Trying to create rotating device/minimum speed. Could use some advice!

[schizotypal_boy]

Hi there..

So, I know pretty much nothing about electronics but have been trying to create a device that will rotate a painting, as slowly as actually possible..

I picked up one of these http://www.mfacomodrills.com/gearboxes/918d_series.html (918D1001ME) Ideally, I would have a motor this size, that could have it's speed regulated by something like this: http://www.maplin.co.uk/panel-mounte...r-module-30310 but due to the voltages not being compatible, this seems not possible. One person mentioned buffering the circuit with a transistor but I tried to look into that and it seems way beyond me! Am I right in thinking I can use the speed regulator with this motor, and it would be possible to slow it down as slow as it can go? http://www.maplin.co.uk/large-single...earboxes-43368 (148:1 Lge Gear Box)

I would hugely appreciate any thoughts, ideas, links regarding this.. I literally want to fix a motor to the back of a 50 x 50cm painting and have it rotate counter clockwise at minimum possible speed.. and I don't have much time left! :S

Thanks for reading and I look forward to hopefully a simple solution!

C.

 

[Harald Kapp]

http://www.maplin.co.uk/panel-mounte...r-module-30310 -> HTTP 400

What are the ratings of the motor you use (Volts, Amps, RPM)? Which gearbox do you use (there are quite a few different ones on the page you linked)?

You can always just try at which voltage the gearbox spins at a rate suitable to you. Adjust the voltage with an adjustable power supply (or, less elegant, use series resistors to that purpose). Once you know the right combination of voltage and/or series resistor you can find (or build) the matching power supply for your project.

Harald

 

[schizotypal_boy]

Thanks for your reply.. Strange, the links from Maplins that I provided doesn't seem to route back to the page I copied the link from..

I did try putting a resistor between the triple A battery pack and the motor, and it reduced the voltage from 1.5 to 0.8v, but I need it slower still.. I tried to attach another resistor so that there would be two which I thought potentially would reduce it a further 0.7v to 0.1v I guess, but nothing happened.. As I mentioned before, I am a complete novice and have very little idea what I'm doing..

this is the speed regulator I mentioned, in any case: http://www.ebay.co.uk/itm/PANEL-MOU..._Control_ET&hash=item4ab5201f97#ht_2392wt_983

The motor I have is 918D1001/1 (1.5v - 3v) WITH RE 280 MOTOR (RATIO 100:1). 4mm SHAFT

and the larger one I mentioned is 950D1481 (4.5v - 15v) WITH RE 385 MOTOR. RATIO 148:1

 

[Laplace]

Does it need to be an electrical solution? Maybe you could add some more gears to the gear motor. Or add some pulleys to reduce the speed. How about a disk of quarter-inch plywood where the wood edge has been routed in the fashion of a pulley, attached to the back of the painting, and the other smaller drive wheel is put on the shaft of the gear motor? That could easily give another 20:1 speed reduction.

 

[Harald Kapp]

I too think a mechanical solution will be the better option. If you reduce the power to the motor too much, it will not start, as you have observed. You need a certain minimum power and with that comes a minimum speed of the motor.

By mechanically reducing the speed you gain two advantages:
1) you don't waste power in a series resistor - your battery will last longer.
2) you have more torque available

Harald

 

[schizotypal_boy]

thanks for all your advice.. I will certainly take note and give the mechanical option a whirl.. I think I need it to go about 1 rotation per minute..

 

[duke37]

You could consider intermittent operation, say 1 second every 10 seconds.

 

[thor]

Sorry guys I have nothing to share, just new here and tying to learn my ropes. But your idea of a rotating painting is really cool. Goodluck!