Large Scale Central

FS: Axle reassembly jig for USAT locomotives

For Sale/Trade/Wanted
#1

There were a few requests in another topic to purchase this jig. It is a 3D-printed block that assists in reassembly of the USAT locomotive axles by centering the gear and assuring the correct back-to-back wheel measurement (40 mm). There are two versions: 2-axle and 3-axle.

You print:

As with anything I design, the files are open source, and you’re welcome to print your own. Here are the files:

https://www.thingiverse.com/thing:3411697

https://www.thingiverse.com/thing:3411701

I print:

$20, including shipping

To order, send the money via PayPal Friends and Family to eric at southroad.net

Be sure to specify 2-axle or 3-axle.

I can also accept Apple Pay or Google Pay on request.

EDIT: 3-axle jig now tested

#2

Eric, what is the clearance for the gear in each (what size gear will fit?)

I’m going to pull some locos apart to see what has the largest gears… I don’t have an SD70 or SD40 though

Greg

#3

2-axle: 22x6 mm

3-axle: 17x4 mm

#4

I have confirmed that the 44T gear fits in the 2-axle version, which I’ve used in the past for GP/F3 gears. Different tooth count, but the same size.

The gears for the 3-axle locos are apparently all the same. The part numbers vary because of the wheel diameter. The PA wheel is 35.5 mm (1.4").

#5

Yep, I have a reference table on my site, but only part numbers and tread diameters:

https://elmassian.com/index.php/large-scale-train-main-page/motive-power-mods-aamp-tips/usat-motive-power#parts

About 1/2 way down the page, fairly comprehensive. That’s where I think I’ll add the tooth count and perhaps the gear diameter.

Thanks, Greg

#6

Hi Eric,

my name is Marco and I and interested in buying the 2 axle and the 3 axle bloc for the wheels please send me an invoice so I can submit the payment thank you. I actually have 3 locos that I need to work on and their 2 F3’s and one PA. Also I would like to know how many tooth’s aid on the gear that you are showing for the PA.

#7

Oh I forgot to mention my email is [email protected]

#8

Eric,

The technical answers you seek are right under your nose …don’t think too deeply into your ventures! Avoid distractions and focus on what you already know! Forget the technical end and focus on what your eye sees from the part numbers you have researched.

#9

Eric Reuter said:

I have confirmed that the 44T gear fits in the 2-axle version, which I’ve used in the past for GP/F3 gears. Different tooth count, but the same size.

The gears for the 3-axle locos are apparently all the same. The part numbers vary because of the wheel diameter. The PA wheel is 35.5 mm (1.4").

#10

Tony Diaz said:

Hi Eric,

my name is Marco and I and interested in buying the 2 axle and the 3 axle bloc for the wheels please send me an invoice so I can submit the payment thank you. I actually have 3 locos that I need to work on and their 2 F3’s and one PA. Also I would like to know how many tooth’s aid on the gear that you are showing for the PA.

Hi Tony,

The PA gear has 26 teeth. It’s definitely the same gear as the SD40, and probably the same as the other 3-axle blocks.

I will send an invoice. I’ll need a couple days to get them printed. They take about 5 hours each.

Eric

#11

I own a 2-axle block made by Eric and I highly recommend it. I currently use it to properly gauge the back to back wheel measurements of the Bachmann 92421 metal wheels on my freight cars. It works great! In the near future, I will be using it to center a new axle gear that I need to replace on my USAT GP-9 as I think it’s cracked.

#12

I’m in for 2 each of each type…

Money should be there already.

Greg

#13

Eric, pm sent

Eric, Thank you for making this jig available to all of us at LSC. The method of repair using the Harbor Freight arbor press and brass sleeves works extremely well however the wooden blocks that I have been using for proper spacing were a bit primitive. These jigs look perfect.

And thank you Greg for detailing this procedure on your website. At first I tried to cheap out and jury rig some c-clamps to press the wheels together but they twisted and spun around and were not very consistent. But then I bucked up and purchased the Harbor Freight arbor press that you recommended. What a smooth and precise operation! The cost only ended up being $47.99 ($59.99 - 20% readily available coupon) which pays for itself in less than one or two locos worth of new USAT wheel sets at $19.99 a set.

#14

No substitute for the right tool in the long run.

By the way, I like to cut the tubing with a dremel, less work to open up the inside when pressing on, the tubing cutter really reduces the dimension of the tube where cut.

Cutting with a dremel, and a light deburring with a countersink tool makes it so I did not have to grind a chamfer on the plastic casting, i.e. faster and easier overall.

Greg

#15

Thanks for another good tip. I ended up using a small tubing flaring tool to re-size the inside diameter after it shrunk due to the compression from the tubing cutter but I can visualize that the burrs left behind from the drummel cut would be much easier to deal with.

#16

Thanks for the orders! It helps to defray the cost of the printer, and I appreciate it.

I’ve worked up a bushing to go between the business end of the arbor press and the upper wheel. It has a 19 mm square indentation in the top to center the press. I’ll include one with each order.

https://www.thingiverse.com/thing:3416241

#17

Eric , just found this thread , will be ordering jig tomorrow , so 2 axle USAT and 3 axle are different ?

#18

Eric, thanks in advance sent you money for printing jig and bushing !

Nick