Myford var speed dc motor

[Robin teslarParticipant @robinteslar]

Hi Myfordians

I want to warn all of you about the cheap dpdt far east switch offered as a reversing switch. Dont use these, they are nasty, intermittent contacts, detent mechanism fails, wasted a lot of my time

Whilst recovering, I read up posts about VFD drives etc and of course you pay ca £500 for a replacement (1/2hp Crompton), more than my old ml7 cost me. So I was looking at an old but serviceable scooter (rascal built for vietnam vets in the usa). Its tough stuff and the motor can put out 1hp continuous @24vdc – variable speed, but it only cost me £50 and its all working, so I was going to try it out on my ml7. Power supply up to 36vdc 40A = 2HP short bursts (does have a high temp cutout) ut that might bend my bed.

What Im saying is that given the cost and Electrical interference, this should be a worthy opponent

An alternative, while Im musing the scots fiasco, hope they dont believe that deceitful liar, there's also a large amount of e-bike kit that can serve as var speed motive power, these are stepper motor types but i would worry about the minute torque changes affecting turning quality?

Not to be confused with pm motors as above.

[Robin teslarParticipant @robinteslar]

using old mobility scooter parts

[John HaineParticipant @johnhaine32865]

I'm, what do you mean by stepper motor type? Steppers have rather low torque for their size. Can you provide a link? Another interesting option would be a car alternator driven by a 3 phase brushless motor driver, with the rotor energised by direct current. Quite a lot of details on the web about this.

[blowlampParticipant @blowlamp]

Posted by Robin teslar on 18/09/2014 19:43:15:

Hi Myfordians

I want to warn all of you about the cheap dpdt far east switch offered as a reversing switch. Dont use these, they are nasty, intermittent contacts, detent mechanism fails, wasted a lot of my time

Whilst recovering, I read up posts about VFD drives etc and of course you pay ca £500 for a replacement (1/2hp Crompton), more than my old ml7 cost me. So I was looking at an old but serviceable scooter (rascal built for vietnam vets in the usa). Its tough stuff and the motor can put out 1hp continuous @24vdc – variable speed, but it only cost me £50 and its all working, so I was going to try it out on my ml7. Power supply up to 36vdc 40A = 2HP short bursts (does have a high temp cutout) ut that might bend my bed.

What Im saying is that given the cost and Electrical interference, this should be a worthy opponent

An alternative, while Im musing the scots fiasco, hope they dont believe that deceitful liar, there's also a large amount of e-bike kit that can serve as var speed motive power, these are stepper motor types but i would worry about the minute torque changes affecting turning quality?

Not to be confused with pm motors as above.

Which one?

Martin.

[Harry WilkesParticipant @harrywilkes58467]

Posted by Robin teslar on 18/09/2014 19:43:15:

Hi Myfordians

I want to warn all of you about the cheap dpdt far east switch offered as a reversing switch. Dont use these, they are nasty, intermittent contacts, detent mechanism fails, wasted a lot of my time

Whilst recovering, I read up posts about VFD drives etc and of course you pay ca £500 for a replacement (1/2hp Crompton), more than my old ml7 cost me. So I was looking at an old but serviceable scooter (rascal built for vietnam vets in the usa). Its tough stuff and the motor can put out 1hp continuous @24vdc – variable speed, but it only cost me £50 and its all working, so I was going to try it out on my ml7. Power supply up to 36vdc 40A = 2HP short bursts (does have a high temp cutout) ut that might bend my bed.

What Im saying is that given the cost and Electrical interference, this should be a worthy opponent

An alternative, while Im musing the scots fiasco, hope they dont believe that deceitful liar, there's also a large amount of e-bike kit that can serve as var speed motive power, these are stepper motor types but i would worry about the minute torque changes affecting turning quality?

Not to be confused with pm motors as above.

You have to speak as you find asuming were are talking about the same switch imported from China via ebay for around £12 well I had mine on my S7 for around 18 months without problems.

[oldveloParticipant @oldvelo]

Hi Robin

The "Heavy Duty" Electric Bike controller is probably capable of driving your 24 volt DC motor.

They rely on the bike moving for cooling son a fan would be necessary.

Be aware that 750 watts @ 24 volts DC = 32 AMPS current so the wiring will need to be adequate.

My workshop machine run on 180 volts DC from a 230 volt AC speed control converter.

This gives excellent constant speed control down to 5% of top speed.

VFD speed control is another excellent alternative lots of info @

http://www.powercapacitors.co.uk/products/transwave-converters/

E ric

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