Hello,

I recently installed a Wow 501 in an Accucraft K-28. I have made no changes to the factory settings as of yet. When in speed steps 28, 1-26 work great but when I get to speed step 27 the loco comes to a abrupt stop and when moving on to 28 it pauses then starts again at a slower speed than speed step 26. I then set CV29 to 50 and redid the speed steps 27 and 28 in the user loadable but is did nothing. Help. Oh and I also did a reset a billion times and a Nuclear reset. Very frustrating.

Bill

Greetings and Welcome! Bill…

I don’t have the slightest idea what you’re talking about, but I can guarantee you’re in the right place here on LSC…one of the fellas around here will know the answer for sure!

Thanks, I sure hope so. TCS is very slow at answering technical questions lately.

That DCC system are you using?

Try changing CV29 to 34. this will turn off the speed table if that is the problem.

Dennis

Dennis Cherry said:

Try changing CV29 to 34. this will turn off the speed table if that is the problem.

Dennis

Hi Dennis,

Thanks for you response. I have tried both ways and still does it. I am using airwire 60. I took a video to show. It appears like it is pulsing weird while increasing speed, if you listen and watch very closely you will see and hear very fast clicking while running. Oh and this is after a full reset no adjustment to cv29 also this time it doesn’t stop on speed step 27 but races on 28. The running gear is fine I tested on straight dc to the motor and it is smooth as glass. The weird thing is I cant get a full reset, it leaves the smoke feature every time even with a “nuclear” reset.

I guess you cant attach

a video with out an address, Ill put on youtube

https://youtu.be/-2GwyVzbB0E

Try this

Bill

Well I received communication for Dan at tech support. supper nice guy, however he had never seen this before, it’s being sent up the chain of command. I know they have a goof proof warranty but the install was done in such a way in the boiler that taking it out is a real pain. I hope someone can help me figure it out. Funny thing is it wont reset all the way. I have mentioned this a billion times, you would think that would be a sign somethings really wrong with it. Oh and No, its not locked.

How does it react on 14 or 128 speed steps? (Yeah, 128 speed steps on the T-5000 throttle is a %#@$!, but it’s worth checking to see if it’s a speed step thing.)

Later,

K

I didn’t notice it on 128 but I was busy trying to calibrate it with the audio assist. never tried 14, Ill give it a try and report back

I received an answer for Dan at Tech support after he requested info on the motor in the loco. I feel like I’m being blown off. Here is his answer. I cant believe this is true because my other Accucraft engines have the same motor and run fine and my batteries are 18volts. Anyone have any thoughts on this, is it true?

Bill,

I looked up these motors, and despite the overwhelming lack of information about them, our engineers have told me that these are motors that are not designed for model trains. While Pittman was well known for locomotive motors back int eh day, today their manufacturing is not focused on the hobby, and motors such as these are not ideal for this application. What you want, optimally, in a locomotive is a 12V (HO) or maybe a 16V (O/G) 5-pole skew-wound DC motor. The fact that this motor is designed for 24V continuous operation is not ideal for model trains. Our decoders, and subsequently our motor control, are spec’d and optimized for DCC systems operating with 11-18VAC on the track. This works out well for 12V motors (or thereabouts). While it is true that G scale runs at higher voltages, in reality you are not trying to control a motor at the same voltage as your track. We don’t claim to be experts when it comes to G or O scale, but running a train above 18VAC is generally unnecessary. Running at higher voltages will introduce excessive heat, more fluctuations in the power supply, and more apparent irregularities in the motor control. (Not to the effect of what you are seeing, however.)

After talking it over with the people smarter than I, we agree that changing out the motor is pretty much guaranteed to solve this issue for you. Simply put, these motors are not designed for the PWM frequencies and motor control methods DCC decoders use.

Regards,

Dan

Ok, as usual I have the weirdest problems with electronics. I was going to swap decoders from another engine when I decided to try it one more time. I brought the engine into my O scale narrow gauge layout, removed the airwire 60, hooked it up to the service track with jumpers then did a complete reset one more time using my lenz system. Took it back to the shop bench and tried it one more time making sure that I only had 18 volts from the battery as per his email. Wouldn’t you know, it now works fine. Man am I glad I didn’t rip apart the engine.

This is not meant to be a battery vs no battery issue, rather a confusion on why 24 volts is not good for large scale trains/motors in trains.

While Steam engines mostly run slow, modern diesels run fast and I do have 24 volts on my DCC system and I also have 24 volts DC for engines I did not convert. I have not had any issues with DCC decoders running in diesels/electrics (Genesis and LCE) at full track voltage and these run great even on DC. (my layout has a dc system available at the throw of a DPDT switch).

Interesting. I wonder if 24v is max voltage for this motor, and its cranky when its operating right at its limit.

I find this interesting in that I have an Airwire T5000 TX and a Bachmann K27 with a G2 RX. I custom installed the G2 such that I can run either with 18 volt battery pack or (through a bridge rectifier) track power using a Meanwell 24 volt switching power supply. I have no issues with either configuration.

Not being familiar with DCC in general I went to the TCS page for this decoder https://tcsdcc.com/1600 and looked for the specs for the board. Having reviewed the Description and Specs tab, I do not see any references to max operating voltage. All references to voltage are for 12 volts DC. From what I am seeing this is what I would refer to as a small scale unit, meant for 0 or smaller scales running on a 12 volt system. That is not to say there are not DCC decoders capable of 18 or 24 volts, by what I read not this one.

As for Pittman motors not able to run on PWM, that is horse puckey. A motor (without any additional electronics) is nothing more than copper wire would into electro-magnets. PWM is nothing more than a variable frequency (length of on) on-off switch pulsing full power to the motor for a variable length of time. The shorter the pulse (on) cycle the slower the motor runs, the closer to continuous power the faster the motor runs until it reaches maximum power/maximum speed. Electronic circuit boards on the other hand generally don’t like PWM.

My opinion based on engineering logic and empirical experience.

I have been thinking about why this happened and I think I have an answer, I just noticed one of my cvp T5000 has some issues with buttons sticking and not depressing all the way. Im thinking in one of my programmings for functions it must have put in some wrong cv’s and messed up the decoder. The big problem was it wouldn’t reset with the convrtr 60. When I disconnected it from that and hooked it up directly to my Lenz system it seemed to reset everything and now it is back to original. If I didnt have another DCC system I would never know. Bottom line is motor and decoder is fine with higher voltages. If they would have listened to my first email and the resting issue it wouldn’t have been 3 weeks of frustration. Oh well all is good now.

https://youtu.be/t-nQNtrfheM

Strange response from TCS. I have two locos with Pitman motors equipped with the TCS Wow decoder. My BBT-equipped “Connie” is about as good as it gets in terms of sound and control. My C-19 is a bit quirky with regard to the motor’s BEMF and the chuff, but otherwise it’s fantastic. Certainly no motor speed issues. Smooth as silk, both of them.

Later,

K

Note that when CV29 is 34 the speed table gets its info from CV 2, 5, 6. If you use CV29 =50 then the speed table is in CV 67 to CV 94 and you can reprogram these values.