TheRailwire

General Discussion => N and Z Scales => Topic started by: Kerbe Neun on January 18, 2016, 07:36:24 PM

Title: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: Kerbe Neun on January 18, 2016, 07:36:24 PM
Hi, All,
Can some recommend what are the appropriate FVM metal wheel sets for the Micro-Trans depressed center flats and heavyweight coaches?
Thanks,
Kerbe
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: garethashenden on January 18, 2016, 08:26:40 PM
MTL wheels have 0.540" axles. I think the coaches have 36" wheels, not sure about the flatcars, but they're probably 33".
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: wcfn100 on January 18, 2016, 08:42:15 PM
We had a good discussion on this flat here:

https://www.therailwire.net/forum/index.php?topic=34236.0 (https://www.therailwire.net/forum/index.php?topic=34236.0)

It really depends on the prototype, which I don't know that we identified, but you could use wheels down to 26"


Jason
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: narrowminded on January 18, 2016, 09:09:35 PM
Won't wheel sizes different from those furnished cause coupler height issues?  Or is .009" resulting from 33" to 36" wheel change accepted as in tolerance.  Then if you go to Z couplers... :|  These are things I don't have direct experience with but the concern crosses my mind every time I see one of these discussions.  Could somebody relate experiences with this?
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: loyalton on January 18, 2016, 09:35:53 PM
Won't wheel sizes different from those furnished cause coupler height issues?  Or is .009" resulting from 33" to 36" wheel change accepted as in tolerance.  Then if you go to Z couplers... :|  These are things I don't have direct experience with but the concern crosses my mind every time I see one of these discussions.  Could somebody relate experiences with this?
You can compensate by adding a spacer between the truck and bolster if the couplers come body mounted.

Z couplers are my thing. I'm slowly converting stuff to body-mounted ones, so they will need a pad or mount built up to sit on, but I then also work in lowering a car to a more proto height if needed at the same time. Make the Z coupler centerline match up with N couplers (using the M/T gauge) for compatibility and there are no problems. You don't even have to modify the Z trip pins for coupling to N cars if magnetic uncoupling is your thing.
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: bbussey on January 18, 2016, 09:45:04 PM
You can compensate by adding a spacer between the truck and bolster.

The model stands too high as it is.  Adding a spacer makes it worse.

The model is designed for 33" wheels.  It can be equipped with 28" wheels if the bolsters are modified and the couplers are body-mounted.
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: Mark5 on January 18, 2016, 11:08:35 PM
To emphasize - Buckeye freight trucks normally used 33" wheels.
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: nkalanaga on January 19, 2016, 01:47:33 AM
"Or is .009" resulting from 33" to 36" wheel change accepted as in tolerance."

The 1977 AAR Interchange manual says that coupler center height can range from a loaded minimum or 31.5 inches to an empty maximum of 34.5 inches.  That's 3 inches, or almost 0.02 inches in N, so 0.009 inches would easily be within the prototype tolerance.
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: wcfn100 on January 19, 2016, 01:49:59 AM
To emphasize - Buckeye freight trucks normally used 33" wheels.

Mark, I'm not sure what your're emphasizing here.  All freight car trucks for the era normally used 33" wheels.

Something that I can emphasize is that some of the prototypes MTL used on this car are GSC 125 ton flats which used 30" wheels and roller bearings (not sure if some started as solid bearings), so none of the MTL trucks will be correct.  At which point wheel size becomes about however you want to decide what's closest or best.

The cars that MTL did that I know should have 30" wheels are the ERIE, Southern and ATSF.  NH also had similar cars with 30" wheels.  I would bet there are several more.  And to the point maybe Mark is trying to make, none of those used Buckeye trucks as far as I can tell.

Jason
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: bbussey on January 19, 2016, 07:06:43 AM
They released NH as a stock item?  I know they made a BLW special run.
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: wcfn100 on January 19, 2016, 09:19:23 AM
They released NH as a stock item? 

Oops, nope.  You'd be the proprietor of that one.

Jason
Title: Re: Replacement Wheelsets For MT Coach and Depressed Center Flats
Post by: Mark5 on January 19, 2016, 11:00:15 AM
Mark, I'm not sure what your're emphasizing here.  All freight car trucks for the era normally used 33" wheels.

Something that I can emphasize is that some of the prototypes MTL used on this car are GSC 125 ton flats which used 30" wheels and roller bearings (not sure if some started as solid bearings), so none of the MTL trucks will be correct.  At which point wheel size becomes about however you want to decide what's closest or best.

The cars that MTL did that I know should have 30" wheels are the ERIE, Southern and ATSF.  NH also had similar cars with 30" wheels.  I would bet there are several more.  And to the point maybe Mark is trying to make, none of those used Buckeye trucks as far as I can tell.

Jason

Apologies for any confusion.

Yeah, my point was about the Buckeyes, which N&W did use on the car MTL painted up:

https://imagebase.lib.vt.edu/imagebase/norfolksouthern/full/ns2499.jpeg

Mark