Build artical on cowls?

[Paul Taylor]

Anyone know of a good "How to build a cowl" articles?

I did see the last one that Bob Hunt did in SN, but it was more or less how to get a good fit. Not building on.

I did a search in the building section and came up empty.


If you could point me in a direction?
Thanks

[proparc]

One word,(actually two) Windy Urtnowski!!

You need cowl making instruction, you need Windy Urtnowski.

[Tim Wescott]

What sort of cowl?

There was a good on in FM a few years back.  It basically had you build a foam core, then mash a balloon over it as sort of a poor-man's vacuum bag.

If you're still looking in a week I'll be reunited with my library, and I'll take a look.

[FLOYD CARTER]

An easy way to make a cowl is 1/64" ply (standard hobby shop item).  My Tipsy Jr. cowl is wrap-around 1/64" ply with 1/2" balsa at the front, and an internal former to keep its shape.  The only "carving" needed is a bit at the front.

Floyd

[RC Storick]

[Paul Taylor]

Type of cowl?
Well with my little mishap at Brodaks where I ripped the gear out of my Vector it did a little damage to the cowl. Nothing a little CA and a little paint would not cover up. I would like to make a new one and maybe make it a little better then the first one.

I wish someone would offer up a Windy tape on making Cowls! I would gladly make a copy and send it back FedX over night! As Windy always says on his tape. "Please share them and pass them around!"

Still looking....

[Paul Taylor]

Yea Sparky I saw this, but did not really tell me how to carve, and shape. The how to part.

I remember someone saying use lite ply for the intake.

[Trostle]

Anyone know of a good "How to build a cowl" articles?

Model World (British), Jan 2000  "Making Fibreglass Cowlings"
Model Airplane News Jul 1957  "Mold it"  shows making fiberglass cowls over a plaster of paris mold
Model Aviation, Aug 75  "How to Make Cowls Rings Wiothout a Lathe"
Model Airplane News, Feb 70  "Scale Aluminum Cowls"
Aeromodeller, Feb 67, "Aluminum Cowlings"
Aeromodeller, Sep 58, "Hinged Cowlings"
Model Aviation, Feb 82, "Quick and Easy Radial Cowls"
Model Aviation, Jul 85, RC column on making fiberglass cowls
Flying Models, Feb 90, "How to Make Fiberglass Cowls"
Flying Models, Jan 95, "Lost Foam Fiberglass Cowl Method"
Ameircan Modeler Annual, 1962, "Easlily Made F-G Cowls"

[Steve Helmick]

Yea Sparky I saw this, but did not really tell me how to carve, and shape. The how to part.

I remember someone saying use lite ply for the intake.

Between the drawing Sparky posted (from Randy Smith, I believe), and the article in MA by Bob Hunt, you should have the basics. Bolt it on there and carve & sand away anything that you don't like the looks of. If you end up with a gap, either plug it with a hunk of soft balsa, or put a scoop or blister over it. Don't overlook some uses for 1/64" plywood, like Floyd said. I'm attaching some pictures that I have in my files from Igor B. that I think are spot-on for clever design features and logical, inexpensive, and easy construction. Combine features you like, and go for it!

For myself, I like a very practical cowl, such as combining the air inlet and glowplug access. I don't like messing with getting the typical glow ignitor through that darned hole...it will get dinged up.  If you use a remote battery hookup, it's fine, as it still allows you to use the ignitor in case of a wiring problem. You'd probably need to have a structural connection ahead of the cylinder fins...maybe a 3/16" hardwood dowel or a 1/16 x 1/4 carbon stick, etc.  Make sure you can choke the venturi and flip the prop at the same time, preferably both upright and inverted. 

The rule of thumb is to have 3 times the outlet area to inlet area. The reason is because the air heats up and expands; the large outlet helps suck air on through. Often not shown well on kit plans, for some reason, but it will vary depending on engine/muffler choice and even fuel used. YMMV.  Steve

[FLOYD CARTER]

And here is another example of a cowl made of 1/64" ply.  Wrapped around a kitchen pot of the correct size, with balsa ring at front and a ply ring inside to keep its roundness.  The ply ring is used to bolt the cowl to the plane's firewall.

Floyd

[proparc]

And here is another example of a cowl made of 1/64" ply.  Wrapped around a kitchen pot of the correct size, with balsa ring at front and a ply ring inside to keep its roundness.  The ply ring is used to bolt the cowl to the plane's firewall.

Floyd

I would need more detail to see how it was actually done. That is why I like Windy videos. He shows you everything little thing, step by step so you can duplicate his procedures exactly.

[Leester]

Hey Paul, I'll copy tape # 2 of Windy's Nobler series were they build the Nobler cowl. OK ??

[Steve Helmick]

Windy's videos work better than Sominex for me. Doesn't seem to matter what's the subject.  Steve

[Leester]

Guess he's not interested  If they put you to sleep you don't have the volume up enough so the opera music will keep you awake 

[Avaiojet]

Paul,

Hope it's for a scale model!

Fiberglass cloth over foam. The foam was turned on a drill press.

Charles

[Paul Taylor]

Hey Paul, I'll copy tape # 2 of Windy's Nobler series were they build the Nobler cowl. OK ??

Hey cool!!!
Thanks Lester!
Let me know what IOU.

[Leester]

Paul, all I need is you to PM me your address.

[Paul Taylor]

Thanks Lester!
PM sent