For what it's worth, the MTH Allegheny at least has a stay-alive capacitor installed from the factory, it will start up with the sound on if that was the state it was in last time, and you can re-map the function keys so that F8 turns the sound on or off. So it would seem that they've at least made a few improvements in that area. I do agree that the programming options on the decoder are still pretty limited, though.
As long as you only run them with other MTH locos. And don't have dirty spots, if running multiple units...
I have the FA/FB set. Both are powered and both have their own sound decoders. SO it does sound pretty nice with the two of them going, even if they are completely in sync, since MTH does not have, or at least it is not accessible from DCC, an option like ESU has to slighty adjust the sync of the prime mover sound so in a lashup of 4 locos, they all can be a beat or so off one another. But their default behavior which also seems to not be changeable, is to come up silent, even if they previously were running. This isn't a problem at home, but the club layout has the older modules using fitter track between them, which due to worn out rail joiners make for some significant dead sections. It's why every train needs a relatively large seam loco with loco and tender all wheel pickup, or double headed diesels - so one can push the other when it stalls. Every once in a while, fresh joiners are used, and the layout works great for that show. With the MTH locos, if one of them momentaril stalls over the dead spot, it goes silent. Then you have to hit F4 to start the sound back up. Except if the other one did not stall and has the sound still working - F4 shuts it off! Very annoying.
The other useless thing is the remote uncoupler. Dropping off the train is no problem. It's coupling back up. You have to slam into the train like it was some cheap toy. Thankfully they provide a set of regular Kadees in the box to swap them out.
Also I guess they didn't want to bother paying for them like Scaletrains and Rapido, but they have working class lights - which can be off, red, or green. That's it. Between Loksound's function control capability and a little extra hardware, Rapido and Scaletrains have managed to make theirs cycle between off, red, green, and white so you get the two most common options plus the others.
As for this working with this Allegheny - the NCE decoders don't have BEMF, so there is no part of the total DCC voltage 'reserved' at the top end, at full throttle, the motor gets whatever there is, so it should be able to spin a little faster.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Quite an involved discussion/process. Surely things to learn if you are an 'electronics type'.
Bottom line for me,...the reason I would never buy MTH locomotives.
(but somehow I have ended up with a couple of them I hope to not hace many problems with in the future)
Brian
My Layout Plan
Interesting new Plan Consideration
Shades_10318 Alright, I've done more testing, and I have some good news. I disconnected the wires from the motor, and installed an NCE decoder for motor control. I can now confirm that: -The motor will indeed run much faster with a different decoder installed -The MTH decoder will still make noises based on the tachometer speed even without the original decoder connected to the motor -It is not necessary to connect a resistor to the original motor leads All in all, I'm pretty happy with those results. Now I just have to repair a couple broken lighting wires...
Alright, I've done more testing, and I have some good news.
I disconnected the wires from the motor, and installed an NCE decoder for motor control. I can now confirm that:
-The motor will indeed run much faster with a different decoder installed
-The MTH decoder will still make noises based on the tachometer speed even without the original decoder connected to the motor
-It is not necessary to connect a resistor to the original motor leads
All in all, I'm pretty happy with those results. Now I just have to repair a couple broken lighting wires...
Pretty close to what I recommended.......
Sheldon
Thank you for the suggestions.
Mel, the resistor idea may be necessary, I'll have to find out if it will work without it or not. Regarding the value of the resistor, a motor is an inductive load, so the current will be equal to a resistor with the same value when first starting up (inrush current), but once the motor gets moving it drops dramatically, so the required current to actually trick the decoder into thinking the motor is attached is much lower. I would have to measure the free running current of the motor and go from there. I could use the load suggested, but that would draw more current than necessary and also generate more heat.
Red,
I appreciate the thought, but unfortunately the E7 is just the "golden locomotive" and not the one that would likely be run with the Allegheny. I could try and see what load it takes to slow down the other locomotives that I would like to run with it, but I would really prefer to be able to run it with any locomotive and any load, if that's going to work out. Personally, I think it's worth the effort to at least try swapping out the decoder if there's a good chance that it would work better that way.
With all due respect to the recommendations your respondents made...I would recommend you do nothing until you find out how many car loads slow down the E7 speed to match that of the unloaded Allegheny. If it's a relatively "small" number like 4 and you will be running more than 4 cars when consisted you will be fine no matter what the car loading provided the faster locomotive (the E7) is on the point. The consist will run just fine at <4 car loading but the slower locomotive will be acting as a "partial" load on the faster locomotive. One key proviso...you must apply enough voltage (DC) or speed step setting (DCC) to get the drive wheels in both locomotives moving (rotating).
I have done the above dozens of times without incident. So have most "older" (aka experienced) DC only operators. The faster locomotive first is a good rule but not absolutely critical...it just avoids the possibility of coupler "buckling" issues at relatively light loadings due to inter-loco compressive coupler forces.
At this point I'm actually thinking about just disconnecting the motor from the original decoder and connecting it to a separate decoder for only motor control. Since the MTH model uses a tachometer to read the motor speed, it should still be able to synchronize the chuffing and the smoke fan. Don't worry about the smoke unit, there's a dial in the tender that I use to turn it off completely when it's not being used.
You might want to hook the motor up to a decent motor only decoder, one that has BEMF, before you go all in. Why? Because with a BEMF decoder, you usually don;t get the full voltage at top speed. Why is that? Because if the decoder produced a full on pulse to drive the motor, and the load increased - more cars, or climbing a grade, there would be nothing left in reserve to maintain the speed and the loco would slow. By saving some of the top end, the decoder can speed up the motor by applying more power even at full throttle. You are likely to see this with any BEMF decoder.
If this is a museum display - I wouldn;t even connect the smoke. If the loco runs the smoke unit dry, it will eventually overheat and burn out. SO unless the loco is always under supervised control and the operator rememberts to refill the smoke unit when it stops smoking, it should stay off. That's ignoring any other issues people have with smoke, like a residue settling over the layout.
Even a non-BEMF decoder is going to not run as fast as applying 14V right to the motor - you don;t get 14V at the motor output of the decoder. 14 is about a common HO scale DCC setting, but the motor is controlled by an H bridge driver in the decoder, which puts 2x diode drops in the motor circuit, so the peak is about 1.4V less than the track voltage - less for the BEMF decoders because of the reserve.
Shades_10318 OK, I've done some testing and I have more information now. Originally, the locomotive was limited to 50smph and did not have enough torque to spin the drivers if held in place. I connected the motor directly to the power pickups, ran it on up to 14 volts DC, and found that the motor now runs much faster, I think (I don't have a scale speedometer), and also has way more torque than before (enough to spin the drivers with the traction tires installed). So that's useful information, it would seem the issue is actually with the decoder limiting the voltage going to the motor and not actually the motor being too slow. Unfortunately that probably means I'll have to replace the decoder... I think a Loksound Select is the only one I've heard of that has support for the smoke unit.
OK, I've done some testing and I have more information now.
Originally, the locomotive was limited to 50smph and did not have enough torque to spin the drivers if held in place.
I connected the motor directly to the power pickups, ran it on up to 14 volts DC, and found that the motor now runs much faster, I think (I don't have a scale speedometer), and also has way more torque than before (enough to spin the drivers with the traction tires installed).
So that's useful information, it would seem the issue is actually with the decoder limiting the voltage going to the motor and not actually the motor being too slow. Unfortunately that probably means I'll have to replace the decoder... I think a Loksound Select is the only one I've heard of that has support for the smoke unit.
I thought so.........
That's not what I meant. On a DCC decoder, the blue common wire is +, each of the function wires is the - side.
On MTH locos, the common connection is -, and each of the individual function wires is the + side. Since they often use small PCBs to mount multiple LEDs on, with independent control (say a high mount headlight with flanking number boards, where the headlight and the number boards are individually controllable), then on the PCB all the LEDs will have their - wired together and then there will be two + wires coming off the board. You can;t just hook that up to a DCC decoder - LEDs require the correct polarity. So you have to do things like cut traces to rewire the PCB to work with a DCC decoder if swapping out the MTH electronics. It makes the job much more difficult than it needs to be.
rrinkerer, MTH also wires the lights completely backwards
Russell
There's a reason I never bought another MTH HO loco after my FA set.....
I'm still not sure if I want to play the game and rip out the electronics and fix it all up with a standard DCC decoder, or just sell the things off (I did get them for a pretty good discount, so I might get close to my money back) and just find another P2K set which are just as nicely detailed.
Way I see it, you have two choices. Just never MU the Allegheny with anything but another MTH loco, or use the slowest one as the new gold standard and adjust the rest all down. Or take it back/resell it, and get something like a Rivarossi one and put a standard decoder in it.
Just regearing might work - since the tach would read the same motor RPM but the loco would be going faster for a given motor RPM. Thus the electronics would think it's going 50, when it really is going 70 because of the different gearing. Forget trying to calculate that exactly, you just need something that gives a greater than 70mph top speed (you can always slow it down) while retaining enough power to pull a decent train - as you put faster gears in it, you are going to lose pulling power.
I just found out I have another locomotive that uses a Mabuchi FK-280SA-10350 as the drive motor. I guess I could just try and see if it will fit or not, then go from there.
I can also discuss with the other staff at the museum whether or not they would like to try slowing all the other locomotives down to a top speed of 50smph. We do have some faster passenger locomotives and some dual service ones though, so I'm not sure if that would work.
So based on what everyone has said so far, it's looking like I may have to replace the motor and the decoder to get it to run faster?
I've already reprogrammed the locomotive to run using the custom speed tables. I'm not sure how the decoder actually regulates the motor speed, although I would think that programming CV 5=255 would still allow the maximum motor speed regardless of what that translates to in smph, at least as long as it's running in the non-smph mode. I'm not sure if that fixes the issue with the decoder not allowing the locomotive to run faster with a faster motor.
rrinker I'm not sure just swapping the motor would do much - the MTH electronics use that tacho input to set the speed to an actual speed - with a DCS controller you tell the loco to move at 10mph, not speed step 10. It's also used to sync the chuffs and the puffing smoke. The MTH locos use higher voltage motors and are geared as they are because there's no difference between the O scale DCS and HO DCS< track voltage is the same, so they took the simple expedient of using a higher voltage motor in the HO models so it works without having to have a scale selector on the DCS equipment. --Randy
I'm not sure just swapping the motor would do much - the MTH electronics use that tacho input to set the speed to an actual speed - with a DCS controller you tell the loco to move at 10mph, not speed step 10. It's also used to sync the chuffs and the puffing smoke.
The MTH locos use higher voltage motors and are geared as they are because there's no difference between the O scale DCS and HO DCS< track voltage is the same, so they took the simple expedient of using a higher voltage motor in the HO models so it works without having to have a scale selector on the DCS equipment.
Shades_10318 it has a tachometer board attached to it.
it has a tachometer board attached to it.
I don't know if it would be appropriate for your museum's display, but I'd instead re-programme the other locos to match the speed of the Allegheny.
I've seen otherwise nicely-done layouts where the operator runs at inappropriately high speeds, to the detriment of the viewing to layout, as it makes it seem toy-like.
Like Sheldon, my layout is DC, and because of the many curves and grades, most of my trains (all steam) are doubleheaded, and often with pushers, too. There's no need for speed matching, and no need for high speeds, either. The highest posted speed limit is 45mph, but with most of the layout at less than that.
It does, of course, suit the layout's features, which may be quite different than your situation.
Wayne
Thank you for the suggestion, Mel. I would be interested in trying out a different motor. I'm not sure about the motor RPMs/volt or the gearing ratio, although there are 2 gears in the gear tower and they are 22 and 26 teeth, I think, and the worm gear has a much higher number of teeth than the usual design. I'll have to measure the dimensions of the motor to see if it's the same as (or close enough to) the Mabuchi 280 motor you mentioned. It will have to be a motor with mounting holes on one end, as it has a tachometer board attached to it. A higher number of RPMs/volt than the usual ones used would probably be a good idea for a higher top speed ceiling.
They're not all my locomotives, it's a local railroad museum and I'm currently in the process of speed matching as many of the locomotives there as possible for ease of use when running trains.
The thing I'm concerned about with running the Allegheny with other locomotives is that the top speed is much slower than the other locomotives, and I don't want to worry about excessive wear on the components of any of the locomotives in the consist. I guess if it ends up being my only option I could just speed match the 2 Alleghenys, but I would like to be able to run either of them together with the other C&O motive power we have on hand.
The only thing is that not only is the DCS completely different than a DCC decoder, MTH also wires the lights completely backwards. So there's a bit more involved than just taking out the electronics and putting in a standard DCC decoder, if you still want the lights to all work. DCC uses a positive common, DCS is all wired negative common.
I don't think there is a problem hitting the top speed on DCC track. On DC though, the MTH locos don't seem to reach top speed until 18V, far in excess of the NMTA standard of 12 volts.
Shades,
One last thought, or a few questions?
How many locos do you have?
Why do you feel it necessary to speed match them all the same?
As explained above, I run all sorts of multi loco lashups in DC with no speed matching.....it works fine.
Safety? "what do you think is going happen?" to quote my 8 year old grandson as he drives the battery powered four wheeler around the swimming pool? Guess what?, nothing bad happened.......
I have 140 powered units on my layout. I can't even imagine trying to speed match them all the same.........