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Discussion Starter #1

This is part of my Ruby conversion to OR&L number 6 but I think the discussions might warrant a new thread, so I started this one.
As you can see from the image above I'm considering changing the direction that my throttle is pointing.
It seems to work; that is, it clears the cab window no problem, and can be connected easily to the oiler if I use the butane line to add some
additional length to the copper tubing from the oiler. But here is the real problem,,, and I'm hoping that more experienced and wiser steam-modelers
than myself can give me some guidance here;

How do cut it down so that the knob (or the control lever I'm putting on its place) fits inside the cab and runs parallel to the fire box sides about 1/4" offset?
Is it possible to cut this throttle down in other words?


REASONS


[*] I want to clear the backhead to add prototypical details like oiler, firebox doors, plumbing and a throttle that works via linkage to the real throttle.
[*] I want to install a removable servo unit in the space between the boiler and the cab sides

[*] I want to cover the existing burner jet with a false backhead made of brass.
[/list]
 

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There is a set screw on the knob that you can take out and then cut down the shaft make sure the shaft is still long enough to attach what you need for RC. Where are you controlling the reverser from?
 

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Richard,

On my FWRR/Ruby, the throttle rod can be backed out completely - just unscrew it. Then, as Jason says, remove the knob and cut off whatever length you like.

I polished the pointy end in an effort to improve operation. It didn't help.
 

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Richard,

I assume the red mark on the throttle shaft is where you want to end up within the cab. You can shorten the shaft of the needle valve, however it might be too close to the throttle body for the factory knob to re attach, so you might have to make your own collar and lever to match the space constrictions.
 

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Are you just wanting to shorten the shaft or do you want to reduce the length of the valve body?

It looks like you could shorten the valve body some, but it depends on how deep the threads are... as in the number of threads and where the gland seal between the valve stem and the body is (not the seat, but the open end). There is probably an "O" ring near the seat for that, so it should not be a problem if you keep enough threads to withdraw the stem far enough to let enough steam through to run the loco and not have the stem fall out or get so loose as to leak or be unstable in the amount of steam being passed.
 

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Discussion Starter #6
Thanks everyone. The red mark is indeed where I want the end of the control lever to be. I checked out C.T.s comments and I'm not sure about the tollerances allowed for the seat. I can put the throttle out about 3/16"

But as you can see from the image above, the o-ring starts to appear. Not to mention that as soon as I open the throttle, this larger diameter rod appears.
My goal is to get the throttle lever as close as 1/4" to the boiler.
I will be moving the Johnston bar back so as not to interfere with forward or reversing the engine. In addition, I'm making throwing and reversing the engine by having an additional lever on the outside, just below the cab. I may even just have the Johnston bar be a dummy that moves with the reversing lever on the bottom of the cab.
 

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If you are wanting to reduce the length down toward just 1/4 inch then you will probably have to replace the valve altogether. Maybe a ball valve could get the distance down to 1/2 inch or a wee bit shorter. But I don't think you can modify the present valve to shorten it much at all.
 

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Discussion Starter #8
I'm not familiar with a ball valve unless you are talking about those used in faucets and gas inlets and stuff. Do they make that small?
If yes, how well do they operate at that scale?
Can they fit the current steam harness?

Where can I purchase one?
 

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I don't remember all the places that sell small valves... let's see, PMResearch, Sulfur Springs I think sold some, Regner, uh... Roundhouse.... um... I am sure there are several others. Somebody that has purchased them in the past can chime in here and give better specifics. The thing I am unsure of is thread compatability and such. They would also be VERY sensitive valves, being 1/4 turn from Off to Full On. Beyond this, all I can do is speculate.
 

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Richard, If you want to get the lever down to 1/4 inch to the right of the boiler, I think you have a problem. However if you can live with it just inside of the cab I think it can be done. The throttle only needs to open about 1/4 turn on the Ruby. As long as the O-ring is still in the valve body you are OK in cutting down the valve body. If you need to go farther the tapper on the end of the valve stem can be shortened a little but you will also have to cut back the shoulder on the valve stem or it won't allow the taper to seat. Send me an E-mail if you want to chat about this and I'll send you my phone #.
 

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Discussion Starter #11
Winn,
I'm going to try those small ball valves that C.T. mentioned, but if they don't pan out, I'm definitely going to need some direction on this one so I'll drop you some email.
 

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Rich,
With using a differenv valve like say the Regner that is a 3mm pipe m5x.5 so you can solder up the pipework and thread it to the valve you will need to make a new take off for the Ruby as the OEM throttle is part of the takepff or banjo.

Here is what I did for my Ruby Porter conversion.

I can take any of those and thread in a valve. Of course on this one I will be taking the throttle from the rear most filler valve as if I used it from here I would get a suction through the glass and pull water out like a injector. You cant have a sight glass on the same banjo as the throttle or steam take off for say a whistle.

The regner valve is the nicest I have seen so far and has a great 1/2" dia cast handwheel. If you need a new lubricator they have a near one that is cast as a dummy air pump too. All threaded M5x.5 for standard 3mm pipework. Ken Johnson can order them for you the lubricator was about 35.00 and the valves were about 25.00

PM research makes come good stoff but they dont seat well. The better ones are Coles or Locoparts.

Locoparts smallest is a 3/16 x 40 and is threaded female only, they do have some new valves with threaded male ends and pipe unions but only listed in Livesteam ads so far. maybe a phonecall to them to find out.

Coles Power Models Its the link to the price sheet, their catalog is mailorder only and not online. Page 4 Truscale pupe fittings I dont have the catalog handy but I think the valves are about 25.00 also not sure of the number on whats what thoguh..

 

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Discussion Starter #13
Jason,
I sent you an email with some additional questions not pertaining to this thread. The links you gave show Globe valves, are those ok to use as throttles?
 

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They are needle valves just the same as Regner and Accucraft and Aster. The design of the housing is just different between all. I am using the Regner throttle valve for these Porters.
 

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Correct, the throttle will be taken from the rear filler on the boiler. It is the ruby kit boiler and has 2 M10 plugs. Hopefully it will work better as a stem dome as its somewhat raised from the boiler tube. The check valve and gauge will be connected though to the glass.The nipple is on the left for the gauge.
 

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Discussion Starter #17
Here is a link to Jason's Porter project
LINK
Great work Jason, can't wait for your next update.
 
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