Has anyone been able to replace the motor in the new 2nd run Intermountain AC 12. We took two to a layout on a 40 car reefer train and they stopped running after a short time. These are the DCC version of the AC12 and the motor will not power the locomotives for any length of time. These are the new ones and they do run fairly well for about ten feet or so before the motor gives out. Well maybe a 100 feet.
Any suggestions if the motor can be upgraded to a large size that actually runs the locomotive. I had one on a roller set and the engine slowed down after ten minutes to a craw. They are nice looking but can only be used for dust on my shelf at this time.
What are the motor’s measurements (length, width, height, shaft diameter)? Is there enough room for a larger motor? If not, there are small high power motors out there that could work. I may be able to point you to a good replacement.
Also, are you sure that it’s the motor, and that something else inside isn’t seizing up?
It seems to be a weak motor. This is a known problem with the new run and has been reviewed on Tony’s Trains page, but I was hoping someone had a solution. The unit has not been taken apart as of today since it is new and they don’t provide a break down drawing. I have two and I know of two more and all the four act the same. The drive mechanism seems to be fairly smooth and not tight at all. The detail is very good on these models and it would be nice to get a fix on this problem.
They are a big improvement over the first run with the drivers slipping on the axles and going out of gauge and quarter. I use improvement lightly but some of the problems that existed with the first run were solved. The motor issue probably can be solved if a proper motor will fit into the chassis.
Wait, is this the IM AC12 that Con Cor has been pushing Pre-Orders for recently? or do they keep turning up new problems? Wheelslip can be fixed with a helper, they had them occasionally, but one is screwed if the motor won’t run at all.
I have heard the same motor was used after adjusting the gear train for higher speeds. Thus, the motor is weak. Making matters worse is that the electrical contacts on the drivers may be pressing too hard, creating a heavy motor load. Also, the dcc assembly overheats, requiring better ventilation and perhaps a better heat sink.
A person with the skills and know-how to fix these problems could find himself a nice cottage industry. He would have hundreds if not thousands of customers.
This is the HO second run Intermountain AC12. The speed of the AC12 is slow overall but after a few minutes. the top speed is just about 15 mph or so. They all seem to slow down after just a few minutes even if they are running without a train.
I’ve heard lubing them will help with the “slow down”, but the motor is indeed under powered. A few weeks ago I saw picture on line of how to dis-assemble one. (can’t remember where) from what I remember, the motor appeared to be about the size of Cannon E22, which is 32x22mm. To small in my opinion for a loco that large. I doubt there’s room for a larger motor without major surgery, so your best bet would be to find one of those powerful rare earth magnet or coreless motor that would fit in the space of the old motor.
Haveing never actually held on of these loco’s in my hand before, this is all jut speculation.
This sounds like a problem that Intermountain should fess up to and offer a free or low cost upgrade under warranty.
Have any of you contacted Intermountain about the problem and see what they say? Too many importers today seem to think that RTR stands for Ready To Rebuild and that modelers are all willing to invest substantial sums of money correcting their mistakes.
The situation is that Intermountain has replaced the first run free of charge to anyone that contacted them but the second run seems to have problems also. We had talked to Intermountain at the Anaheim show last year and found out they were going to replace the first run AC12’s because of the driver issue. I would be very surprised if they replaced these after the mess with the first run, but it is possible. The review on Tony’s Trains is interesting.
We sent two of the new ones back for replacement for other issues and they replaced those two again, but the motor problem is a serious issue that can only be solved by replacing it. I have some brass ones so these will just be display locomotives if the motor cannot be upgraded. There was a note to lub the model which I did but the drive line is not tight.
My hope was someone out there has already taken one apart and knows the size of the motor in this model and inaddition, can a larger one be installed?.
If it is indeed the size of an EN22, why not replace it with an EN22?[:D] They have as much or more torque than a Pittman DC-71, and can easily handle a Cab Forward. You can get the EN22 for a good price here. I’ve bought quite a few motors from this guy, and he is a very reliable seller.
Have you tried contacting Intermountain about disassembly instructions? If they’re any good at all, they should at least try to help. Do they not include an exploded diagram?
That is good news if it is the size of the EN22. I will attempt to disassemble the model again soon. Intermountain does not provide any clues or diagrams, but I do have some instructions from someone at the La Mesa club so it should be possible to take it apart. After removing the three screws that are below the steam dome, the SA feedwater heater and the turrent cover as they suggested, the boiler top would not move but there is probably a way to removing it. I will figure it out but was hoping someone had already tried and could furnish some infomation. Intermountain is reluctant at this point to do anything since they did replace the first run free of charge and expected the problems to be over. I was surprised at that move since it must have cost them a lot of money to take that loss.
Thanks for the information and if any shop out there has the know how to do this work, please send me a private message.
Well, at least you have some instruction for disassembly. Modern steam engines can be very difficult. It took me a while to figure out the to get the boiler off my Genesis 2-8-2, I had to lift the back above the weight and slide the whole thing forward. And I still don’t know how the Spectrum 2-10-0 boiler is mounted.
Incase you didn’t know, the EN22 is 33x22x18mm, and has a 2mm shaft. The large Mashima motor sold by A Line is the same size, and there are a couple others that would fit too, like Kato’s HO motor or the can motor sold by Micro Mark. All should be powerful enough for the Cab Forward.
Thanks for the reply. I have a Micro Mark catalog and will check on the motor when I know for sure its size. Some of the latest plastic model can be tricky when diassembly is required. I really hate the way you have to remove the ends of Genesis Athearn UP centepede tenders to get inside the tender.
I have the 2nd run and have experienced the same along with the chuff rate --approx 2 / revolution. Intermountain support has been helpful. They recommended adjusting (relaxing) the tension on the driver pickups or removing them. They will accompish the task or coach you. I was skeptical as I did not want to sacrific electrical contact integrity/reliability/resiliancy for reliable operation on dirty track --the real issue is the motor
I decided I had nothing to loose and removed the pickups and was able to get a sustained speed to 70 (35 prior to warming up) under no load on my roller test stand using the Baccrus speedometer. On my club’s layout www.socmrrc.org I was able to pull 17 cars up the helix without slipping ( started with 20 cars). I could not measure the sustained speed but it was improved. I would estimate in the 30-40 mph range.
Also after removing the wipers I did experience some stalling on a few turnouts and parts of the layout at low speed due to moderately dirty track – so my assumption on trading off electrical integrity for speed was validated.
So I went back to Intermountain – “is there a re-motor motor replacement or would they do it on a T&M basis?” – “No” but they did supply detailed documentation on disassembly and would reinstall and adjust the wipers under warranty
The chuff rate is still a problem --adjusting the CV’s per the manual does not seem to make any effect.
So, I’m in a holding pattern now-- mulling sending it back for the wiper reinstall and tension adjustment or attempting the re-motor myself – I’m inclined to send it back, retest, and then do a remotor if necessary. The chuff rate actually bothers me m
Open up the two covers at the bottom of each set of drivers, and you’ll see that the wipers are very stiffly set against the wheels, making far too much friction. Ease them off, and reshape them to effect a far more gentle touching. That should cure the constant overheating and slow-downs to almost zero mph.
A Mashima 1833 is an almost drop-fit replacement, with a minimum of work. It will greatly raise the rather poor top speed to something approaching 60-70 scale mph.
I agree that the chuff rate is a major problem and I talked to Soundtrax aboutthe problem when I installed the first one in a Genesis Challenger. It is the Tsunami’s problem with the CV’s not having the correct amount of adjustment when you select articulated type. The regular two cylinder type selection works fine. What I believe happened is Soundtrax designed the CV parameters around the first run AC12 with the 1/48 gear ratio. That one will actually chuff four times in the articulated mode, but then the wheels fall off or go out of quarter. It is always something. It seems you can’t win!
Thanks for the information. I probably will fix one of mine and shelf the other. I would like to raise the speed to at least 50 mph and use one of the AC12’s on a passenger run.
The first time I ran the new and latest AC12, it over heated on a set of rollers and the tension on the pickups also will help that. That problem is the same as running with the brakes on. The motor sounds like a good way to go.
A pleasure - it really is a simple fix, and you should do both locomotives (although the motor replacement is a bit more complicated). Here’s two YouTube videos of my AC12’s, which shows what can be achieved. The first one is on the club layout, and both trains are MU’d and had been running at that speed for about 20 minutes:
Does anyone have the instructions or know how to take these apart? I would like to know also so i can re-motor mine as well.
I applied the Frog Snot to one set of drivers and that helped a lot with the pulling capabilities, but it still runs pretty slow even after relaxing the pick-up tabs. Any help would be greatly appreciated!
I have never even unboxed mine although after reading this I think it’s probably a good time for it to find a new home and I’ll just continue with my Westside versions. They’re already painted and remotored with Sagami’s and I don’t use DCC or sound anyhow.
Just bought the Intermountain version becuse it looked so nice, had no idea it was such a “pain”…
P.S. I also have several BLI versions and they “all” run beautifully, guess the old rule still applys, you get what you pay for eh?