Cowl mounting question
 

Hey guys,

I've been flying my Phoenix Models Strega with a YS 110 for about 4 months. One problem I've noticed is that the cowl mounting screws are wearing the cowl and slotting out the holes. I tried adding two more screws (for a total of 6) and used the little cowl mounting grommits from World Models on the screws. On Sunday I noticed that two of the grommits are missing even though the screws are still in place. It looks like the YS is going to beat the cowl to death.

Any suggestions?


Chris

RE: Cowl mounting question
 

Yes, reglass the current cowl on the inside and maybe it will live awhile longer or buy a new cowl. $15 from Tower. Those cowls are egg shell thin and if you have been flying several months it is just normal wear and tear.

RE: Cowl mounting question
 

Problem is the cowl was painted and shot with automotive clear to match the full scale. I can't do that every few months.

I've thought about gluing some 1/32" G10 fiberglass washers inside the cowl.

There's got to be a better way to mount the cowl though.

RE: Cowl mounting question
 

Chris-what I've done on a couple of my "shakers" is add additional glass on the inside of the cowl to reinforce and rebuild the missing glass, and add a rubber faced washer on the exterior. They have galv and stainless, in # 2 to 10, can't believe how they hold on hatches and cowls on gas engine aircraft. I get them from McMaster Carr with other items I order for the business, but I believe they will sell to individuals. If you're not familiar with them, they are a modelers dream source for goodies like metric socket head cap screws, nylon bolts, nylock nuts and a host of other "gotta have" fasteners. Prices are good also, check em online and I think you'll have another hobby shop to support the habit. Randy

RE: Cowl mounting question
 

or a few patches of kevlar on the inside.....;)

Roger on beating the cowl to death....same issue on the ME 163 and Madam Ashley had to go to 2024 t3 aluminum back plates, blue locktite on 4-40 fasteners

RE: Cowl mounting question
 

Randy, I know exactly what you are talking about. I used them on RC boats back when I raced them.

Rob, Just replied to your PM. Kevlar is a good idea. I'm also intrigued by your backplates idea. I picture a thin washer with a small protrusion to go through the cowl. Am I on the right track? Got a picture?

RE: Cowl mounting question
 

Hi Chris,
I've been doing this for years and never had one come loose. Inside the cowl where the screw holes are ,epoxy a piece of 1/32" plywood and cover it up with a piece of light glass cloth. Fill the existing screw holes with epoxy. Drill and tap for 6X32 Nylon bolts and use them as needed. The bolts will stretch and not come loose. Since they are plastic they will not wear out the cowl and the wood is tougher than the glass is to vibration. I've use this for all sizes of planes from .25's to 120's and latest a Moki 210 on a Sundowner. The larger planes might require 8X32. Good luck.
Tom

RE: Cowl mounting question
 

I might try a combination of Rob's Kevlar with Tom's 1/32" ply over the top. That should hold up, eh?

Thanks for the ideas guys.



Chris

RE: Cowl mounting question
 

Kevlar patches on the insie work great, as do CA hinges. I always keep a few in my field box, easy to CA them to the inside of the cowl and fix it fast. I add them to new build cowls now too.

RE: Cowl mounting question
 

good call on the ca hinges;) And the nylon screws - but would only want flush or low profile heads

Hey Chris - after a few cycles and the cowl gets beat to #%*@ then any further abrasion won't worry you so much:D


Just start painting your new cowl now - Make two:)