Timescapes - Digital Timelapse Discussion
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Newbie motor question
https://forum.timescapes.org/phpBB3/viewtopic.php?f=24&t=5461
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Author:  mrl72 [ Mon Sep 12, 2011 4:14 am ]
Post subject:  Newbie motor question

Hi all

Great forum! I'm excited to try and get my feet wet with some motion timelapse but have a few questions on the types of motors to be used in my project. I am just looking at doing a simple pulley system on my Igus slider, so motor at one end with pulley to wind cord/string attached to carriage. That simple really, eventually I plan to make a better system but I'm just getting into it and don't want to invest a lot of money at this point. I've been looking at motors and what not and I really don't want to order from China and wait 3 weeks to get the parts so am looking for something I can salvage from a home item ie printer etc. but have a couple of questions:

1. For stepper type motors how do you control these? What parts are needed and where can I get them from?
2. For servo type motors do I need a gear system?
3. Has anyone used something like the innards of a cordless drill? You can pick these up for under $20 and they have variable speed motors 0-720RPM including chargeable battery packs. Just wondering if anyone has tried this? Seems the motors are high torque also and include a PWM but not sure if the PWM can be changed from trigger operation to a variable resistor or would I need to add a cheap PWM controller (like this one: http://gb.suntekstore.com/DC-12V__24V-3 ... oller.html) instead?

Lastly which is the easiest/cheapest solution? It looks like the servo route is the better solution but again looking for something that is relatively inexpensive with parts sourced in the US.

Cheers.

Author:  Antz [ Mon Sep 12, 2011 10:16 pm ]
Post subject:  Re: Newbie motor question

Almost any electric motor you can salvage will be far too high in speed in time-lapse.

Value for money you can't beat prices from ebay if you can be patient.
Here's a really cheap setup...
http://www.ebay.com/itm/320681934776?ss ... 1439.l2649
http://www.ebay.com/itm/New-DC12V-24V-3 ... 2566c38074
I built a winch using these, and also got a 1rpm motor as well for really slow stuff.
With the speed controller you can typically get down to about 20% of the rated speed and still drive to motor reliably, so 1RPM on a 5RPM motor at slowest speed.

For steppers you are getting into more expensive controls and a whole lot more complicated.

Author:  mrl72 [ Mon Oct 03, 2011 11:09 am ]
Post subject:  Re: Newbie motor question

Thank you! I bought both the items you linked to. The motor took forever to get here whereas the PWM was pretty fast.

Has someone got any instructions for connecting the PWM (as per the one in the link?)

Image

Cheers!

Author:  sciencelookers [ Mon Oct 03, 2011 12:24 pm ]
Post subject:  Re: Newbie motor question

From the picture, I'd guess that you attach wires by way of those green screw terminals. One pair should be 12v dc in, and the other pair should be wired to the two lugs on the motor. If I had to guess further, I'd say the ones on the left are for 12v in. The capacitor will probably be on the in side, but I'm not buyin you another board if i'm wrong about that. Those Chinese guys didn't include instructions or mark the board in a language other than Chinese? What a surprise. It would also be nice to know which side of the"in" screw terminal pair is positive and which side is negative. Getting these wired backwards can probably fry the board. If the board doesn't have a + or - next to it, Look at the barrel shaped capacitor. One side of that should be marked to show if its positive or negative. You can probably follow a trace on the circuit board back to the "in" screw terminal. The polarity of the "in" connections should match the polarity of the capacitor, if that makes any sense.

Author:  mrl72 [ Mon Oct 03, 2011 12:51 pm ]
Post subject:  Re: Newbie motor question

Hey, thanks. Looks like on closer inspection I see "M+" and "M-" on the one green terminal block which I'm assuming is motor connections. Everything else is in Chinese and I got no instructions with it so will keep my fingers crossed it works :)

Author:  Antz [ Mon Oct 03, 2011 8:19 pm ]
Post subject:  Re: Newbie motor question

Yep, just a 12v battery in on one side, and connect the motor to the other side.
You might want to rig it up so you can change polarity easily on the motor side if you need to get the motor to run in the opposite direction. I rigged up mine with a switch on the motor side that would reverse it if I wanted.

Author:  Kitwn [ Mon Oct 03, 2011 8:46 pm ]
Post subject:  Re: Newbie motor question

I just had a look at the link to ebay and there are clear + an - signs on the green terminal block next to the blue one. Presumably the other end has the M+ and M- which should be your motor connections.

The online hobby supplies shop I've been looking at here is Australia wants $75 for what looks to be the identical motor! I think I'll spend more time searching eBay from now on.

Kit

Author:  mrl72 [ Tue Oct 04, 2011 4:46 am ]
Post subject:  Re: Newbie motor question

Antz wrote:
Yep, just a 12v battery in on one side, and connect the motor to the other side.
You might want to rig it up so you can change polarity easily on the motor side if you need to get the motor to run in the opposite direction. I rigged up mine with a switch on the motor side that would reverse it if I wanted.


Good idea! I'll be stopping at the shack later today to get all the parts. Did you use any particular wheel with one of these motors? I'm wondering the best place to go get one. I had read some people used the track wheels from sliding doors which you can get from Home Depot. Curious to know what everyone is using on the motor shaft?

Cheers.

Author:  Antz [ Tue Oct 04, 2011 8:00 pm ]
Post subject:  Re: Newbie motor question

I have one of these set up on a little winch I built. It just uses thin twine on a shaft because I can't use belts in extreme cold.
The main thing with any wheels is to make sure they are perfectly round to avoid any wobbling images. Some cheap skateboard wheels are not.

Author:  mrl72 [ Sun Oct 09, 2011 10:01 am ]
Post subject:  Re: Newbie motor question

I'm having a hard time finding a pulley that I can connect to the shaft on the motor. Looks like the motor shaft is about 4mm and most pulleys I've found have 3/8 holes. Does anyone know where I can get a pulley from that not only will fit a 4mm shaft but also have a set screw?

Cheers

Author:  Antz [ Mon Oct 10, 2011 1:36 am ]
Post subject:  Re: Newbie motor question

For the first winch I made I used some rod end bearings (look them up on ebay) and a shaft I put together on my lathe.
The second one, I just connected the motor directly to a fishing reel.

The motors are pretty easy to mount, the shafts are typically 6mm or sometimes 4mm.
The front mount threads on the motor body are usually 3mm or 4mm tapped holes.

There are lots of couplers / universal type joints etc available at hobby stores.

Author:  mrl72 [ Sat Oct 29, 2011 2:59 pm ]
Post subject:  Re: Newbie motor question

Just thought I'd report back with my results. Overall I'm pretty happy with What I've built for the cost. I do have a couple of question though.

1. Even with the PWM at its lowest setting the motor seems to not have enough torque to pull the sled, although it does at around 30-40% of the 5rpm motor. So what happens is it will move happily for a few minutes and stop. This means at the best setting without it sticking is a max 15 min pull from end to end of my 3' slider. Do I need to find a higher torque motor or is there a better solution than the simle pulley+nylon cord I am using (ie using gears and belts)?

2. If anyone is using the 5D2 I'd love to hear how you get 1 second intervals out of this thing. No matter what setting I try the time to take a shot, open mirror, close mirror etc. is definitely more than one second. If controlling from a laptop (ie DSLR Remote Pro) it continually lags behind. 2 seconds is fine but I'd like to try and get 1 second intervals. Is that possible with this camera?

Cheers.

Author:  Antz [ Sun Oct 30, 2011 2:52 pm ]
Post subject:  Re: Newbie motor question

You may need to get an extra (slower) motor if it can't handle the extreme slow settings.
The 5D2 will definitely handle full raw at 1 frame per second no problem, you just have to have a high speed compact flash card. The delay is typically just the time it takes to write the data to the card.

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