Author Topic: My Butler Robot: Wheelchair Motors (Read 20763 times)

MaltiK · « **on:** January 27, 2009, 10:16:25 AM »

OK, so I just received my two wheelchair motors rated at 24V DC here are some pictures:

I got it from ebay, from a seller who had 100%, I tried contacting him regarding a data/spec sheet but he was clueless, so I received it today and took some pictures:

http://i99.photobucket.com/albums/l303/_Corrupt_/HPIM2501.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/HPIM2502.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/HPIM2503.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/HPIM2504.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/HPIM2505.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/HPIM2506.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/HPIM2507.jpg

Each motor came with four wires, two red, two black, one pair of thicker ones and one thinner, I took a picture of both the origin of said wires, as well as the strange connector, they fit into each other? Anyone know what kind of connector these babies are?

This is a continuation of http://www.societyofrobots.com/robotforum/index.php?topic=6681.0 This thread, since my question was answered I made a new one.

the ebay page said this:

PRIDE POWER WHEELCHAIR MOTORS & TRANS, ROBOT BATTLEBOT

Item Specifics - Item Condition
Condition: Used

" THIS IS A NO RESERVE AUCTION FOR A MATCHED PAIR OF CLEAN AND WORKING...HEAVY DUTY MOTORS WITH TRANSMISSIONS AND PR1MO POWERTRAX (NO-FLAT) TIRES, SIZE 3.00-8. REMOVED FROM A PRIDE JAZZY MOBILITY POWER WHEELCHAIR "

Clean and tested to be working nicely with no physical damage. Looks to have been very well cared for.

These units were removed from a working power chair that had other issues and we bring them to you with no reserve. Simply be the high bidder to be the buyer.

Fixed shipping is based on delivery to any of the lower continental 48 states.
We do not ship outside the USA.
Shipping insurance is available upon request.
Buyer pays actual insurance cost added to invoice.
These units are very heavy and shipped either UPS or USPS.

We usually ship within 3 to 7 working days from item payment.
Please ask if it's important that we ship sooner. Often times we can accommodate.
Local pick up is never a problem and there is never a service charge for this, just let us know.

Questions welcome

Thats all that was provided, and a search of the customer part number, part number, and model number yielded inconclusive results, can anyone help me find a datasheet of some sort for these guys?

Edit #2:

I found this schematic for a Motor Driver capable of handling the amount of AMPS s, depending on the relays. It only has one PWM chip, and can drive two motors and operating voltage is extremely high (30ish?)

http://www.megaupload.com/?d=I7OEOSXH

its a .rar file with a schematic and placements

Is it good for my task? (Sending high/low commands from MCU PWM output?)

Soeren · « **Reply #1 on:** January 27, 2009, 12:03:38 PM »

Hi,

It's a plain old DC-motor.
Thick wires are for the motor, thin wires are feedback from the encoder.

Can you provide a sharp photo of any markings on the encoder (could it be a Renco unit)?

Can you find any other markings than the label you posted a pic of?

MaltiK · « **Reply #2 on:** January 27, 2009, 12:57:15 PM »

Its not a braking mechanism? What is the L shaped bar on the motor? And if it were an encoder, wouldn't there be three wires: red, black, and signal?
Also no other labels, but I have better resolution pictures:

http://i99.photobucket.com/albums/l303/_Corrupt_/SDC10388.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/SDC10389.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/SDC10390.jpg
http://i99.photobucket.com/albums/l303/_Corrupt_/SDC10391.jpg

Also, I cant figure out where they are to be mounted?

pomprocker · « **Reply #3 on:** January 27, 2009, 01:56:07 PM »

maybe the bars are for balance?

MaltiK · « **Reply #4 on:** January 27, 2009, 01:57:18 PM »

Oh your probably right good call.

pomprocker · « **Reply #5 on:** January 27, 2009, 01:58:18 PM »

you probably dont need em. they look removable

airman00 · « **Reply #6 on:** January 27, 2009, 01:58:36 PM »

no its not , its to brake it, if i recall correctly

Turn it to one end and you'll see what I mean. They are removable , one the sides is a hex screw. Make sure you turned the L lever to the correct side before removing it!

MaltiK · « **Reply #7 on:** January 27, 2009, 02:15:19 PM »

I think one of the red wires might be power brakes, ok so on to my question... suitable motor controllers, anyone?

ArcMan · « **Reply #8 on:** January 27, 2009, 02:33:54 PM »

I just built a robot with wheelchair motors very similar to yours.

The thin wires are to release the brake. Just apply 24VDC to them and the brake will release. Make sure you energize (release) the brake before you try to run the motor. In my robot, I just have the E-stop circuit disengage the brake since I don't need it for normal operation.
The handle you see is a manual transmission engage/disengage lever. Turn it one way to engage the motor and brake, turn it 90 degrees and the output shaft will free spin. I wouldn't remove them if you don't have to. They are very handy for wheeling the robot around in the shop.

Soeren · « **Reply #9 on:** January 27, 2009, 03:38:33 PM »

Hi,

Quote from: MaltiK on January 27, 2009, 12:57:15 PM

Its not a braking mechanism? What is the L shaped bar on the motor? And if it were an encoder, wouldn't there be three wires: red, black, and signal?
Also no other labels, but I have better resolution pictures:

I don't think it's a brake, however likely that may sound in a wheel chair motor - I might be wrong of course, but I know this motor is manufactured with an encoder.
It doesn't have to have 3 wires to provide a pulse output, it could be eg. magnet(s) rotating and a coil would pick it up.

This label on the encoder may what's needed to get the answer. What does it say?

Quote from: MaltiK on January 27, 2009, 12:57:15 PM

Also, I cant figure out where they are to be mounted?

Each of the two flanges on each motor/wheel combo should have support on both sides it seems.

MaltiK · « **Reply #10 on:** January 27, 2009, 05:51:07 PM »

Regarding the encoder label, it says:

Inertia Dynamics Inc.
Collinsville, Conneticut
1904-0060 24VDC
0002-9362 Rev. D 0901

Thanks!

MaltiK · « **Reply #11 on:** January 27, 2009, 05:53:08 PM »

Quote from: ArcMan on January 27, 2009, 02:33:54 PM

I just built a robot with wheelchair motors very similar to yours.

The thin wires are to release the brake. Just apply 24VDC to them and the brake will release. Make sure you energize (release) the brake before you try to run the motor. In my robot, I just have the E-stop circuit disengage the brake since I don't need it for normal operation.
The handle you see is a manual transmission engage/disengage lever. Turn it one way to engage the motor and brake, turn it 90 degrees and the output shaft will free spin. I wouldn't remove them if you don't have to. They are very handy for wheeling the robot around in the shop.

So, I must continuously apply 24v to the brake wires to make it release/go, with the thicker wires, or just to operate freely (by hand) without any extra voltage.

Also what controller did you use? As that would help my search very much.

Ro-Bot-X · « **Reply #12 on:** January 27, 2009, 07:34:18 PM »

I have a question for you, these motors have backlash? I mean with the brake disengaged, try to freely move the wheel with the motor not powered and see if there is a little free movement. That is the backlash. If it has, it would be great to measure it at the wheel circumference.

Thanks in advance.

ArcMan · « **Reply #13 on:** January 27, 2009, 08:48:08 PM »

Quote from: MaltiK on January 27, 2009, 05:53:08 PM

So, I must continuously apply 24v to the brake wires to make it release/go, with the thicker wires, or just to operate freely (by hand) without any extra voltage.

Also what controller did you use? As that would help my search very much.

BTW, I was referring to any thin wires coming from the motor case, not the encoder case. Thin wires coming from the encoder are encoder wires, not brake wires.
Given that - Yes, if they are brake wires, you continuously apply 24V to release the brake (to the thin wires). The thick wires are, of course, your motor armature leads.
I'm using the Dimension Engineering Sabertooth 2X25 drive to drive them. I control them with a PIC micro.

MaltiK · « **Reply #14 on:** January 28, 2009, 05:39:33 AM »

Quote from: Ro-Bot-X on January 27, 2009, 07:34:18 PM

I have a question for you, these motors have backlash? I mean with the brake disengaged, try to freely move the wheel with the motor not powered and see if there is a little free movement. That is the backlash. If it has, it would be great to measure it at the wheel circumference.

Thanks in advance.

I am not able to move it at all with the motor not powered.

airman00 · « **Reply #15 on:** January 28, 2009, 06:11:20 AM »

Let me explain this whole mess

if the motors are powered they will turn when the transmission is engaged and when the brakes are engaged. However they will not turn when you try to turn them manually with your hand.
when the transmission is disengaged the wheel is in a free spin
When the motors are powered they will turn BETTER when the transmission is engaged and when the brakes are NOT engaged

MaltiK · « **Reply #16 on:** January 28, 2009, 06:31:06 AM »

Brakes must be engaged to move? So along with the 24 volts I must apply to make the motor rotate, I must apply 24v with the brake wires to make the wheels rotate? Eeek?

If thats not thew case then my main issue is finding a suitable motor driver capable of withstanding 20+ amps

Soeren · « **Reply #17 on:** January 28, 2009, 04:27:59 PM »

Hi,

Quote from: MaltiK on January 27, 2009, 05:51:07 PM

Regarding the encoder label, it says:

Inertia Dynamics Inc.
Collinsville, Conneticut
1904-0060 24VDC
0002-9362 Rev. D 0901

I was wrong it seems.
Take a look at http://www.idicb.com/idiprod.htm to see if you can find something similar to yours and then a datasheet, although you'd probably get by just fine without it.

It's probably just to add 24V for either brake/clutch and 0V (or High Impedance, shouldn't matter) for the release of the brake/clutch or the reverse of that - it's quick to try.

MaltiK · « **Reply #18 on:** January 28, 2009, 04:50:43 PM »

Alright, thanks mate, I just need to find the suitable/cheap batts. I was aiming for two 12v 18ah Sealed Lead Acid Batteries wired in Parallel. Is 18Ah suitable, in Airman's Butler Tut, he stated 20AH is required, but I don't believe I will be using this for such long periods of time.

And still am in search for a suitable motor driver, I have found this:

http://lh4.ggpht.com/_umPMytEL7tw/SWkJyhbUKKI/AAAAAAAAAjM/eirxcLWb-OA/s800/Hobbybotics%20Motor%20Controller_6.jpg

Now are the relays in the controller circuit the only thing holding the controller board back from being able to drive higher amp motors. For example, the relay in the schematic is rated at 20amps, so if I increase this to say 24 Amps, would I be able to control a 24AMP motor?

MaltiK · « **Reply #19 on:** January 30, 2009, 05:28:36 PM »

Quote

Quote from: MaltiK on January 27, 2009, 12:57:15 PM
Also, I cant figure out where they are to be mounted?

Each of the two flanges on each motor/wheel combo should have support on both sides it seems.

Does that mean they are to be mounted vertically?

MaltiK · « **Reply #20 on:** February 02, 2009, 04:22:33 PM »

I am worried about mounting the Motors, are they to be mounted vertically? For example:

Three pieces of wood in a U formation and the motors mounted on each side. Because they can't be mounted underneath. Also can one screw/screw hole support all this weight? Here is a picture:

http://i99.photobucket.com/albums/l303/_Corrupt_/SDC10388.jpg

If this is my best bet I know L Brackets are necessary, but what else?

Edit: I have already consulted Airman's Butler robot tutorial, his motors have multiple screw holes, and at the bottom, to be mounted horizontally

ArcMan · « **Reply #21 on:** February 03, 2009, 01:33:05 PM »

I have seen wheelchair motors mounted both horizontally and vertically on commercial equipment, so orientation shouldn't matter. On my own yard robot, my current horizontal mounting doesn't give me enough ground clearance, so I'm switching to vertical mounting.

Those holes Soeren identified are definitely mounting holes, but I would not recommend mounting them in just that one spot. Isn't there another hole or threaded hold somewhere else on that gearbox where you can have an additional mounting point?

MaltiK · « **Reply #22 on:** February 03, 2009, 05:55:34 PM »

if u look at the link at the bottom, it shows the entire motor+gearbox, I am not sure. And could you give me more details as to the materials you use when mounting them horizontally?

Admin · « **Reply #23 on:** February 07, 2009, 11:12:36 AM »

Quote

Does that mean they are to be mounted vertically?

They were designed to handle the weight of some guy on the chair while mounted vertically.

Unless you plan to put a lot of weight on it and mount it horizontally, you shouldn't have a problem.

Admin · « **Reply #24 on:** February 08, 2009, 03:19:05 AM »

MaltiK, please do not double post.

I just merged your topics.

MaltiK · « **Reply #25 on:** February 08, 2009, 05:25:45 AM »

Alright, My question is, is 6mm stainless steel angle bit strong enough to support at least 150 lbs? Or am I better off using two thick (1"?) plywood at an angle with an L bracket?

Admin · « **Reply #26 on:** February 15, 2009, 05:07:33 AM »

Quote from: MaltiK on February 08, 2009, 05:25:45 AM

Alright, My question is, is 6mm stainless steel angle bit strong enough to support at least 150 lbs? Or am I better off using two thick (1"?) plywood at an angle with an L bracket?

Only two ways to answer that question . . . experimental test, or calculate it.

Here are the equations:
http://www.engineersedge.com/beam_bending/beam_bending8.htm

You also need to look up the material properties of your steel/wood.

Use the 'Deflection at the unsupported end' equation. If the number is high, that means its bending too much.

ArcMan · « **Reply #27 on:** February 15, 2009, 06:10:10 PM »

As requested... The mounting of my wheelchair motors.

The motors came with hardware to mount them to 1" tubing (ala wheelchair frame), so I did that.

cooldog · « **Reply #28 on:** February 15, 2009, 06:22:36 PM »

looks great

ArcMan · « **Reply #29 on:** February 15, 2009, 10:04:25 PM »

Thanks. Problem is, it has too little ground clearance. So I'm going to re-do the frame to mount them vertically and switch to 10" diameter knobby tires.

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Author Topic: My Butler Robot: Wheelchair Motors (Read 20763 times)

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