24v Motors, run on 12v?

Can they? Im looking at a pair of 24v wheel chair motors…

Logic tells me, they would at 1/2 RPM and 1/4 of the hp?

I know they wont’ run as fast, but would they work?

Thanks in advance,

Jacob

Well that all depends on the motor… you will get an output from the motors although it will not be near as great as if you ran them on 24VDC. Why not use the 24VDC (unless you are looking to use them for FIRST reasons).

You numbers may be close… but it all depends on the motors.

-Greg The Great

As far as I know, it was illegal to use motors not in the kit for all the past competition years.

I know the speed controls I have wil handle 12v, they have in the past

Im just not sure they will handle 24v…

I built one a long time ago out of random things, and it worked. So I built a frame I designed in cad from scratch and was planning on using these 2 motors, hooked to their own 12v battery and esc to poewr the thing.

The esc’s are both old, and have reverse… one is a mechanical one, and the other is a old mc something… I figure ima have a problem getting a smooth response from them and getting equal output from the motors to go straight…

but then again if this works, i’ll get money and upgrade to better Esc’s… but until then… i’ll use what I have =^)

24V motors running on 12V?

I think thats where the term ‘half-fast’ originally came from :^)

they will run- it will be like running a 12V motor with a battery that is drained down to 6V (think about how a FIRST bot runs when its battey is almost dead and you’ll get the idea).

I guess the bottom line is your application - if all you need is 1/4 of the rated HP, and its all you have to work with, its better than nothing.

They will almost definately run, but like you mentioned earlier, the power output will be greatly reduced. DC brush motors are generally not very picky about voltages. If the motors have a nameplate, try to find the manufacturer and they can prolly hook you up with the data sheet, which should have a chart that you can use to determine the power output at x voltage. If you have 4 speed controllers and they are old an you are thinking of replacing them, then you might be able to feed 24v through them if you wire 2 in series for each motor and use Y cables. This will prolly work, but no gaurentees.

Im currently watching a couple motors on ebay, If I can get them at a good price I plan to… Im thinkin anything under 75 for a pair of wheelchair motors will be good =^).

Also, I only have 2 speed controls, I was never huge in Electric RC cars so i didnt’ collect much. My favorite RC car I have is my nitro =^)

anyway, If this works, and I have a working robot I’ll be more prompt to spend money on speed controls that can handle 24v, however your idea to run a speed control on each better then just hook them up to the motor, sounds great if i had the other 2 speed controls :-p

Thanks guys, i’ll be sure to keep a eye on that auction now =)

The speed control is not a big problem. You can create a very simple custom circut that can control speed. I am trying to find the website I used to have that had a real good layout for it. Also try contacting a local university… they may have some speed controllers that rate 24VDC thay may just give you if you make them a deal to throw a little business-card size logo on your robot. If I find that circut diagram I will post it.

Good Luck with your work…

-Greg The Great

I’d appreciate that site :slight_smile:

There really nothing but a thermostat switch, essentially…

right now I wish I had all my autocad drawings, I have some I did on paper somewhere but all my comp ones are gone(did the at school) one of which was a isometric view of my robot in scale :-/ o well guess i’ll just have to remake it now :wink:

its a simple design, but it’ll impress people around here…

You have a link to the auction? Also, what speed control(s) do you currently have?

Also, I actually have a pair of high current (80 amp) 24-36V single-direction speed controls I’m trying to get rid of for around $160 for the both if you’re interested.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2584207426&category=42920

hopefully I can get them, im not sure what a good price is for em but i was willin to go up 50-75$

the others have a side shaft, or so i call it, this one has the straight hsaft out the front,which is what i want…

I just need to find tires for the motors…

You could try www.robotmarketplace.com for wheels/hubs/tires.

Well If you are looking for something simple like that… look at a local autoparts store (ask for a switch catalog) and I am sure they will have a switch that can be used for a robot. You probabally will not have f/r but that can be run to a seperate switch using a simple relay (I can tell you how to build one if you don’t know how) I would also be nice to run the motors through a braker panel. I know a place that can sell you the 40 AMP’s (I believe you will need 40’s for WC Motors) or you can just get them from innovationFIRST and make a custom housing (I can also tell you how to do that if you need the help).

I have a lot of blueprints and images for just about everything you are thinking of doing. (I worked on a project of my own similer to what I believe you are trying to do and I have a lot of info and drawings on the subject)

If you need the help let me know…

AOL IM- GregTheGreat04 (no spaces)
E-mail- G.Ullstam@comcast.net

-Greg The Great

Thanx greg :slight_smile:

Im wanting a lil more control then full on/off, however If I could find somekind of rotary switches at autozone or whatever, I suppose I could mod it and hook a servo to it and control it that way. I’ll check that out in the next couple days.

on my first one I made I used power window motors, which worked great since they fit straight into the wheels I had and powered the thing great. However me being me took one apart (boredom I suppose) put it back together and shortly thereafter it went out…

All in all my first attempt was a success, made with less than 20 bux in it, and worked :-p so now im working on a “real” one that I designed and built the frame, (the previous one wsa actually a old computer case… hehe)…

I got stuck at the motors last year, was suppost to get some from my shop teacher, never did. Im not in shop this year(Essentially a joke class) so im trying to pick this project up again since im pretty much to the wiring section of it and have everything I need…

Also for batteries, I have 12 volt hobby batteries, sealed…

Thanks again guys, this forum is awsome.

Sounds like you need some help? We did a project for our community last Christmas.

We were asked by a local Ballet to Robotize a wheelchair. They used this wheelchair as a stage prop in THE NUTCRACKER. IN previous years they had a guy sitting in the wheelchair. Now this wheelchair was heavily modified. Almost everything was torn of except the controls.

The operater had to sit beneath the human angels dress totally blind. He even had to have a coordinator tell him where and how much to move through a Walkie-Talkie. This was not easy…

This wheel chair had 2 12 volt batteries hooked up in series. We had to use FIRST control systems and everything on the wheelchair was 24 volts. SO we had to come up with something to make this work…

We powered the control system with one battery (12 volts) and also used both batteries(24 volts) to control the motors.

We also needed to find 24 volt speed controls. So we looked to Innovation FIRST’s other company http://www.ifirobotics.com/ and we used their Battle Bot speed controls!
We then just hooked up the PWM signal to the Speed Controls.

If you didnt understand my post or you need to know more just let me know!
Bad BRad

Or you could save 50 bucks and go with something like this http://www.robotcombat.com/marketplace_robowars.html

You could try something like this - http://www.solorb.com/elect/solarcirc/pwm1/
I believe that that steps up the voltage using capicitors charged in parallel and drained in series.

Best of luck!
Kevin

I’ve never tried this, and not extremely informed on circuits and such tho i plan to learn…

why couldnt’ you just get a potentiometer and modify so you can hook a servo, or small motor to it to turn it on command.

Then hook it to the motor…

would that not satisfy as a cheap speed control?

or am I just waayyyy out in left field here…

You would need a circuit to convert the potentiometer signals to pwm and you would also need some transistors to actually handle the power. And some sort of chip to run it all.

ooo I see, I always thought the potentiometer was always just essentially a dimmer switch like you use in your house for lights, that it would go in between the motor and the battery and by turning it you would increase the motor speed, vice versa…

Guess not :-p…

Im also now looking at some wiper motors if these wheel chair motors fall through, The first one I built I used power window motors and they worked great but I can’t remember what model car they were from, and cant’ find any that look like them:-/