This is my first attempt at an instructable . I have virtually no experience in electronics but at 80 years old I figure you are never too old to learn. Mowing the lawn was getting to be quite a chore so I decided to build an easy to use mower that I could either ride on or sit on my back porch and mow from there. I bought a used electric wheel chair on Craigs list for $100 to start the project off. After stripping wheels, motors, and battery box I mocked up the chassis with 2x2" lumber This also allowed me to fit the donor mower to the frame. I used the deck from an old Briggs 22" walk behind push mower. Once that was done I welded up the steel frame from 1 x 1/2" steel tubing. I tried building the electronics from a previous project in Make but I just didn't have the talent or experience. I decided to go with a Sabertooth 2x25. I already had the motor wiring and was set up for 24 volts. The folks at Dimension Engineering were a great help in advising me how to set up the DIP switch. I got a used 54 MHz. RC set up from a friend who fly's model airplanes. The Sabertooth is a no brainer to hook up. It even supplies the 5 volt power for the receiver. A switch, and fuse were all I needed to complete the job.
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Signing UpStep 1: Materials
STEP 1
Materials
Used Electric wheelchair $100.00
Steel Tubing $25.00
Donor 22" mower $ 25.00
Sabertooth 2x25 $125.00
Lawn mower batteries (2) $68.00
Misc. Nuts, Bolts, Switch , and fuse $15.00
Used RC TMX, AND RCVR $35.00
TOTAL $393.00
Materials
Used Electric wheelchair $100.00
Steel Tubing $25.00
Donor 22" mower $ 25.00
Sabertooth 2x25 $125.00
Lawn mower batteries (2) $68.00
Misc. Nuts, Bolts, Switch , and fuse $15.00
Used RC TMX, AND RCVR $35.00
TOTAL $393.00
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(350 / 24) I have that circuit fused at 20 amps. inline with the positive terminal to the Sabertooth. I try to protect the controller in any way I can.
I used a 30 amp fuse because It was handy.
.
Great instructable, I have been inspired, and nearly have all the parts!
I managed to pick up a cheap wheelchair on eBay that actually had two fantastic batteries that hold a good charge. The seller thought that they were flat and useless! The problem is that after charging the chair and testing it out for power, I am doubtful if the two 180w motors will push the RC mower up a hill (I am not building one with a chair, and hence it will not be carrying a passenger up hill). What do you think? What size motors are you using, and would it make it up a 30 degree hill? I am not sure if the motors will be too weak, or if the wheelchair motor controller is limiting power.
Your advice would be much appreciated.
Sorry about the delay, I have been traveling.
I don't think you will have any problems with power if you are using wheelchair motors. I am using 13 amp motors on mine. That equates to 312 watts..(Volts times amps = Watts. Using that formula it looks like you are using 7.5 amp motors. That seems a little light for a wheel chair.
I don't think you will have a problem though. I hope you will be using the Sabertooth 2 X 25 . It delivers smooth power to the motors even at very low RPM.
Let me know how you are doing
Happy building
Mickydee
btw, can i use a 4 channel remote radio for this project? or it should be 6 channel radio transmiter?
tnx
You only need two channels. One for forward / reverse and one for left / right.
You can set it up for one joystick (serial) or two sticks (tank steering)
depending on how you set up the Sabertooth controller.
Complete instructions come with the Sabertooth .
You don't need any servo's.
I used one joystick as it felt good.
Have fun as this is a simple project.
Mickydee
Oh, and the propeller motor is from a broken drill. I rigged it up with a switch and it spins.
Here's the pic, thanks again!
Thanks for the good idea
Mickydee
Sounds like your little ones are in for a fun time. The wheelchair motors are powerful enough for just about anything you want to build, and the range with U-1 batteries is very good. I have mowed my lawn 4 or 5 time between charges and still had power to spare. Check out my Sitway instructable for another use of these motors. I been playing around for at least a month and I haven't had to re-charge it yet. Have fun and let me know how you are doing.
mickydee
If I had it to do again, I think I would have spent a little more and used an electric start motor. If you make one for your brother, this would really give him a feeling of independence . My motor starts easily but I am not bound to a wheelchair.
I wish you all the success in the world. It is not a difficult project
mickydee
Paul
This one is a real improvement on the RC lawnmower concept i saw recently by johndavid400.
I hope that should i make it to your age, if i can be half as productive and show as much ingenuity as you then i will have lived a happy and contented life. BTW - can you adopt me Mickydee?
I would appreciate any help to solve this. I know it can be done ,because I watch other peoples video's
Thanks
mickydee
http://www.instructables.com/id/Arduino-RC-Lawnmower/
-thai
I couple questions about how well it works?
Does the unit drift often, and do you find yourself correcting the steering often?
I am sure you adjusted the trim on the transmitter to compensate.
I am very impressed with the runtime, and your setup would blow a kid's motor powered car out of the water! It seems like your project does not suffer from getting stuck on low ground or cement edges.
I would like to make a little car to let kids ride around in that way I would have better control of where they are going, and if made correctly, I could jump in with them :P I could also put a pull behind mower as an accessory.
Thank you for the inspiration Micky, very well done for your first instructable!
I tried it on 12 and didn't seem to lose much power. I think the range would suffer though. Great idea! let me know if you build one and maybe I will build yours for my grand kids.
mickydee
It will have to probably wait until this winter when there isn't as much activity going on, that way it could be ready for spring!
I would actually prefer the remote control over a steering wheel so that "we" the grown ups would have control over the vehicle. They like to rid their bikes into things, and occasionally people!
I would probably work towards aluminum, fiberglass reenforced wood, or steel butted tubing similiar to what is used on bikes to reduce the weight some, and add some efficiency. I have quite a bit of time ahead to brainstorm the process. I am just thankful for your footwork into the "meat" of the project which is where all my questions would have been. Anyone can build a box car, but making it electric and remote controlled is where it becomes fun!
Thanks again Micky, Best Regards!
Josh
I guess it probably took about a month
mickydee
Cut the lead from the ignition coil and put it in series with ground. thru the switch.
You can mount it anywhere you want but this keeps the leads short.
Hope this will help
mickydee
A good idea is a good idea....
I would also like to be like you when I grow up.
Just to let you know ,You instructable was the reason I bought my first Arduino Uno
I tried to build your controller and H-Bridge. but it was just too much for me. I decided to build something that the average guy tinkering in his shop could build.
Thanks for the comment and the inspiration.
mickydee
Good Luck
mickydee.
It would also be great fun to see a video of this in action.
I just figured it out and posted a short video at the tail end of my ible.
Take a look and let me know what you think
mickydee