Drill Motor Speed Difference

[Mark Jones]

Has anyone noticed the huge difference in the drill motor speeds between forward and reverse? We measured the current draw on all of our Bosch drill motors at no-load in both forward and reverse and noticed a big dip in current draw and speed in reverse. Too much to compensate with programing!! Last years drill motor indicated only a very slight difference in current and speed.

Therefore, if any of you are using the Bosch drill motors for your drive system and are experiencing some tracking problems this is the reason. You need to add an additional spur gear to change the direction of your final output on one side to ensure that both motors are turning the same direction.

Mark Jones
Metal-in-Motion (MIM)
Team 343

[Dave]

Yessss... this is a problem with us too, we ARE compensating for it in programmin.. I think a value of around 175 on the faster motor will = a 255 or whatever on the slower one... play with it... and get a tachometer on it... I don't know much... I don't do the whole programming thing.

[Ian W.]

Does anyone have an exact value for the differences? I'm doing the programming for my team, and we realized this would be an issue, but not that much of an issue. Last year we did something crazy with the EEPROM, but this year we'd like to do something on the fly, but we need the difference between the speeds so we can make it at least semi-work.