Chris's Worthington Brewery Pump

[tghs]

looking great,, need to get in the shop and finish mine,  watching what you do with the steam piston rings..

[Kim]

If you turn out some lights and squint hard, you can see the finished engine!   

Wow!  Almost done with another one!  You're fast, Chris! 

Kim

[crueby]

Wow!  Almost done with another one!  You're fast, Chris! 

Kim

Doesn't  run well yet, needs a LOT of pressure!   

[rklopp]

So, this is my chance to experiment with a metal piston ring. I've did some testing last week, and decided on a bearing bronze piston ring in the brass cylinder.

Chris,
I tried running a 544 phosphor bronze piston and crosshead against 360 leaded brass cylinder on a Cracker live steam locomotive. It was a disaster. The materials galled quickly. I found that a 303 stainless steel piston and crosshead performed much better. I have not tested 660 high tin bronze against 360 brass. Perhaps it would behave OK.
-RKlopp

[crueby]

So, this is my chance to experiment with a metal piston ring. I've did some testing last week, and decided on a bearing bronze piston ring in the brass cylinder.

Chris,
I tried running a 544 phosphor bronze piston and crosshead against 360 leaded brass cylinder on a Cracker live steam locomotive. It was a disaster. The materials galled quickly. I found that a 303 stainless steel piston and crosshead performed much better. I have not tested 660 high tin bronze against 360 brass. Perhaps it would behave OK.
-RKlopp

I've  used the 932 bearing bronze against  brass for lots of things, they work fine together. The 303 does work well with both too.


 

[samc88]

Interesting project Chris, looking forward to following this

[crueby]

Glad to have you following along Samc!  This is a type of pump that I've wanted to do for a long time, finally got the information to design it.   

[crueby]

Yesterday afternoon I started making up the arbor to hold the center section tube for shaping. It is too large a diameter to support in the Sherline steady rest, plus I need to cut the window in the side that you can see in the picture in the first post. What I came up with was to use two slices of round bar mounted on a 3/8" rod. The ends of the rod have been center drilled for tailstock supporting later. The slices were cut/trimmed and loctited onto the rod yesterday, then today I drilled for a pin in each, also loctited in place. Then turned the OD of the slices down to just fit into the tubing:

The first tube blank, rough sawn overlong, and the arbor will drilled for a pair of screws to hold the tube in place. The arbor holes were tapped for the screws. Also drilled matching holes in the other tube.

With the first tube attached to the arbor, and the arbor held between the vertical rotary table and the tailstock. Then aligned the tube so the screws will be between the cylinders, and started milling in the opening.

Each cut was taken down in several passes to full depth, and the final cut freed the window piece. Wonder what that will get used for someday?   

Then the ends were trimmed to length last. The tube had been stress relieved, but it might spring out slightly when the window was cut. I want to ensure that the ends are parallel to each other, so they were trimmed last in case the tube distorted a tiny amount. Both ends were trimmed with the arbor still in the chuck.

The same steps were done on the other center section. Here are the parts so far. On the left you can see the outer end caps that were drilled yesterday, I had also turned in the shape on the outer face.

That all went well! Next time I'll start shaping the end caps for the center section. They will have the rims turned to fit into the ends of the center section tubes, and will be loctited/pinned in place. They form the end caps for the cylinder and pump body as well, and hold the glands for the piston rod - that is why the tube ends need to be trimmed to be parallel.

[Kim]

Love that fabricated mandrel for milling out the windows in those tubes.  Very neat! 

Kim

[crueby]

Thanks  Kim, it worked out quite well.

[crueby]

Glad that I  was worried about the center section tube distorting when cutting the window, it did very slightly. Even with the stress relieving heat treatment, the center of the tubes are now 2 thou larger OD than the ends. Putt8ng a straightedge down the sides, they are bowed out slightly near the window, and bowed in slightly on the area opposite the window. That means that if I  had trimmed the tubes to length before cutting the window, the ends would no longer be quite parallel. Trimming the ends last means they are parallel now. This is very important  since the center section is a structural  piece holding the steam cylinder in line with the pump housing. Good to plan ahead and know how the metal will react!

[cnr6400]

  Great start on the round bits, tube, and end caps Chris!

re the cutout pieces from the windows - might make a nice delivery chute like the ones on concrete trucks, for getting the 8 ton shipments of popcorn down into your storage bins. (lock em up after use or the shop elves might fill the bins with barley for brewing, or concrete for a work to rule action! Loc-elf 356624 is growing... ) 

[crueby]

Great start on the round bits, tube, and end caps Chris!

re the cutout pieces from the windows - might make a nice delivery chute like the ones on concrete trucks, for getting the 8 ton shipments of popcorn down into your storage bins. (lock em up after use or the shop elves might fill the bins with barley for brewing, or concrete for a work to rule action! Loc-elf 356624 is growing... ) 

Chutes! Perfect!  Maybe a snowplow for the Lombard steamer...

[crueby]

Next I decided to make up the inner caps. There are four of these, two on the steam cylinders, two on the pump housings. They each get a gland for the piston rod. To start, I drilled the piston rod holes and counterbored a recess for the O-rings.

Then moved over to the horizontal rotary table on the mill, centered it up, and moved out to the position for the gland mounting screws and drilled for those. The rotary table makes it easy to get the holes centered across the piston rod hole - drill first one then rotate the table 180 degrees and drill the second. As usual, spot drilled first.

While the rotary table was in position for those holes, next was to drill the mounting holes in the rod the glands will be milled out of. The rod was drilled in the center for the piston rod on the lathe. The rod is long enough to get all four glands out of, and I drilled deep enough for all four.

Then switched to an end mill to do more shaping. I've gotten question on how I make this shape of gland, so I'll show all the steps. Those that have seen it before, take your shop elves out for a snack!   
With the cutter lowered enough to cut two parts, and the rotary table still set on the 'zero' angle from drilling the holes, a flat was milled across the back side in several shallow cuts.

Spun the rotary table 180 degrees, and did the same set of cuts to the same depth

With the mill table still at the position where the flat ended, I start doing the angle cuts. To keep the center section rounded, I turn the rotary table a few degrees and make a pass, turn a few more and another pass, repeating till I get the angle needed to be close to the outer hole. In this case it was 20 degrees. The final angle will vary on the size of the gland. Whatever it is, make a note of it.

Turn the rotary table back to zero, and start making cuts by turning the table a few degrees at a time in the opposite direction, ending at the same number of degrees from the starting point.

Then turn the table 180 degrees from the starting point, and repeat for the third side...

and the fourth side:

Then move the chuck over to the lathe and part off the two pieces, remembering to shape in the protrusion on the end of the second one before parting it off.

Then I'll move the chuck back to the rotary table and repeat the process for the final two pieces...

[PaulR]

Why were glands made in this shape on lots of pumps, there doesn't seem to be anything that would interfere with an easier to make circular gland?