motor to pull camera dolly

[apostolakisl]

JimS,

For now, I'll use whatever I'll find in my garage or basement. You mentioned this previously:


Am I right that I can use the gear motor from this rechargeable battery powered screwdriver? It says Type 1 2.4V and 150/min RPM. On the other side, it says NOM 2,4v.

150 rpm is still going to be too fast for you I am pretty sure. If you used threaded rod the speed would probably end being a foot a minute or somewhere in that general region. I suppose you could turn it on/off/on/off etc if the spacing between your photos doesn't need to be super-precise.

But it would be easy to use that in a direct connection to the threaded rod. Just take two nuts and turn them against each other at the end of the rod and put a socket adapter on the screwdriver. At the other end of the rod you will need a bearing. If you had a small wheel sitting around you could use that. If not, Harbor Freight sells those types of thing for dirt cheap.

Lastly, you need the carriage that attaches to the sled. Here it would be nice to have a welder. It would be very easy to weld a nut to the end of metal bracket that attaches to the sled pulling it along. With no welder, you might take a piece of wood, drill a hole that is just a touch smaller than the outside dimension of the nut, and pressure fitting it (ie hammer it in) with a bunch of epoxy to help hold it. Then the wood bracket can attach to the sled. For a more stable carriage, you could use two nuts spaced an inch or two apart that attach to the same carriage.

 

[v1rtu0s1ty]

Hi Lou Apo,

I was thinking that I can make it slower by implementing the way a racer bike's gear works. If we set the gear to speed 5(maybe 1, forgot which way, hehehe) which is a bigger sprocket, our pedaling will be easier but it's slower. So I was thinking of adding a circle gear(i don't konw how it's called ) along the path.

 

[apostolakisl]

Hi Lou Apo,

I was thinking that I can make it slower by implementing the way a racer bike's gear works. If we set the gear to speed 5(maybe 1, forgot which way, hehehe) which is a bigger sprocket, our pedaling will be easier but it's slower. So I was thinking of adding a circle gear(i don't konw how it's called ) along the path.

Yes, that is what I was trying to explain at the beginning of this thread, I guess I just wasn't making it very clear.

If you could find a variable speed screwdriver it would be a lot easier. Certainly my DeWalt can run very slow by just barely pushing the trigger and it still has good torque. But it would be a tough thing to tear apart a $150 drill to use it like this. Maybe you can find a cheapo drill and tear it down. If you are like me, you have boxes of old stuff ready to be ripped apart and put to good use. So, perhaps you have an old cordless variable speed drill ready for the taking, like my old POS Black and Decker one.

 

[v1rtu0s1ty]

Yes, I have a cordless drill where the battery only lasts for 5 minutes. It's been collecting dust for 4 years now. However, I don't recall if I can change the speed. I do recall I can adjust the torque.

 

[apostolakisl]

Well, if it does have variable speed, then you'll need to find a transformer with the correct voltage and sufficient amps to hard wire it. You'll also need to replace the trigger with a different way to trigger it so that you can set a speed and walk away. It may just be that a simple potentiometer is all it takes.

 

[mustangcoupe]

Well, if it does have variable speed, then you'll need to find a transformer with the correct voltage and sufficient amps to hard wire it. You'll also need to replace the trigger with a different way to trigger it so that you can set a speed and walk away. It may just be that a simple potentiometer is all it takes.

A quick test may be done with the battery and using a ziptie on the trigger just squeezing it enough to start the rotation. this could even be a final solution if the battery last long enough

 

[apostolakisl]

A quick test may be done with the battery and using a ziptie on the trigger just squeezing it enough to start the rotation. this could even be a final solution if the battery last long enough

Totally agree with you as far as a proof of concept and before tearing down the drill. But for the long term you would probably want more precise control of the speed. Some photo shoots might require the sled move 1 foot an hour, others maybe 1 foot every 5 minutes, and so forth. That would be hard to do with a zip tie.

 

[v1rtu0s1ty]

I tried pressing the trigger lightly. The drill's high pitch "eeeee" sound is so annoying when it tries to fire it up.

 

[apostolakisl]

A descent quality variable speed drill will not do that. In fact, you can get a descent quality 120vac drill for not much money if you don't mind running an extension cord to your contraption. But if you want to stick with cordless, I was at costco and they had an ok hitachi model for about $50.

 

[v1rtu0s1ty]

I'm thinking of buying a stepper motor instead. However, I'm not sure what it does. I was told on irc the other day about it but I couldn't find the user anymore.

 

[v1rtu0s1ty]

This is it. This is what I am going to do

http://www.youtube.com/watch?v=_maToB8xqmM

 

[apostolakisl]

Came across these on ebay looking for something else.

http://cgi.ebay.com/4pcs-SBR16UU-16mm-CNC-Router-Linear-Ball-Bearing-Block-/250671144536?pt=LH_DefaultDomain_0&hash=item3a5d2a1e58

You will need to 16mm rods for them to ride on, but this would elliminate all the "rigging" for the other home made methods. The "Asia Seller" ebay guy sells these things in lots of sizes. He sells them with rods too, but they aren't that long and the cost goes way up, presumably becuase of shipping.

 

[v1rtu0s1ty]

Cool. I'll check it out. I'll look at my plans again. Thanks!