Winton Air Pump

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daves1459
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Joined: Mon Jun 07, 2010 7:58 pm
Location: Plainfield, Illinois

Winton Air Pump

Post by daves1459 »

I'm building three Winton 1 1/2" scale Westinghouse 9 1/2 air pumps using the original casting that I have had for a very long time. I'm building to the first design, drawings dated August 1969. Winton Brown was not bashful about making things complicated. I'm currently working on the Steam Cylinder Head which is drawing #19 of the 26 drawings that I have. The drawings are numbered individually. Not 1 of 26, 2 of 26, and etc. So, I do not know if I have a full set. The cylinder head drawing has 'NOTE: USE DRILL JIG FOR ALL PORTS". None of the 26 drawings contain any details of a drilling jig. This is a long shot, but does anyone happen to have a copy of the drill jig drawing, or any other drawings that I may be missing, that I can get a copy of?

Dave
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Greg_Lewis
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Re: Winton Air Pump

Post by Greg_Lewis »

I also have 26 pages, so that suggests we both may have all that there are. As to the jig, somewhere in my memory I seem to recall seeing a photo of such a jig, but I think it's just something you make up to hold the head while working on it. I've never seen a jig drawing and I have drawings for perhaps six different versions of similar pumps. I think it was a square block that you just set up to mount the head on and use as a reference for measurement in order to get the various ports and holes in the right place.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
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Bill Shields
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Re: Winton Air Pump

Post by Bill Shields »

Exactly..
Too many things going on to bother listing them.
daves1459
Posts: 279
Joined: Mon Jun 07, 2010 7:58 pm
Location: Plainfield, Illinois

Re: Winton Air Pump

Post by daves1459 »

My thoughts too. I added a chucking piece to the top of the cylinder head casting. The plan is to chuck the cylinder head by the base diameter and skin cut the chucking piece to 3/8" diameter. Then collet the cylinder head on the chucking piece to finish the base bolting face, O.D., and pilot valve bore. Then transfer the collet to a square collet block and leave it there to do the rest of the machining which is mostly drilling and tapping. There will be a few set ups of the block as there are holes from several directions.

Thanks for replying, Dave
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Greg_Lewis
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Re: Winton Air Pump

Post by Greg_Lewis »

Hey Dave, how's it going with the pumps?
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
daves1459
Posts: 279
Joined: Mon Jun 07, 2010 7:58 pm
Location: Plainfield, Illinois

Re: Winton Air Pump

Post by daves1459 »

Greg_Lewis wrote: Thu Mar 30, 2023 8:22 pm Hey Dave, how's it going with the pumps?
Hello Greg, thanks for asking.

The bodies of the pumps are finished. I have done the solid modeling of the steam cylinder head/valve body and 3D printed the waxes for investment casting. I'm currently looking for a lost wax casting source. I recently asked for suggestions for casting shops on another CHASKI thread and got a few suggestions.

I designed the base plate/cylinder cap portion of the valve body thicker so I could use larger ports to the top and bottom of the steam cylinder. The original design called for the tapping drill of a #5 screw making the 1 1/8" diameter bore rather under ported. I'm attempting to use a #6 tap drill and maybe a #8 if I can squeeze it in. Still under ported, but better.

I'm following Winton's original design that used close fitting piston valves for both the pilot and shuttle valves. Each valve has a rather fussy sleeve with ports machined in that is lapped for fit after being pressed into the valve body. I have the valves and sleeves made. By the way Winton's drawings call for .00003" valve to sleeve clearance. I think that is too close for this application, and nuts from my point of view. I'm shooting for .0002"/.0003".

I'm still wrestling with what to use for the piston ring and valve rod seals in the air cylinder. The problem is no lubrication. i had thought about using spring loaded virgin Teflon lip seals. But they cost close to $50 each. Recently I found square Teflon piston rings with a O-ring on the inside diameter to push the piston ring against the cylinder wall. They only cost $4 each. i thought I'd give them a try.

Dave
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