Kato low pro geared wheelsets in current Atlas trucks?

[sizemore]

According to the NMRA gauge the Kato wheel flanges are perfectly in gauge. Squeezing them in would put them out of gauge. I broke out the micrometer and the Kato axles are .564" and the Atlas axles are .534".

*edit* Shortly after posting I went back into ACME Labs to tinker. I pulled apart a wheelset and noticed the axle was not blackened like the wheel. So I took a chance and chucked it in the NWSL Puller. Using just fingers torque I pressed the axle point, like any pressed metal shaft under pressure it gave a (tiny) pop. I had to dial it back out then repeated the process on the other half. I assembled the axle and dialed it against the NMRA gauge. Then cleaned up the axle points as they were slightly deformed, using a 640 grit sanding stick. Put the truck back together and checked freewheel and mesh followed by checking for electrical connectivity. Everything checks out.


The S.

[peteski]

I'm glad that you figured out what to do. But I'm still confused why does everybody think that pressing the half-axles inwards will change the gauge - it does not.  I'm scratching my head here...

As far as the point goes, I use a small piece of sheet aluminum (0.040") between the steel part of the press and the axle point. The aluminum is softer than the axle so there will be a dimple created while the axle is being pushed. But no damage to the axle point.

[sizemore]

I'm glad that you figured out what to do. But I'm still confused why does everybody think that pressing the half-axles inwards will change the gauge - it does not.  I'm scratching my head here...

As far as the point goes, I use a small piece of sheet aluminum (0.040") between the steel part of the press and the axle point. The aluminum is softer than the axle so there will be a dimple created while the axle is being pushed. But no damage to the axle point.

Wheel gauge, which is what everyone else it talking about is measured by the flanges. You press the half axles inwards you're also moving the flanges toward center since halfaxles are "one piece". Taking the flanges out of gauge (towards) center effects how a truck will perform in relation to guards, switches, crossing etc.

While what you have done will most likely work, its not in spec by the NMRA gauge.



The S.

[peteski]

You still don't get this. The distance between the wheels (thread or flanges) does not change when pushing the half axles inwards into the wheel). I'm going to have to make a drawing to show you.

[garethashenden]

You still don't get this. The distance between the wheels (thread or flanges) does not change when pushing the half axles inwards into the wheel). I'm going to have to make a drawing to show you.

It sounds as if you are pushing the two half axles closer together while in fact you are moving the wheel on the axle.

[sizemore]

Yeah I am going to have to scream Mea-Culpa I obviously glazed over specifics in your posts. My apologies to Pete, we did the same thing.

Gonna go back to Elementary School now and work on reading comprehension.

The S.

[peteski]

Yeah I am going to have to scream Mea-Culpa I obviously glazed over specifics in your posts. My apologies to Pete, we did the same thing.

Gonna go back to Elementary School now and work on reading comprehension.

The S.

LOL, tha's ok. I was just puzzled why people were saying that pushing the half-axles inwards would reduce the gauge.  The only way to reduce the gauge would be to trim the plastic axle tube.  Just to make this clear to everybody, here is a diagram showing how I reduced the overall axle length (to make these Kato wheel sets properly fit Atlas locos).

[peteski]

Here is my method for fast and repeatable way of adjusting the half-axles.  For measuring I use a $15 digital caliper from Harbor Freight.

Additional info is in red.

First, I find that the stock Atlas wheelsets tight in gauge.  This also makes them a bit too loose in the bearing cups (too much play). Spreading the wheels out until they are in gauge (measured with the NMRA gauge) also spreads the axle ends to the proper length.  This wheelset can now be used for axle length reference.

Next take the Kato replacement wheelset and make sure it is also in gauge.  Adjust if necessary. I find the Kato wheelsets (part # 932090) a touch narrow in gauge when the wheel backs are tightly against the ends of the plastic axle tube. I make spacer washers and install them in between the wheel back and the axle tube on the side closest to the gear.   I made multiple thicknesses and in this instance I use a 0.010" washer.  This will prevent the wheelset from ever getting narrow in gauge.

I make these washers from Evergreen styrene sheets. As shown, I used 0.010, 0.015, and 0.020" sheets. I first draw a grid with enough spacing to be able to punch out the washers, then I drill the appropriate size hole in each intersection of the grid. For 1mm axles I use #57 drill bit.  Once the holes are drilled, I use a hobby punch set (from Micro-Mark) to punch out 2mm diameter washers.  I line up the drilled hole in the center of the 2mm punch hole, then punch out the washer and move on to the next hole. It is a bit tedious but in no time I have bunch of washers. They are not all perfect, but they will do the job.


AxleSpacers.jpg

Now that the Atlas and Kato wheelsets are in gauge, measure the total axle length of each.  Then, since Kato length is longer than Atlas, subtract the Atlas length from Kato's, then divide the result by 2.  That is how far each Kato half-axle  has to be moved inward.

Next, take the Kato wheelset apart and measure the inboard length of a half-axle.  To that dimension add the distance the half-axle has to be moved inward. Using that dimension construct a gauge. Make it slightly larger than the wheel diameter. Drill a hole in the center, slightly larger than the half-axle diameter.

I like using aluminum for a gauge because it is easy to file or machine.  That gauge will control how deep the half-axle will be pushed inwards.  That gauge could also be made from plastic (styrene or acrylic).  But make sure the top and bottom are parallel.

I get my aluminum raw material from various sources.  Home Depot (and other hardware stores) sells aluminum bars and I also found other thicknesses at a local industrial metal distributor. They used to sell scraps and cut-offs, but they no longer do that. However I have a good stash accumulated which will likely last me for years.  Then, with a luxury of owning a milling machine, I can mill the aluminum stock to any thickness I need. But other materials can be used too.

I would say that various thickness of sheet styrene can be used. Styrene is softer than metal, but with the relatively large area of pressure (the entire back surface of the wheel) it should not deform much under pressure. You should be able to stack and glue together several different thicknesses of styrene sheet to arrive at the desired thickness.  I would probably not use a solvent cement, since it can soften the styrene. I think using CA glue will work better.  If the gauge ends up slightly too thick, carefully sand it down by rubbing it on sandpaper placed over a plate of glass (or another very smooth surface). That should sand the gauge down evenly.  You do want to make sure that the top and bottom surface are parallel, so the axle being rammed is also parallel to the ram.

You will also need a piece of metal, softer than the half-axle material, to keep the pointy axle end from being distorted. Again, I use a piece of aluminum.  I use a 1/8" thick aluminum strip, but the thickness is not critical. The following diagram shows the procedure and placement of all the components.


KatoHalfaxlePush2.png

This is an example of my setup. But in this photo I'm actually performing a reverse procedure on a Walthers Mallet tender wheel (pushing the half-axle further out of the the outside wheel face).  A drill press should also work if an arbor press is not available.


ArborPress9291a.jpg

Just put the spacer with the wheel installed on it under the center of the ram.  Then take a piece of aluminum and hold it over the the axle point. Lower the ram until it contacts the spacer, then push the ram further down until you feel the half axle bottom out on the arbor's base.  This setup makes the procedure easily repeatable.  Once the pointy axle makes a dimple in the aluminum spacer, just put the point of the next axle in the same dimple.  Since aluminum is soft, it will not distort the pointy axle.

Here are some photos comparing the Atlas (rigth) and Kato wheelsets.  In this example there is a 0.010" washer installed in the Kato wheelset.


Atlas-Kato02.jpg


Atlas-Kato03.jpg


Atlas-Kato01.jpg

[MK]

Thanks Peteski!  I have the HF caliper, the drill press and some raw material.  But a few questions:

1.  It looks like those washer are home made.  From various thickness styrene?
2.  Where/how do you find the right thickness aluminum for the gauge?  I would imagine the calculation may come out to something werid, e.g., 0.0143" or something.

[peteski]

Thanks Peteski!  I have the HF caliper, the drill press and some raw material.  But a few questions:

1.  It looks like those washer are home made.  From various thickness styrene?
2.  Where/how do you find the right thickness aluminum for the gauge?  I would imagine the calculation may come out to something werid, e.g., 0.0143" or something.

I edited my earlier post with the answers.

[tehachapifan]

Are the half axles fully seated into the plastic sleeve with no extra room to spare at all? I'm fine with wheelsets being a little narrow per a gauge as it seems many loco wheelsets are set slightly narrow to begin with. This seems a way easier solution than what you've taken on, Peteski.

[peteski]

Are the half axles fully seated into the plastic sleeve with no extra room to spare at all? I'm fine with wheelsets being a little narrow per a gauge as it seems many loco wheelsets are set slightly narrow to begin with. This seems a way easier solution than what you've taken on, Peteski.

Yes, it seems that the model manufacturers do make the axle tubes a little short so the wheels are narrow in gauge when fully seated.  But I like to make mine gauged properly (after all, there are reasons to follow specs, right?).  The washer is there to make sure the wheels will not go tight in gauge. Going wide in gauge will also be difficult since the axle-end bearings prevent that from occurring.

I like to complicate my life.    But seriously, in the grand scheme of things, it is not *THAT* difficult to fabricate bunch of washers and install them on wheesets which are already taken apart for resetting the half-axles.  There are others here on TRW who do a lot "crazier" things than this. 

EDIT:  I again checked the wheelset against the NMRA gauge, and even without adding the 0.010" washer they are still within spec.

[tehachapifan]

Ok, so these wheelsets are a little tight in at least some Atlas locos only when the gauge is set perfectly? In other words, they will turn freely when in the Atlas trucks if the gauge is kept slightly narrow...only via pressing the half axles into the sleeve a tiny bit (if they're not set slightly narrow to begin with)?

[peteski]

Ok, so these wheelsets are a little tight in at least some Atlas locos only when the gauge is set perfectly? In other words, they will turn freely when in the Atlas trucks if the gauge is kept slightly narrow...only via pressing the half axles into the sleeve a tiny bit (if they're not set slightly narrow to begin with)?

On most of the Atlas models (straight from the factory) the wheel backs are either tight against, or pretty close to touching the ends of the axle tube, making them tight in gauge.  If you have an NMRA (or even MTL) gauge, you can check yours.  But that also makes the total axle length too short, making them a bit loose in the axle end bearings (which is not desired).  If you spread them out a bit to be in gauge, that will also increase the total axle length, so they will have less play in the axle bearings (which is good).

[nickelplate759]

that's a nice little arbor press.  Might I ask where you found it?