Building a Power Model Water Pump

[John_S]

I was going to keep adding on to my Allen mogul thread, but I thought this would be of enough interest to put in its own.

I acquired water pump kit from a fellow member and have finally taken it out of the box, studied it at great length, and even had Rich_D sit and go over it with me. I can say, without a doubt, this will be the most complicated and precise machining I will have done to date -- after all, everything I know I learned during the building of my mogul.

This kit can be built to pump either water or air. I'll be building it as a water pump.


(All of these photos are thumbnails. Click them for 1024x768 resolution.)

The kit:


Starting with the valve body casting, a very long time getting it absolutely perfect in the 4-jaw:






Faced and turned to dimension, ready for boring the steps for the reversing valve stem opening:


Boring completed:


First setup complete... next up is a bunch of setups in the mill:


More to come!

[RichD]

John,
one thing I forgot to mention. That little pocket for the reversing rod
serves 2 purposes. Of course it's a seal between the valve chamber
and the steam cylinder, but more important is the O-Ring grips the rod
to hold the valve position as the rod itself will act like a piston and
cause strange performance. Be sure the rod is a tad stiff to move.
Good luck.
OK, guys. Dust off those kits under the bench and get busy.
BTW. there are two serious errors on the steam head drawing dimensioning.
These pumps are lost wax silicon bronze and make a great water or
air pump. Seems to me someone has the old patterns now and may be
selling a cast iron version.

[Greg_Lewis]

BTW. there are two serious errors on the steam head drawing dimensioning.

And they are.....

[Bill Shields]

i built a drilling box to hold that head

it allows me to mount the head then bolt down on any of the six sides, and drill through the box as a drill jig to put each hole in the location where needed...including set the head up an angle for those holes requiring it. I drilled the center hole and put in a dowel pin + used that for a reference 0 0 0 point.

i will warn you right now - i have 2 of those pumps here in my shop and all of the brass - bronze castings are porous.

i sleeved the cylinder units with bronze sleeves to save them when i though is was an isolated casting - before long i had 4 cylinder and 2 steam head units the leaked like a sieve.

i gave up on the heads and mike V sent me new ones.

This was a congenital problem with the red brass - bronze units and cost me many months of headaches.

yes, there are some dim errors, and i found - fixed them. mike V has the corrected drawings

[10 Wheeler Rob]

I purchased a air compressor version form Mr. Tansky last fall. Not sure who machined and assembled it. I since have converted it to a water pump by replacing the umbrella valve plates on the back with a check ball housing assembly, and putting a bronze liner with water pump pistion in the lower housing. Pump runs on air and the water pump pumps air, have not tested the with steam and water yet.

The builder had took some liberties with the umbrella valve set up (i.e. deviated form prints) they were done as a 2 plate arangment.

It is a very nice looking appliance when finished.

Rob

[John_S]

Bill, Rich_D mentioned the porosity problem. I'm keeping my fingers crossed that I don't run into any pockets in this set of castings.

I spent most of last night just figuring out how to hold the darn thing so I can drill the six stud holes in the head. It's all setup on the mill now, but I called it a night before making any chips. I really need to purchase a smaller vice for my mill so I can have the rotary table with a vice mounted to it set up. My Grizzly doesn't have quite enough vertical clearance.

[10 Wheeler Rob]

A seasoned builder at my club recomends making fixture blocks to hold both housings at once and doing the larger bore first in the upper housing and then boring the second housing all in one set up. That way it keeps both bores concentric and aligned. He says it is even more critical if your making a duplex pump.

There are machinist with the tallent to do it as separate peices, but for the rest of us self tought ones some fore thought on getting that near perfect alignment helps.

Have fun, this project will provide a lot hours in your shop.

Rob

[10 Wheeler Rob]

I usually do not bother with setting up the rotary table for just a couple of hole paterns, My mills are crank and dials, no DRO. If you got a DRO, they usually have radial hole function.

I just lay the hole pattern out on the 2D CAD and dimension x & y to the center line to each hole. They always come out pefect. The new printers print very acurate also, so often I print out a template, tells me if I am off a crank turn in a hurry just buy laying it on the part before drilling.

Rob

[Bill Shields]

when i get back to the states, i can send you pictures of the fixture.

STRONGLY RECOOMMEND THAT YOU NOT try to do this in a vise and - or rotary table

you must come at this thing from 8 sides (6 cube + 2 angle). if you get any of the angles or positions
wrong, the holes will not align, and you will be in big trouble.

[John_S]

I decided to ditch the crazy setup and just go with using the vice. Drew up the X/Y offsets in CAD, set up the part, dialed it in so it was absolutely perfect in the vice, and went to it.



It all was going well... until, as Ralphie said in "A Christmas Story," Ohhhh fuuuuuudddddggeeeee...


I cannot believe of all the possible things to screw up on this I break a stupid 5-40 tap off.

[Bill Shields]

the problem is that once you work that face, you then need to be EXACTLY 90 DEGRES to some of the holes you create for other setups....that don't use the exiting finished face.

without the fixturing, .....if you are off just a little, the holes will not intersect in the middle of the head.

or holes will intersect other holes that they are not supposed to intersect.

mike V has spare heads....you will need one.

[johnpenn74]

This is a little off topic, but does the bolt for the aforementioned tapped hole go all the way through the cylinder casting? Do all the others do the same? or just studs out of the casting?

JP