Which steam pump would you build?

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jeanluc83
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Which steam pump would you build?

Post by jeanluc83 » Wed Oct 23, 2019 5:35 pm

I just picked up the first 12 issues of Modeltec off ebay for, what I thought was, a reasonable price of $25. The main reasons for picking up the issues was for the plans for the Fairmont section car but I was also interested in the Simplex/Duplex pump by Bob Maynard and BSCSP steam pump by Moodie Braun.

Even though it is going to be a good while before I tackle a steam pump project but I like thinking ahead. Also my next project, once I finish my Clishay, is to build a 1 1/2 scale 0-4-0 camelback. Part of the charm of the locomotive is the prominently placed steam pump forward of the cab.

My main requirements are reliability and prototypical appearance. My preference is for a Simplex pump or a simplex-ish pump like Bob Maynard's. Another consideration is the relative ease of fabrication. I’m not adverse to a challenging project but I also don’t want to set myself up for frustration or failure either.

How does the BSCSP compare to the 1 1/2 scale VanBrocklin single cylinder steam pump? Also if anyone has a source for the VanBrocklen plans let me know.

On to the main question, which steam pump would you build and why?

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Builder01
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Re: Which steam pump would you build?

Post by Builder01 » Wed Oct 23, 2019 8:52 pm

I built the Van Brocklin 2 cylinder pump. I used the drawings done by Bill Shields. I built the smaller 3/4" & 1" scale pump. It is 100% reliable and seems to be self starting with the pistons in almost any position. It was also relatively simple to build, the 1-1/2" pump would be just as easy to build. I run it on air to fill my empty boiler when starting at the beginning of a steaming day. Once steam is raised, I use it as a auxiliary boiler feed pump. My injector and axle pump are the primary source of water.

I have the drawings for the BSCSP pump and it seems more complicated even though it is a single cylinder pump. I am not concerned about things looking "scale" or not. My loco is a miniature steam loco, not a scale model.

Bill's drawings are available on the net. Perhaps he can chime in once again with the address link. He has actually posted it here several times if you have the time to search this forum.

David

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Bill Shields
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Re: Which steam pump would you build?

Post by Bill Shields » Wed Oct 23, 2019 9:23 pm

virtually anyone with basic machining skills can build a dual pump. put steam on them and they always start and always run.

the single cylinder pumps are a lot more finicky to build and run -> and can get locked up if you feed them a shot of wet steam. If you have NEVER built a pump before, suggest that you NOT start with a single cylinder model from anyone (they are all basically the same)

Yes, there are folks that have / do build them but they know what they are doing...and I am willing to bet that their FIRST pump probably did not run as expected (or at all).

Plans for the BvB single cylinder pump are available for the asking in 1" and 1.5" scale

www.mehrs.com is where I keep the public stuff - help yourself

before you ask, the CAD / solid model files are not available
Too many things going on to bother listing them.

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Greg_Lewis
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Re: Which steam pump would you build?

Post by Greg_Lewis » Wed Oct 23, 2019 9:33 pm

Great question. I'd also like to hear about the Allen Models pump.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
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Harlock
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Re: Which steam pump would you build?

Post by Harlock » Wed Oct 23, 2019 9:37 pm

Greg_Lewis wrote:
Wed Oct 23, 2019 9:33 pm
Great question. I'd also like to hear about the Allen Models pump.
We have a crosshead and an axle pump, but not a steam pump...
San Lorezo Flume & Lumber Co. #2 - "Felton"
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Product Development and E-Commerce, Allen Models of Nevada

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Greg_Lewis
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Re: Which steam pump would you build?

Post by Greg_Lewis » Wed Oct 23, 2019 9:48 pm

Mike: I have Allen drawings for a one-lung pump that can be made up for either air or water, print numbers 1501 and 1502. Bought them from Gene years ago.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

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Dick_Morris
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Re: Which steam pump would you build?

Post by Dick_Morris » Wed Oct 23, 2019 11:28 pm

Be advised that some errors were corrected on the BSCSP pump a couple of months after the initial article.

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Bill Shields
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Re: Which steam pump would you build?

Post by Bill Shields » Thu Oct 24, 2019 6:45 am

the drawings of the Allen single cylinder Pump, which I have had for 40+ years, are virtually identical to the BvB pump

It has the same construction and operation concerns.
Too many things going on to bother listing them.

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Marty_Knox
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Re: Which steam pump would you build?

Post by Marty_Knox » Thu Oct 24, 2019 8:10 am

The pump drawings Allen Models used to sell are the VanBrocklin pump.
They are now available from Friends Models.

jeanluc83
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Re: Which steam pump would you build?

Post by jeanluc83 » Thu Oct 24, 2019 8:42 am

Thanks to all for the information.

Going into this I figured the answer was to not bother with a single cylinder pump. It is probably advisable to start with a two cylinder pump. Besides a twin cylinder pump would look at home on my Clishay. I am still interested in building a single cylinder pump at some point.

@Bill Shields Thanks for the info. I also have the plans that Bill Harris ran as part of the Mich-Cal Shay series in Live Steam as another option. The two designs look very similar. I need to print them both out and look at them side by side. First blush it appears that the Harris design has more ports that need to be sealed off.

@Dick_Morris Do you happen to know what issue had the corrected information on the BSCSP? So far I only have up to April 85.

Has anyone built the Maynard pump? It appears that it is a compromise between a single and twin cylinder pump. I haven’t studied the plans in detail yet but all of Bob Maynard’s designs are well thought out and geared towards the novice.

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Bill Shields
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Re: Which steam pump would you build?

Post by Bill Shields » Thu Oct 24, 2019 12:42 pm

you are observant:

the changes that I made were tilted toward easier port drilling and less plugging than BvB's

otherwise, there are no other significant intentional changes

there are lots of variations...BvB did a duplex that had 'rocker arms' like LBSC's design...but in the real world, as soon as the arms / pivots begin to wear the pump becomes unreliable at starting (not good).

Overall, I think I have maybe 20 of BvB's designs floating around on paper and disc...the real world being what it is, the duplex you are considering is where he (and others who offered 'variations') settled because...TA DA!!!! -> it was the most reliable.

The Germans did some very interesting single cylinder pumps...some of which were ALSO an air compressor - all on one shaft.

Not sure what you would do if you wanted air and not water...or water and not air...sure there is some valving to support that need.
Too many things going on to bother listing them.

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Greg_Lewis
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Re: Which steam pump would you build?

Post by Greg_Lewis » Thu Oct 24, 2019 6:56 pm

I recall reading one of those steam catechisms of the era that consisted of questions and answers as a learning device. One question was, "What can be said of the single cylinder air pump?" The answer was, "Not much."
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

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