Author Topic: N Scale Truck Reamers?  (Read 6180 times)

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nscalbitz

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Re: N Scale Truck Reamers?
« Reply #120 on: December 03, 2017, 07:15:13 PM »
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Interesting education going on.
Sorry to low-brow the topic, but my 'restoration and refurb' of a decades worth of worthless (or near too) ancient cars and rolling stock.

Included over last 3 years, examining truck and axle/wheel profiles, reaming out truck frames if wear and distortion were apparent with a simple awl and small sized drill bit (so old its size is worn off); reviewing wheel and spin performance on a 1.5metre incline; then swapping plastic wheels for kind.

A graphite pencil was used to clean the reaming surface and provide a lubricant. Given I had to sharpen pencils I know it was going inside ok. If fails then trialled metal wheels (mostly Atlas new in pack- of which maybe 3-5% were failures with twisted insulated inserts). If failed again, tried new MTL trucks. If those failed set aside for further review.

Where successful or if the truck frames appeared warped, cut losses and scrapped entirely (setting aside components for future loads in gons/ flats etc.).

This trial and error cheaply turned the old stuff into free rollers able to reach 40 car trains rolling for half an hour without mishap- or until something showed up!.

I was also changing 'sets' of component cars to Unimates. The Con-Cor rigid coupler trucks were useful adding weight and "balance" to light cars like Atlas 50' flats etc. Now experimenting with MTL TS couplers.

Improved friends fleet of variable runners and my own rarely used on layout collection. FWIW.
regards d

freedj

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Re: N Scale Truck Reamers?
« Reply #121 on: February 19, 2020, 08:05:34 PM »
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Bringing this topic back from the dead...

After finishing a weathering job on an old roundhouse reefer I was dismayed to discover that even my best locos could only pull a few cars up my curving 2.5% grade with this car in the train.  The car really doesn't roll freely but I didn't realize exactly how big of an impact that would have.  I looked for info and came across this thread from waaay back. 

Inspired by the arc tester I put one together with a 900mm radius and printed it out:
https://www.thingiverse.com/thing:4171719

After mounting up a piece of Atlas code 55 flex I set about testing trucks!

There were real measurable differences in the trucks I was testing but the ones from the car that didn't roll seemed to test OK.  I was very confused but decided to try putting the entire car on the track.  What a difference.  The car in question would only change directions ONCE and come to stop at the dead center of the test rig.  Other similar length cars would test at 4+ direction changes with my new Intermountain 50' box getting 6 direction changes consistently.

There is something going on with those trucks under load!

Another neat feature of testing the whole car is that it doesn't seem to matter how much the car weighs.     I took a floor weight from an old car and set it on top of a few of the other cars I was testing and it did not make any difference to the number of direction changes.  There are 2 reference marks on the ramp and if you line up the center of the car (center of mass) with the mark you get repeatable results.

This will let me standardize my fleet on some number of minimum direction changes to make it on the layout.  Im currently thinking 4+ will be a good starting point.

I think I may draw up a 'test car' platform that will just set onto a pair of trucks (build the kingpin into the platform floor) that can be weighted to some middle ground weight and use that as a test standard. 

Maletrain

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Re: N Scale Truck Reamers?
« Reply #122 on: February 20, 2020, 09:59:35 AM »
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Are you sure that the wheels on that troublesome car are not rubbing against something on the car body?  If not, then check that the axle lengths are not overly long for the trucks.  Or perhaps overly short, so that they come out of the truck pits when there is a little weight on them, so that they then rub on the car floor.

craigolio1

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Re: N Scale Truck Reamers?
« Reply #123 on: February 20, 2020, 03:40:06 PM »
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Any interest in such a tool?

Yes please. Put me down for 1.

Craig