srry if this was already discussed, but its kinda urgent.
we just started to test our arm and claw, but the Taigene motor doesnt hold the wieght. the motor doesnt lock and is slipping. is there away to program the speed controler to have it lock or something we did wrong w/ the motor.
can anyone tell me how to fix it or is this supposed to happen???
is anyone else having the same problem???
(just our wrist is about 6lbs)
if anyone can help plz hurry
we NEED this done b/c our program mentor is comin and we need a complete robot
We had the same problem. You would hope that the worm gear would keep it from backdriving, but it doesn’t. So we went with the Keyang instead. Programming won’t help “lock” it. You are talking about running the motor at a stall (just enough voltage to stop the movement), which is never a good idea. Think about a design mod to solve your problem. Teams in the past with this sort of problem have added in a locking mechanism (like a brake). Or you can try the Keyang motors, they don’t backdrive.
we ran into this problem…its messy to try and create a brake…change the motor…we went through 3 different prototypes…the first with a fisher price and the other with the taigene motor and the third with a taigene motor and a brake…the arm just got too heavy
Just for the sake of clarity, remember that while using Brake mode will cause your motors to slow down more abruptly, it will not prevent your motor from backdriving. If you want to prevent backdrive, you’ll either need to add an encoder and control it in software, add a mechanical brake, or use a motor with a worm gear (such as the Denso).
we are familiar with your problem since we encountered the same problem about a week and a half ago. The taigene worm gear inside is all plastic and fine, thus unable to hold in place.
Our solution was two-fold. We used a larger gear ratio to pivot our arm and used springs and frame stop points to smooth the flow.
The main thing is design. Our design eliminates the problem of whether the arm can move or not once a load is present. It doesnt matter for our robot.
The same thing will happen with the window motor, however a double step reduction eliminated any arm movement problems on our second joint. The double reduction eliminated the need for such a huge sprocket at the top of our arm joint, keeping us within design dimensions.
just a note*
there is an Allen screw on the side of the motor and when you tighten the screw it will keep it from falling.
we have ran into some issues with the plastic teeth in the inside of the motor braking off. up to 5-10 teeth in a row. we had all the specs looked up and planned out and we did the calculations to only find that we are only using 60% of each motor (on on each side of our arm mechanism)
if any other teams have experienced this problem and have a solution and would share that would be greatly appreciated, if you could, please PM me your reply.
Does anyone have any estimates on how much load it takes for this to occur? We were planning on using the taigene motor for our elevator (haven’t run the whole thing yet) with a 4" spool to reel in the cable. How much weight do you think this will support before backdriving?
We are also using the Taigene motor to operate our lift and also noticed that it slips when we try to hold with the the trackball up. Does anyone know how much load it takes to start failing the plastic teeth?
what kind of reduction are you using?? cause I’m sure it will help, we are about to test tomorrow if our arm can lift the ball up and we have a double stage reduction of about 4:1 and it can carry a 10 pound weight pretty easily
I don’t have any numbers for you, but I’m pretty sure reductions can fix any problems you might be having!!
we wern’t even lifting the ball and we have two motors on each side of the ball, calculated to be working at about 60% of what they could and they blew in no time for us, moved up and down about 5 times and you can just hear when the teeth of the plastic gears pop off.
i will try to get our gear specs and what not to share with everyone, for now here are some pictures.
are we even allowed two of those motors?? maybe they worked against eachother??? cause we haven’t had a problem with ours yet and we are only using one motor. can you show whats on the end of your arm (weight wise and leverage)
ok well the motor can only handle 30lbs as far as I can remember. so that may be the problem.
Secondly, are those motor exactly the same, or are they a left and a right? (cause I think there are left and right versions). if they are the same they may be fighting eachother like I said earlier.
Hopefully that stuff helps and I hope I’m not wrong about anything:D
alright, well even with the second motor, shouldn’t it be distributing the load?
they are both a right or a left (not sure which) but we have one of them inverted because yes they would have fought each other if we didnt invert one.
we are working with our engineers that helped us with the arm and we are coming up with some ideas that may also help.
one of the seniors on our team said thursday night "hey frates(a coach), arn’t these the motors we kept blowing in '05? i guess they blew 5 before the shipped in '05…and now they bring it up…ha oh well.
<R60> Items specifically PROHIBITED from use on the ROBOT include:
Electric motors and/or servos different from, or in addition to, those in the Kit Of Parts, with
the exception of those specifically permitted by Rule <R59>.
Electric solenoid actuators (note: electric solenoid actuators are NOT the same as pneumatic
solenoid valves – the latter are permitted, the former are not).
<R59> only permits servos and additional CIMs
I’d reccomend switching to Keyangs or Fischer-Prices, if one taigene
motor can’t do this.
Also, that looks like very little reduction for an arm of that size. Assuming that the arm takes any more time to raise than a moment, and that reduction is about 5:1, you are putting tremendous load on the motors. You might want to consider further reduction.
Note the emphasis in my previous post. Just because a motor is in the kit dosen’t mean you can automatically use as many of them as you want on your robot.