Kato parts special steam mech.

[wcfn100]

Not sure how useful this is but...

http://www.katousa.com/Zcart/index.php?main_page=product_info&cPath=148&products_id=1900&zenid=892d1721194365bde688329efabd5bee

Jason

[Cajonpassfan]

Great price, great mech, but for the little BoxPok like drivers. If they were spoked, I'd buy a couple...Otto K.

[garethashenden]

Any idea what the wheel diameter and axle spacing is?

[peteski]

Any idea what the wheel diameter and axle spacing is?

Driver (tire) diameter is 0.370", axle spacing about 0.423". It is an older mechanism, but still fairly smooth running.

[jargonlet]

Does anyone know if those drivers are interchangeable with the USRA Mikado? I could use one driver for a Erie Mikado.

[up1950s]

One could think out the firebox and make a fireless locomotive as a shop switcher . All sorts of config's out there , so only an expert would know if it ever existed , and he or she would still admire your inventiveness .

[peteski]

Does anyone know if those drivers are interchangeable with the USRA Mikado? I could use one driver for a Erie Mikado.

No.  Totally different design.

[pmpexpress]

Pete,

Having never dissected a Kato steam locomotive, was wondering if the drive wheels are constructed like those on the Atlas Moguls?

The reason for the question is because as I recall, DKS made an aftermarket cast resin replacement spoked center for the Mogul locomotive drivers.

A similar solution might resolve the Boxpox driver issue.

[peteski]

Pete,

Having never dissected a Kato steam locomotive, was wondering if the drive wheels are constructed like those on the Atlas Moguls?

The reason for the question is because as I recall, DKS made an aftermarket cast resin replacement spoked center for the Mogul locomotive drivers.

A similar solution might resolve the Boxpox driver issue.

Yes, Like Atlas Moguls or Americans this loco has solid-back metal drivers with plastic inserts for the detailed wheel face.  I would have to check how easy it is to remove them.

[pmpexpress]

Yes, Like Atlas Moguls or Americans this loco has solid-back metal drivers with plastic inserts for the detailed wheel face.  I would have to check how easy it is to remove them.

Now that you mention it, DKS formerly manufactured replacement driver inserts for the Atlas American locomotives.

Depending upon how easy it is to remove inserts, you might actually wind up assisting Kato in selling some of these JNR mechanisms.

[peteski]

Now that you mention it, DKS formerly manufactured replacement driver inserts for the Atlas American locomotives.

Depending upon how easy it is to remove inserts, you might actually wind up assisting Kato in selling some of these JNR mechanisms.

If I have some time on Monday, I'll try to see what needs to be done.  The mechanism is fairly crude: the worm is attached directly to a long motor shaft, and the motor is rather large by today's standard. But it still is a fairly smooth running loco, since like Kato Mikado, it picks up power through all the drivers via the bearings (no wipers).

[peteski]

I took my Kato D 51 apart.

This is the older (original?) run of these models. I think that is the mechanism Kato is selling.  I believe the latest run has a totally redesigned mechanism which uses a coreless motor.



As you can see, the gearing and side rod design is similar to their Mikado.  Also notice that the axle tube of the front driver is split. The 3rd driver's axle tube with the gear is also split (not visible).   So that could be something to watch out for.



As for the driver design, the metal part of the driver (tire, flange and wheel-back) are not keyed for the plastic spoke insert.  Then the spoke and the half-axle are all one piece press-fit into the metal wheel.



The quartering and alignment with gear teeth is accomplished by using squared off shape for the axle tube home and the plastic half-axle.  If one wanted to replace the spoke insert with another type of spokes, the new casting would have to include the half-axle in the back. I would not trust rather brittle casting resin or even a 3D printed part for that job.  But that is just my opinion.

@wcfn100  : Jason, I think it would make sense to add "D51 2-8-2" to the subject line for future searches.

[pmpexpress]

I took my Kato D 51 apart.

This is the older (original?) run of these models. I think that is the mechanism Kato is selling.  I believe the latest run has a totally redesigned mechanism which uses a coreless motor.



As you can see, the gearing and side rod design is similar to their Mikado.  Also notice that the axle tube of the front driver is split. The 3rd driver's axle tube with the gear is also split (not visible).   So that could be something to watch out for.



As for the driver design, the metal part of the driver (tire, flange and wheel-back) are not keyed for the plastic spoke insert.  Then the spoke and the half-axle are all one piece press-fit into the metal wheel.



The quartering and alignment with gear teeth is accomplished by using squared off shape for the axle tube home and the plastic half-axle.  If one wanted to replace the spoke insert with another type of spokes, the new casting would have to include the half-axle in the back. I would not trust rather brittle casting resin or even a 3D printed part for that job.  But that is just my opinion.

As for the driver design, the metal part of the driver (tire, flange and wheel-back) are not keyed for the plastic spoke insert.  Then the spoke and the half-axle are all one piece press-fit into the metal wheel.



The quartering and alignment with gear teeth is accomplished by using squared off shape for the axle tube home and the plastic half-axle.  If one wanted to replace the spoke insert with another type of spokes, the new casting would have to include the half-axle in the back. I would not trust rather brittle casting resin or even a 3D printed part for that job.  But that is just my opinion.

@wcfn100  : Jason, I think it would make sense to add "D51 2-8-2" to the subject line for future searches.

Thanks for taking the time to disassemble and explain how Kato's D51 Mikado chassis is constructed.

Looks like a relatively simple and reliable setup.

As for the driver design, the metal part of the driver (tire, flange and wheel-back) are not keyed for the plastic spoke insert.  Then the spoke and the half-axle are all one piece press-fit into the metal wheel.

If the metal parts are not keyed for the plastic ones, once the plastic spoke insert has been worn due to continued use, what prevents the metal portions of the drivers from spinning separately from the press-fit plastic castings (i.e., like circa 1960s - 1970s N Scale trucks with wheel-sets that were constructed of chemically blackened metal and/or nickel silver rims that were mounted on plastic hubs that were attached to either brass or steel axles do)?

If one wanted to replace the spoke insert with another type of spokes, the new casting would have to include the half-axle in the back. I would not trust rather brittle casting resin or even a 3D printed part for that job.  But that is just my opinion.

Given the fact that the plastic parts would be regularly stressed in use, would absolutely concur with your assessment.

So much for an easy solution for modifying the Boxpox drivers to spoked ones.

[peteski]

If the metal parts are not keyed for the plastic ones, once the plastic spoke insert has been worn due to continued use, what prevents the metal portions of the drivers from spinning separately from the press-fit plastic castings (i.e., like circa 1960s - 1970s N Scale trucks with wheel-sets that were constructed of chemically blackened metal and/or nickel silver rims that were mounted on plastic hubs that were attached to either brass or steel axles do)?

Nothing except for the tight fit prevents the metal part from spinning around the spoke insert/half-axle. The plastic inserts are press-fit and while they fit fairly tight, if I apply some pressure I can move the metal part around the plastic insert .  But in normal operation they should not slip.  As I mentioned, the newer models do not use this type of construction for the drivers.

[up1950s]

I ordered the thing D51 and a couple of bear can tank cars . I will build something fireless , maybe pistons ahead and cab behind like the streamlined Pennsylvania one , or cab and pistons rearward like the German one . It will be a corporation owned with no basis on reality , so no pox on using boxpox . Hmm ...  something Pickle Works works for me .... maybe ?