I’ve been into R/C trucks for a while so I know a little about things but I need help from you Battle Bot guys/gals on this one.
I’m in a wheelchair, I mostly use a manual chair but got a Pride Blast 850 to play with, well I never did think it performed the way I wanted it to in the first place, the thing I didnt like about it was the power ramp up or what ever it’s call’d. If I was in soft dirt and try’d to get out and gave it full power it just sat there like a bump on a log, it had to move before it had any power, the faster it went the more power the controller gave it. Safty I know but not good enough for me. When I push the joystick I want it to move or get stuck ya know. Well now I have over heated it to many times try’n to get out of easy obstacles and the speed controller has went south, it’s out of warranty and a new controller cost like $600 and will be the same ol piece of junk I had before. I want more !!!
It has a pair of BIG 4 pole motors, a pair of 12v 80ah batteries.
The controller it has now has 5 settings for speed and power output.
If I had a controller that ONLY has one setting and uses the joystick for all power out put and speed thats ok with me, I’m 35 years old and rid a 100 hp Kawasaki ZRX Trike, I can take care of myself and my actions, say’n this as the wheelchair people wont even talk to me about any of this for liability reasons.
SO I have been looking at a few speed controllers that seem to fit the bill. Like the 4QD-150D. But I dont know how to make a battle bot controller work with a joystick for a power wheelchair, can I alter mine to work, what kind of stick would I need ?
This is what I want but need help making it work, Thanks for any help I can get.
P.S. I have my old controller out if anyone wants to try and make it work or mod it ?**
Hi and welcome to ChiefDelphi! Normally your post would have recieved numerous replies by now, but yours is a special situation that may be introducing some reluctance to many to replying for a number of reasons. As you are aware, most members on this forum are associated with FIRST in some way or another (not BattleBots!). We do indeed like to design and build robots, and I’m certain there are many on this site that can address your situation. Some concerns are, however, that when we make a mistake with our robots, generally only the robot suffers. In your case, however, bad advice could cause injury to YOU! Not something any of us wants to cause.
From your description of your problem, it sounds as if wheelchair speed controllers are designed to NOT provide full power to your drive wheels if it’s not moving. The reason being that your motors are able to provide enough torque at full power to flip you upside down. Translated that means if your wheels are stuck and too much power is put to your drive wheels, you would simply be flipped out of your chair backwards. That is why your controller is designed to slowly increase power as you pick up speed. I imagine the same circuitry would prevent you from flipping if you were going backwards and suddenly changing directions to forward.
As far as burning your controller out, I would hope that a breaker of some sort is built into the circuit, to prevent over amps. I am guessing, though, that even with this protection, the controller still gets hot if you get stuck often enough. Maybe some additional cooling fans will help prevent this. Also try driving with a little more strategy. If you are going over some rough terrain that you know may cause you trouble, keep your chair moving until you find a good stopping spot that won’t block your wheels. If you do get stuck and no one is available to boost you out, try rocking back and forth to get your wheels moving (like people in snowy areas do when their cars get stuck).
It’s likely that one or more MOSFTE transistors in your speed controller have blown. It should be possible to measure them with a meter to determine which have burned out and replace them.
As for not powering the wheel when they are stopped, I agree with TubaMorg. This is done for saftey. You would need to hack the controller software to disable this restriction. It should be possible, especially if the speed controller processor has a flash memory, but would require some programming expertise.
While I can’t help with your question I do have a suggestion. You have caught the FIRST community at a bad time. The new game has just been released so most people on here are looking for game rule clarifications and robot tips. You may want to try again at a later date when people aren’t so busy and will have more time to help.
I’m not too sure of the electronics end of this, as I’m a mechanical guy, but if you end up hard wiring your speed control system, you’re going to want to put something behind your main drive wheels. This could be almost like a wheelie bar on a drag racer, or something along those lines. This would help out with not flipping if you do happen to play with the power settings.
As far as getting something done at this time, I highly suggest you look around www.usfirst.org to find the FIRST team local to you. Knowing FIRST teams, they’d be the best outlet of help, and in the spirit of GP, would most likely be glad to help you out.
**Thanks guys, yes it has a soft start deal for safty but getting stuck out back isn’t real safe ya know, and anytime it wallows around it over heats and stops.
I end’d up drilling some holes in the case (with out the board in side) and mounted a cooling fan, that help’d ALOT. And no the holes did not let in dirt or water so thats not why it stop’d working.
Also it has wheelie bars sort of on the back so no probs with flipping over…
If I could find the most capable Hack I would send my controller to you and let you have at it, if you cant fix + mod it keep it and do what ever you want with it, I still would mainly like to know how to make my joystick work with a Bot controller like that of a Ampflow Dual Speed Controller !!!**
Check this site out and see if there is a team near you. Contact someone from that team and see if they can help out. They might want to work with you after the build season, so it’s worth a shot!
From an electronics standpoint if all you are trying to do is bypass the current speed controller and install one like the amp flow there are a few ways to do it.
The ampflow speed controller can be controlled in a few different ways.
R/C Radio mode
R/C Radio is the most popular, simplest and least expensive method to build and operate a remote controlled robot. The controller supports many configurable options, including joystick calibration of min, max and center positions and dead band adjustment. Full optical isolation is provided on all R/C control inputs. This method requires the generation of PWM (pulse width modulation) signals which can be created by any standard RC receiver or a robotic based micro controller(like those we use in FIRST).
Serial Port (RS232) mode
The controller may be interfaced to a microcomputer for autonomous operation. More advanced operations are possible, including remote control via the Internet, using a wireless modem or wireless network adapter. This method is more straightforward for using any micro controller. If you were to wire your joystick to the controller which interprets the potentiometers within the joystick you could do this.
The last method will seem to be the easiest.
Analog mode
A simple 0-5V analog control mode is also provided for direct connection to potentiometers or joysticks. You hardwire the potentiometers in your joystick to the controller. Obviously you will have some calibration to do, but according to the documentation for the speed controller this doesn’t seem to be too hard.
Typically I would just end this with saying “good luck with your project” but something inside me requires me to say “be safe with your project” also that any information provided here is for reference only and Myself or chiefdelphi can not take responsibility for your actions based on recommendations in this post. So please be safe and good luck.
**I fully understand the safety concerns about it all, it’s like reloading ammo, people can tell you what loads they like but to have you do the same may not be safe, plus THAT is why I’m asking lots of questions FIRST. I will be moving my seat forward, plus it has wheelie bar wheels, start off slow and work up. Hey I ride a 100 hp Kawasaki Trike. :ahh: **
