Worn Atlas loco wheels? Fixable?

[Steveruger45]

I’m working on yet another older non dcc ready LL GP60 I just acquired.  It was a little noisy but I have it running really smoothly and quietly now. Quieter than a brand new Kato AC4400cW I just got from MBK.
Anyhow, While I was doing the refurb I checked the truck wheels against my last few new spare Kato wheel sets. 
They are essentially the same.  Same offset gear with same number of gear teeth on the same outside diameter and yes the Kato wheel set is still wider across the axle points by about the same amount as they are to the Atlas sd50/60 wheels.  I tried changing the wheels and they worked ok but were just too tight for the truck to roll freely. They need to have the axles pressed in about 0.3mm. I’ve put the original and worn wheels back for now, it runs great and quiet on these worn wheels too, while I brainstorm a simple home made press. 

 I know you can put the Atlas GP40-2 trucks in the LL GP60 so I’m pretty darn sure the Kato wheel sets will fit the GP40-2 as well and be a tad too wide.

[Tom L]

Do you guys that have done this think something like this would work to press the axles in?

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F351789004917

Tom L
Wellington CO

[Steveruger45]

I think this one is more reasonably priced. 😁😁
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F223185054009

It looks to me that it may do the job nicely and for $2 and change I just ordered one to find out. I’m thinking to place some nylon or other hard plastic on the pointed end to protect the pointed axle shaft.

Thanks for posting the link Tom.

[garethashenden]

I still suspect that those are the same wheesets.  The part number is just too similar.    Maybe one was made by Kato and the other in China? The all seem to be based on original Kato design (which started with the U30C). If you had both handy, you could easily check.  Just verify the dimensions of both.

I’ve ordered a couple of sets to upgrade GP9s, I’ll report back on how they compare to the stock wheels.

[Tom L]

I think this one is more reasonably priced. 😁😁
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F223185054009

It looks to me that it may do the job nicely and for $2 and change I just ordered one to find out. I’m thinking to place some nylon or other hard plastic on the pointed end to protect the pointed axle shaft.

Thanks for posting the link Tom.

Ha! Not much at stake here to find out. I'm wondering if it's worth 2 more dollars to have it ship from US? I'm in no hurry, so probably not.

Tom L

[rrjim1]

Do you guys that have done this think something like this would work to press the axles in?

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F351789004917

Tom L
Wellington CO

Thats a little different than the tire press I use but it should work. With any press you will still need something to protect the pointed end. I use a piece of brass with a taper cut in and a small hole drilled threw it. 

[MK]

I’ve ordered a couple of sets to upgrade GP9s, I’ll report back on how they compare to the stock wheels.

Thanks Garet.  Looking forward to your findings.

[peteski]

Thats a little different than the tire press I use but it should work. With any press you will still need something to protect the pointed end. I use a piece of brass with a taper cut in and a small hole drilled threw it.

I agree. That is why I use a piece of aluminum. The steel axle is much harder than the aluminum so when I press the first axle it makes its own depression in the aluminum. That increases the contact are between the surface of the steel cone and the aluminum and the subsequent pressings do not seem to deepen the depression.

One thing I see problematic about using the watch bracelet pin press is that the diameter of its ram is a tiny.  It will be difficult to line it up with the axle. It would be much easier if the ram was a larger flat object.

[rrjim1]

One thing I see problematic about using the watch bracelet pin press is that the diameter of its ram is a tiny.  It will be difficult to line it up with the axle. It would be much easier if the ram was a larger flat object.

The pin unscrews leaving just the screw, you would still need something like a cap to screw on to be able to press against the axle. I would make a brass cap with a hole in it just deep enough to hold the axle.   

[Steveruger45]

The pin unscrews leaving just the screw, you would still need something like a cap to screw on to be able to press against the axle. I would make a brass cap with a hole in it just deep enough to hold the axle.

Yeah, that’s exactly how I’m thinking after brainstorming this a bit more.   Ace hardware have copper rivets that I think will fit in the end of the threaded rod in place of the provided watch press pins and solve both issues by providing a softer surface and wider diameter. Also they have nylon spacers that I would plan on using on the fixed end to rest the wheel back on.

[peteski]

Copper is softer than brass so I think it would make a good ram for those steel axles.

[rrjim1]

Copper rivets are going to be about the same hardness as soft brass. MOHS Scale =  copper 2-1/2 - 3,   brass 3-4. I use a softer brass because it is much easier to machine.

[peteski]

Copper rivets are going to be about the same hardness as soft brass. MOHS Scale =  copper 2-1/2 - 3,   brass 3-4. I use a softer brass because it is much easier to machine.

Good to know. I'm sticking with aluminum because I have plenty of it handy and I know it works very well for me in this specific application.  And no, I don't know which specific alloy it is - it is just aluminum. 

[Steveruger45]

Copper rivets are going to be about the same hardness as soft brass. MOHS Scale =  copper 2-1/2 - 3,   brass 3-4. I use a softer brass because it is much easier to machine.

I’m more familiar with the Brinell Hardness Number which IMHO gives a better gauge for metals/alloys rather than the MOHS scale for minerals. Below are some comparisons.  Anyways, soft brass will work well I think and may actually be a better option than copper as it would be more durable.   But as I don’t have a lathe I would plan on changing the copper rivets if and when they wear out for the few cents they cost.

Brinell is the scale used to compare the different hardnesses of the metals described here:

Nickel Aluminum Bronze (Alloy #958)-
This alloy is 79% Copper, 10% Aluminum, 4% Iron, 2% Manganese and 5% Nickel. This alloy is more durable than 100% copper, Red and Yellow Brass. Hardness is approximately 150-190.

Yellow Brass (Copper Alloy #865)-
Yellow Brass, also considered a "Bronze", is 60% Copper, 33% Zinc, 2% Iron, 1.5% Aluminum, 1-5% Manganese, 1% Tin, .5% Nickel. Brinell Hardness of 100.

Soft Steel-
Hardness of under 30 on Rockwell C scale, around 279 Brinell.

Malleable Iron-
Brinell hardness of around 134

Aluminum-
Brinell hardness of around 70

Copper-
Brinell hardness of around 40-50

Lead-
 Brinell hardness usually in the 30's

Hardened Tool Steel-
Brinell hardness of around 600 - 700+

[garethashenden]

I’ve ordered a couple of sets to upgrade GP9s, I’ll report back on how they compare to the stock wheels.

Follow Up:
The Kato axles fit in Altas GP7/9 trucks. They need the same axle readjustment, the side frame is bowing out quite noticeably.
Although I haven’t tried it yet, these wheels should also fit the RS1, RS3, and U25B. They all have the same offset gears.