cox 010 thread

[mitchg95]

Hi, I am working on a final project for a precision machining class at a local high school/trade school and I am working on a cox radial 9 engine, I have the prints for one that utilizes 9 .049 cylinders, heads, and piston/rods assemblies but want to make this one with 9 .010's. The end result will be 4.9 times smaller that the .049 version, I would like to find out what the thread is that the cylinders use to mount in to the crank case, thanks!

[SuperDave]

Mitch:

don't believe compressing that design for .010's is possible.

Prove me wrong.  

SD

[Cribbs74]

I think it's probably possible, but finding 9 .010 cylinder assemblies will be almost impossible.

Unless.... You plan on machining them and if that's the case you will suddenly have a whole bunch of new friends here on CEF.

Ron

[Cox International]

Thread size:

0.3281 - 56 N.S 3A
Min 0.3062
PD 0.3165 - 0.3145
MAJ 0.3281 - 0.3240

[Jason_WI]

Cylinders are on ebay now. Finding pistons will be harder.

[Mark Boesen]

i think SD was trying to motivate, there's no reason it couldn't be scaled down from plans, it will cost a couple bucks more.

[roddie]

Thread size:

0.3281 - 56 N.S 3A
Min 0.3062
PD 0.3165 - 0.3145
MAJ 0.3281 - 0.3240

I had a feeling you would supply this info Bernie. I did a lengthy web search earlier today; because I was interested in the .049's size... stated to be of 17/32-40 as per this chart... it does not however list the cyl./glow-head thread size for the .010... and the Pee Wee .020's listing cannot be right... as it's listed as being 17/32-40 for the cyl. "neck" only... no glow-head thread is listed. It would seem to be a "typo" carried down from all the .049 listings directly above and below it.

http://www.mh-aerotools.de/airfoils/cox_techinfo.htm

[Cox International]

the 020 is .390 - 48

[mitchg95]

thanks a whole bunch guys! ive been basically experimenting with the idea. I think that a .020 version would be more viable than the afore mentioned .010 version

[Cribbs74]

Possibly, it would be easier to obtain them that's for sure. Might still be expensive though.

I hope you can make it happen.

[John Goddard]

It's no mean feat Mitch, particularly if you want it to run.
To my knowledge there's still only Phil the Engineers radial on you tube.
BTW
It doesn't need to be compressed.

 

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