Hi All, I am building a robot beach cart and using a wheelchair base with jazzy motors. They each have an axle, probably around 3" in length designed with a Double D shaft. I have two 42mm beach wheels from Wheeleez with a round open hub center bearing. There are 4 bolts holding the hubs together, which I was going to use a backing plate somehow.
Does anyone have any suggestions how I should connect the wheel to the shaft, utilizing the DD design on the axle? Keep in mind that I have minimum space as my width needs to remain under 36" so I can’t have the wheels sticking too far out from the motors.
Thank you in advance!
Victor
I guess you would have to find or make a hub for this. Hub would go through the center of the wheel, or you could screw on the bearing plate and the center of this hub should fit double D shaft. Something that would look like this somehow:
Probably there are other solutions, but this is the first one that comes to my mind.
Hi Igor, once again thank you for your reply. I’ve thought of a few different methods and one that I am going to try first is with a 3/4" DD tube, used for steering columns in cars, it’s hollow. I am going to attach (weld) a backing plate to it to screw on to the wheeleez. The only issue I have with this application is that the motor axle is slightly larger than a 3/4" inside measurement of the tube (it’s probably metric) and so I will have to grind off some of the girth from the axle to fit through the sleeve. I then plan on running a long screw through the plate and through the tube to screw into the existing hole in the center of the axle, which is the hole that the original screws were mounted to.
The only concern I have with this method is the strength of the tube and whether or not the torque of the motor will twist the metal.
Once again!!! Thinking outside of the box which I have a hard time doing! That’s a great idea and the tube is long enough for me to test it! Thank you again Igor!
Well. I’ve made some progress. I’ve had the jazzy motor spindles ground down some and now they fit precisely in a 3/4” hollow steel shaft, all to extend the axle. I do plan on welding on a backing plate to the end of the axle for the inside of the wheeleez wheel hub. Doing something similar on the outside of the hub to relieve some of the pressure on the four bolts.
I’ve installed a sabertooth 2x32 and wired both motors and both batteries to the unit. I have a radiolink remote currently programmed to operate forwards and backwards and I think I figured out how to turn left and right.
I purchased swivels and somewhat smaller wheels for the front of the cart.
I need to charge the batteries back up as I wore them out today, I might find out that they’re too old, having purchased them last year and never really kept them on a charge.
Here are some current pics. Stay tuned as I am going to need much more guidance and assistance, things where I don’t do well.
Hi All,
Time for another update and a request for some additional guidance from the experts!
Well, since my last post, it’s been two steps forward and only one step back. I had to buy new batteries which is fine, the others we’re probably ok still but I’m better off starting fresh. I had to rewire the motors a few times as the motors weren’t consistent. Now the motors work great and the dip switches are set correctly. I did try to add the electromagnetic brakes to the existing E660 Jazzy motors and the brakes seemed to act as a hindrance to the operation of the motors. I tried a few different wiring options but the brakes never seemed to disengage when I tried operating the motors. Removing the brakes pretty much solved that problem.
I had to go to Plan B for the axles and the welded backing plate. The welding distorted the axle tube and just wasn’t going to fit right. I found a company with a plasma cutter that agreed to cut four 3.25" discs with a center hole designed to fit the Double D axle. That way I am hoping that the axle and discs do more of the turning when bolted up to the wheel hubs and relieving any pressure on the bolts themselves.
Here’s my next challenge. I was trying to use the crossbar from the wheelchair to mount the wheeleez swivel wheels to. The problem I am having is that with the swivels attached, it raises the front of the cart at an angle of about 33 degrees and I need to lower the front which means I need to relocate the crossbar higher on the cart. I ground some metal off of the cart to clean it up and now need to figure out how to mount the cross bar which holds my swivels, higher on that square steel post. Also, I need to push the crossbar and swivels about 2 more inches out from the cart so they can have a full spin without any interference. See if you can figure out what I am asking from the pictures.
Thanks again for allowing me the ability to write up the progress with the beach cart, I still believe that this will all come together sooner than later.
UPDATE TIME!!! Making good progress here and Igor, thank you as always for your thoughts!
I made the wheel plates, inside and out and had them plasma cut to fit on the Double D pattern axle. I just bolted them together and installed them with the axles, although I have to still cut the axles down and bolt them on the motor shafts.
I had a section of 1.5" square tubing welded to the back of the cart where I installed the swivel bar. Although it works, that is still going to be a problem. As you can see in the pics, I am not getting a fuil spin as they still hit each other and each hits the corner of the cart. Any thoughts on what to do? I need to still push the wheels more apart and further out.
PS. The torque and power on this cart is incredible. I did remove the electromagnetic brakes because I thought they we really holding the cart motors back but I didn’t expect the power that they pushed out once all connected!
