Wow very nice …8 batteries?? You found you needed that much battery storage? Have you used this on any rough/steep terrain?
Also if I may ask another question what size fuses did you use and they are wired where in your system. Right before the motors?
You have brakes on this too? Wow. Now on the fuses …they are located where then? They are to protect what? As you can guess I am a little new to some of the electronics aspect. My needs are going to be pretty demanding. This is all very interesting to me …although I have a lot of hobbies and so the robot idea is totally to take care of things I hate to do because of they either dangerous or very very strenuous. We have a farm that has some very steep areas that normally I only take care by hand with a weed eater, hand sprayer etc. The robot is going to mow, weed eat, spray or whatever else I find intrusive to do. Basically a rc controlled 4 wheel drive garden tractor. Thanks for your help on this.
Once again …thank you for the response. I assume the brakes that are usually in these motors have to go and would not suffice for the breaking you have implemented. I read that those original brakes had to be taken out but I forget why. I can envision what you mean if the yardbot is stopped on a hill it could start rolling down hill …those brakes are rc controlled too I assume. What happens if you lose RC control in any way?
yes I know I need to study this more and will. The input I got about the brakes comes from a book I am reading about building an all terrain robot …as well as several Youtube videos that indicate they pull the brakes off to do RC lawnmowers. However I see the application for them in my need. These others seem to be primarily doing mower for a lawn that I would just mow myself …I need the exercise!
Were those standard rectifier diodes that you used on the brakes?
And just wired in line I assume?
Hi …Jongig has been great in responding. I will see if I can add my newbie two cents here. As I understand it the brakes are only activated when no power comes to them. So looking at my connectors on my motors …there are the power leads for the motors as well as the power leads for the brakes (all in the original wheelchair connector). It seems that Jongig felt it necessary to put rectifying diodes in the connection for the brakes. Although I don’t understand why this is necessary since the original installation in the wheelchair did not have these. I am wondering if I could not just hook them up to the Sabretooth just like they were hooked up to the wheelchair power supply and controller …with the Sabretooth taking the place of the wheelchair controller.
Of course it helps ! I thank you for all the great info. And what you described is what I thought. But just to be sure …in your diagram M1,M2 are M1,M2 on the Sabretooth …and the circle with the M in it is the actual motor. I am not sure how you are then wiring up the brakes for power …unless they too are connected to M1/M2 on the Sabretooth. I will have to look at my motors again but I only recall the positive and negative for power for them coming out of the motors. Which means to me that there must be some wiring internally for the brakes to get their power. I have not opened up the brakes to take a look yet…so they may be just like you are describing and I will have to look at your digram at that time and figure out how to wire in the diodes. With all this said …if the wheelchair already had a breaking arrangement with the brakes etc. Why did you feel the need to wire in the diodes …why couldn’t I just connect the motors as if they were connected to the wheelchair? Wouldn’t that accomplish the same thing? Again …since you have been through this and are more knowledgeable I thank you for helping a newbie here.
Why six wheels now? Are you not getting the traction that you need?
That is my thinking …but I have not tried it yet. Hopefully Jongig can respond to why he felt the diodes were necessary.
Good looking machine there …nice work!
What is the short list of electronics used in this project? I’m going to build something similar.
2 drive wheels, mixing to make it go left and right. doesn’t need to skidsteer.
I am building a rig very similar to yours. I also have the motors with the dynamic brakes. I do not, however understand your schematic. I’m quite good at the mechanical aspects (Mechanical Engineer), but the electronics still trip me up. Basically, I also need to keep the brakes active while bypassing the old wheelchair control box. Any help would be greatly appreciated.
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First, I’m sorry for not replying to the recent post. I always reply but I didn’t and I’m sorry. I’m not sure why I didn’t see the post but I didn’t.
Anyway, I myself in need of a little help and I was hoping someone might simplify what I’m trying to do.
The yard-bot has been a great tool for around the house and I’ve not had to do any maintenance to it. My wife gets a kick out of me because I put
a egg crate on it, load it up with tools from inside the house and ride to wherever I need to work. It might even be part of the reason I’m gaining weight.
The yard-bot is also a great tool for moving my 10 foot trailer around the yard, even when full.
I have a new use for it, carrying and dumping dirt. I have added a removable aluminum dump box that is over 7 CU-FT. It fits inside the yardbot and doesn’t require removal of the original box or sides.
The dump is hinged to its own integral frame and I’m in the process of installing a 24 volt actuator to lift the dump.
I want to use a RC channel from my RC radio. I want to have center off, full one side would be up and full to the other side will be down.
I want to be able to stop the dump from going all the way up or down by going to center stick of the channel.
I was able to think that I could use two battle switches. The first would be on/off and the second would be up/down but this
would require two channels. It might be possible to use the battle switches to turn voltage on in one direction and the other to turn voltage on plus activate a relay to reverse the voltage.
My second thought was mechanical with the use of a single servo and some type of 3 position switch connected to it.
The actuator is 24 volt DC with limit switches.
I’ve looked for some type of electronic switch but I’ve not found one.
Any better ideas, I’d love to hear them.
I have figured out my dilemma.
Jomar products make’s a electronic double switch. I will use this with a DPDT relay and a SPST relay. At the extreme high side of the stick the dump will go up and at the extreme low side the dump will go down. At middle stick the dump will not move.
I also re-read the post asking about the diodes in my breaking schematic, the diodes are required and the breaks will not work correctly without them.
Hello, new to the forum and I am working on a similar project. I would like to compare what I am doing with your schematic. I keep looking for the attached schematic that was mentioned but I cant see it. I was trying to interface with the wheelchair controller and had some success but I decided to dump it and get the sabertooth for better control and less safety dumping of the wheelchair controller. Any help will be appreciated with the schematic. Thank you.
I’ve been using my design without any problems and I’ve since built a dump body that sits in the bed of the vehicle and has a electric ram for dumping.
I don’t see that I can add a picture so you’ll have to contact me and I’ll send you the picture.
John