aggie84

I bought my Chipmunk already built from a flying buddy of mine. I originally put a 61 FX in it. Last summer the engine died on takeoff (hole in pressure line) and I nosed it in. Not much damage done but it totaled out the cowl. I decided to take out the 61 (it went quite nicely in a Venus) and put a 91 FS back in its place. I ordered a new cowl from precision-fiberglass-prod.com and it arrived today. (Very nice btw and good price). Does anyone have any pictures of how they cut their cowl? Anthing you'd do different or better?

There has to be a way to get the cowl over the cylinder and needle valve without cutting it to pieces but I can't see it. I'm sorta thinking about cutting the right side off, hinging the two pieces together at the top and figuring out a way to attach the two pieces at the bottom (maybe a strip of lite ply overlapping the two pieces and then screw into the lite ply). This seem like a lot of trouble but it would be easy to put on and take off.

Just wondering what to do,

Thanks for the help,
Tim

FLYBOY

My Feedback: (11)

I tend to like to leave it whole. I like to cut the hole as tight as possible on the engine, and sneak up on it. Don't try to cut it all at one time. Start where you know you need a hole, then work it larger and larger till it fits. You will have to put in on and take it off many times to do it, but make small cuts with the round sanding wheel on the dremel. I use a sharpie pen to make the marks on it, and cut till the mark is gone. I start with a hole the size of the cyl head and keep enlarging it till it fits. Don't take too much off at one time so you dont make a mistake.

Good luck. Hope you get the fit you want.

TexasAirBoss

My Feedback: (22)

Aggie huh ? I'll type slowly. Ask Minnflyer. I bleieve He did exactly what you are talking about.

DaveB

A good method of cutting the cowl is to first mount the engine and then make a pattern of the portion of the engine that will protrude on a small piece of poster board or similar. Tape the pattern to the fuse and mark its location on the fuse. Remove the engine and fasten the cowl. Now, align the pattern on the marks trace the pattern on the cowl and cut the cowl as needed. It should be very accurate.

DaveB

MinnFlyer

My Feedback: (4)

The original cowl comes in two pieces seamed down the center. You are instructed to glue a strip of scrap plastic from the cowl over the seam, but I did as you're hoping to do - I glued the plastic strip to one side (Top and Bottom) and used 8 screws (4 top - 4 bottom) to hold the two halves together.

I see no reason why you couldn't do the same with the FG cowl, except to say that if you use plywood, make sure you fuel-proof the hell out of it.

DVI

Hi Aggie84
I just spent the weekend fitting a new fiberglass cowlen to my CG Chipmunk. The kit came with a ABS cowlen in two halfs split doen the center. I used the ABS cowl and cut out openings as nessary then laid it over my fiberglass cowl and cut it out. Worked very well!
To get the fiberglass cowl over the engine you will need to remove the head of the engine. Good luck with your project.