Team 2980's Open Source FIRST BOT

[Brandon_L]

Were having a big problem...

We are using two window motors into a small sprocket to a bigger 60 tooth sprocket via chain, similar to what you guys are doing:
http://i187.photobucket.com/albums/x...g/DSCN1408.jpg
(no chain is on in this picture..)

The entire setup works, but the motors like to lock up and when they do we have to put full power on them for them to unlock. The result being the arm slamming into our frame or flying into the air. Motors also tend to heat up a bit when this happens, but nothing extreme. We have two bungee cords down the back as a counterweight.

What did you guys do to prevent it from locking? We don't have a clue

EDIT:
I saw someone mentioning that having a jaguar controlling the arm might be doing something. I don't know if this is true, but we are using two jaguars.

[eedoga]

we recently started running into a similar problem. for us it was an alignment issue. the large sprocket attached to the arm was pulling out of alignment. That was why we added the two large brackets on the side. there is still too much play so we are adding a longer shaft when it comes in on Friday in the hopes that that will solve the problem. check the heck out of your alignment. Also I think when under strain the window motors can sort of bind up internally. It might be that you are overcoming the seasing.

finally I have heared that using some Electronic speed controllers makes the window motors unhappy. we are using a spike relay for each of these motors.

[anyheck]

Originally Posted by Brandon_L

Were having a big problem...


The entire setup works, but the motors like to lock up and when they do we have to put full power on them for them to unlock. The result being the arm slamming into our frame or flying into the air. Motors also tend to heat up a bit when this happens, but nothing extreme. We have two bungee cords down the back as a counterweight.

What did you guys do to prevent it from locking? We don't have a clue

EDIT:
I saw someone mentioning that having a jaguar controlling the arm might be doing something. I don't know if this is true, but we are using two jaguars.

We had a jaguar running our lift mechanism on a window motor and it was locking up as you've described, probably once every few up-down translations. Switched to a Victor and no further problems.

http://www.chiefdelphi.com/forums/sh...ad.php?t=83973