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

@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.

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.

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 :)

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

@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 ...

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 ...

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.

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.

@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?

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.

@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 ...