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Re: Building a Power Model Water Pump

Posted: Mon Feb 11, 2013 9:11 pm
by John_S
Started on the steam gland tonight:
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There's a very small internal bore for the o-ring that still needs to be done and then part it off:
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Spent half the evening machining that and the other half making the tiny boring tool out of HSS. Tomorrow I should be able to bore that internal o-ring groove on this gland and machine up the gland for the water end as well.

Re: Building a Power Model Water Pump

Posted: Tue Feb 12, 2013 8:15 pm
by John_S
Still moving along...

Finished grinding my wee little boring tool to do the internal bore for the o-ring in the steam and water glands. Hate machining in a place where you cannot see the tool or what's happening!
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The steam and water glands finished up, other than some light deburring and smoothing:
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The glands temporarily installed in the spacer:
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Wish I didn't have to work for a living. I'd get more done each night!

Re: Building a Power Model Water Pump

Posted: Fri Feb 15, 2013 9:22 pm
by John_S
Steam piston, machined from brass. I didn't have any 1.375" 303 stainless, which is what the print calls for. Brass will do:
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Piston finished up:
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The small reversing plates, one goes in the steam piston and the other in the head assembly:
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And got started on the piston rod. Started with a piece of 303 0.250" SS which had to be turned down to .219"
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Re: Building a Power Model Water Pump

Posted: Fri Feb 15, 2013 9:28 pm
by Bill Shields
you better get it very smooth and very straight and even.

that rod goes through an o-ring, and if there are any binds or leaks, the pump won't work.

if it is rough, it will wear the o-ring quickly and the pump won't run.

I admire your tenacity, but even with a CNC Swiss style (sliding headstock) lathe at my disposal, I just purchased a piece of ground rod.

Re: Building a Power Model Water Pump

Posted: Sat Feb 16, 2013 7:55 pm
by John_S
Bill Shields wrote:you better get it very smooth and very straight and even.

that rod goes through an o-ring, and if there are any binds or leaks, the pump won't work.

if it is rough, it will wear the o-ring quickly and the pump won't run.

I admire your tenacity, but even with a CNC Swiss style (sliding headstock) lathe at my disposal, I just purchased a piece of ground rod.
Actually, it goes through two o-rings, one in the steam cylinder gland and one in the water cylinder gland :)

Re: Building a Power Model Water Pump

Posted: Sat Feb 16, 2013 8:06 pm
by Bill Shields
ah...i thought it was the trip rod....sorry.

same concern....

Re: Building a Power Model Water Pump

Posted: Sat Feb 16, 2013 9:02 pm
by John_S
The trip rod I bought material that is already the correct dimension, so there should be no problems with it.

Bill, have you had a chance to snap a photo of your jig for machining the valve body yet? I've been holding off doing any work on it until I got a chance to see what you had come up with.

Thanks!

Re: Building a Power Model Water Pump

Posted: Sun Feb 17, 2013 1:31 am
by Harold_V
John_S wrote: Started with a piece of 303 0.250" SS which had to be turned down to .219"
Indications are you're using a C5 or C6 grade of brazed carbide. You'll have much better success using a C2.

Trust me on this one. I've machined several times my weight in 303 SS.

Harold

Re: Building a Power Model Water Pump

Posted: Sun Feb 17, 2013 7:18 am
by Bill Shields
yes

it is a 5 sided box that allows me to remove any side and still have 'normal' surfaces to work with when machining. the pin in the center of the 'flange face' is my 0 0 point for all measurements.

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Re: Building a Power Model Water Pump

Posted: Sun Feb 17, 2013 8:28 am
by Bill C
Bill, thanks for posting those photos! With a casting like that, I can sure see the utility of the box. Very neat idea, I have saved the photos in my "someday I will need this" folder!

Thanks again,

Bill C.

Re: Building a Power Model Water Pump

Posted: Sun Feb 17, 2013 8:45 am
by John_S
Harold_V wrote:Indications are you're using a C5 or C6 grade of brazed carbide. You'll have much better success using a C2.

Trust me on this one. I've machined several times my weight in 303 SS.

Harold
The C5 is working nicely, but I'll give a C2 a shot on the next SS part and see how it goes. The piston rod turned out with an exceptionally fine finish on it.

Re: Building a Power Model Water Pump

Posted: Sun Feb 17, 2013 10:11 am
by Fred_V
John_S wrote:The trip rod I bought material that is already the correct dimension, so there should be no problems with it.

Bill, have you had a chance to snap a photo of your jig for machining the valve body yet? I've been holding off doing any work on it until I got a chance to see what you had come up with.

Thanks!
in the casting set I have Art Olds machined a brass block with all the holes and openings. He was going to cut a new flat head and silver the block to it. He thought that would be a lot easier than using the casting. I have the head casting so I would like to try making it; I can always fall back on the brass block.