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DIY motor and motor pwm speed controller how ?
  • I want to build a speed controlled motor for slider or/and product turn table ...

    I need to find information on about what motor can work 0.1 to 10 rpm (or more) with at least 7.2V (Sony npf battery) and to be strong in order to rotate or move at least 5-10 weight ... This should be with PWM controllable speed motor ... Found some speed controllers on eBay but don't know what motor to choose. Any suggestion is welcome ...

  • 27 Replies sorted by
  • @Feha, I could be wrong but I don't think you will get a motor to do 0.1 rpm, I think you will need to gear it, for torquey motors look at those used in Rock Climbing Radio controlled cars.

  • A stepper motor will do 0.1-10 rpm without gears. Though the motion might not be smooth enough. Some controllers support "micro-stepping" which should alleviate that. Haven't tried that though.

    I 've recently controlled stepper (and DC) motors by Arduino + SeeedStudio motor driver: http://www.seeedstudio.com/wiki/Grove_-_I2C_Motor_Driver_V1.2

  • A stepper motor will be your best best for slow speeds and accuracy, You can also control the exact positions that they move to and build programs with the right systems as suggested above.

    However for a very rough solution by using standard DC motors, MFA COMO motors have very highly geared motors, up to 3000:1 with loads of torque http://www.mfacomodrills.com/gearboxes/gearboxes.html with a variable voltage supply you can get the speed on it down to 0.1 rpm I'd imagine with plenty of torque still, maybe around 1-2v at 3000:1

    I have a 6:1 geared version of the 540 size and that has quite a bit of torque so I'm sure the 3000:1 will have more than enough to spin upwards of 5kg as long as the bearings are smooth on your setup.

    Let me know if you need anymore help. I will do my best, if you choose to go down the DC motor route I have some experience in setting up DIY remote controlled system (I have developed a remote wire dolly with circuit boards and all the rest). But I don't know much about Stepper motors, looks like dtr may be able to help you more with that as I do believe it would give you the most future proof system.

  • @dtr, @FilmCat, @kavadni thank you. I was checking this controller: http://www.ebay.ie/itm/330742041947 But the missing is "Reversible" that could be fixed by external switch i think by reversing a polarity ... but what DC motor could work with this one ?

    Arduino controller would be great but i do have limited knowledge about this, however it is very interesting and i may need to put some effort on learning how this works.

  • Reversing polarity of the input voltage on that board doesn't seem like a very good idea. The board's components are powered by it too...

  • You might want to try endless RC Servo motors (DIY mod a cheapo servo or buy for 10$ from ebay -> 15KG Spring RC SM-S4315R 360 degree Servo SpringRC 360°). They are good, but noisy. Battery wise you have to use 4,8 V up to max 6 Volt.

    you keep wired control this a Servo tester or a wireless by a remote control. You can control speed but not where it is supposed to stop! Very cheap, pretty good, noisy but should give good results. I will post video when my slider is ready.

  • @dtr , no i mean the output wires powering the motor ?!

    @hellrazor, thank you ...

  • It looks to me as though it would work with any standard DC motor, although you'll need a power supply and I don't recommend using any camcorder batteries as they wont have the 'pushing' power to power large DC motor (by large I mean 540 or even 360 size [that's mm]) Grab yourself a rechargeable RC battery, but you'll need a charger and that's going to cost more, it could get quite expensive :/. Sorry if this isn't making much sense, I'm kind of thinking out loud. If you are in the UK I can send you some small DC motors for their postage cost that you can keep and test out and a 2.5:1 MFA COMO motor that you can test out if you return or buy, I'm just trying to think of the best way to go about this with the most reliable outcome at a reasonable cost (under £100). I'll get back to you tomorrow because I'm off to bed. Also let me know if you need any custom laser cut plywood for mounting the motor and PWM board etc. as I have access to a 10grand laser cutter and I can get them dirt cheap :)

  • @hellrazor 's point about endless servos is great too, I was thinking about servo motors and totally forgot you could have endless ones. Might be a great cheap way to go about it. That way if it doesn't work out as you wanted you've haven't invested much. They are noisy though!

  • @FilmCat, I'm located in Sweden ...

  • OK i bought the http://www.ebay.ie/itm/330742041947 , will check when it arrives, now will search for the motor that can be controlled by this unit ...

  • @FilmCat can this 2.5:1 MFA COMO motor work with the controller i bought ?

    I decided to test: 6V DC 10RPM Powerful High Torque Gear Box Motor

    http://www.ebay.ie/itm/221040786060

    6v and 12v version ...

  • Ah yes... motors and batteries are not a great combo. Only do it if you really have no choice.

  • Please any one else already done/doing a DIY motor controlled solutions, please post on this thread. Let make it a thread where we van exchange the experience about this ...

  • @feha -- I've done one for my Vararon Slide, strong enough to be used vertically. I used a 22.2V battery and a Nema 34 stepper motor.

  • If you only need speed control, go with a normal DC motor with gearbox. I think you can get some very useful parts from the RC world.

    If you want position-control use a stepper motor and something like an Arduino board + motor controller. It will be more work to program it, but than you can make pre defined movements.

  • Try taking a look here:

    http://www.servocity.com/

  • I actually have all these parts for sale right now. I built a custom motor slider option out of all the normal stuff from Servo City and from the parts list the main guy who created this lists on the web. I'll take a pic of all of it if you are interested in buying it. It was made for the Varavon S900 36" slider and I used it on the Palms Inn Resort photo I posted a few months back. Worked really well except for vertical stuff. I needed to refine it and lock everything down a bit but ran out of time before I had to fly out.

  • @vicharris , would be nice to see some pictures ... At present time i use a "merlin dolly" (only horizontal) see picture ... But also interested on other sliders ...

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  • @Feha Ah, that's pretty large there and a bit heavy. Not sure if what I did would pull that but it doesn't go vertically does it? How long is it too?

  • @vicharris, it is horizontal only, 1.5m length, i plan to test this one by using a motor just on one wheel ...

  • Oh, seems like it might work then. I'd imagine that there's barely any tension. It looks like it rolls really smooth. All the damn motor parts add up quick! I think after it was all said and done I spent $150 in parts but I did buy two servos that have two different max speeds in case I wanted to change out. Also I don't know if putting one of these cheaper servos on the carriage itself is a good idea. They aren't the smoothest things.

  • I hope this really crude drawing of mine might a help a bit, although I assume this is likely to be similar to something you have thought of. Theoretically this will work with no problems, might have to be changed so that the motor is on the wheel with gravity on it's side ( on top ) but the principle is the same, whether or not it will be smooth is a different story however, rubber washers are a must in this case.

    This method will also leave your slider virtually original as it only needs two small holes in the metalwork. Mounting the motor at the end with a small rope tied to the dolly would eliminate vibration but wouldn't be quite as easy to do.

    If I had a slider I'd build something and package up all the rights parts into a pdf so others could buy them and do the same because I more than enough parts to build it. but as it happens I don't have a slider haha.

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  • @FilmCat , thank you very much for your proposal a great idea, that's great will try to make it same or similar way ... will have some problems to fix the wheel on motors shaft ... rubber washers etc ... Will inform you on progress for this DIY Now waiting for motors and controller ...

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  • Great, I'd love to hear about how it goes, like I said before I can send you any laser cut plywood designs if you need them, they can be very very useful, all the mountings custom cut etc. and it'll be about 50SEK to send it to you :) and if you need any parts like washers etc. I can send them over for 25SEK but I'm sure you can find them near you :)

    I love Sweden so much I know the exchange rate :P Although I haven't been in a while.

    As for mounting to the wheel, try this, it's cheap enough (~30SEK with shipping) that if it doesn't workout then it doesn't matter and I've checked it will fit the motor you've bought.

    Prop Adapter

    Max.