Full sized Cretor's. Am I nuts?

[black85vette]

Been kicking this around for some time. Watched Brian and Stew build the 1/3 scale engines and loved the looks of them but think the full sized looked pretty good.

Thought about using castings but get no email response from Myers or Coles.

Looking over the plans Brian posted and scaling them up, the only real problem area I see is the crosshead guide. It will be about 3 inch diameter and about 14 inches long. That is a big chunk to chuck and bore. I have a 12"x48" lathe and have the steady rest for it. So I guess it is possible but I have never done anything like that.

Or, I could make it in a couple of pieces and weld it up.

What do you guys think?

 

[Jasonb]

No reason not to weld it up, make the actual piece that the cross head runs in as one and then weld more to it but leave the parts longer so you can machine them back after welding using the guide part as your reference

J

 

[Philjoe5]

Making a large crosshead guide can be done easily by making parts, then joining them by welding or silver soldering.

These are the two parts I made using 2" black pipe and a piece of CRS:

I had a friend silver solder them, then I cut the access slots after machining to size. This picture shows parts made in 2 scales, the smaller guide having a bore of 0.8", the larger one is over 2".

Like Jason said make the pieces slightly oversized, then when they are joined, machine them to final dimensions.

Good luck

Phil

 

[rleete]

Are you nuts? Yes. Yes, you are.


Did anyone say that was a bad thing?

 

[black85vette]

@Philjoe5

That looks like a good route to go. I can get DOM tubing in the wall thickness I need and reduce the amount of boring required. This may not be as difficult as I feared.

 

[black85vette]

Are you nuts? Yes. Yes, you are.


Did anyone say that was a bad thing?

You may be right
I may be crazy
But it just may be a lunatic you're looking for.

-Billy Joel

 

[Jasonb]

As they were such small engines its quite feasable and cartainly not nuts, my current steamengine is 17" long, bigger bore than a full siz epopcorn and most will be fabricated.

J

 

[Brian Rupnow]

You may not be nuts, but you're damn brave!!! That being said, the popcorn engine is one of my best running engines, but man, thats some BIG machining.

 

[black85vette]

You may not be nuts, but you're damn brave!!! That being said, the popcorn engine is one of my best running engines, but man, thats some BIG machining.

Not sure I would attempt this without your plans and watching your build. It will be a challenge to scale it but it would be impossible to do it without anything to work from.

BTW; love seeing the Atkinson run!

I do have my "ace in the hole". My friend Danny is a professional machinist in a tool and die department and I have access to his equipment if I get stuck.

 

[black85vette]

Been getting together a materials list that needs to be ordered and shipped. I have most materials available locally. One of the things I am looking at is cast flywheels. Like the looks of them and I don't really want to fabricate an 8" flywheel.

Saw this one: http://www.martinmodel.com/MMPflywheels-subfiles/FW080-6S-C-RG-XXXX-CI.html

It is $40 which seems OK to me. Anyone have other ideas or sources?

 

[Brian Rupnow]

Depends on how pretty you want it. I hear that folks make flywheels from weights for lifters barbells. 40$ is very cheap if you consider your time to be worth anything at all.

 

[black85vette]

Complete change of plans! Literally. Managed to get a set of castings and plans from Cole's for the full size Cretors. So I am going to build it from castings rather than bar stock. Still might be crazy. The parts are really big.

The base is way to big for my X2. Right off I can see several trips to my friend's Bridgeport mill. No problem since I am over there every week working on our other project; a 1967 Camaro.

When I get going I will start a build thread.