a bolt in them for a stop, but the safety cable is also easy to do and has worked on cubs for a LONG time.  The trick is to have them long enough so they don't hit the stops on a "normal hard landing" yet keep the prop from hitting the dirt in the event that the bungie turns loose.  

 

[Willja67 144]

I was having some issues uploading yesterday and into today for some reason. So yesterday i finally opened up the nostrils. As you can see the left (airplanes left)nostril is smaller than the right. Pretty sure the engine mount has some offset built into it as the dimensions are constrained by the prop hub and the cowling mounts that are partof the engine mount. Anyway moving forward  

[Willja67 144]

i think/hope I'm in the homestretch building the plug. I added a little lip/ spoiler under the cowling and started the fillet between the cowling and windscreen.  It'll probably need another coat of mud but maybe i can sand what's there good enough. The next step after all the sanding is done is to coat it in packing tape to act as a mold release. 

 

One thing to watch out for is sanding too far into the white foam if it's unsupported. I did that and it started bubbling up. Might have to fix that when i get to the fiberglass stage.

Edited 4 Nov 2018 by Willja67

[Yamma-Fox 403]

Hey maybe consider renaming this topic as "Fabricating a Cowl" or something so that people might find it easier in a future search.

You can do that by clicking the "edit" button on the very first post.

[Willja67 144]

Hey maybe consider renaming this topic as "Fabricating a Cowl" or something so that people might find it easier in a future search.

You can do that by clicking the "edit" button on the very first post.

ok i can see your point. Title changed

[Yamma-Fox 403]

Thanks!  Now I'll be able to find it later when I get to my cowl work!