Goin' Crackers.

[mklotz]

For spur gears, the correct center-to-center spacing is given by the average of the pitch diameters of the two gears.

(Spur) gears can be thought of as two cylinders (of respective pitch diamters) in rolling contact with teeth added to (the gear addendum) and subtracted from (the gear dedendum) to prevent slipping. The spacing between the two cylinders is of course the sum of half the diameter of each cylinder = the average of the diameters.

 

[vlmarshall]

Thanks, Shred. Great to know I'm not too far off.

Marv, thanks for that giant collection of applications. Your gear calc gave numbers within .002" of what I used. :bow:

 

[BMyers]

Interesting PW lathe, that IS a monster. I really like the looks of that little South Bend you've got... the first lathe I ran was an old open-belt head like that, and I've had a soft spot for them ever since.

Not to hijack the thread; the PW is a great lathe, it now belongs to someone else. I am downsizing to machines easier to move in anticipation of relocating to chase work ( I have been unemployed since Feb). The South Bend is a 1928 22A jr. I really like it, does nice work and will stay with me. I want to compliment it with a 9 or 10" lathe with a GQ gear box and power cross feed.
Now, back to the regularly scheduled posting.
Thanks for the info on the gears, I will file that away for when I build mine

 

[vlmarshall]

...The South Bend is a 1928 22A jr. I really like it, does nice work and will stay with me. I want to compliment it with a 9 or 10" lathe with a GQ gear box and power cross feed...

Nice little lathe, I really like it. No worries about hijacking my thread, I ramble off-topic in other people's posts all the time, I wouldn't expeect any different in my own, and besides, it'd get boring if it was ALL Cracker here.

Speaking of boring, I finally got around to cutting chimney holes in the smokeboxes, and have decided to try an alternate part, cutting the smokebox out of a slip coupler like Shred and everyone else. I have a pair of them here, so they went into the mill after the rounded ones.

It's been a few days since I've posted a new photo, so I had to show something. ;D

 

[vlmarshall]

I'll even post a link to a not-so-exciting video of the smokebox cutting. ;D
[ame]http://www.youtube.com/watch?v=rTfshaaOQsE[/ame]

 

[zeeprogrammer]

I watched the entire 4.24 minutes.
But maybe I'm just trying to make you think you made a good offer? (The guinness...remember? I do.)
But really...I like watching videos of machining operations.
Thanks.

What was that noise at the very end? It sounded like a kid?

 

[vlmarshall]

I watched the entire 4.24 minutes.
But maybe I'm just trying to make you think you made a good offer? (The guinness...remember? I do.)
But really...I like watching videos of machining operations.
Thanks.

What was that noise at the very end? It sounded like a kid?

Yep, that was my 4-yr-old daughter asking, :Hey dad, can I talk now?" ;D I'd asked her to be quiet while I made a movie.
Guinness? What Guinness, I don't remember any offer. :big: ;D :big:

 

[vlmarshall]

This evening I punched fiber gaskets for my steam line banjo fittings, laid out the bushing holes on the boilers, Loctited the crank throws onto the crankshafts, trued up the alternate smokeboxes, deburred them, removed the stop lugs so they'd press onto the boiler tube, and still managed to spend all evening on here. How?
Resource management. ;D

 

[zeeprogrammer]

And all I managed to do is mount a chuck on a RT on a mill. That and a little more ranting. Could've used the Guinness.

I didn't know you were that young. And blonde too. ;D

Isn't it a joy?

I hope you don't mind my intrusion...put a cap on that head...even if the machines aren't running...have her develop the habit.

 

[vlmarshall]

And all I managed to do is mount a chuck on a RT on a mill. That and a little more ranting. Could've used the Guinness.

I didn't know you were that young. And blonde too. ;D

Isn't it a joy?

I hope you don't mind my intrusion...put a cap on that head...even if the machines aren't running...have her develop the habit.

Ha, I saw your rotary table post, and I'm glad for it. Nice little table. Chuck's kinda tall though.

Nope, I'm not that young, or blonde. I'm lucky, both her and her mom are interested in this kinda stuff. A cap or at least a hair tie's a good idea... she's even wearing one on her wrist like I do when my (too long) hair's not tied back. Good idea to start safe, young. Thanks, Zeep. ;D

 

[vlmarshall]

Well, I cut the bushing holes in the boilers yesterday. Straightforward, quick and easy.

 

[zeeprogrammer]

Post 15? stickpoke

Where do you get the copper from?

 

[vlmarshall]

The big tubing, 1.375" OD, 1.250"ID, came from some plumbing service place, where my dad knows someone working there. ;D
The small-diameter stuff came from Lowes... nothing special about that one. Sold as 1/2" tubing, ( or pipe, whatever, I'm no plumber) it measures .625" OD and .555" ID. Go figure. ???
The end caps are cut from the big tube and hammered to shape over a mandrel.
The little bushings are turned from some Phosphur Bronze that came from Mcmaster-Carr.

Today I silver-soldered the whole works together... my first attempt at silver-soldering. Luckily we have a good set-up at work... it didn't go too badly. ;D

I see a few pinholes around the bushings... I wonder if they'll leak.

 

[zeeprogrammer]

1st attempt! That must have been exciting.
I see a lot of references to silver soldering on this forum.
I know I'll have to have a go at it some time.

Did you see 'firebird's setup for testing his boiler and pressure? I want to build the little pump he made.

 

[vlmarshall]

1st attempt! That must have been exciting.
I see a lot of references to silver soldering on this forum.
I know I'll have to have a go at it some time.

Did you see 'firebird's setup for testing his boiler and pressure? I want to build the little pump he made.

Man, it was.. I didn't know if I'd melt it into a blob, or what. Although, I can braze, stick weld, MIG, and TIG with reasonable skill, I'd never tried this stuff, or anything with copper, other than soldering.

I wanna build that little pump too.... I need it, now. ;D

 

[zeeprogrammer]

other than soldering.

Which is the sum total of my experience melting anything other than toy plastic soldiers.

 

[shred]

FWIW, there's a slightly-easier-to-build piston pump stashed in my Slightly Loco thread. It works ok, but the lever kind like Firebird's isn't much more work and probably a lot more controllable.

 

[vlmarshall]

Which is the sum total of my experience melting anything other than toy plastic soldiers.

Yeah, you can solder... this wasn't much different. Cleanliness and flux are the secrets, just like soldering.

FWIW, there's a slightly-easier-to-build piston pump stashed in my Slightly Loco thread. It works ok, but the lever kind like Firebird's isn't much more work and probably a lot more controllable.

Thanks, Shred, I'll go look for it. I bet I've already saved a picture, or Crap-o-cad, of your pump...along with everything else in your thread. ;D

 

[vlmarshall]

Well, I made the saddle mounts for the boilers yesterday, out of some pressed-mica block. The stuff is a bit abrasive, but not too hard to machine to machine, but if you try to drill it with the 'grain', it'll split easily.

I'll add some pictures here eventually.
The front block is drilled straight through, with a bolt through it from the smokebox, threaded into the front frame crossmember.
The rear block is just a saddle bolted to the footplate, with a counterbore for bolt head clearance under the boiler.

 

[zeeprogrammer]

Very cool! :bow:



Hey! What are you doing over here? I need your help. :big: