Need help fine tuning the Hogwarts Model--Photos Added.

[Don Gibson]

QUOTE: In other words you think the problem is what I said the problem might be two pages ago??? ...

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Before you dislocate your arm (patting yourself on the back) this is the FIRST time I recall you mentioning those 2 magic words "S CURVE".

If you can fit a 4 inch piece of straight between those tunout's, your problem may be solved.

[selector]

Don, thank you for your compliments, to me and me mither earlier. You are very kind.

Mouse, I don't have my glasses so I can't see your truck pictures (hee, hee)

Seriously, is it possible that the subframe near or just in front of your forward set of drivers is bent upwards, or that the post to which you screw the truck is deflected forward? I can't otherwise tell from the pics what the problem is, but I do see what you mean by the front wheels riding up; hence, my question. If nothing else works, maybe you can (wait for it) bend the post backwards slightly, perhaps with a little heat. Then, with the truck screwed down so that there is minimum wobble (not NO wobble), see if that fixes the problem. Maybe the new angle will help the front axle ride closer to the rails.

Remember, I am still new to this hobby, so laugh off line, you guys.

[M636C]

Chip,

Looking at your photographs, it is clear that the boiler is tilted upward, but it appears to be tilted relative to the frame, which looks to be level. Now you indicate that the truck screw actually screws into the boiler, so it is tilted at the same angle as the boiler. Thus the truck follows the boiler, not the frame.

There are two possibilities, the boiler isn't mating with the cylinder saddle casting correctly and is sitting too high at that end, or it might be sitting too low at the cab end. From the photo, I'd favour the front being too high, but I wouldn't bet on it without seeing the model.

Is it possible that "flash", excess metal from joints in the mould (or die, since it is from Model Die Casting) on either the boiler or cylinders is causing the boiler to sit too high? (this might sound stupid, but I can't tell from the photos).

If this isn't the case, is it possible to raise the cab end to make the boiler level, even temporarily, to test the loco in that form? Is it possible to attach the truck to the chassis without the boiler, possibly by using nuts on the existing screw and test run it in that form?

How is the cab end attached to the frame? Is this a tongue in groove attachmen? Is it possible that excess cast metal is causing it to sit low at that end?

I'm not trying to impune your modelling here, I just think that the boiler looks wrong in those photos!

This loco is a Southern Pacific (Harriman Standard) prototype. Is it made from the old Varney dies? If so it must date back to the late 1940s or very early 1950s, and the accuracy of interfaces might have suffered.



Peter

[SpaceMouse]

QUOTE: Originally posted by M636C

Chip,

Looking at your photographs, it is clear that the boiler is tilted upward, but it appears to be tilted relative to the frame, which looks to be level. Now you indicate that the truck screw actually screws into the boiler, so it is tilted at the same angle as the boiler. Thus the truck follows the boiler, not the frame.

There are two possibilities, the boiler isn't mating with the cylinder saddle casting correctly and is sitting too high at that end, or it might be sitting too low at the cab end. From the photo, I'd favour the front being too high, but I wouldn't bet on it without seeing the model.

Is it possible that "flash", excess metal from joints in the mould (or die, since it is from Model Die Casting) on either the boiler or cylinders is causing the boiler to sit too high? (this might sound stupid, but I can't tell from the photos).

If this isn't the case, is it possible to raise the cab end to make the boiler level, even temporarily, to test the loco in that form? Is it possible to attach the truck to the chassis without the boiler, possibly by using nuts on the existing screw and test run it in that form?

How is the cab end attached to the frame? Is this a tongue in groove attachmen? Is it possible that excess cast metal is causing it to sit low at that end?

I'm not trying to impune your modelling here, I just think that the boiler looks wrong in those photos!

This loco is a Southern Pacific (Harriman Standard) prototype. Is it made from the old Varney dies? If so it must date back to the late 1940s or very early 1950s, and the accuracy of interfaces might have suffered.



Peter

When I read your post I excitedly went down to check the model to see if indeed the boiler was askew. But alas, it is just the photo. I had to take the photo on a curve because there were no straights on the edge of the layout. So with the macro lens, the boiler appears to be up.



Looking at the image you can see the catwalk is high in the front, but as I look at i here on the desk it is perfectly level. As to how the bolier fits, the boiler cab assembly hooks to a tab in the rear on which it pivots. You then pull the boiler down to fit in a cradle that sits on the chassis. The screw that holds on the trucks passes through the chassis and the cradle to screw into the boiler. The fit is tight. There is no flashing or gap of any kind.

[SpaceMouse]

I want to thank each of you for you contributions. I know how hard it is to make guesses without seeing and testing for yourself. Probably most of you would be able to figure this out if you could only look at it.

[davekelly]

Space,

It does seem from your picture that the frame is level, and it is very obvious that the truck is canted upwards. Get the old screw, put it in the frame without the truck and gently (very gently) bend the thing a bit. Put the truck back on and see if it sits any leveler (is that a word? how about "more level"?). If it does, then just keep tweaking (Tim Taylor word here) until the truck sits level. Than give it a test.

This has been a very interesting thread. I love the fact that so many folks are taking this as a challenge. We're gonna get that locomotive running!!!!

[Anonymous]

Chip
How much clearence or play is there between the post and the hole in the truck? Is it close (the hole rubs the post) or loose? I don't like to recommend butcher work, but how about enlarging the hole slightly, with a round file, in the truck where the post goes through. I don't like the idea of bending anything. You know how easy something could break.

[selector]

Mouse, if we forget everything that could be wrong with the frame, except for the pivot on which the truck mounts, then that is where we should address ourselves. I say this because we all seem to agree that the frame and driver interface are fine, both in relation to each other and to the track. With truck removed, it goes fine...you said so yourself.

So, I reiterate, and Dave seems to agree, that you should concentrate on getting the truck back level by bending the pin/pivot backwards towards the rear.. Someone with more experience in these things might suggest a gentle heating to minimize damage, but it seems to me that if the truck seems to pivot with out much sloppiness, then reorienting the pivot to bring the front axle down a couple of mm will have you and the Apple of Your Eye making train whistle noises in no time.

If this suggestion is unpalatable, could you file the rear part of the truck pivot journal so that it has more room for the rear axle to rise relative to the front drivers?

I'm trying here!!!

[Don Gibson]

It should be easy to see if the Pilot truck tracking problem is vertical or
lateral.

REMOVE the body, and run the chassis with the the pilot trucks in place.

[davekelly]

Space,

How goes the battle? I'm sure I'm not he only one waiting to see!

[SpaceMouse]

I did not get to work on it last night. I did pull the wheels to let my son run it as a 0-6-0 and wouldn't you know it, the one place I didn't test it as an 0-6-0, the point where my down hill rejoins level grade, the front end hits the turnout and it derails every time. The unspported front end is too long without the truck.

And I even build--I don't know what you call it--a vertical easement.

[Jetrock]

a transition grade.

I'd definitely recommend getting some metal wheelsets to replace the plastic ones in the lead truck--metal wheelsets on your rolling stock will also greatly increase the lengths of your trains, due to reduced friction. The added weight will prevent derailments, too.