AC motors

[GDRMCo]

does anyone know where to get AC motors for modeling. I want to convert my SD70MAC into a real AC locomotive.

[GDRMCo]

does anyone know where to get AC motors for modeling. I want to convert my SD70MAC into a real AC locomotive.

[Anonymous]

I see you live in AU, so before I can answer that I need to know if the water swirls clockwise or anticlockwise in your toliet?

[Anonymous]

I see you live in AU, so before I can answer that I need to know if the water swirls clockwise or anticlockwise in your toliet?

[Anonymous]

QUOTE: Originally posted by GDRMCo

does anyone know where to get AC motors for modeling. I want to convert my SD70MAC into a real AC locomotive.

Why would you want to do that?

[Anonymous]

QUOTE: Originally posted by GDRMCo

does anyone know where to get AC motors for modeling. I want to convert my SD70MAC into a real AC locomotive.

Why would you want to do that?

[GDRMCo]

flee307: the toilet water does not go clockwise or anticlockwise, it flushes.
billkamery: my DCC system like everyone elses uses AC. the locomotive picks it up and the decoder sends it indirectly to the motor by making the AC more like DC. i want to find a way to make my decoders supply the AC directly as AC. the motors would be mounted on the axles and that would leave room for sound systems and interiors. i want to have a sound system in my SD70MAC but superdetail it and make the side doors open revealing a veiw of the inside fully mdeled interior.

[GDRMCo]

flee307: the toilet water does not go clockwise or anticlockwise, it flushes.
billkamery: my DCC system like everyone elses uses AC. the locomotive picks it up and the decoder sends it indirectly to the motor by making the AC more like DC. i want to find a way to make my decoders supply the AC directly as AC. the motors would be mounted on the axles and that would leave room for sound systems and interiors. i want to have a sound system in my SD70MAC but superdetail it and make the side doors open revealing a veiw of the inside fully mdeled interior.

[Anonymous]

The way you decribe dcc and ac is incorrect. Most past and current DCC stations will run on 16 VAC or 18 VDC. The DCC station converts the AC or DC to pulsed DC and the decoders apply a chopped section of this pulse to the motor as pulsed DC as told to it by the signal which is multiplexed on the line with the pulsed DC.

[Anonymous]

The way you decribe dcc and ac is incorrect. Most past and current DCC stations will run on 16 VAC or 18 VDC. The DCC station converts the AC or DC to pulsed DC and the decoders apply a chopped section of this pulse to the motor as pulsed DC as told to it by the signal which is multiplexed on the line with the pulsed DC.

[Anonymous]

ive been it the indusrial electric motor repair business for 15 yrs...ac motors run at a constant speed depending on how they are manufactured...typically 900,1800, or 3600 rpm constant.....dc motors are designed to change speed by vaying the voltage to them...ac motors can only tolerate a 10% variation in rated voltage...plus this does nothing to change its speed...(unless u let it run to long this way and then it will burn up and stop..speed change accomplished)....aside from attaching a gearbox to ur ac motor....dc is the only way to go..its used in rc cars, boats,trains of all sizes....scott

[Anonymous]

ive been it the indusrial electric motor repair business for 15 yrs...ac motors run at a constant speed depending on how they are manufactured...typically 900,1800, or 3600 rpm constant.....dc motors are designed to change speed by vaying the voltage to them...ac motors can only tolerate a 10% variation in rated voltage...plus this does nothing to change its speed...(unless u let it run to long this way and then it will burn up and stop..speed change accomplished)....aside from attaching a gearbox to ur ac motor....dc is the only way to go..its used in rc cars, boats,trains of all sizes....scott

[GDRMCo]

Ive done it before with the motors mounted on the axles but forgot which company made the motors.

[GDRMCo]

Ive done it before with the motors mounted on the axles but forgot which company made the motors.

[Anonymous]

Don't do this.

Seriously, fitting motors inside the trucks will result in very odd gearing, possible problems with synchronising the motors, etc, etc. In the UK we've only just started to get away from truck-mounted mechanisms and into decent US-style drive systems, There is little or no space for the gearing you will need to avoid problems with slow running and excessive top speeds. Also, I find it hard to believe that axle-mounted motors (In HO scale anyway) would be able to generate enough torque to move a decent length train. I'm also a little puzzled as to why you would want to model the interior - to the best of my knowledge locos never run with their side doors open, and a static "loco under repair" could be better represented with a cheap dummy loco.

[Anonymous]

Don't do this.

Seriously, fitting motors inside the trucks will result in very odd gearing, possible problems with synchronising the motors, etc, etc. In the UK we've only just started to get away from truck-mounted mechanisms and into decent US-style drive systems, There is little or no space for the gearing you will need to avoid problems with slow running and excessive top speeds. Also, I find it hard to believe that axle-mounted motors (In HO scale anyway) would be able to generate enough torque to move a decent length train. I'm also a little puzzled as to why you would want to model the interior - to the best of my knowledge locos never run with their side doors open, and a static "loco under repair" could be better represented with a cheap dummy loco.

[Anonymous]

slossmo says, "ive been it the indusrial electric motor repair business for 15 yrs...ac motors run at a constant speed depending on how they are manufactured...typically 900,1800, or 3600 rpm constant....."

That's not true, brushed AC motors have been used for years to power among other things sewing machines. I know that they will run from almost 0 rpm to well over 10,000 rpm depening on the voltage being sent by the footpedal which is just a big resistor. We also have frequency controlles on our three phase motors and they will run from near zero to max rating or anywhere between. What about ceiling fans, they have 3 speeds built in ususally and also can be speed up and slowed down with a motor "dimmer switch" . They are AC inductive motors. Todays state of the art locos use AC traction motors and they seem to be able to run different speeds without burning up. The only reason they used DC traction motors for years was know one could figure out how to make an AC controller big enough to control the current required to run 4000 hp locomotives. So what's the deal with your statement?

[Anonymous]

slossmo says, "ive been it the indusrial electric motor repair business for 15 yrs...ac motors run at a constant speed depending on how they are manufactured...typically 900,1800, or 3600 rpm constant....."

That's not true, brushed AC motors have been used for years to power among other things sewing machines. I know that they will run from almost 0 rpm to well over 10,000 rpm depening on the voltage being sent by the footpedal which is just a big resistor. We also have frequency controlles on our three phase motors and they will run from near zero to max rating or anywhere between. What about ceiling fans, they have 3 speeds built in ususally and also can be speed up and slowed down with a motor "dimmer switch" . They are AC inductive motors. Todays state of the art locos use AC traction motors and they seem to be able to run different speeds without burning up. The only reason they used DC traction motors for years was know one could figure out how to make an AC controller big enough to control the current required to run 4000 hp locomotives. So what's the deal with your statement?

[Anonymous]

Not to mention the obvious. Marklin & Lionel AC.

However, the track voltage for DCC is actually pulsed DC, not AC, and an inverter is big & heavy.

[Anonymous]

Not to mention the obvious. Marklin & Lionel AC.

However, the track voltage for DCC is actually pulsed DC, not AC, and an inverter is big & heavy.

[dknelson]

I seem to recall that years and years ago American Flyer had some HO which might have been AC. That was back when DC motors were usually 6 volt. Before my time actually.
Anyway as to mounting motors on the axles that should work and there was a product called the SPUD which could do this. It was a small DC motor with, I think, the axle shaft also part of the motor shaft.
That way for example a tunnel motor could actually have a see-through rear vent, and trolleys could have detailed interiors. But if each axle was a motor I do not know about current draw and frankly I do not know if I ever saw an article on converting SPUDs to DCC for that matter.
Dave Nelson

[dknelson]

I seem to recall that years and years ago American Flyer had some HO which might have been AC. That was back when DC motors were usually 6 volt. Before my time actually.
Anyway as to mounting motors on the axles that should work and there was a product called the SPUD which could do this. It was a small DC motor with, I think, the axle shaft also part of the motor shaft.
That way for example a tunnel motor could actually have a see-through rear vent, and trolleys could have detailed interiors. But if each axle was a motor I do not know about current draw and frankly I do not know if I ever saw an article on converting SPUDs to DCC for that matter.
Dave Nelson

[Anonymous]

see the digitrax web site appnote at http://www.digitrax.com/faqdt.htm

DCC is AC data pulses, the decoder has a rectifier and pulse modulator to convert the AC data packets to controlled DC pulses for the motor. If AC is applied directly to an AC motor, it could not run in reverse unless the field winding is reversed; DC motors use permanent magnets instead so they can be made smaller. Also the drive gearing allows a lot more low speed torque to be applied to the wheels with the motor running at a higher speed, kinda like first gear in a car. Direct drive would lose all this torque.

I had an American Flyer S scale as a kid, it must have been AC powered since to reverse one had to fully stop the train, then apply power again to cause a stepping relay in the tender to swap field winding polarity. Then re-apply power to run in reverse; repeating the sequence would set it to forward again. That was in the days before silicon diodes were available and the usual selenium type rectifier had way too much resistance for low voltage, so AC and a variable turns ratio transformer was the only way to go other than batteries and rheostat. But they still geared the motor down.

PS Mine all swirl counterclockwise. Is that correct for the Northern hemisphere? If not that Coriolis force thing just got debunked.

[Anonymous]

see the digitrax web site appnote at http://www.digitrax.com/faqdt.htm

DCC is AC data pulses, the decoder has a rectifier and pulse modulator to convert the AC data packets to controlled DC pulses for the motor. If AC is applied directly to an AC motor, it could not run in reverse unless the field winding is reversed; DC motors use permanent magnets instead so they can be made smaller. Also the drive gearing allows a lot more low speed torque to be applied to the wheels with the motor running at a higher speed, kinda like first gear in a car. Direct drive would lose all this torque.

I had an American Flyer S scale as a kid, it must have been AC powered since to reverse one had to fully stop the train, then apply power again to cause a stepping relay in the tender to swap field winding polarity. Then re-apply power to run in reverse; repeating the sequence would set it to forward again. That was in the days before silicon diodes were available and the usual selenium type rectifier had way too much resistance for low voltage, so AC and a variable turns ratio transformer was the only way to go other than batteries and rheostat. But they still geared the motor down.

PS Mine all swirl counterclockwise. Is that correct for the Northern hemisphere? If not that Coriolis force thing just got debunked.

[Anonymous]

AC is a sign wave. DCC is pulsed DC that has a positive and negative component that is phase shifted. It's like a pulsed DC power pack that has pos and neg leads and ground. The pos is +12v from ground, the neg is -12v from ground, and they are 24v apart from each other. But they are still DC.

[Anonymous]

AC is a sign wave. DCC is pulsed DC that has a positive and negative component that is phase shifted. It's like a pulsed DC power pack that has pos and neg leads and ground. The pos is +12v from ground, the neg is -12v from ground, and they are 24v apart from each other. But they are still DC.

[timmatthews]

Maybe someday the makers of model trains will incorporate Alternating Current type motors into our "toys". The technology to control their speed/torque does exist (I've been working with it for 20 years) but I've yet to hear of it in model trains.

If more than one motor were to be fitted into each loco, synchronization should not be a problem. AC motor speed can be regulated by utilizing "variable frequency control". If all motors are running from the same current source they will be synchronized.

Keep wishing for that to come about. No more brushes!

[timmatthews]

Maybe someday the makers of model trains will incorporate Alternating Current type motors into our "toys". The technology to control their speed/torque does exist (I've been working with it for 20 years) but I've yet to hear of it in model trains.

If more than one motor were to be fitted into each loco, synchronization should not be a problem. AC motor speed can be regulated by utilizing "variable frequency control". If all motors are running from the same current source they will be synchronized.

Keep wishing for that to come about. No more brushes!

[Anonymous]

Brush problems? Do you really have brush problems? I have never replaced a set to date.

[Anonymous]

Brush problems? Do you really have brush problems? I have never replaced a set to date.