Modern chassis for MIR 121 Class

[DiveController]

As there is presently no rtr 121 Class locomotive available from any manufacturer, I am considering completing a MIR 121 kit and mounting it on a modern chassis.

Ideally, the chassis would have to be at least DCC ready with a view to potentially putting a decoder/sound decoder in this at some point.

I would also like the chassis to be equipped with directional lighting from the outset if possible.

 

Most importantly the chassis should be a modern chassis with excellent operational qualities, and good slow running speed.

Previously the Athearn SW1500 switcher seems to have been a popular or necessary choice. However, these did not necessarily run to the standard we have no come to expect. As I understand in more recent years (maybe around 2011 or 2012), Athearn upped its game and improved its SW chassis to include a modern 5-pole skew wound motor with flywheels and all-wheel pickup on it B-B switchers. There is a bewildering variety of new SW1500 switchers out there so I am uncertain about which ones meet these requirements.

While trying to research the subject I also realized that some of the switchers have different trucks/bogies, some being AAR A-type, B type or Flexicoil bogies. Since the MIR kit side frames seems not to be compatible with the Athearn chassis I would like to select one with bogies that most closely resembles the 121 class locomotive.

 

If anyone has used more modern SW1500 switchers by Athearn or another manufacturer, I would be grateful for any advice you can offer. If anyone can offer any advice on the bogies, this may help me to narrow down the road names that I might be looking for as a donor. Any specific recommendations are also very welcome.

Many thanks

Edited December 26, 2015 by DiveController

[UP6936]

Get yourself a Southern Pacific SW1500, the trucks the Espee specced look a good bit more like the export trucks under a 121 than do the standard EMD switcher truck.

[Irishrailwayman]

I have used the new Athearn SW1500 chassis which is DCC ready and has two bulbs forward and back which give directional lighting and fit neatly into the double headlamps of the 121 body...

[DiveController]

Get yourself a Southern Pacific SW1500, the trucks the Espee specced look a good bit more like the export trucks under a 121 than do the standard EMD switcher truck.

Thanks for the advice. I had a look at prototypical Southern Pacific SW1500 switchers and found some good photos of the bogies / trucks.

The 121 has bogies like 134 seen here at Dublin

And the Southern Pacific like these

The Athearn model has the same bogies as the SW prototype

 

It may be that the bogies are similar but the side frames are not

[Glenderg]

If memory serves, the whitemetal bogie sideframes on the MIR 121 were extended to suit the 1500 chassis and are much bigger than prototype.

[DiveController]

If memory serves, the whitemetal bogie sideframes on the MIR 121 were extended to suit the 1500 chassis and are much bigger than prototype.

 

Hmm, I was told by someone that had built a kit that the white metal sideframes didn't suit the SW1500 chassis but I forgot to ask why

 

I found some spec on the prototypical SW1500 switchers on a US website. I suspect that the SW1500 has been used as it was/maybe still is the closest to the 121

 

EMD SW1500 Switcher

Engine Builder: EMD Engine: 645E 12 cylinder Speed: 65 mph

Trucks: 4-Wheel Configuration: B-B

Quantity Built: 807 Dates: 7/1966 to 1/1974

 

Total Length 44'-08"

Wheel Diameter 40"

Truck Wheel Base 8'-00"

 

Center Bolster 22'-00"

Center Front Truck to Front Pilot 2'-04"

Center Rear Truck to Rear Pilot 2'-04"

Distance between Truck Centers 30'-00"

 

Now to search for some on the 121

Edited December 27, 2015 by DiveController

[Noel]

Would be possible to use an MM 141/181 model as a donor and shorten the chassis slightly? Then you get a quality Bachmann runner with scale bogies.

[DiveController]

Would be possible to use an MM 141/181 model as a donor and shorten the chassis slightly? Then you get a quality Bachmann runner with scale bogies.

 

I probably could but I simply don't want you to be strung up or banned by a Moderator for making blasphemous suggestions.

 

I do have enough MM141/181s that I could sacrifice one but would I do it for something that looks like it was dipped in an orange chocolate fountain and not exactly fine scale. I'd probably feel obliged to butcher the body to add finely detail parts to the MIR:confused:

[Noel]

I probably could but I simply don't want you to be strung up or banned by a Moderator for making blasphemous suggestions.

 

I do have enough MM141/181s that I could sacrifice one but would I do it for something that looks like it was dipped in an orange chocolate fountain and not exactly fine scale. I'd probably feel obliged to butcher the body to add finely detail parts to the MIR:confused:

 

LOL - the chocolate fountain description is hilarious.

 

PS: A recent model Athearn SW1500 chassis would probably cost more than an MM141 or 181 with current $USD exchange rates.

[Blaine]

Would be possible to use an MM 141/181 model as a donor and shorten the chassis slightly? Then you get a quality Bachmann runner with scale bogies.

 

Its been done........consider a Brawa V100 too

[Dave]

Would be possible to use an MM 141/181 model as a donor and shorten the chassis slightly? Then you get a quality Bachmann runner with scale bogies.

 

It's a good idea, but your destroying a beautiful model that's no longer made. I wouldn't have the cojones to do it!

[Noel]

It's a good idea, but your destroying a beautiful model that's no longer made. I wouldn't have the cojones to do it!

 

Yes I too would find it uncomfortable to discard an MM141/181 body shell, but they still are relatively easy to come by and cost the same or less than a decent donor chassis with equivalent drive capabilities. Destroy might be too strong a word, as one would be creating something new and useful out of it, and the bogie sides would be fine scale compared to coarse white metal sides lacking finese.

[DiveController]

 

EMD SW1500 Switcher

Engine Builder: EMD Engine: 645E 12 cylinder Speed: 65 mph

Trucks: 4-Wheel Configuration: B-B

Quantity Built: 807 Dates: 7/1966 to 1/1974

 

Total Length 44'-08"

Wheel Diameter 40"

Truck Wheel Base 8'-00"

 

Center Bolster 22'-00"

Center Front Truck to Front Pilot 2'-04"

Center Rear Truck to Rear Pilot 2'-04"

Distance between Truck Centers 30'-00"

 

Would anyone happen to have the dimensions of the 121 to hand for comparison with the SW1500 chassis please?

[Blaine]

It's a good idea, but your destroying a beautiful model that's no longer made. I wouldn't have the cojones to do it!

 

Trains are for playing with this includes converting and weathering them

[Garfield]

Trains are for playing with this includes converting and weathering them

 

...if the owner so desires.

[Irishrailwayman]

I have used the new Athearn SW1500 chassis which is DCC ready and has two bulbs forward and back which give directional lighting and fit neatly into the double headlamps of the 121 body...

 

At the end of the day, there are no easy answers prior to a good rtr 121 becoming available. We were in the same boat trying different HO chassis when we had only the MIR 201, 071, 141, 181 body kits available....

[DiveController]

At the end of the day, there are no easy answers prior to a good rtr 121 becoming available. We were in the same boat trying different HO chassis when we had only the MIR 201, 071, 141, 181 body kits available....

 

G, thanks for your reply. I have a sneaking suspicion that your SW1500 is going to be the best option but since I don't see the 121s being available inside a couple of years at least for various reasons (all principally economic in one way or another) I'm exploring others.

 

EMD exported the GL8 in various modified forms to several countries including Brazil which took the lion's share. All (except GA8s) seem to have had the same export bogies similar to the 121 class. The Brazilian model maker, Frateschi also produced a 1:87 scale model with bogies that appear relatively finescale and prototypically correct. I'm not sure about the axle boxes but they don't look bad and may even be correct.

 

 

My main concern with this is that I don't know much about the running qualities of the model which would be important. I'm also not sure that it has any directional running lights or is DCC ready (or even compatible)

Another concern would be that it's under scale at 1:87 not only the bogies as would be with the SW1500 but would also be physically not long/wide enough for the MIR OO scale kit (which is why I was looking for some specs on the 121 above)

 

Most importantly if someone has any experience with Frateschi running qualities could you please post or PM me

Thanks!

Edited December 28, 2015 by DiveController

[Garfield]

Most importantly if someone has any experience with Frateschi running qualities could you please post or PM me

Thanks!

 

I posted about the suitability of a Frateschi chassis for the SSM Sulzer body here:

http://irishrailwaymodeller.com/showthread.php/5080-Sulzer-Kit?p=81162&viewfull=1#post81162 - I included a YouTube video of a loco which looks like it's running rather smoothly.

 

Re. concerns over scale... it's clear that some Frateschi models are actually closer to OO than HO, even though they're marketed as being the latter. It's possible the GL8 could be one of these but you'd need to measure up an example to be certain.

[Noel]

This Black'n'Tan Athearn SW1500 runs very smoothly, does low speed crawl, and runs reasonably smoothly over Peco insulfrog point work. I'd be very happy with it under a 121 or even a C class. I will post a video of it running slowly over pointwork when I get a chance. I presume the model I have is one of the later versions because it doesn't seem to have any of the rough running attributes of older Athearn's.

Edited December 28, 2015 by Noel
Typo

[Mayner]

G, thanks for your reply. I have a sneaking suspicion that your SW1500 is going to be the best option but since I don't see the 121s being available inside a couple of years at least for various reasons (all principally economic in one way or another) I'm exploring others.

 

EMD exported the GL8 in various modified forms to several countries including Brazil which took the lion's share. All (except GA8s) seem to have had the same export bogies similar to the 121 class. The Brazilian model maker, Frateschi also produced a 1:87 scale model with bogies that appear relatively finescale and prototypically correct. I'm not sure about the axle boxes but they don't look bad and may even be correct.

 

[ATTACH=CONFIG]21926[/ATTACH]

 

My main concern with this is that I don't know much about the running qualities of the model which would be important. I'm also not sure that it has any directional running lights or is DCC ready (or even compatible)

Another concern would be that it's under scale at 1:87 not only the bogies as would be with the SW1500 but would also be physically not long/wide enough for the MIR OO scale kit (which is why I was looking for some specs on the 121 above)

 

Most importantly if someone has any experience with Frateschi running qualities could you please post or PM me

Thanks!

 

 

The Frateschi loco seems to have the edge on the SW1500 in terms of bogies an looks like a low cabbed version of the B121 Class which would kind of make sense as some Brazilian lines were built to 5'3"

 

The MIR 121 looks reasonable and runs well on the SW1500 chassis, the whitemetal body adds to the smooth running and pulling power. The loco was good by the standards of whitemetal diesels of the 80s, though may be overscale for 1:76 or OO, the original bogies were designed around the DS10 motor and the sideframes are longer than scale.

[David]

 

[ATTACH=CONFIG]21926[/ATTACH]

 

 

Would you not just get one of those and modify it to look like a 121? It even has the vents in the right place and the correct number of steps on the bonnet sides. A little bit of cutting and shutting, along some detailing and a nice spray job, will have that looking like a nice 121.

 

Or... Wait for the MM 121 to come out?

[DiveController]

I posted about the suitability of a Frateschi chassis for the SSM Sulzer body here:

http://irishrailwaymodeller.com/showthread.php/5080-Sulzer-Kit?p=81162&viewfull=1#post81162 - I included a YouTube video of a loco which looks like it's running rather smoothly.

I must have missed a couple of pages of the SSM Sulzer Kit thread as really busy coming up to Christmas. Thanks for that, Patrick!

 

Re. concerns over scale... it's clear that some Frateschi models are actually closer to OO than HO, even though they're marketed as being the latter. It's possible the GL8 could be one of these but you'd need to measure up an example to be certain.

That's encouraging, warning duly noted:tumbsup:

 

The Frateschi loco seems to have the edge on the SW1500 in terms of bogies an looks like a low cabbed version of the B121 Class which would kind of make sense as some Brazilian lines were built to 5'3"

I think most of the Brazilian heavy rail lines are 5'3" and narrow gauge at 3' 3"3/8. I think that's exactly what it is, a lowered cabbed version. I think ALL (América Latina Logística) the Brazilian logistics company have the closest to the 121 (high cabbed), but on US freight bogies, I think. I'm not aware that this was ever modeled

 

The MIR 121 looks reasonable and runs well on the SW1500 chassis, the whitemetal body adds to the smooth running and pulling power. The loco was good by the standards of whitemetal diesels of the 80s, though may be overscale for 1:76 or OO, the original bogies were designed around the DS10 motor and the sideframes are longer than scale.

 

The Athearn SW1500 chassis would be much better in the last 3-4 years. The chassis itself would be HO or 1:87 so if over scale that would be o my advantage. Wasn't sure if you were referring to the MIR whitemetal side frame castings which may be over scale, by all reports

[Noel]

Video of Athearn SW1500 model on DC. It's not as ultra smooth a runner as MM/Bachmann 141/181, but not bad either. Below was tested on DC. Will repost a clip when I get around to popping a decoder in which may improve the smoothness due higher track voltage (i.e. for pickup continuity and motor pulsing).

 

Athearn SW1500 Black'n'Tan

[DiveController]

Would you not just get one of those and modify it to look like a 121? It even has the vents in the right place and the correct number of steps on the bonnet sides. A little bit of cutting and shutting, along some detailing and a nice spray job, will have that looking like a nice 121.

 

Or... Wait for the MM 121 to come out?

 

Hi David, that would be nice but I have a feeling that unfortunately the body on that one is a custom job already. Otherwise, while not up to your caliber, would still have a go.

Yes, if MM landed have a dozen 121 liveries in the morning, I'd buy one of each. I'm sure they'll be beautiful if they come, just not sure when

 

Video of Athearn SW1500 model on DC. It's not as ultra smooth a runner as MM/Bachmann 141/181, but not bad either. Below was tested on DC. Will repost a clip when I get around to popping a decoder in which may improve the smoothness due higher track voltage (i.e. for pickup continuity and motor pulsing).

 

Athearn SW1500 Black'n'Tan

 

Thanks for that, Noel.

Not as slow as your usual MM 071 vs. 141 challenge but certainly an adequate runner. Would be interested to see how that performs on DCC. Seems pretty smooth otherwise.

I think it's a 21pin PnP DCC chassis but report back if you would if you're able to DCC her

 

Its been done........consider a Brawa V100 too

 

Looked up the Brawa, Ed. Wasn't aware of it before your post. What would the advantage be? I have never seen one run (that I'm aware of)

Edited December 29, 2015 by DiveController

[Noel]

Hi Kevin. It takes an 8 pin decoder. If I get time later I will put a Lenz silver+ decoder in it for side by side comparison with a 141/Lenz combo. Don't know if the BMEF will make a difference but I'm hoping the higher constant track voltage will help slow her down more over points. Noel

[Blaine]

Wasn't aware of it before your post. What would the advantage be? I have never seen one run (that I'm aware of)

 

Nice smooth continental mechanism, was acquired cheaply though which helped

[Irishrailwayman]

The 121 is fairly unique and the chassis details differ even from the 141/181 I believe. The Athearn chassis are also HO but this does not affect performance or looks in OO too much. I have 5 of these and the DCC ready, lights and running qualities are excellent although the fuel tank/bogies are ok they don't completely match the 121 prototype.

 

Even if correctly spaced bogies can be found, they will probably foul the ladders at both ends of the body. One other option might be to get Black Beetle motors/wheel sets and power the model in that way attaching 121 bogie sides. Again, all modelling is a blend of affordability, time/patience available, what level of "correctness" is acceptable etc...

[Noel]

Athearn SW1500 body removed. Just two screws under kadee box at each end and the body pulls off. Careful of the lighting wires.

 

Light wires easy to remove from PCB as they are just pinched on with plastic tabs.

 

Looks like it can take either a 9pin decoder, or an 8 pin. Just about to read manual.

 

I suspect two metal lugs at each end of the chassis the kadee's screw into may have to be cut or filed, or alternatively cut slots in the MIR body for them to protrude.

 

Centre drive, double flywheel, all wheel pickups.

 

Now to fit a Lenz decoder and test run again alongside an MM141/181

[Dave]

How do you find the Lenz decoder Noel? I have ordered 10 for re chipping locos for my shunting layout.

[Noel]

How do you find the Lenz decoder Noel? I have ordered 10 for re chipping locos for my shunting layout.

 

Hi Dave. Quite happy with them and good prices from German web sites. They seem quiet and smooth presumably due to the BEMF. Have used the Lenz Silver+ on my MM 141/181, and 071 (no cab lights). 183 in the video below is using a Lenz Silver+. The 071 is a LokSound, both at speed step 1.

The baby GMs crawl speed which would only be used buffering up or starting off on a heavy train is impressive. All the best. Noel

[Dave]

That's impressive as the cheaper decoders struggle with shunting speeds. I got 10 decoders for €24.99 and free shipping.

[DiveController]

I got 10 decoders for €24.99 and free shipping.

Dave, that's a typo, right? Which decoders?

[Dave]

Dave, that's a typo, right? Which decoders?

 

Sorry, yes should be €24.99 each! Lenz Silver 21 pin decoder

[Noel]

Sorry, yes should be €24.99 each! Lenz Silver 21 pin decoder

 

Yes that's the same price I paid in Germany. Great value for a quality decoder.

[Noel]

As promised video clip of Athearn SW1500 running under DCC with Lenz 8-pin silver+ decoder fitted.

 

Side by side SW1500 with MM0183, both fitted with Lenz Silver+ decoders (8 pin & 21 pin respectively). Also segment of slow running over insulfrog points.

 

[video=youtube;Gzv2__Jg-Ws]

 

There was a marked improvement in low speed smoothness under DCC compared with DC. I presume this is down to higher track voltage helping pickup continuity, and BEMF on the motor drive. The motor drive is nearly as good as the amazing MM141/181 and seems equal to MM071s.