Thread: power drive

Hi Mike,

I would definitely go a DC motor so you can easily have variable speed via a PWM speed controller. Maybe look at one from oately electronics. Also one with an integral reduction gearbox so that you don't have to slow it down too too much with the speed controller and it will also gain some extra torque too.

I would look at maybe a 100 - 150W motor in a 24 or 36 volt DC motor. The reason I would go 24 or 36V over a 12V motor is because it will draw less current for the same power. A 240V - 36V transformer @ 4Amps (144VA) will be easier to get and less expense than a 12V transformer @ 12Amps.

Also since these motors are extensively used in electric bicycles and scooters, they are readily available and the controllers are dirt cheap.

My 2 cents worth!

Cheers,

Simon

Hi Simon

Yes 24V was what I was thinking of . A friend of mine supplies me with near new 12v gel cell batteries that his work chucks out . They are backup power at a ABC transmitter site and replaced every 6 months . Two of them in series would be ideal .

I don't like mains power supplies from a safety aspect and the intermittent use the thing would get means batteries would last for ages .

I will have to keep my eyes open for a old scooter motor . MIKE

HI,
I actually done some Research recently after reading through this https://www.woodworkforums.com/f65/mo...-mills-117064/ . I found this Motor and Gearbox not that Cheap though Titan 90mm 90 Watt Geared Electric Reversible Motor, Available with Terminal Box, Single Phase 220-240 Volt AC, Replaces SPG and Oriental . I have not priced them through this mob, but maybe they might be Cheaper SPG .

I just came across this Weblink http://bbs.homeshopmachinist.net/showthread.php?t=34117

"Motorised head for HM-48, HM-46 and HM-45 mills"
This is my thread on doing exactly this on my HM-45.
I went through all the options and settled on a 115VDC motor off US Ebay as I couldn't find anything suitable in 24V,at the time. It might be different now...
I'm an electrician, so it was relatively easy to step down 240VAC to 115V ish and rectify and smooth it.
I used toothed belt drive so I could changes speeds easily without having to use a PWM speed control.( KISS principle)
It works very well.
I will be interested to see how you do it.

Sterob

Hi Mike,
What about a 12V cordless drill? As for a power supply
(is you arent going to run it off batteries) and old pc power supply should do it.

I believe you can reverse starter motors if you really wanted that much power.

Stuart

ta for that link :

I downloaded the yahoo group plans ... looks interesting . MIKE

Good idea Stuart .... I do have a old cordless drill around somewhere . They are torquey as well , I have seen people use them to start stationary engines .

Some lateral thinking required !

Hi Mike,

One thing I forgot to mention, if you decide to use a 24V motor, another option other than the use of batteries is to buy a pond pump. A 24V 105VA pond pump would be quite cost effective. All there would be left to do would be to run it through a bridge rectifier and perhaps a couple of largish smoothing caps. Some pond pumps are even IP rated so no need to worry about coolant or other stuff.

Cheers,

Simon

Would this motor be suitable for my needs ? MIKE


12 volt dc 160 watt electric motor/gearbox drive 12 mil output shaft | eBay

Originally Posted by morrisman

Would this motor be suitable for my needs ? MIKE


12 volt dc 160 watt electric motor/gearbox drive 12 mil output shaft | eBay

I think the high current of this motor (16A?) would make this problematic to use.( switching high DC currents the most obvious.) That is the reason I went for a higher voltage motor ( to keep the current at more manageable levels )

I can't remember the figures now, but I worked out what speeds I needed to achieve certain head travel speeds and used that as a guide to choosing the gear motor output speed I wanted.
Too slow will be a bit annoying and too fast will be too hard to stop at desired points.
Hope this helps.
Sterob

Hi Sterob

I wonder if using a car headlight relay would work to switch the high current - it works out at 13 amps with that particular motor .

PWM 30 amp boards are available very cheap on ebay .... but not reversable I think.

PWM is the way to go for speed control

MIKE

Hi Mike
Have you thought about using the motor from electric windows in most cars these days?

Roger

Originally Posted by rogerbaker

Hi Mike
Have you thought about using the motor from electric windows in most cars these days?

Roger

Yes thats a possible way to go....

Originally Posted by morrisman

Hi Sterob

I wonder if using a car headlight relay would work to switch the high current - it works out at 13 amps with that particular motor .

PWM 30 amp boards are available very cheap on ebay .... but not reversable I think.

PWM is the way to go for speed control

MIKE

You can always reverse the motor with a DPDT switch after the speed. Controller,.

Simon

Originally Posted by simonl

You can always reverse the motor with a DPDT switch after the speed. Controller,.

Simon

yeah that's true ...........MIKE