barefootcyborg5000
barefootcyborg5000 PowerDork
12/1/22 6:40 p.m.

So I'm building a thing. Without getting too detailed, I find myself needing a piece lathed. 
the basic idea is a 6" long piece of 3" round bar, with a 1" dia. hole bored in the end, 4" deep. 
 

as a rough example. I don't know anyone locally who can machine such. I could conceivably order the bar and attempt to use a drill press to do the do. I don't envision being successful. I think this is a job for a lathe. 

Exterior diameter needs to be 3" but all other dimensions are negotiable. Steel. 
 

I'm willing to pay for materials, shipping, etc.  That said, folks here seem to always have solutions I haven't thought of. Maybe someone has scrap, or knows where to source some, or knows a place to order something. I am trying to keep this relatively inexpensive, within reason. 
Any help or pointers appreciated. 

RX Reven'
RX Reven' UltraDork
12/1/22 7:00 p.m.

I was thinking you could buy commercially available pipe and weld a plate on the bottom but a 1" wall thickness isn't common with such a small OD.

BTW, I have a sneaking suspicion what you're building; careful.    

Mr_Asa
Mr_Asa UltimaDork
12/1/22 7:02 p.m.

I can lathe that. If you wanna order a piece of metal mailed to me ill get to work on it. How tight is the ID tolerance?

7rx
7rx New Reader
12/1/22 7:02 p.m.

Can the hole go all the way thru? If so thick wall tube from McMaster might work. Little over priced but easy to get and fast shipping if that matters.

Datsun310Guy
Datsun310Guy MegaDork
12/1/22 7:03 p.m.

Pipe is nominal but you can get tubing as that's called out by OD and wall thickness however not sounding like your application. Think tubing like exhaust tubing.

barefootcyborg5000
barefootcyborg5000 PowerDork
12/1/22 7:06 p.m.

In reply to RX Reven' :

Careful. Yes. There will be much distance for safety. 
We're working with baseballs and loose tolerance, so there isn't too much mass involved. Also the 1" sidewalls should be more than adequate. 

barefootcyborg5000
barefootcyborg5000 PowerDork
12/1/22 7:06 p.m.

In reply to 7rx :

No. I need a blind hole. 

travellering
travellering HalfDork
12/1/22 7:14 p.m.

How are you going to fit a baseball in a 1 inch diameter barrel?

matthewmcl
matthewmcl Dork
12/1/22 7:15 p.m.

In reply to barefootcyborg5000 :

I can do it for you also, and without getting into too much detail, do you also need a hole, just inside of the blind end, a little larger than 1/8"?

matthewmcl
matthewmcl Dork
12/1/22 7:15 p.m.

Also, golf balls make a good size...

Keith Tanner
Keith Tanner MegaDork
12/1/22 7:27 p.m.

In reply to travellering :

Maybe this is part of the bat. Won't be fast to swing, but it'll pack quite the punch.

Mr_Asa
Mr_Asa UltimaDork
12/1/22 7:53 p.m.
travellering said:

How are you going to fit a baseball in a 1 inch diameter barrel?

Same way the elephant deflowered the mosquito?

barefootcyborg5000
barefootcyborg5000 PowerDork
12/1/22 7:54 p.m.

In reply to travellering :

The whole thing will be part of a larger assembly. Baseballs are roughly 2.9" if you're curious. 

barefootcyborg5000
barefootcyborg5000 PowerDork
12/1/22 7:56 p.m.

In reply to matthewmcl :

Slightly smaller than 1/8 I think. But I can manage that part. 
And golfballs are not quite ambitious enough. We're still very much in the brainstorming phase, but it's been occupying a large part of my thinking lately. 

barefootcyborg5000
barefootcyborg5000 PowerDork
12/1/22 7:59 p.m.

In reply to Mr_Asa :

ID and depth are not super critical. I'm aiming for a volume roughly 3" ^3. Math says 1"x4" should do. 

barefootcyborg5000
barefootcyborg5000 PowerDork
12/1/22 8:01 p.m.

In reply to travellering :

The ball is the piston. The 1" bore is just the combustion chamber. To bring in automotive terms. 

travellering
travellering HalfDork
12/1/22 8:29 p.m.

I have been responsible for turning a thing that looked like a silencer, but fit a racquetball. It sent one about a tenth mile down the railroad clearance, and just blew a hole in the next one.  Apparently dollar store racquetballs are not to exacting tolerances...

 

 

 

 

matthewmcl
matthewmcl Dork
12/1/22 9:01 p.m.

I met a guy that did concrete-filled beer cans...

Toyman!
Toyman! MegaDork
12/1/22 9:23 p.m.

1" x 4" is a lot of powder. It may shred your piston. 

I launched a 4" fireworks mortar with about that much powder and it shredded the shell and the whole thing exploded in the tube. Made a good bit of racket and shattered the 3/4 plywood base. 

Toyman!
Toyman! MegaDork
12/1/22 9:25 p.m.

I may have a piece of steel in the shop. I'll check tomorrow. 

barefootcyborg5000
barefootcyborg5000 PowerDork
12/1/22 10:19 p.m.

In reply to Toyman! :

I'm figuring that will be the max. Gonna start at 1/4 capacity and work up. The goal is maximum distance without shredding. For science. 

Toyman!
Toyman! MegaDork
12/2/22 7:30 a.m.

In reply to barefootcyborg5000 :

50 Funny Science Memes For The Brainiacs | THE ROCKLE

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