The Home Machinist!

I made up a drawing for Bill Cleary's Mogal for an axle pump that has the check valves on the bottom for easy removal and draining.

Please make comments or offer corrections if needed. To get a copy of the CAD send me a PM with your address.

Hi All,

I just finished building and testing the pump. It works great and was pretty easy to build. Here is a link to a short video showing the pump being tested.

http://youtu.be/ssiPoPAQ8cA

I appreciate Bob Grandle sending me a sketch of his pump which provided the initial design idea. Fred's design is very straightforward and has only a few moving parts. I will post some photos of the parts in a few minutes.

Happy New Year,

Bill C.

Hi All,

Here are photos of the parts and the pump. Hope this is helpful. Please let me know if you have questions.

Bill C.

Nice design. Like the idea that you can service the pump while it's under the loco...instead of having to disconnect and extract the entire pump assembly. Certainly something to remember for the future.

Following my axle pump rebuild experience (see previous post), it was suggested I consider using high strength fluoroelastomer rubber check balls, instead of the typically used stainless steel balls. Would have been nice to know these were available before I closed up the pump and installed under the loco. Perhaps the next time the pump is out for service, I'll exchange the check balls. While these may be a little "pricey"...one advantage is they are less likely to "hammer" brass check ball seats after repeated pump cycles. Here's the info from the McMaster Carr. FWIW...Carl B.


Ultra-Strength Corrosion-Resistant Viton® Fluoroelastomer Rubber: get the high performance of Viton® fluoroelastomer rubber with even greater strength. Ideal for use in harsh and corrosive environments, Viton® fluoroelastomer rubber has exceptional resistance to heat, aging, weather, ozone, oxygen, and sunlight, as well as to a broad range of fuels, solvents, and chemicals. Tight-Tolerance Balls—Smooth Finish. Meet ASTM D2000 HK. Balls are seamless. Durometer hardness is 70A (hard). Durometer tolerance is ±5.

Dia. Dia. Tolerance $ each
3/16" ±0.003" 3645K1 $2.10
1/4" ±0.003" 3645K2 2.87
5/16" ±0.003" 3645K3 3.20
7/16" ±0.004" 3645K4 3.25
1/2" ±0.004" 3645K5 5.42
5/8" ±0.004" 3645K6 9.66
3/4" ±0.004" 3645K7 8.61

Looks great Bill and Fred! While my mogul has the eccentric for the axle pump and I machined the strap for it, I never actually built the pump as I went with two injectors instead due to their reliability.

Hi John,

Thanks, I may end up going the two injector route, but I at least wanted to give this design a try. I enjoy the machine work and the learning. We'll see....

Have a great new year!

Bill C.

John_S wrote:Looks great Bill and Fred! While my mogul has the eccentric for the axle pump and I machined the strap for it, I never actually built the pump as I went with two injectors instead due to their reliability.

John,
Are you interested in selling the strap(s) ive purchased a used Mogul that has everything but the eccentric straps.
Anthony

utahwestie wrote:

John_S wrote:Looks great Bill and Fred! While my mogul has the eccentric for the axle pump and I machined the strap for it, I never actually built the pump as I went with two injectors instead due to their reliability.

John,
Are you interested in selling the strap(s) ive purchased a used Mogul that has everything but the eccentric straps.
Anthony

I still have the strap; it is partially machined. You can have them for the cost of postage. PM me your address and I'll mail them to you.

if you are going to use soft balls for checks, you want to redo the seats.

hard check balls like sharp / square seats while the softer balls like large flat seats...

in essence, you need to cut a generous 45 degree chamfer for the balls to seat on.

you must also be very careful about having anything sharp that the ball can bump against as it opens / closes. Anything sharp will cut the ball, eventually causing it to fail.

Viton is really not the material you want for this application.

VERNAY makes check balls just for this type of service

http://www.vernay.com/Markets/Medical/P ... Balls.aspx

Follow their suggestions...