Hip Pocket Builders' Forum

Control Line Forum => Engines for Control Line Aircraft => Topic started by: jerryCashman on April 03, 2019, 09:13:47 PM



Title: Method for holding muffler for OS Pet III
Post by: jerryCashman on April 03, 2019, 09:13:47 PM
Hi team,

I've dug an old OS Pet (I think, a Mk III) from the depths and have cleaned it up and it's a great little runner and I'm looking forward to building a little C/L stunt/trainer to get my hands back in after xx years...

The only bit that's missing is the spring gadget that used to hold the muffler on to the head...

Other than fashioning a strip of brass to fit - does anyone have any other suggestions on how to safely fix the muffler on?

cheers. Jerry in Canberra.

(https://www.osengines.com/history/osm640/osm-1971-pet-iii-099.jpg)


Title: Re: Method for holding muffler for OS Pet III
Post by: strat-o on April 04, 2019, 02:13:24 PM
Winding your own spring might seem like a tedious proposition, but I think any alternative would have it's difficulties.  Given a long piece of suitable wire, access to a vice and a steel pin or nail to wrap against as a mandrel should land you in the ball park.  Also a pair of pliers will allow you to pull the wire to a good tension as you wrap.

Marlin


Title: Re: Method for holding muffler for OS Pet III
Post by: NormF on April 04, 2019, 04:27:48 PM
How about using two pieces of wire, tension it by twisting, ala safety wire. Run the wire in some silicone fuel line to add some vibration resistance and also protect the finish of the engine.

Norm


Title: Re: Method for holding muffler for OS Pet III
Post by: jerryCashman on April 04, 2019, 06:08:30 PM
Thanks guys - Norm, I think you are on a winner there with the twisted wire and I do like the fuel-tube cushioning - I'll give it a go! Thanks :-)