I just finished rewireing my Mogul for DCC and like someone else mentioned the start voltage has to be quiet high. I set the CVs so that it runs pretty good. There is a small jump at start. My question is has anyone determined if the motor is at fault or something else? There seems to be some kind of inertia to over come. Could it be the lack of a flywheel?
Thanks Lee
I've got an IHC Mikado that I recently put a Tsunami into. (Yeah, once again, I spent more for the decoder than I did for the engine.) I found that the initial start voltage was too high, even with CV 2 set to zero or 1. The engine would step out quite smartly, even at speed step 1, with a load of cars to boot. I ended up putting in a lot of acceleration momentum to get a more smooth start.
The Tsunami has turned this engine into a real winner, by the way.
What decoder did you put in yours?
It takes an iron man to play with a toy iron horse.
Lee,
How did you adjust the starting voltage? This is what I do:
Trying to make adjustments without a known stating place is just frustration! Also, having a computer interface with Decoder Pro makes doing this quite easy.
Jim Bernier
Modeling BNSF and Milwaukee Road in SW Wisconsin
Thanks for the tips guysI installed a D13SRJ (motor only), that I had on hand to see what kind of a loco I have.I used Decoder Pro to set the speed chart so it had straight line acceleration and raised start voltage untill the loco moved at step one. This left me with a slight jump at step one. I didn't think about adding momentum. I shall look at that as soon as I can.It has been a busy few days. My hard drive crashed and I'm just getting some of my data loaded in the new computer. Are we having fun yet?
And again thanks for the tips.
Lee
Lee, I am guessing this is a NCE decoder? If it is does it support CV 116 and 117 Torque Compensation? If so, you might give it a try. I am new to NCE decoders, in fact I just made a post about them. Playing with CV 116 and 117 breathed new life in to a RTR Athearn SD 50 I had not ran in 2 years.
Ken
I hate Rust
OK Guys I have an up date.
I have the NCE decoder installed and working fine even though the start voltage is high. I used Decoder Pro and it starts on step one in forward and reverse. MOST OF THE TIME. When starting in forward there are times when it takes several power steps to start. I suspected drive line binding. I lubricated everything lightly. Still binds. I have chased it down and the bind seems to be between the motor and drive gear. Although I don't see Any wobble in either one. I even dropped the drive train and left just the drive gear and the motor. It still seemed to have a tight spot. I think I will try and check the drive gear one tooth at a time.Trying to explain a problem may help me to solve it.
Any ideas?Thanks
It's likely just the motor itself, of course with allt he moving parts a steam loco will have a bit more 'stiction' get get all the pieces moving. It could be the quartering just SLIGHTLY off, not enough to make it bind or wobble, but enough that it takes a little more power to get it moving depending on the position of the rods when stopped.
You might be able to get it to work better by continuing to play with the toque compensation settings, it's mostly a brute force sort of thing, keep adjusting until it gets the way you want it. The two values work together.
A BEMF decoder would probably help a great deal, and be able to keep the motor spinning at the ultimate lowest speed possible.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
RandyMy rambling post probably didn't make it clear. The problem is that it starts fine in both directions except, forward start sticks ever so often and requires step 5 to get it moving. I've narrowed the problem down to the worm gear and it's enter action with the drive gear. I did this by dropping the rest of the drive assembly and starting and stopping the motor many times. I just can not see any wobble in the worm or the gear that the worm runs against.Is it possible that this kind of motor can have a dead spot like the starter on a car?
Thanks
It can I had a brand new Atlas/Kato RSD-5 that was like tha.t But if there's a dead spot in the motor and it was stoppedon it, it would NEVER move no matter how high you cranked the throttle. It sounds liek there is quite a bit of free play in the armature so the worm is moving back and forth as you switch directions. This could be fouling up the gear mesh just enough to need a bit of extra power at times. On a diesl like an Athearn you can put thrust washers on either side of the worms to keep the drive line from moving back and forth too much. If the worm is supported on both sides you could do the same here. If the worm is just there with no bearings it's goign to be hard - dependign ont he motor you might be able to take it apart and add the thrust washers on either side of the armature core.
Liek I said, for those times when you have to goose it to speed step 5 - a BEMF decoder would do just that, and keep it moving at step 1 (assuming the start volts was set right). BEMF can cover for a lot of things, if the binding is very mild and not easily fixed it's a viable alternative., If the thing wouldn;t run worth a darn anyway, BEMF will NOT fix it, but it sounds liek an option. That, or a better motor with less free play.
Is this a new engine, or a veteran that you're just now putting DCC into?
If it's new, I'd set up a loop and let it run around and around for a couple of hours, some forward, some reverse, some clockwise, some counter-clockwise. Break it in a bit. Give the gears some time to learn to work together as a team.
MisterBeasleyIs this a new engine, or a veteran that you're just now putting DCC into?
It's probably a veteran of world war one. I picked it up at a swap meet. It was DC.There is slop in the motor mounting so that the motor moves front to back when reversing direction. I shimmed some movement out, but too much and you get more binding. The failure to start at step one at random times still persists,hmmm I haven't tried shimming the armature yet but I have the feeling the problem is more likely between the worm gear and the big gear.Hey thanks. Trying to explain a problem may help to solve it.
I've converted 4 of these to DCC (Tsunami). One I went full tilt on and replaced the motor, added a flywheel. I used the original worm and gear. That did not turnout as good as I had hoped. I will try a NWSL drive mechanism to see if that is worth it.
Other Moguls I simply added the Tsunami. They run rather well with just the tinkering of the motor control CV's. They now crawl along quite well from a dead stop..
There is so much slop in this drive that a bind may be difficult to pinpoint and illiminate. Best is to lube motor bearing both ends, lube the shaft that goes thru the lower gear. This lower gear is simple enought to remove and clean up. What could also happen is the frame is worn out. No bearings for the axels on this loco and the driver shafts can wear the area out. Gets worse if the quartering was off from day one, axels crash into the frame bearing surfaces. Check the lower gear for flash as it can catch on the frame or the power pick ups that run along each side.
You might try the Torque kick rate and strength that where mentionned above to see if this helps you along, Specialy if they are at '0' at present time. If you put the start voltage to anything higher than '0' at this time you will be defeating your work. If it leaps at 1, try 0. Adding momentum will not change a thing for you on step 1.
Marc