Author Topic: New Project from Powered Wheel Chair (Read 2679 times)

c02cutter · « **on:** September 23, 2009, 09:21:21 AM »

New to the forums here, my compliments to all of you! Nice informative forums. A bit of history, I have built small robots in the past for my pleasure, and work on projects at work for automation of jobs we run using PLC's at the heart.

   I just found out I am inheriting a powered wheel chair. Never actually used, and just waiting to be mutated to my whims. Won't actually see it till this Saturday when I go pick it up, but am excited as it will be the beginning of a new fun project. Don't even know the model of the thing, my girlfriend just told me we have to go get it out of the nursing home it has been at. So the wheels are turning on a new bot.

   What to do...hmm. First thought was a battle-bot, but being that there isn't that many of them around to battle, kinda pointless. Second was the old lawn mowing bot, would be useful with over 2 acres of lawn, but boring. Though the Amish in the neighborhood would probably get a kick out of it. Or be scared, either way I would get a laugh. What about a snow removal bot? Winter is coming, we have to have the drive cleared by 5:30 am each morning anyways for the school bus to leave. Interesting idea I think.

   It's up for brain storming, so bash it as much as you like, will be working on some concepts today for it. Or for that matter if someone comes up with a better idea let it be heard, at this time I am open to ideas for the chair mutation.

ArcMan · « **Reply #1 on:** September 23, 2009, 12:56:17 PM »

First of all, congratulations on the girlfriend. That's impressive for a robot geek.

Check out this site to see a wheelchair-based bot doing some snowplowing:
http://www.evatech.net/

I have myself built a R/C lawnmower using wheelchair motors on a frame of my own construction. (Check out "Mowzilla Lives" in the videos forum).
It may be boring to you, but the passers-by love it!

Have fun!

c02cutter · « **Reply #2 on:** September 23, 2009, 01:26:22 PM »

Took me a bit to find the snow plowing video there. That is down right cool.

I like the concept there of mower and plow. might be a consideration to take into account.

c02cutter · « **Reply #3 on:** September 24, 2009, 01:55:28 PM »

   Was doing a bit of thinking on this, and checked out something I found last week while mowing a trail for the kids mini bike. In a stand of trees out back of our new place was a decent looking snow blower. Last night I pulled it out and drained the tank, cleaned the carb, hooked up the jumper cables and it started right up.
   I like the mower aspect, as you need to be able to play with it when there isn't snow on the ground also. So am thinking on making the drive aspect of the thing modular. I like the plow in the videos, but know that we get too much snow for it to push a plow. It may be ok in 6 inches of powder, but we get piles of heavy wet snow. Hench the snow blower.
   I think the modular aspect would work well. Just not sure if there will be enough oomph to push the blower well. Have to wait till Saturday when I pick up the chair. Need it's vitals and do some calculations.

ArcMan · « **Reply #4 on:** September 25, 2009, 11:07:58 AM »

A robot with wheelchair motors would definitely be able to carry around a snow blower. I would remove the handles and wheels and mount it to the front of the bot. Keep the batteries and motors in the back to balance it out. You might have to add 50 lbs. or so to the rear to get good traction.

I briefly considered doing this with mine for some winter fun, but I decided I like my plow guy too much (He gets up at 3:00 AM so I don't have to).

c02cutter · « **Reply #5 on:** September 25, 2009, 12:42:23 PM »

Lol, i am my own plow guy... Hence the need for a new snow toy.

c02cutter · « **Reply #6 on:** September 26, 2009, 07:52:27 AM »

Picked up the chair last night. It's new basically, but the batteries are dead. Currently trying to jolt them back to temporary life. Definately am happy as it really is basically new. Just been sitting in a nursing home unused for 3 or so years.

Update to this post, batteries seem to be holding charge, kids having a ball tooling around on it. Had to play on it myself...

Joker94 · « **Reply #7 on:** September 26, 2009, 07:09:20 PM »

you'll be able to reuse the control stick on one of your bots or do you plan to use it to controll the vehical your building.

c02cutter · « **Reply #8 on:** September 27, 2009, 12:51:27 PM »

Currently I believe I'll be 86ing the joy stick and current motor driver. Still looking into the interface and options for it.

Joker94 · « **Reply #9 on:** September 27, 2009, 05:33:52 PM »

I think a good way of control would be a simple transmiter radio like the one Arcman used to control his lawn mower. The only reason i say that is it would be really simple and you can re-use the transmitter radio on what ever you want. Or if you have easy access to one you could use it for testing if you dont have control set up yet.

The best way would be using one of those mind set head sets and interfacing that with the veichal then you could sit on the couch and control it from the comfort of inside.

The only probelm with that would be that the head set is pretty expensive and it would be very complicated ti interface with the robot.

What ideas have you had in terms of controlling the robot. $:-\$

c02cutter · « **Reply #10 on:** September 28, 2009, 09:59:38 AM »

Initially I plan on going radio control, very similar to Arcman's set-up. Once I get that worked out and working reliably, then on to automated aspects.
Today I took one of the motors off for modeling and worked up my basic bracket for attaching them to the new frame. I run a laser shop so am able key all parts for proper alignment. Nice to get paid to play too...

ArcMan · « **Reply #11 on:** September 28, 2009, 03:12:40 PM »

She's a beaut.
Nice modeling. What package are you using?
I used Google Sketchup for mine.

c02cutter · « **Reply #12 on:** September 28, 2009, 04:02:02 PM »

I use Solidworks for modeling most of the time. I do all the programming for our machines so I have a few programs at my disposal.(Solid Edge, Rhino, BobCad) I will say that Solidworks is a really nice modeling programming. It is expensive but worth it's weight in gold if you constantly use it.

Here is another with the second drive modeled out. The gear boxes on the motors are designed for right and left hand on the chair I have.

Arcman, did you use the 25amp saber? Also from our reply to my message that you pumped the RC input into a pic micro, then to the Sabertooth.. Did you do this for the added control, or for some other reason? The saber is capable of signal loss shut down, and acceleration limiting on it's own. I can understand for added options of control, and for adding automation in future.

Curious minds wanna know.

Joker94 · « **Reply #13 on:** September 29, 2009, 12:24:04 AM »

nice cading and good design

ArcMan · « **Reply #14 on:** September 29, 2009, 03:12:19 PM »

Quote from: c02cutter on September 28, 2009, 04:02:02 PM

Arcman, did you use the 25amp saber? Also from our reply to my message that you pumped the RC input into a pic micro, then to the Sabertooth.. Did you do this for the added control, or for some other reason? The saber is capable of signal loss shut down, and acceleration limiting on it's own. I can understand for added options of control, and for adding automation in future.

The Sabertooth has a problem (IMO) with throttle/steering to differential PWM conversion. If your throttle is, say 50%, and you turn the wheel right... The right wheel will start backing off speed, then stop, then reverse (as expected). Keep turning all the way and the right wheel reverses to 100% speed and the left wheel speeds up to 100%. The end result is that you can't "spin" at less than 100% speed. Unacceptable to me. I spin quite often when mowing, and I want to do it slowly.

c02cutter · « **Reply #15 on:** September 29, 2009, 06:40:09 PM »

I did not know that about the saber, thanks for the information. I will then look into a similair set-up.

c02cutter · « **Reply #16 on:** October 07, 2009, 05:31:14 PM »

Got really busy at work for a bit there, tomorrow should be able to put more work into this again. Did get to pull one on some customers at work today. Was tooling around the shop in the wheelchair and covering for a guy on a machine. Talking with the customers and motored to the machine and got out of it to change the part... lol was a priceless moment.

c02cutter · « **Reply #17 on:** October 13, 2009, 10:33:18 AM »

Cut out the modeled motor mounts this morning. Just tacked them together.

ArcMan · « **Reply #18 on:** October 15, 2009, 08:35:09 PM »

Must be nice to have a LASER cutter.

There's no emoticon for "seething with jealousy".

c02cutter · « **Reply #19 on:** October 16, 2009, 01:39:03 PM »

Yes it is nice. There are times it comes in very handy. I can do up to about 1" thick on our 4k machine. Though really wish we had a mill and lathe here too. I get access to those too, but have to travel a ways to use them. So I have gotten into the habit of designing around milled parts as much as possible.

MangoBot · « **Reply #20 on:** October 30, 2009, 03:07:00 PM »

you could make it a lawnmower, and then make it so that you can add and remove the snow plow.

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Author Topic: New Project from Powered Wheel Chair (Read 2679 times)

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