Large Scale Central

How do I regauge this?

Modeling
#1

I have an AristoCraft Pacific motor block. I ran it a bit on my track and it seems to run OK. But, when I put the AristoCraft gauge against it, it doesn’t look good at all. I know this would not make it through any of my switches.

I measured with my caliper…

It’s anywhere from 1.522 to 1.535 - a far cry from the recommendation. Here’s a properly gauged Sierra Valley wheelset in comparison

You can see that back to back is off by almost a full GIANT flange. I cannot believe how large these flanges are…thick AND deep. But, the main issue is: What’s the best way to re-gauge these? I notice that there are screws that hold the wheels on (I assume), but I’m afraid I’ll get out of quarter if I start screwing with them.

#2

Bruce,

I think that you are right about the set screws. Probably no Loc Tite, though. That seems to be an after market upgrade. :lol:

You might think about indexing the wheels on one side against each other, then one of them against the body. A small dab of paint whill do the trick, and is easy to remove, after.

Let us know how it comes out.

Steve

#3

Bruce, I have a detailed writeup about the “prime mover” motor block and assemblies on my site:

http://www.elmassian.com/trains-mainmenu-27/motive-power-mods-aamp-tips-mainmenu-35/aristo-motive-power-mainmenu-72/prime-mover-basics-mainmenu-256

there are 2 metal half axles with tapered ends, and the wheels go on the tapers and the screws secure the wheels to the axles.

3 ways to fix the back to back:

  1. Turn down the backs of the wheels, thins the flanges and increases the back to back. (on thick flanges, not a bad option)
  2. Take some thin brass shim and put on the end of the axle and reassemble. (Not a great option, hard to make a conical shim and keep wheels true, and you might have slippage, which Aristo is famous for already)
  3. Take the gearboxes apart, and purchase or make shims that go between the half axles and the central nylon gear (most labor intensive, and what I have done).

Regards, Greg

#4

That’s really way off! I have never actually looked at the gage on my Pacific–it’s working, so I’m going by the “if it aint’ broke” school. But that’s clearly goig to cause some problems.

How do you shim the half axles? it looks like they fit tight inside the plastic housing, with no room to be moved outward

#5

You can pull the wheels off. I had to heat the screws with my big soldering iron and use needle nose vise grips to loosen it, screwdriver did not in most cases. Then mix up some J&B weld, put it on the axles and slide the wheels back on, check with the gauge and in 24 hours they will be solid! Had to do it with my Challenger build.

#6

Mike, you have to open the gear case to see how the axles are screwed to the worm gear. You cannot see it very well unless you pull the axle bearing out and peer inside.

Jerry, you are very brave, if you get the quarter wrong when reassembling, you will have a hard time removing the wheel again.

Also, if you put enough in there to widen the gauge, how did you keep the wheels running true?

Regards, Greg

#7

Wow. Some neat ideas.

Greg, I like your site tips…I thought I’d been everywhere there but that was new to me.

I’m really leaning towards option #1 - Turn down the backs of the wheels. It will take some time, but I think if I just re-gauge I still have the problem with REALLY THICK flanges. It should be interesting. I can’t help but compare this to my Bachmann Connie. I was expecting at LEAST that level of quality and I’m rather disappointed with the Aristo block.

#8

I think it’s like a lot of aristo stuff–it’s a really good basic design idea, very clever, but with just a few too many compromises made in production. The huge flanges are ok for people lke me, with sloppy track work, but the’re not reall an excuse for the gage and the wheels slipping n the axles. Both could have been fixed with a little more quality control.

On the positive side you can load a lot of weight on it and it pulls like mad

So–what are you going to make? Those are honking big wheels in 1:20, aren’t they?

#9

Those wheels scale out to 50" in 1:20. The EBT Mikado has 48" drivers, and I want to make something similar. I still need another driver and some other pieces, but it looks doable…:wink:

#10

Well, this is interesting. :frowning: I’ve been slowly grinding off the backs of the wheels. It’s rather boring, so I only do it for about 10-15 minutes at a time.

Today I sat it down on the track to run it and two wheels fell off from one side. The screws had come loose somehow, and now the wheels are off the axles.

Looks like it will be time to re-quarter as well. Any hints?

#11

you probably heated them enough to destroy the loctite bond! hehehe Do I really want to send you another pair of wheels to destroy?

#12

Yes, more wheels to destroy!!! :smiley:

Actually, I think I’ll be OK. I’ve got one set done. I just keep readjusting the drive rods. :wink:

#13

Bruce,
I guess I just don’t understand what grinding off the backs of the wheel flange is going to do. Won’t that make the gap even larger?

#14

Steve,

The “standard” should be something like 1.574", if I recall correctly. The current wheels - back to back - are anywhere from 1.522 to 1.535.

Grinding off the back of each wheel increases the back to back spacing.

I’m sure I’m missing the “benefit” of the way these wheels are mounted. I would think they’d be keyed to hold quarter.

#15

Keyed to maintain spacing wouldn’t hurt either.

Dave

#16
Bruce said:
I would think they'd be keyed to hold quarter.
I agree, unfortunately, Lewis doesn't.

I had one of my Mikes freeze up because the wheels slipped out of quarter. I had to send it back to Navin to get fixed.

Question… by shaving off the back, you will get the B to B measurement closer, but the wheels will still be out of gauge because the front of the flange distance hasn’t changed, so I don’t see what you have gained, or did I jump the track somewhere?

#17

Well, unless I’m missing something here (quite likely, I suspect), when I get the back to back correct, the flanges should be quite a bit thinner and in the right place. Or, am I overlooking the obvious?

#18
Steve Featherkile said:
Question.... by shaving off the back, you will get the B to B measurement closer, but the wheels will still be out of gauge because the front of the flange distance hasn't changed, so I don't see what you have gained, or did I jump the track somewhere?
I'm puzzled too, Steve. Shaving the back will make the thick wheel flange look better, but how would it change the gauge? Ralph
#19

This is how it looked originally.

(http://www.jbrr.com/Pics/Locomotives/EBT/AristoPacific/IMG_6014.JPG)

Notice the gauge is too narrow. Now, after grinding backs of both wheels, the gauge is correct.

(http://www.jbrr.com/Pics/Locomotives/EBT/AristoPacific/IMG_6022.JPG)

#20

Nice work Bruce

Getting them in quarter isn’t hard, but I agree they should have keyed the axle. Or barring that, they should have lapped the joint for a tight fit. Aristo typically has clever designs harmed by just a bit too much cost cutting