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Discussion Starter · #1 ·
I have an Aster Jumbo that has always worked very well. However, about 1-2 years ago I started to have axle water pump problems (and I always use distilled water.) I find that the Jumbo, with its small boiler, badly needs a working axle pump for max enjoyment. I had been troubleshooting the problem on and off for a year, without success. This year at Diamondhead Gordon Watson was there and I told him of my "tail of woe." Right of the bat he suggested that I start troubleshooting with the water supply. I started measuring everything in the supply from the tender to the pump supply check ball. What I found is that the engine/tender connector severely constructs the water supply. Gordon recommends a minimum free diameter of 3/32" (.0938") or 2.4mm. The engine/tender connector was just .055" in diameter. I took out the tiny little tube in the connector and tried a 1/8" od plastic tube connector. I believe that it would be used for vacuum hoses in an automobile or model airplane fuel lines. This gave me a open diameter of .076."

I also modified the Banjo bolt and opened out the inside of the bolt (carefully, so that you don't damage the pump check ball seat.) I used a # 44 drill (.086") but a # 48 (.076") should probably be the right size. I also opened out the two cross holes slightly with a #55 drill (.052") (again, be careful)

What this did was to open out the entire water path from the tender to the pump. Without doing serious surgury on the pump (which I would have no clue if it would still work,) my mods only makes the water passageway about 2/3 the cross sectional area that Gordon recommmended, but it opened it up to twice what the original was.

I ran the engine on my roller for over 50 minutes. I never used the hand pump and the water level at the end was still up the top!! Total success!!

The only problem is with the connector I cobbled together. (see above) It is not totally water tight, but certantly it is functional. I have a new connector on order from Milton Locomotive Works in England.

http://www.sm32.co.uk/ (click on products then Aster)

This long winded explaination is to help anyone else that has axle pump problems. The connector is the big problem. Did I have to modify the Banjo bolt, I don't know. I went whole hog into the modification without doing 1 step at a time, like a good troubleshooter should do!
The Aster pumps themselves are certantly designed well but, according to Gordon, water supply to the pump is the first thing to look at when a pump is working poorly or not working at all.

Diamondhead this year was a lot of fun. It really is great to be able to learn from experienced people!

Dan
 

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This sort of post is what this site should be all about. Thank you Dan!
 

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Try Milton locomotive works site link as well as looking it up....link does not work, as at least for me at this time.
 

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Discussion Starter · #5 ·
This is interesting. After your post, I got the website. Now about an hour later it isn't working
 

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I have to admit to being a bit doubtful about opening up the water supply side for the simple reason that I have never had a problem with an axle driven water pump on an Aster model! In particular the Aster Jumbo tends to over pump.

Clearly some folks are having a problem and for that reason I am stocking the part mentioned by Robert (Zephyra). They are actually made by Tony23 who has been a regular contributor to this forum. I can supply them for $15 – please contact me off-board.

I shall also ask Aster to look at this issue for future models.
Andrew
 

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Tom, I have found the same thing, open the by-pass and give it a pew pumps, and opening the by pass while running for a few seconds to get rid of any air.
 

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Discussion Starter · #10 ·
I guess that my situation with the Jumbo was different. I had hand pumped when stopped, when running, bypass open, bypass closed and until I did the mod, it wasn't keeping up. What ever is made or assembled by man (kit built by me,) including cnc work, there can be enough variation that caused my Jumbo to be "special."
Your mileage will vary!
The important thing is that it now works.

Dan
 

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Tom,

You know that as an engineer making comparisons of two different things isn't equal. You need to buy a Jumbo and then report your findings!
 

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Tom said "I originally had a problem keeping the boiler full with my Duchess. I found that if I primed the pump, by hand pumping it in the recycle mode, the problem was solved."

I find the same with my Duchess. Also if the tender tank runs dry then I refill the tank with water and I need to give a few strokes with the hand pump with bypass open and then a few strokes with bypaas closed to re-establish a full water circuit. That way the duchess axle pump works perfectly and keeps up with the boiler.

it is these quirks that make the operation of our live steam locos so enjoyable.
Andrew
 

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Where did I learn that?
Somewhere along the way, I learned to check that water was going through the system by opening the bypass valve, pumping manually, and checking to be sure that water was returning to the tender during steamup preparations. I checked my Aster operation instructions and it is not there, I checked online coal fireing articles and it is not there. Maybe it is something John Shawe told me during coal fire training.

At any rate it is something I always do and so far I have not had a pumping problem.
 

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Somewhere along the way, I learned to check that water was going through the system by opening the bypass valve, pumping manually, and checking to be sure that water was returning to the tender during steamup preparations. I checked my Aster operation instructions and it is not there, I checked online coal fireing articles and it is not there. Maybe it is something John Shawe told me during coal fire training.

Dave et al,


Page 7 of my Accucraft instruction manual "The tender is also equipped with the hand pump, which needs to be used to prime the axle pump." Obviously, this also applies to Aster.
 

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Great info - thanks!

My Berk initially had a poorly performing axle pump. Apparently Aster updated the piston (O ring grove was too deep) and eased the restriction on a banjo bolt. With the updated parts from Aster she can, under the right circumstances keep the boiler full, but with a heavy load and not running at full speed she still drains the boiler down. I will look into the tender/loco connection. Thanks again for the suggestion!

-Mark
 

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The advise to look at the suction side water circuit derive from my work years ago designing irrigation systems and diagnosing pump problems..
the suction side pipe friction losses are more important than the delivery side ..if you have a pump which is marginal in its delivery from whatever reason..assembly , grit on a seat, leaking packings etc, then lowering the suction side friction loss wiil help its delivery, it doesnt fix the pump fault,
but it will "get you home" today!

Gordon.
 

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Posted By Taperpin on 01/31/2009 10:39 PM
The advise to look at the suction side water circuit derive from my work years ago designing irrigation systems and diagnosing pump problems..
the suction side pipe friction losses are more important than the delivery side ..if you have a pump which is marginal in its delivery from whatever reason..assembly , grit on a seat, leaking packings etc, then lowering the suction side friction loss wiil help its delivery, it doesnt fix the pump fault,
but it will "get you home" today!

Gordon.


Kind of makes some sense of what I have noticed on many water pump systems... larger hose on the supply side than on the delivery side. Thanks!
 

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Just checked the tender water supply connector on my Berk - I couldn't make an accurate measurement without disassembling the fitting, but the aperture was no more than 0.060". There wasn't much material left to work with, but I will trying opening up the restriction before I start making a new connector. Thanks again for the heads up!
 

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Discussion Starter · #20 ·
To follow up on my earlier posts about the connectors

The Larger connector availability that I know of is listed below. There are 4 ways to buy them (I think.)

The Milton Loco Works web site is back up. (at least as of 6 Feb)

http://www.sm32.co.uk/

Also, the connectors are available on EBay

http://cgi.ebay.co.uk/ASTER-Gauge-1-LIVE-STEAM-LARGE-BORE-WATER-CONNECTOR_W0QQitemZ180326418707QQcmdZViewItemQQptZUK_Trains_Railway_Models?hash=item180326418707&_trksid=p3911.c0.m14&_trkparms=72%3A1700%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

Or from

mailto:[email protected]

Or from

Andrew Pullen
 
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