Author Topic: Steam Tractor 3/4" (Rudy K)  (Read 242010 times)

Offline crueby

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #945 on: November 21, 2017, 01:04:59 PM »
Full fat cows milk is the best for copper
Where did you find safety glasses to fit the cow you keep in the shop?   :ROFL:

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #946 on: November 21, 2017, 05:26:25 PM »
Yes, safety first!


I was just wondering about the smell of the rotting milk in the shop.  I don't mind the smell of oil & grease.  But rotting milk mixed around with the swarf - that seems a little much for me!  :lolb:

Kim

Offline Dave Otto

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #947 on: November 21, 2017, 07:59:18 PM »
I have machined quite a bit of copper at work, milling, drilling, and tapping. The soluble oil in my VMC seems to work just fine.
I do also run small copper job at home, the Micro-Drop mister using their synthetic lube also works great. I think modern cutting oils have come a long way since the days of using whole milk to machine copper.

Dave

Offline scc

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #948 on: November 21, 2017, 09:36:10 PM »
Looking good Kim,    I've never had to machine copper so I'm watching and learning....................Terry

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #949 on: November 21, 2017, 10:40:51 PM »
Thanks Dave and Terry,
Yeah, the cutting oil I'm using seems to be doing fine. I'm sure there could be something better, but this hasn't caused me any problem.  Oh - yeah... except for my broken center.  But I'm not sure I can blame that on the cutting oil.  I think I was just getting too careless.  Everything was just swimming along so nice, I forgot to be cautious and was pushing things a little hard and fast.  Live and learn...

Thanks!
Kim

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #950 on: November 21, 2017, 10:43:47 PM »
Day four of my boiler odyssey:

Today I made all the bushings.

I started with a 5/8” round copper rod.  Turned it down to 9/16”, then put a 1/2" step in it to fit in the End Cap holes I made yesterday.  After a nice trial fit, the part was cut off:


After cutting two 1/2" bushings, and two 3/8” bushings (for the top of the boiler) I moved to tapping them.

I flipped them around in a 1/2" collet, faced off the flange to the correct width (1/16”) then drilled and tapped.  The first two (the 1/2" ones) were both supposed to be 1/8”-27 NTP.  Having never done a tapered thread before, this was a new experience for me.  According to the table I looked up, if you don’t have a Pipe Taper Reamer (which I didn’t) you should use a “Q” bit for a 1/8”-27 threaded hole.  This was ‘just’ big enough to start the taper tap.  Taping the copper was hard going – Not sure how much of the challenge was the copper ,or how much of it was the taper – the further you go in, the more threads you were cutting at once.  But taking it slow, using lube and backing out a lot to clear chips, I made it just fine.


I tried one of the fittings in there and realized I needed to make the taper go much deeper.  So, I kept going till the fitting went about half way in, which seemed reasonable.
 



One of the 3/8” bushings was to be 5/16”-27 MTP.  With research, I’d learned that MTP stands for “Model Pipe Thread”, and that 5/16”-27 MTP is the same thing as 1/16" NTP (National Pipe Thread).  So, I did the same maneuver with this one, using a 1/16"-27 NTP tap.

The final bushing was just a simple 10-32 straight thread.  Got that one done in a jiffy!

And here is my family of bushings:


Now I’m down to the boiler tubes left to make before I start soldering!
Kim

Offline b.lindsey

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #951 on: November 22, 2017, 12:37:37 AM »
Tapered threads can be a challenge in even brass or aluminum. I can imagine the "grabby" copper was even worse. Nice work getting those done Kim .

Bill

Offline 10KPete

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #952 on: November 22, 2017, 12:42:32 AM »
From the quality of the finish it looks like you're doing just fine with copper. Super sharp tools, easy cuts with thin chips...

Beautiful!

Pete
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Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #953 on: November 22, 2017, 01:26:57 AM »
Thanks Bill and Pete!

I'll be glad to be done with the copper and back to more standard materials soon!

Kim

Offline Flyboy Jim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #954 on: November 22, 2017, 02:45:50 AM »
Great work Kim.  :ThumbsUp:

One of the many things I've learned from your thread is that, if I ever go to a bigger lathe, it will have to have the capability to have a 5C collet chuck! That looks so nice to work with.

Jim
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".

Offline 10KPete

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #955 on: November 22, 2017, 02:52:37 AM »
The good ol' collets made like that 5C will hold right on a small step like a bulldog! That's something the ER collets won't do. But they were designed as tool holders...

Love those collets!

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline Flyboy Jim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #956 on: November 22, 2017, 02:57:56 AM »
The good ol' collets made like that 5C will hold right on a small step like a bulldog! That's something the ER collets won't do. But they were designed as tool holders...

Love those collets!

Pete

I've got a set of 5C collets and collet blocks, so have already bonded with them.  :Love:  I just haven't found a 5C collet chuck for my Sherline lathe yet!  :lolb:

Jim
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".

Offline 10KPete

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #957 on: November 22, 2017, 03:51:23 AM »
And what's stopping you from making one? I dunno, it might be possible.....

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline rklopp

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #958 on: November 22, 2017, 03:54:05 AM »
The rule of thumb for how deep to tap taper pipe NPT threads is to go until 6 thread of the tap are still sticking above the surface.

As for boiler bushings, phosphor bronze is good and machines much more easily than Cu.


Sent from my iPhone using Tapatalk

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #959 on: November 22, 2017, 05:21:02 AM »
...if I ever go to a bigger lathe, it will have to have the capability to have a 5C collet chuck! That looks so nice to work with.

Yes!  I love that collet chuck.  It was on the spendy side, but I purchased the Bison chuck from Grizzly when I got my lathe.  And boy, was it ever a good move!  I use that chuck 90% of the time probably.  Over the last several years I've picked up a square and hex collets which makes it even more versatile.  I would highly recommend it a 5C collet!

However, I agree, it might be a bit tough on the Sherline.  The collet chuck would probably take over half the length of the lathe! :)

Kim

 

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