scratching an engine

[wellsprop]

Hey all,

This is a first for me. I have a plan to build an Auster V with its engine on display. It has a tiny Lycoming O-290 and is very basic in design. I have a 1/32 lycoming engine from a Pa-18 (this engine os basocally a bigger version of the O-290) and i can use this to take measurements and make comparisons.

However, my main problem is how to scratch build an engine. I have various peices of sprue to use plus plastic sheets you get on electrical appliances. Ive test built one piston out of various bits of metal tube which went fairly well. I have metal wire plus stretched sprue for wiring/pushrods etc.

Any help would be appreciated.

Ben

[Raven Morpheus]

First off I'd start with the engine block itself. I'd use styrene sheet and tubing to build the engine block (probably made by Evergreen). Basic construction would be tubes put together and covered in styrene sheet (imagine a box with tubes in it). Depending on the configuration and number of pistons (straight, V, or W, 2, 3, 4, 6, 8 etc.) you'd do that once or more for each bank of cyclinders.

Then for the pistons, crankshaft and rods I'd again use styrene rod, with obviously the rods for the pistons themselves matched to fit nicely inside the tubes used in the engine block...

Without looking at what you're building that's as far as I could go and I'm not that much of a scratch builder anyway.

Edited January 5, 2015 by Raven Morpheus

[heloman1]

Make a sketch form pics or your 32nd parts, then from that make a 72nd scale three view drawing. This will give you an idea of the size and shape, then work out the sizes of all the parts brocken down into the crankcase and the cylinder block. Once you have a drawing it makes it lot easier to see where you're going. Once you start making up the various parts check they are what you are trying to achieve and if not remake them, it's not wasted time just practice. Most of all don't rush it. Then once you have made one, make another it will turn out better.

To simulate the cooling fins on the top half of the cylinders you could wind fine wire around the part you use for the cylinder.

Colin

[s.e.charles]

anyone have a good way to make spark plugs? and attach wires without boots? like the old Rajah screw terminals.