A cheap source of DC motors?

[RainbowsParticipant @rainbows]

[RainbowsParticipant @rainbows]

With the fresh knoledge of how to use a rectifier to power a DC motor off mains and a wish to have infinitely variable speed I was wondering if anyone knew a good place to get cheap DC motors of the ~1/4 HP variety.

The scrapyard, my tried and trusted source of motors, only has AC ones. New from the internet runs in the £200 range. I last checked treadmill motors but they only come in 1hp or above and would rather not have the adept I intend to power flying across the room and making a hole in the wall if the tool digs in.

I think 150 – 250W would be the minimum and maximum power values.

[Brian OldfordParticipant @brianoldford70365]

I think even 1/4hp may be a bit OTT for an Adept . Have you considered a sewing machine motor along with its usual foot control?

http://www.ebay.co.uk/itm/YDK-SEWING-MACHINE-MOTOR-AND-FOOT-CONTROL-PEDAL-LEAD-NEW-SINGER-BROTHER-NEWHOME-/350714545662?pt=LH_DefaultDomain_3&hash=item51a83745fe

f'rinstance

[John Stevenson 1Participant @johnstevenson1]

" fresh knoledge of how to use a rectifier to power a DC motor off mains"

Home made arc furnaces.

110 volt drills on mains ?

Is it just me or is anyone else wondering what his post code is so they can move at least three counties over ?

[Les Jones 1Participant @lesjones1]

Hi John,
I am definitely avoiding attempting to give any advice in this case.

Les.

[RainbowsParticipant @rainbows]

Hey now, those other two projects used AC and only one was out of the ordinary.

The current set up is a sewing machine motor connected directly by belt. I have a countershaft I got from the scrapyard which would give a better speed but I was waiting to see if any better motors were available first. I think it is the exact same model as that ebay in fact. However I am not a fan of foot pedals. It is difficult ot keep a standard speed, it is uncomfortable to use for extended periods and I think one day the footpedal will burn through the floor with how hot it can get.

90W does work but if I could get some more power I would take it. Any idea how much power a treadle makes? The original adepts would attach to them. I would like to think my foot makes a tad more than 90w.

[John Stevenson 1Participant @johnstevenson1]

Posted by Rainbows on 17/05/2015 17:51:55:

I would like to think my foot makes a tad more than 90w.

.

It definitely would if you were running away from something on fire or exploding.

[Bob Brown 1Participant @bobbrown1]

So what is wrong with a scooter motor?

250 watt about £30.00 and a speed controller add £15.00 (fleabay)

Bob

[Neil WyattModerator @neilwyatt]

Well the world record cycling hour record holder managed about 300 watts over the hour so I very much doubt you can approach a constant 90W with one leg.

The difference between you and a motor, of course, is that you produce the maximum torque at lower speeds (which is why cyclists use gears to keep their cadence down) stop when the going gets harder you don't stop, you just slow down.

Neil

[MuzzerParticipant @muzzer]

Hate to point out that treadmills run from rectified mains….

Looks as if they are typically around the 2HP mark, brushed and fairly compact with a speed control. Might make a nice drive for a machine tool if you had one kicking about, although a sewing machine motor is probably closer to what you need.

[RainbowsParticipant @rainbows]

Posted by Bob Brown 1 on 17/05/2015 18:27:41:

So what is wrong with a scooter motor?

250 watt about £30.00 and a speed controller add £15.00 (fleabay)

Bob

Someone give this man a medal

 

Gonna go for a smaller 120w for £14 since there appears to be a agreement that smaller is better here. 

Edited By Rainbows on 17/05/2015 19:11:32

[MuzzerParticipant @muzzer]

You perhaps need to convince yourself it will still be running a month or two down the line. Some of these scooter parts are rather ropey. In contrast, commercial grade sewing machines seem more likely to display some degree of longevity.

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