The idea that I had to run two motors in series did not work, they ran erratically. I went back to the parallel configuration and they worked as normal. This is a follow up to a previous post. Robert Brown.
24 volt DCS and 12 volt motors didn't work
machiningfool
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The site is meant to be sharing information, thus we ARE INDEED paying more attention to building trains, to make the information better and easier to find.
Greg
Greg
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I'm only going to say this:
While what Robert did was not proper, it certainly doesn't the excuse the constant badgering in about 2/3rds of the posts on this particular thread (from several people by the way, not just one). Robert made a mistake, he said he won't do it again, what else is there to discuss? I'm not going to butt into personal feuds between individuals, but from someone outside the conversation this thread is riddled with comments from people who don't seem to grasp the concept of forgive and forget.
Robert, I suggest just letting this thread go. Get back to the original thread and continue posting there. I'll be happy to follow the conversation from there.
As for everyone else, can we please just let this issue go? We've all got better things to do with our days than criticize others for minor mistakes. The only thing that makes a forum better is forgiving and forgetting, not by following a mistake with 3 pages of criticism.
As I said, I'm going to leave the conversation there. In the meantime, I'll be enjoying other threads which actually contribute to the forum in a positive way.
--James
While what Robert did was not proper, it certainly doesn't the excuse the constant badgering in about 2/3rds of the posts on this particular thread (from several people by the way, not just one). Robert made a mistake, he said he won't do it again, what else is there to discuss? I'm not going to butt into personal feuds between individuals, but from someone outside the conversation this thread is riddled with comments from people who don't seem to grasp the concept of forgive and forget.
Robert, I suggest just letting this thread go. Get back to the original thread and continue posting there. I'll be happy to follow the conversation from there.
As for everyone else, can we please just let this issue go? We've all got better things to do with our days than criticize others for minor mistakes. The only thing that makes a forum better is forgiving and forgetting, not by following a mistake with 3 pages of criticism.
As I said, I'm going to leave the conversation there. In the meantime, I'll be enjoying other threads which actually contribute to the forum in a positive way.
--James
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Not constant badgering... actually answering questions... if you ask "hey is this good or bad" and you cannot handle the answer, don't ask.
Back to the motors, we all hope the 12 volt motors won't be damaged by the 24 volt electronics... no one wants his motors to melt down.
Also, in the spirit of trying to understand what is happening, are the NWSL motors equipped with a tachometer strip and sensor as the MTH locos are?
Greg
Back to the motors, we all hope the 12 volt motors won't be damaged by the 24 volt electronics... no one wants his motors to melt down.
Also, in the spirit of trying to understand what is happening, are the NWSL motors equipped with a tachometer strip and sensor as the MTH locos are?
Greg
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It is all MTH electronics including the speed sensor. I printed a new striped decal and put it on the NWSL flywheel, and relocated the sensor. I reduced the number of spaces, from 48, 24 white and 24 black, to 20, 10 white and 10 black, because the MTH gear ratio is 10:1 and the NWSL gear ratio is 25:1. Also the wheel size had to be taken into account. F7 has 40" scale wheels and the E8 has 36" scale wheels, so adjusting for both of those variables hence the lesser stripes.
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I'm interested in why your results don't seem to match what most of us predicted.
To be clear, I want to understand, and since I do give a lot of advice, I don't want to give bad advice. So I appreciate you responding to these questions.
So I have gotten a bit confused, the loco that has this "series / parallel" issue, is it the F7 or the E8? I'd also like to know/verify:
1. only one motor per truck, right?
2. both trucks powered?
3. all powered trucks have a tach strip, or is it only one tach per loco?
Many of the MTH installs I've seen internally were steamers, so most only one motor.
Thanks, Greg
To be clear, I want to understand, and since I do give a lot of advice, I don't want to give bad advice. So I appreciate you responding to these questions.
So I have gotten a bit confused, the loco that has this "series / parallel" issue, is it the F7 or the E8? I'd also like to know/verify:
1. only one motor per truck, right?
2. both trucks powered?
3. all powered trucks have a tach strip, or is it only one tach per loco?
Many of the MTH installs I've seen internally were steamers, so most only one motor.
Thanks, Greg
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The loco is an E8, MTH electronics, onboard TIU, battery powered, one motor per truck, both are powered, only one truck has a tach strip, NWSL trucks. The reason I mentioned the F7 is that the original electronics was taken from an MTH F7, different gearing and different wheels. An allowance, "fewer stripes", had to be rendered for the difference of gearing and wheel size, to get a ballpark register of speed. After tonight, I won't be able to answer posts for a month, my brother had a stroke and I am going to Arizona to stay with him. Robert Brown.
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Very sorry to hear about your brother, I hope he recovers quickly, my dad just had one recently and it can be tough.
Thanks for the info on the trains, will chat when you get back.
Regards, Greg
Thanks for the info on the trains, will chat when you get back.
Regards, Greg
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Speed sensor explanation
I am back and thanks for your concern about my brother, the operation was a success and now he has a long road to recovery through therapy. As to the explanation of the number of stripes reduction on the flywheel to get the correct mph speed. Assume that the original MTH motor that is 10 to one gearing, at a speed register of 40 mph, with 48 spaces on the flywheel was changed to the 25 to one gearing and the power to the motor did not change. The speed in mph would still read 40 mph, but the lower gears would slow the actual speed of the loco to say around 12 mph. In this condition, the only way to match the speed in mph would to reduce the number of spaces or stripes on the flywheel to 20 spaces, 10 white and 10 black. This way the readout of mph is reduced to match the lower gear. You said there are some people that do not agree with my explanation, so I would like to hear the argument that they have where they disagree or agree. Now the actual number of stripes mathematically came out to be around 18.7, but I chose 20, because it was easier. Robert Brown---- Since I gave this explanation, I have tested further as explained in the threads to follow on the 4th page, but to more closely link what I did, here it is. To get a more exact reading on the speedometer, I further reduced the stripes to 8 white and 8 black and the result was almost right on. With a 34 foot section of track at 40 mph scale speed the loco should move at 1.833 feet per sec. Divide that into 34 feet and it comes to 18.5 seconds, in a test it timed out to 18 seconds, so the number of stripes is as close as I can get without changing the diameter of the flywheel, and I am not going to do that. The actual scale speed is probably 41 mph. so that is close enough for me, because I don't plan to lash up. I will probably run at half speed, around 50, so I doubt if the voltage difference will be a factor, if it does, I will let you know. NWSL is thinking about producing 24 volt motors possibly, so that will solve any problems that I may have. Robert Brown.
I am back and thanks for your concern about my brother, the operation was a success and now he has a long road to recovery through therapy. As to the explanation of the number of stripes reduction on the flywheel to get the correct mph speed. Assume that the original MTH motor that is 10 to one gearing, at a speed register of 40 mph, with 48 spaces on the flywheel was changed to the 25 to one gearing and the power to the motor did not change. The speed in mph would still read 40 mph, but the lower gears would slow the actual speed of the loco to say around 12 mph. In this condition, the only way to match the speed in mph would to reduce the number of spaces or stripes on the flywheel to 20 spaces, 10 white and 10 black. This way the readout of mph is reduced to match the lower gear. You said there are some people that do not agree with my explanation, so I would like to hear the argument that they have where they disagree or agree. Now the actual number of stripes mathematically came out to be around 18.7, but I chose 20, because it was easier. Robert Brown---- Since I gave this explanation, I have tested further as explained in the threads to follow on the 4th page, but to more closely link what I did, here it is. To get a more exact reading on the speedometer, I further reduced the stripes to 8 white and 8 black and the result was almost right on. With a 34 foot section of track at 40 mph scale speed the loco should move at 1.833 feet per sec. Divide that into 34 feet and it comes to 18.5 seconds, in a test it timed out to 18 seconds, so the number of stripes is as close as I can get without changing the diameter of the flywheel, and I am not going to do that. The actual scale speed is probably 41 mph. so that is close enough for me, because I don't plan to lash up. I will probably run at half speed, around 50, so I doubt if the voltage difference will be a factor, if it does, I will let you know. NWSL is thinking about producing 24 volt motors possibly, so that will solve any problems that I may have. Robert Brown.
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As far as I know, you correctly compensated for the change in gear ratio, exactly as you have explained.
Bear in mind that wheel diameter also needs to be factored in. Are the original wheels and the wheels on the new motor block the same diameter?
The tachometer drive is a nice feature of MTH, it allows for precise calibration of speed, such that different locos will all run at the same physical speed for the same throttle setting.
Greg
Bear in mind that wheel diameter also needs to be factored in. Are the original wheels and the wheels on the new motor block the same diameter?
The tachometer drive is a nice feature of MTH, it allows for precise calibration of speed, such that different locos will all run at the same physical speed for the same throttle setting.
Greg
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Correct number of stripes for MTH/NWSL trucks sensor
I set up a test for the speed sensor in My E8, and here is what I found out. I had to reduce the number of stripes wrapped around the flywheel to 8 white and 8 black. It read correctly at 40 scale mph. Here is how I did it. At 40 mph readout, the loco. travels at 1.833 ft. per sec. My track circle is 34 feet, so it should take 18.5 seconds to travel that distance. It took 18 seconds, so the real speed is around 41 scaled mph, but that is as close as I can get. This test was for MTH electronics, NWSL 3 axle truck, 1:32., So there you go. Robert Brown
I set up a test for the speed sensor in My E8, and here is what I found out. I had to reduce the number of stripes wrapped around the flywheel to 8 white and 8 black. It read correctly at 40 scale mph. Here is how I did it. At 40 mph readout, the loco. travels at 1.833 ft. per sec. My track circle is 34 feet, so it should take 18.5 seconds to travel that distance. It took 18 seconds, so the real speed is around 41 scaled mph, but that is as close as I can get. This test was for MTH electronics, NWSL 3 axle truck, 1:32., So there you go. Robert Brown
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I'd say that was **** good... very few people other than Raymond Manley venture that far (and succeed).
Regards, Greg
Regards, Greg
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MTH one gauge motors are 12 Volt not 24 volt.
After all of this worry about MTH electronics applying 24 volts to the locomotive motors, was unnecessary. The supply to the TIU is 24 volts, but the processor in the loco, supplies 0 to 12 volts depending on the speed that you desire, so my NWSL motors are completely compatible with the MTH power. This info. was obtained from an MTH tech. named Jeffery, he gave me permission to use his name. After all of this discussion about the voltage applied variably or sustained it turns out that that voltage is variable controlled by the speed controller, 0 to 12, in the loco. Robert Brown.
After all of this worry about MTH electronics applying 24 volts to the locomotive motors, was unnecessary. The supply to the TIU is 24 volts, but the processor in the loco, supplies 0 to 12 volts depending on the speed that you desire, so my NWSL motors are completely compatible with the MTH power. This info. was obtained from an MTH tech. named Jeffery, he gave me permission to use his name. After all of this discussion about the voltage applied variably or sustained it turns out that that voltage is variable controlled by the speed controller, 0 to 12, in the loco. Robert Brown.
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Overvoltage to your train motors will not be a problem. Here's why:
You regulate the speed of the loco by varying the voltage to the motors. If your loco contains 12v motors, when you dial up the voltage to 12, the train will be running REAL FAST, so you won't exceed the designed voltage anyhow.
Ok, you can take this to extreme and try to run it on pulses so high as to arc the commutator and destroy the motor with 4KV pulses though the average voltage is 9, but with any reasonable train equipment, that's not going to happen.
You regulate the speed of the loco by varying the voltage to the motors. If your loco contains 12v motors, when you dial up the voltage to 12, the train will be running REAL FAST, so you won't exceed the designed voltage anyhow.
Ok, you can take this to extreme and try to run it on pulses so high as to arc the commutator and destroy the motor with 4KV pulses though the average voltage is 9, but with any reasonable train equipment, that's not going to happen.
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OK, originally the consensus was that MTH had 24 volt motors in their locos, that is not the case. The motors are 12 volt just like my NWSL motors, so you are correct, there is not a problem.
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Well, I doubt that the motors get 0-12 volts, but they are pulse width modulated with full track voltage minus about a volt or 2.
I'd have to get someone to put a scope on the motor outputs.
Having analog DC voltage control takes BIG transistors and BIG heat sinks, neither of which I see on the MTH circuit board.
Many people put a volt meter on the output, and the meter averages the pulses, just like the motors do. They will swear that it is 0 to 12 volts all the way to the grave.
The definitive answer is a scope on the motor output.
The motors may indeed be 12 volt, and capable of handling the 24 volt pulses, but at full speed they should get track voltage.
I'd like Jeffery to tell me that there is a 12 volt regulator or limiter in the MTH decoder electronics... and that it is NOT a pulse width modulated circuit... ask him these questions.
read this thread, Ted Hikel states that the MTH motor drive system is PWM, which means variable pulses of FULL track voltage.
Greg
I'd have to get someone to put a scope on the motor outputs.
Having analog DC voltage control takes BIG transistors and BIG heat sinks, neither of which I see on the MTH circuit board.
Many people put a volt meter on the output, and the meter averages the pulses, just like the motors do. They will swear that it is 0 to 12 volts all the way to the grave.
The definitive answer is a scope on the motor output.
The motors may indeed be 12 volt, and capable of handling the 24 volt pulses, but at full speed they should get track voltage.
I'd like Jeffery to tell me that there is a 12 volt regulator or limiter in the MTH decoder electronics... and that it is NOT a pulse width modulated circuit... ask him these questions.
read this thread, Ted Hikel states that the MTH motor drive system is PWM, which means variable pulses of FULL track voltage.
Greg
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Well, I did just that last night. At around 60 mph, my volt meter was reading 12 volts and the motors sounded like they were going to explode. The loco was a stock F3 one gauge. I don't think that they are supposed to go faster than 60. Thanks for your input Greg.
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No problem, as I said, the motor and your voltmeter will average those full track voltage pulses to something lower.
Many times the motors can handle it... in early times some manufacturers warned against "pulse power", but more recently manufacturers have put integral fans and cooling slots in the motors to shed heat.
A lot of motors are essentially 18v motors and seem to work ok.
Regards, Greg
Many times the motors can handle it... in early times some manufacturers warned against "pulse power", but more recently manufacturers have put integral fans and cooling slots in the motors to shed heat.
A lot of motors are essentially 18v motors and seem to work ok.
Regards, Greg
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Thanks again for your knowledge. I know now that at 60 mph it will be putting out 12volts, so that is as high that I would run my loco anyway. Robert Brown.
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One last tip, if you can touch the motor after a "hard run" you can basically tell if you are working it too hard.
Harbor Freight also has those "temperature guns" for cheap on sale, so you can test without grabbing and picking up the loco.
http://www.harborfreight.com/infrared-thermometer-93984.html
Basically, motors are damaged if they heat up so much that the insulation on the motor windings fails, it's a very thin enamel coating, and if it melts, then the adjacent coils short, altering the characteristics of the motor, drawing more current, making it less efficient and creating in turn more heat. Turns into a vicious cycle. There are other failure modes, but this is the primary one.
Regards, Greg
Harbor Freight also has those "temperature guns" for cheap on sale, so you can test without grabbing and picking up the loco.
http://www.harborfreight.com/infrared-thermometer-93984.html
Basically, motors are damaged if they heat up so much that the insulation on the motor windings fails, it's a very thin enamel coating, and if it melts, then the adjacent coils short, altering the characteristics of the motor, drawing more current, making it less efficient and creating in turn more heat. Turns into a vicious cycle. There are other failure modes, but this is the primary one.
Regards, Greg
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