REM37BY a Disappointment

[jgerard]

Re: REM37BY a Disappointment

I would love to borrow them Carl. Any luck selling your plane yet?

Jason
N43643

[Dick Smith]

Re: "Bumps"

The last time I was in Stoddard's Aircraft in Anchorage, they had some of the bumps like I have on my 85 hp BC12D. They are about 11.25 inches overall, including the flange portion. http://www.stoddardairparts.com/
Dick

[Carl Ellis]

Re: REM37BY a Disappointment

Carl - can you briefly describe the process of reproducing a part from a part?
I may want to try doing that with the fiberglass thing that goes around the air filter.- Mike

You can make a female mold from the original using bondo or plaster. You can either lay up the glass *into* that or make a male mold from the female mold and lay up *over* that.

- Carl -

[Carl Ellis]

Re: REM37BY a Disappointment

Here are the bumps - they came in a box of parts with the airplane.

The white bump looks like it was vacuum formed and the other appears to have been layed up over the first.

The inner dimension of the bump is 10" long X 2 5/8" wide. The flange is about 3/4".

- Carl -

[Carl Ellis]

Re: REM37BY a Disappointment

I would love to borrow them Carl. Any luck selling your plane yet?

Jason
N43643

Jason -

Give me a postal address and I'll get them to you. Or ... I can bring them with me to Columbia.

No luck on selling Sweety yet. I've had a fair number of calls but nobody has taken the next step yet. It all takes time - I'm in no hurry.

- Carl -

[flyguy]

Re: REM37BY a Disappointment

Jason,
Sounds like you have some masters for bumps lined up. I will still check to see what my buddy has: ref. cans and bumps.
General Discussion:
I did some measurements to see how the aluminum bumps that Univair had would fit a while back. Cripes! I would have to effectively cut my top cowlings in half to install them. No thanks.
I'm just going to tough it out and try to get everything to fit under the "hood."
Mike,
Keep us informed of the progress on building the cans. I haven't seen the info for those so it will be all new to me.
Darryl

[mulwyk]

Re: REM37BY a Disappointment

Carl:
I'd like to barrow your bumps to reproduce. I've done a bit of fiberglass work on boats and such. I could make the resulting mold available to T-craft folks who want to make their own bumps.

Mike:
Reproduction in fiberglass:
Attach your part (bumps or whatever it is) to a 1x6 board or plywood or masonite.
Spray the part and the board with a mold release...cooking spray works good.
Cover the part with 2 or 3 layers of fiberglass/resin.
After the resin cures, remove the now hardened fiberglass from the part and you have a female mold. Fill any holes or defects with a little Superfill.

You can make dozens of copies of the original part by laying up fiberglass inside your mold. Don't forget the mold release each time you make another copy.

Bob Gustafson

[mhorowit]

Re: REM37BY a Disappointment

Bob - thanks for the explain. BUT.... won't the resulting 'copy' be slightly larger than the original? Does that ever cause a problem? - Mike

[VictorBravo]

Re: REM37BY a Disappointment

Carl - can you briefly describe the process of reproducing a part from a part?
I may want to try doing that with the fiberglass thing that goes around the air filter.- Mike

Before you go trying to make molds and patterns and such for re-producing an existing teardrop, allow me to point out that you can make a set of one-off parts in half the time.

For the teardrop spark plug fairing, here is how to do it with the least amount of effort. (same would hold true for the air filter fairing)

Remove the old fairing and rivets. Close up the cowl with everything in place. Cover the area carefully with Saran Wrap making sure to smooth out all the wrinkles. Get some oil based modeling clay, and put a big blob of it over the spark plug and onto the cowl.

Using your fingers, popsicle sticks, spoons, knives, or even fancy clay sculpting tools, shape the clay blob to a teardrop shape. Stick a pin through the very top to make sure you have at least 1/8" of clay above the top of the spark plug wire.

Once you are happy with the teardrop, cut three pieces of 3 ounce weight fiberglass cloth that will drape over the teardrop and extend an inch out onto the top cowling in all directions. The critical thing is to cut the pieces of cloth so that the weave pattern is angled 45 degrees OFF of the longitudinal axis of the part. This means that the weave will be 45 degrees to the thrust line of the airplane basically.

Get some "West Systems" epoxy laminating resin (I think number 105 resin and 205 slow hardener), which is sold by any homebuilt airplane supply. Better yet, find a guy building a homebuilt airplane and buy him a 6 pack in exchange for a few squirts of West Systems epoxy and save $50 worth of materials.

Lay out the three cloth pieces on a piece of flat glass or mirror, pour a little of the mixed epoxy onto each cloth piece, and either brush or squeegee the epoxy until it has wet the entire cloth. Blot up all the excess epoxy or squeegee it off of the cloth with a popsicle stick. Lay the first wet piece onto the clay and work out ALL of the wrinkles, and make sure the cloth is laid down onto the clay with no airspace under the cloth. You will be able to see the difference easily whether it is all down on the clay or not. then do the second piece, and whan it is down on top of the first piece PREFECTLY go ahead and put on the third piece.

Allow the epoxy to cure for 2X the stated curing time in the instructions.

Pull off the fiberglass piece and scrape out all the clay. Trim the outside shape with aviation tin snips, and sand the edges smooth with 220 grit sandpaper.

Use Bondo or other body filler type material to fill in the texture of the surface, or "Feather Fill" or whatever good two part filler you prefer. Sand smooth, prime, and paint as desired.

Hold the teardrop fairings in place with screws or small nuts and machine screws as desired.

Buyign a set of stamped aluminum teardrops is cheaper and faster, but I understand they are not easy to find. The plastic vacuum formed ones are junk and will not last long.

Bill

[flyguy]

Re: REM37BY a Disappointment

When working with epoxy:
For mixing a small amount or for a work board for saturating small pieces of glass fabric I wrap aluminum foil around a stiff piece of cardboard. Mix and fill on the foil surface, and discard the foil after you are finished. If you set the leftover material to the side you can check it in a little while to see if the batch is setting up without disturbing your part.
Darryl

[mulwyk]

Re: REM37BY a Disappointment

Mike:
Copy will be the same size as the original. Reason: you make your mold on the OUTSIDE of the original, then make the copy on the INSIDE of the mold. The copy comes out exactly identical to the original, right down to those little defects in the original that you didn't notice until you made a copy of it.

Bob Gustafson

[Forrest Barber]

Re: REM37BY a Disappointment

37 is a very "cold" plug .... stay with the 40 ..... bye "Publicius".

[Yellow Duck]

Re: REM37BY a Disappointment

Hey guys I have a bunch of M41E (old style, non shielded) if anyone nedds a set, let me know. I will be at the Alliance fly-in. I have purchased a new set of Slick mags with plugs, but have been thinking about the BY's they are 3/8 inch shorter. Purchased the cowl bumps (44 bucks for the pair) Have not installed them yet, hoping the shorter plugs will work ?

[mhorowit]

Re: REM37BY a Disappointment

Lee - I'd appreciate three; you wanna wait until Alliance or I'll pay for shipping?
Mike

[mhorowit]

Re: REM37BY a Disappointment

Mike:
Copy will be the same size as the original. Reason: you make your mold on the OUTSIDE of the original, then make the copy on the INSIDE of the mold. The copy comes out exactly identical to the original, right down to those little defects in the original that you didn't notice until you made a copy of it.

Bob Gustafson

Oh - so there are two operations. First, make a mold from the original, then make the new part from the mold. Got it - Mike