G Scale Model Train Forum banner

1 - 12 of 12 Posts

·
Premium Member
Joined
·
394 Posts
Discussion Starter #1
Today, the snow had finally melted and the weather was beautiful, so I fired up my new K28 on my layout for the first time.





It ran very well with a really nice chuffing sound. I ran into two correctable problems. First, it derailed several times at an Aristocraft #6 turnout. Finally, I noticed that the connecting link from the ground throw to the throw bar was sticking up too far and hitting the cylinder drain valve mechanism. There was a fair amount of interference and the loco still made it through without derailing more than half the time. After dinner, I went out and bent up a new low-profile link.



The other problem came when hand pumping water from the tender reservoir into the boiler during the run. The loco was up to its full 60 psig operating pressure and the soft, black rubber hose which came with the loco swelled noticeably with each pump stroke. Finally, the hose split near the boiler and the next pump stroke splashed water everywhere but into the boiler. I have sent an email to Accucraft to ask for their advice. Have any of you run into this? If so, how did you fix it?
Llyn
 

·
Premium Member
Joined
·
3,378 Posts
Llyn
Seems to be a check valve problem. If you check at Ryan's post on the GS4 modifications sticky you can retrofit the valve thus fixing the problem
 

·
Premium Member
Joined
·
24 Posts
Hi Llyn,
I had virtually the same experiences last year. I had the same problem with the same Aristo switches! You did the right thing. When the water tube swelled up, I replaced it with a brake line hose from an auto parts store. That and a slightly slower pump motion cured the problem.

Joe
 

·
Premium Member
Joined
·
1,437 Posts
Llyn:
FWIW - Accucraft's tender pumps can use some improvement too. They are very hard to pump and are poor pumpers. Dave Hottmann changed the pivot points (lowering the holes for the connecting rod) so the pump is easier to pump and improves its pumping action. You might send him an email and ask for his photos of his modification. Dave posted the pump mods awhile back so the thread is in the archives, but emailing Dave probably would be easier than trying to find the thread.
 

·
Premium Member
Joined
·
1,044 Posts
I have seen the water hose on other Locos split as well. Like Charles said, sometimes when a Loco sits up for a while the ball in the clack valve can get froze in one spot causing more pressure on the hose itself. Tapping on the valve can sometimes free it up.
 

·
Premium Member
Joined
·
684 Posts
The issue lies not in the pump, although it is better suited for a 3/4" scale ride on engine, but rather in the joke that Accucraft calls a check valve. Using some odd contraption of a spindle and oring to seal up against a seat, along with a very heavy spring to hold the spindle against the seat, these valves take in upwards of 15psi to unload them from the seats, hence why it is such a pain to pump water in.

An easy solution for those with access to a lathe is to look at what I have done with the stock valve, replacing the internals with a 3mm SS ball and a lift limiter (1.7mm hex head screw). You can find photos of this here: GS-4 Mods. Although it is for a GS-4, the princple is the same and it works flawlessly, having done it on near 10 engines that have been through the shop, including 3cly shay's and K--28's. Just ask Dave Rose about his shay pump.

Llyn, If you would like, you can send me your checkvalve and I'll modify it for you.
 

·
Premium Member
Joined
·
394 Posts
Discussion Starter #7
Hi Ryan,

I agree that the pump is not the problem. Having to overcome the boiler pressure combined with the pressure needed to lift the poppet valve was the problem and the tube just wouldn't take it. I had topped off the boiler once successfully and know that the basic system is OK. Your GS4 instructions seemed quite clear and I do have a lathe and milling machine; so, I think that I'll be able to do the valve modification myself. Thank you so much for the offer to do the work, though.

Llyn
 

·
Registered
Joined
·
170 Posts
Llyn, how did the suspension mod work out?
 

·
Premium Member
Joined
·
394 Posts
Discussion Starter #9
Hi Paul,

It worked well. Now -- a disclaimer. I bought the loco mid-winter and had no opportunity to try it out unmodified. It just seemed that having vertually no suspension travel made no sense; so, I made the change.

When I went out to do the first run, the snow had just melted off and I had done nothing to level or adjust the track. Other than for the problem with the turnout linkage mentioned above, the loco derailed twice. Each time, it was clearly a case of the track needing some adjustment. Once the adjustments were completed, the loco ran without any further incidents. If I were to buy any other locos with the same limited suspension travel, I would not hesitate to improve it.

Sometime in the next few days, I plan to do a posting with photos showing how I went about increasing the suspension travel.

Llyn
 

·
Premium Member
Joined
·
201 Posts
Llyn,

The stock Accucraft pump setup is not good (as you quickly learned). The hand pump has a huge ram, sending tons of water through a very inefficient check valve with each stroke. This puts a strain on the hose and it’s connections, so either the hose bursts or shoots off one end….

I replaced my entire K-28 pump set-up from end to end. I used a Fyne Fort Fittings pump I purchased from Sulphur Springs http://www.sssmodels.com/. I also ordered new tubing from McMaster Carr and a spring that fit around it for added strength. I then used a 3/16x40 Check Valve from Loco Parts http://www.locoparts.net/valves.html. The check valve will not thread into the Accucraft back-head bushing because the bushing is threaded M5x.5. I have some 3/16x40 to M5x.5 adapters made from David Bailey that I used. All this can be costly and somewhat complicated. I have found sending my pump and check to Ryan much easier & cheaper with the same results. He did my 3 Cylinder Shay and it works quite well.
 

·
Registered
Joined
·
1,110 Posts
Great looking trainset.

Rare to see that logo and a green boiler in vibrant color. So used to B+W photos of the real thing in various books. Thanks for posting the photos, nice eye candy :)

What track are you using? You mentioned the switch as Aristo, but is the rest Aristo track? Pretty good looking ties. I always thought Aristo had more LGB/European style ties.
 

·
Premium Member
Joined
·
394 Posts
Discussion Starter #12
David,

I have in mind to experiment initially with stronger tube. I did manage to steam at a friend's layout today and tried another approach. I had a goodall valve on hand which has the right threads to fit the water fill port. So I used that and a squeeze bottle which I had purchased from Royce Brademan a while ago. Actually, it worked quite well and was very cheap to do since I had the materials on hand already. Eventually, I'd like to get a BF water level sensor and electric pump to automate the operation.

Matt,

The back half of my layout is AristCraft code 332 brass track. The front part, where I took the two posted pictures, is Sunset Valley rail (some nickel silver and some stainless steel) mounted in Accucraft standard gauge ties. (All of my sparkie equipment is 1:29 standard gauge). In the front part of the layout, I have a Sunset Valley #6 turnout which works really well.

Llyn
 
1 - 12 of 12 Posts
Top