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

[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.

[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.

[davekelly]

Space,

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

[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.

[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!!!

[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.

[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!!!!

[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.

[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.

[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

[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.

[Don Gibson]

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

.

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.

[SpaceMouse]

I appreciate your point of view. However, my wife's job just came to an end and until we replace that income, I doubt an new engine is in the works.

Now back to the problem.

Here are the pictures I promised. Sorry about the truck close-ups. It did not seem tweeked and road the rails well without much slop.



This photo best illustrates the problem. Notice that when the engine is at rest the front wheel of the truck is about 3/64ths higher than the back truck which is firmly on the rail. The flanges just barely grab the inside of th rail. As soon as it moves, it pops out.

[dave9999]

Chip,
I have to admire your determination, but Roadtrp has a point. It's seems to
me that you are spending a lot of time and effort, not to mention the grey hair
that you are obvious getting, on one locomotive. Put it a side for a while. Work
on something else, And some time in the future, if you feel it's still worth the
effort (headache), give it another shot.

Remember, The best way to suck the fun out of a hobby is to turn it into work.
Good luck, Dave

[Roadtrp]

I hate to admit it, but at times our wives are right. [;)]

I had one locomotive that was making me absolutely crazy. I stayed up until 2:00 AM a couple of nights trying to get it to run properly, and went to work dead tired the next day. One night I stayed up until 4:00 AM messing with it and called in sick the next day -- there was no way I could work.

My wife asked me how many hours of work it would take me to replace that locomotive. I said two hours... maybe three hours after taxes. She nicely asked me if I was totally out of my freaking mind for spending as much time on it as I did. I had to admit she was probably right.

I dumped the locomotive in the garbage can and bought a replacement. The replacement ran perfectly right out of the box. I have come to the conclusion that the occasional piece of lousy equipment is just something you have to deal with in MR. You can let it make you nuts or just replace it. In the long run, the money spent replacing it far less costly than the sanity lost in trying to fix the lemons.

[SpaceMouse]

The S curves are turnouts back to back and cannot be replaced without totally starting over and I'm not going to do that until build my basement layout in a couple months. I will tell you this, I've worked those turnouts until every other engine in the stable makes through without derailing--ever. The 4-6-0 makes it through these S turns at speed with the front truck removed.

The issue right now is not that it doesn't make it through an S curve, its that it doesn't make it a quarter inch on the straight.

Now I may give up on this 4-6-0 some time in the future, but until I find that the problem is unsolvable--like it is an known design flaw of later model MDC 4-6-0s, I'm going to work on it. Those of you that are giving up for me, you may yet prove right, but there is still a lot of things to try before I reach that point.

[howmus]

QUOTE: Originally posted by howmus

Chip,

It sounds like the front truck is binding somewhere. It may be that in the S curve, the engine is pointing one way while the truck is going in the other and the truck hits the side of the frame.

QUOTE: Originally posted by Don Gibson

MOUSE

Your Pilot truck's float and are not totaly making the curve, because:

Rigidly coupled drivers are pivoting one way, while the pilot trucks are trying to follow the rails. CLUE: The pilot truck's track when not attached to the body.
The body 's lateral angle is too great for the pilot truck to follow .

Get rid of your problem causing 'S' curve by either straightening out, or inserting a piece of straight .

In other words you think the problem is what I said the problem might be two pages ago??? LOL I love it when the experts like yourself agree with me (and I do consider you to be one of thee experts). Makes me feel like I actually know some things. [:D]

[selector]

Dave, I second that excellent post. I fooled around with my BLI 4-6-4 because I thought it squatted a tiny bit over the rear truck. It looked like the cab roof was not high enough compared to the tender next to it. So, I tried putting a ball-point pen spring under the rear truck, and, depsite eventually cutting the spring until only 1/3 of it was left, it still lifted the rear drivers off the rails. Needless to say, I went back to the original plan that the designers had all along. (sigh) Bottom line- it didn't work until I put the old spring back in.

[Anonymous]

Regarding this pilot truck problem... Make sure the wheels are in gauge and mounted squarely on the axle (and it sure wouldn't hurt to replace the plastic pilot truck wheels with Northwest Shortline wheels).

Make sure all the parts are assembled in the correct direction. The spring is shaped like a cone and the wide end should sit inside a ring molded into the truck. The truck mounting slot is a slight arc which means there is a front and back side to the truck assembly - the arc should "point" towards the front of the locomotive. Replacing the MDC parts should be unnecessary unless they've been damaged.

If the truck mounting screw is not square with the locomotive frame, the screw could put unwanted stress on the truck. Adding washers between the truck and spring is likely to be a source of trouble as this would not only prevent the spring from sitting inside ring, but could also introduce strange forces.

The weight of the locomotive has no effect on the front truck (adding weight will only increase pressure on the drivers). Adding weight to the front and rear of the truck (i.e. above the axles) might help but should be unnecessary. BTW, a properly weighted model locomotive will balance between the front and rear drivers.

The following is unrelated to the pilot truck problem... The MDC 4-6-0 has a fairly long rigid wheel base (distance between front and rear drivers). Blind center drivers or narrowing the gauge of the drivers by 2-3 thousandths of an inch might help this locomotive run on sharper (less than 24 inch radius) curves.

[Don Gibson]

CRANDELL:
You make too much sense. Your mater must have been one smart 'mither', too..

[selector]

I agree with CNJ831. You can't make a silk purse out of a sow's ear...as me dear ol' mither used to say.

Mouse, your first priority, if I have any sense of your circumstances, is to get your child to enjoy the trains. That's #1. Number 2 is that YOU are not enjoying this part of it. So, how will your autistic child enjoy it if you can't? Now, let's see how the missus is viewing all of this, because she, too, is very much in the equation....probably somewhat dimly, right? She's not too thrilled?

If I hear you, and read you correctly, you have no practical choice but to move on. I know that money doesn't grow on trees, so maybe you will have to defer the rest of the layout for a couple of months, or so. It happens, Dude. Go the sane way, get a replacement, and move on. Besides, you'll have time for a second look at your plan. You may surprise yourself by seeing some needed changes. That, too, happens.

Good luck, and don't despair. Another thing me mither said was, "All good things come to he who waits."

Best regards.

-Crandell

[Anonymous]

WHAT LUCK!

Walking around in my train room barefoot paid off! I stepped on something so i picked it up, turns out it was my pilot spring completely undamaged. YAY![:D]

[West Coast S]

I duuno if this is worth a grain of salt for your problem. Replace the plastic pilot wheel with a quality one from Northwest Shortline. I had to do this with Every MDC, besides better appearence my experience is they maintain proper guage and track better.

[Don Gibson]

MOUSE

Your Pilot truck's float and are not totaly making the curve, because:

Rigidly coupled drivers are pivoting one way, while the pilot trucks are trying to follow the rails. CLUE: The pilot truck's track when not attached to the body.
The body 's lateral angle is too great for the pilot truck to follow .

Get rid of your problem causing 'S' curve by either straightening out, or inserting a piece of straight .


(signed) Grumpy Don

[Anonymous]

oh, well, my search begins.....

[SpaceMouse]

Sorry, I'm not missing the spring I just didn't want to figure out how to draw one in the program.

[Anonymous]

NOOOOOO!!!!
]
I just finished painting my MDC 4-6-0. Ran it around today, runs great, but then i noticed.... I forgot to put the pilot truck back on. So i got the pilot truck and the sleeve to put it on, but lo and behold, no spring!!! For now i am stuck running with no pilot, if you find a source for that spring please tip me off! My model is identical to yours so whatever spring you get is what i need.


Thanks in advance[8D]

[DigitalGriffin]

Could one of the wheelsets be out of gauge causing it to ride up the rail? I dunno, I'm just guessing.

[Anonymous]

QUOTE: Originally posted by davekelly

I think Gary is on the right track.

Nice pun dave. [swg]