Been looking for a specific MTH loco for a long time in 3rail, but cannot find one. ran across the two rail version and was wondering how complicated the conversion is and how much it would cost.
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If it's a MTH loco that is designated as 3/2 rail convertible, then all you would need to do is change out the 2 rail wheelsets for 3 rail wheels. Very easy, take off the bottom plate on the truck and swap them out, then replace the cover. As for adding 3R couplers, that is not going to be easy as these are designed to have Kadee type couplers- which is what I would use anyway. We need more info here to provide more details.
Tender pick-up on an MTH 3/2 convertible Russian Decapod. The roller would be removed. Wheel isolation for two rail is in place both the Tender and the locomotive.
sell the two rail and buy a three rail?? 
Ok here is some more specific information. MTH premier SD70mac
- Full 1/4" scale dimensions
- MTH Proto 3.0 full electronics and sound package
- DCC equipped
- Operating diesel exhaust
- Die-Cast Truck Sides, Pilots and Fuel Tank
- Intricately Detailed ABS Body
- Metal handrails, decorative horn, and other detail parts
- Moveable Roof Fan Blades
- Directionally Controlled Headlights
- (2) Precision Flywheel Equipped Motors
- Lighted Cab Interior with 2 cab figures
- Locomotive Speed Control In Scale MPH Increments
- Scale (2-rail) wheels
- Kadee Compatible Coupler Mounting Pads
- Fixed pilots
- Convertible to 3 rail AC operation for "3 rail scale" operation
So is my understanding correct...all I would need to do is change the wheels to 3 rail High Rail wheels and flip the switch to 3 rail operation? I assume I would not need to do anything with the couplers since it says its it has kadee compatible mounting pads, which implies to me it has regular claw couplers from the factory.
2 things....can I use 3 rail high rail wheels (or do they need to be 3rail scale wheels) and how easily are replacement wheel sets to get?
I'm a little confused as MTH has never offered the SD70MAC in 2 rail- they are all 3/2 locos as shown in your description. If it has 2 rail wheels then just change them, but nobody with 2 rail is going to have claw couplers on the loco-
Jeff78rr posted:I'm a little confused as MTH has never offered the SD70MAC in 2 rail- they are all 3/2 locos as shown in your description. If it has 2 rail wheels then just change them, but nobody with 2 rail is going to have claw couplers on the loco-
So what you are telling me is that more than likely 3 three rail unit with 3 rail wheels and claw couplers that could be converted to 2 rail?
I know for a fact this was sold as a 3 rail unit, but not sure if it is set up for 2R or 3R. It left the MTH facility as 3R unit as indicated above. There is no way to give you anymore info than this based on what you are telling us- do you have a pic? That would solve it immediately.
Jeff78rr posted:I know for a fact this was sold as a 3 rail unit, but not sure if it is set up for 2R or 3R. It left the MTH facility as 3R unit as indicated above. There is no way to give you anymore info than this based on what you are telling us- do you have a pic? That would solve it immediately.
I do not have a picture. I have inquired with the seller for more information and to see if any conversion was made to it after it left the factory.
Thanks for all your input.
Bill
You or the seller has something mixed up here as Jeff has pointed out.
Either it's not an O scale SD70MAC, or that description is from another item.
Sometimes the MTH box, is not accurate!
Forget about the more recent catalog descriptions.
Bossman284 posted:Ok here is some more specific information. MTH premier SD70mac
- Kadee Compatible Coupler Mounting Pads
- Fixed pilots
- Convertible to 3 rail AC operation for "3 rail scale" operation
So is my understanding correct...all I would need to do is change the wheels to 3 rail High Rail wheels and flip the switch to 3 rail operation? I assume I would not need to do anything with the couplers since it says its it has kadee compatible mounting pads, which implies to me it has regular claw couplers from the factory.
2 things....can I use 3 rail high rail wheels (or do they need to be 3rail scale wheels) and how easily are replacement wheel sets to get?
No! It means there are no couplers included!
As stated above, the information on the MTH box may not be 100% accurate. If it has a fixed pilot, that definitely tells you that it was produced as a 2-rail engine. It would have been expected to have scale couplers installed and would not have had lobster claws from the factory.
As Jeff and Joe say, something’s mixed up here. MTH made SD 70M-2s and 70ACes in two rail, but not 70MACs. Knowing the MTH item number of what you’re looking at would help us help you.
RM
Rich Montague posted:As Jeff and Joe say, something’s mixed up here. MTH made SD 70M-2s and 70ACes in two rail, but not 70MACs. Knowing the MTH item number of what you’re looking at would help us help you.
RM
You are correct. These are in fact 70ACes. (my mistake) They are two wheel (from the factory) and have fixed pilots and kadees installed from the factory. They come with 3 rail sets in the box so they can be converted by installing the wheels and flipping the switch.
Thanks for all your input and sorry for the confusion.
it's called the "why would you do that?"
Bossman284 posted:Rich Montague posted:As Jeff and Joe say, something’s mixed up here. MTH made SD 70M-2s and 70ACes in two rail, but not 70MACs. Knowing the MTH item number of what you’re looking at would help us help you.
RM
You are correct. These are in fact 70ACes. (my mistake) They are two wheel (from the factory) and have fixed pilots and kadees installed from the factory. They come with 3 rail sets in the box so they can be converted by installing the wheels and flipping the switch.
Thanks for all your input and sorry for the confusion.
Well, someone added the KDs. They do not come installed on the engines. The seller also added extra 3 rail wheels by this description? Otherwise I believe he means that it comes with the 3 rail pick-up rollers (center rail +) in the box. You install those, and then flip the switch for 3 rail.
