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View Full Version : Recommends on DC gear-motor, that can output > 10ft/lbs



scowby
06-01-2009, 10:43 PM
Hi, I'm looking for a DC gear motor that can output at least some decent torque, say 10 foot-pounds of torque. Preferably the "flywheel" would already be some sort of gear meshing to interface with other parts.

Anyone have any recommendations on finding something like that? A supplier of motors or some piece that could be ripped out of something?

Thanks!

Adrenalynn
06-02-2009, 01:00 AM
The DeWalt PowerDrive motor/gearboxes have been looking pretty interesting. About 400in-lb @ 450 RPM
http://www.robotmarketplace.com/products/0-TD-RCM515.html

You'll need at least a 160A/channel motor controller...

But since you "only" need 10ft-lbs, the little wiper motors are probably more what you're looking for: http://www.robotmarketplace.com/products/AME-218-2001.html (make sure you get a left and right...) - best of all, you could get away in the 25A/channel motor controller arena unless you're going to be pushing them hard continuously.

scowby
06-11-2009, 11:28 AM
One question about these gear motors - can the RPM's be controlled very easily? Like, say I want this thing to spin up/down, can I just vary the voltage I'm sending to it in order to change the RPMs?

Adrenalynn
06-11-2009, 11:41 AM
Yes - but now you're getting into the realm of a motor controller. You're not going to just slap a pot on there unless you enjoy setting things on fire. Those gearmotors are, per-force, a high current drain application.

scowby
06-29-2009, 03:21 PM
So, I'm trying to put this whole picture together.

I've got 3 pieces:
1) power supply
2) motor controller (adjust motor RPM)
3) motor

I've got 1 out of the 3 pieces of the equation and that's the AME 218-series motor (http://www.robotmarketplace.com/products/AME-218-1003.html)

Any suggestions on where to find the power supply or motor controller? I would like an AC power supply, which I can just plug in and not worry about batteries.

What about a motor controller?

Adrenalynn
06-29-2009, 03:32 PM
One motor? Two? How many? (and if more than one, hopefully you got both left and right handed...)

Independent control of more than one motor?

Single channel motor control: http://www.trossenrobotics.com/store/p/5108-SyRen-25A-regenerative-motor-driver.aspx

Dual channel: http://www.trossenrobotics.com/store/p/5466-Sabertooth-dual-25A-motor-driver.aspx

These can be controlled with analog input (a pot) like you were asking for.

Before answering the power supply question - I'd like to know how many and what you're doin' with 'em roughly. Just as a gauge of load.

This is worth browsing: http://www.dimensionengineering.com/appnotes/atxguide/atxguide.htm

scowby
06-30-2009, 08:30 AM
I'm planning to hookup one motor only at this time. The AME-218 series pull 1.5 Amp w/ no load, and somewhere around 22 Amp at "stall" load.

The idea is that this gear motor will power a little flywheel, which in turn powers an arm pumping back and forth. Increase speed on the flywheel and the speed of the armature moving increases. I'm expecting the physical "load" the armature will be moving will tax the motor at about 50%, no more.

I'd like to be able to adjust the speed
a) via a computer - some sort of computer control that says faster / slower
and
b) manually - via some sort of dial that I could adjust the speed myself

Can this motor controller do that?

http://www.trossenrobotics.com/store/p/5108-SyRen-25A-regenerative-motor-driver.aspx



Given this info, do you think the home-brew ATX power supply would work? I might be spending just as much as buying something off-the-shelf though, if you have another already put together solution in mind.

Thanks!

Adrenalynn
06-30-2009, 09:32 AM
Honestly, that's one of the best motor controllers for the job - it fits all the requirements handily - and more.

Big ATX supplies are pretty cheap these days BUT - that's still more amps than most can source off the 12v rail. They handle that in that article by buffering spikes with a gel cell battery. That said - if you're at 50% load 24/7, you're going to kill the supply.

Something like this:
http://www.bestrc.com/teamcheckpoint/chargers/index.html - first device on the list - might just work out well for you. I couldn't find the one I last used, but the specs here just about dovetail. (I'm running late out the door, but wanted to get you a quick answer. Followup as needed)

scowby
06-30-2009, 12:49 PM
Great. So sounds like

1) the AME-218 series motor
2) the motor controller: http://www.trossenrobotics.com/store/p/5108-SyRen-25A-regenerative-motor-driver.aspx
3) and the power supply: http://www.bestrc.com/teamcheckpoint/chargers/index.html

will be my final setup.

One last question is how would you "program" the motor controller? Do you know if it's got a programming language? Or how do I tell that to go "faster/slower" using a computer program?

That's awsome, thanks so much for helping me!

scowby
06-30-2009, 03:24 PM
What about this for a motor controller?

http://www.trossenrobotics.com/PhidgetMotorControl-HC.aspx

Does Trossen sell the LV model, for single motor control? i couldn't find it, only could find it on the phidgets website:

http://www.phidgets.com/products.php?category=12&product_id=1060

Alex
06-30-2009, 03:42 PM
The LV is being discontinued from Phidgets, so we didn't restock it when we ran out. Just an FYI, the LV isn't only for single motor control: "Control two low-voltage DC motors independently for direction, velocity and acceleration". Both the LV and the HC can control a single motor, so I'm not quite sure what you mean by "for single motor control"

Adrenalynn
06-30-2009, 07:45 PM
The Syren uses a very easy serial protocol, or a more advanced packetized serial protocol - your choice.

It is TTL level, so a TTL to USB or TTL to RS232 must be used.

The big advantage to packetized serial is being able to gang multiple devices on to a single line. If you don't need that, you just send a single byte over the serial port for simple serial: 0 = Full Reverse 255 = Full Forward with integers in between being proportional, 127 is full-stop.

The SyRen also supports analog (the pot you originally wanted to use).

It's speed can be updated at about 2khz if required.

The Phidgets has much lower current rating ( <14A continuous), doesn't support analog, is USB-only, and is much more complex to program. For more money.

The SyRen has many more features - but whether you care or not about them is another matter. Although - it sure is nice knowing future projects are "insured"...

scowby
07-09-2009, 03:31 PM
Okay, I've ordered these parts

- the AME 218 motor
- the Phidget HC motor controller
- the 25A power supply from Checkpoint

Let the games begin!!!

Thanks for your help, I'll put up a prototype as soon as I've got one :)

scowby
07-09-2009, 03:34 PM
Just on the motor controller (going with the phidgets vs SyRen), I have experience programming phidgets so, to me, the ramp up time figuring out how to interface this with a computer (linux laptop) is worth the $$.

I totally expect to get into it more so when I burn up the phidgets controller then I'll probably learn about analog signals and getting the SyRen online.

Thanks again for the help

Adrenalynn
07-09-2009, 03:47 PM
The syren takes pure digital serial input. With a control protocol infinitely simpler than the phidgets. I'm not sure where the "learning analog" comes from...

#echo 255 > /dev/ttys# [enter]

You just controlled the SyRen with the linux laptop. Woot! Now let's see if you can get the phidgets going faster than that... ;)

scowby
08-03-2009, 10:19 AM
Definitely I think this is something I need to learn.

Plus, there's a different in controlling the thing using the command-line in linux and using a programming language. I chose 'c' since the phidget library is written in that, but I could/would use anything.

What language would you use to program that analog motor controller?

Adrenalynn
08-03-2009, 11:24 AM
>> there's a different in controlling the thing using the command-line in linux and using a programming language

Conceptually - no. No difference. You're just using a program someone else built instead of one you built.

What language would I choose personally? Tough question. Whatever fit the project guidelines and goals, or whatever was handy. The last time I controlled a Sabertooth programatically it was in "Wiring" with the Arduino, which is pretty c-like. Before that - C#. Before that - Assembler.

jes1510
08-03-2009, 12:33 PM
Look at the pyserial module for python. Here is the pythonic equivalent of Adrenalynn's post:

import Serial
ser = serial.Serial(/dev/ttyUSB0, 9600)
ser.write("255")