Hello,
There's been a while now, since I got keen on timelapsing, so I felt the need to get some more dynamics in my timelapse shots. I started building a motorized timelapse dolly. I wanted to keep it quite simple and stiff, to end up with nice, fluent movements, so I went for a screw-driven design (which is in progress). Here you have a small video with what I have, so far. Sorry about the rough editing and doubtful quality, but I just wanted to upload it as fast as I could.



The rail is aluminum, it was a single rail, 2.5 meters long, and I cut it down in half, so the length of the dolly is 1,25 m. The sled is made of steel corner-fittings for... furniture, I guess (or whatever they're used for). The 4, big wheels are skateboard wheels (ABEC 3 bearings), and the rest, are bearings (also ABEC 3). The sled weighs about 3 kg, and will be fitted with a video head (0,5 kg). The camera (D7000, with 2 batteries, a medium weight lens and grip) is about 2 kg. So, the stepper motor I've bought, will have to lift/push about 5 kg. I will be pleased if it can lift the whole thing vertically.
I'm not very good at electronics, so I've asked a friend of mine to help me with the electronic controller part. Hopefully, in the end, it will be able of ramping, various speeds, photo/video modes etc.
As far as I've seen, I had similar design and functionality ideas with the Jack Ripper's Chronos system. Hope you haven't patented it, yet.
I don't really know if i should use reduction gears for the screw... I've taken a look at Jack's system, and he said that the motor could lift 25 lbs (almost double what i need). As far as I know, my stepper is a 12 V, 2 kg/cm motor, with 1,8 angles/step.
Should I use reduction gears?
Do you, guys, think, with the right controller, I will be able to lift my camera vertically?
Sorry about any language mistakes.
Any comments/opinions/questions are highly appreciated!

Looks real nice!

No patents here.

as for gear reduction, you really need to get the motor running and just see how much torque you are getting at what speeds. In my setup the stepper has a LOT of torque and power at low speed, if i went with gear reduction it would just be too slow. Get that motor running, then see what speeds you can run it, that should give you an idea about any gear reduction you need.

Hey man, thanks a lot!
I guess I'll survive to shoot another day
Well, my friend got the motor running, and he said it's a preety torquey motor. I hope it is as powerfull as it gets, so I won't need any more reduction gears.
Hope I'll be shooting like you, guys, soon!