Thread: dc motor/ speed control, from 100 to 1500RPM at spindle

It sounds like a used 4 pole 3 phase motor connected to a budget level Variable Frequency Drive (VFD) would be your cheapest solution.

The VFD is a programmable box of tricks that converts 240 V single phase to 240V 3 phase plus give you full speed control (plus a bunch of other things which could produce some interesting effects for art work.

A 0.5HP motor sounds like it will be more than adequate.

The motor should be able to be configured in ∆ mode (the other mode is "Y" or star) and it usually says this on the motor name plate.
Some of them even say 440/240V on them - in that case it will be a dual ∆/Y motor.

Please bare in mind that fiddling with all this stuff is high risk but at least you might learn enough to talk sensibly to an electrician about it.
There is lots about these motors and configurations thereof in the metal work forum

Hi Bob,

Thank you for your reply.

Yes, I am just after enough information so that I can either contact my motor shop, or more preferably shop on ebay or online somewhere to get a secondhand unit. Just inching towards what exactly is the best motor/parts for the purpose.
And then I will install it into the box and to finish have an electrician wire it all up.

Are you able to provide me with a link for a motor like the one you suggest so that I might know what I am looking at?

I have just looked at variable speed controllers and they seem to start at about $150 then go up.
This might bump up the price out of my reach once I purchase the motor as well.
Perhaps it might be best for me to start my prototype as a single speed or three speed unit before to keep costs down. ( someone has told me three speed motors are cheaper than variable speed)

However re the Speed controllers - I am very interested in the 'other effects' you mentioned. Also, can you program these, so you have three preset speeds and just use those speeds?

Once I build one machine I will be building a few more. Thus need to keep the costs down.

If I simply want a one speed machine or a three speed, which motor would you suggest for about 1400 RPM?

Thanks very much....

Ben

Have a look at Oatley Electronics in Sydney http://secure.oatleyelectronics.com/...acsruced1ekv86
They sell DC variable speed motors and motors for scooters and bikes. Some of their motors have reduction gearboxes and they also sell power supplies.

Good luck with your project.

Alan...

Originally Posted by zongatron

Yes, I am just after enough information so that I can either contact my motor shop, or more preferably shop on ebay or online somewhere to get a secondhand unit. Just inching towards what exactly is the best motor/parts for the purpose. And then I will install it into the box and to finish have an electrician wire it all up.

A good move.

Are you able to provide me with a link for a motor like the one you suggest so that I might know what I am looking at?

I buy all my motors as used motors for relatively low $ (e.g. $30) or pick them up for nothing but I am able to bring along testing gear to make sure that they are OK.
This might not work for you as most electricians would not like working with an old motor.

I have just looked at variable speed controllers and they seem to start at about $150 then go up.

a $150 VFD would be fine.

However re the Speed controllers - I am very interested in the 'other effects' you mentioned. Also, can you program these, so you have three preset speeds and just use those speeds?

These units can be programmed to go up and down, and clockwise and anticlockwise over a wide range of speeds.

I looked a bit longer at the video and realised, what about an old washing machine motor/ They are only single phase but will have more than enough power to do the job and some of these even have several speeds.

I have fever tried it but I believe a VFD can even be used on some types of single phase motors but they must not have a built in start switching circuit.

Hi Ben

Old motors from washing machines are often free, especially at local council kerbside clean up time.