does anybody know what the shelf life of a drill motor is because we were trying to run some tests on them and all the used ones were dead but they were still working when we took them out of the robot during the competitions.
I don’t know what you really mean?
The expectancy in a drill or in the robots (average)??
I do know that cordless drills will run for years and years if treated properly!
Our drill motors would last forever on our robot if we treated them properly too…
They have lasted for a 3+ competitions maybe even more for us.
the drills we were trying to use had been taken out during the competitions still running but when we went to use them again they were dead.
i was wondering how long a drill should last just sitting there in our tool box
Drill motors should not go bad just sitting there… I have a cordless drill that is 8 or more years old, and it still runs just fine. You must have done something to them for them to just stop working.
Cory
Is there any rust on them?
Also, I would suspect metal shavings getting into the motor and shorting out windings and such.
When you go to store motors, wrap them in clean rag and put them somewere cool and dry.
-Andy A.
*Originally posted by team222badbrad *
**Our drill motors would last forever on our robot if we treated them properly too…
They have lasted for a 3+ competitions maybe even more for us. **
I dont think that is true, cause just think about this, when a company desgins a drill, they expect it is gonna be used the most maybe 15 seconds, and we use these things for 2 minutes at a time, they may not have been designed to take that kid of stress, i am amazed that ours last as long as they do
We’re going in our 5th year of FIRST, and have used drill motors all 4 years… as a matter of fact, all of our robots are still running with the same motors they ended their season with, we might have replaced one or two but for the most part those motors hold up pretty well…
There may be the possibility that a shaft or component made of steel, etc. rusted. If the area they were stored was damp or humid its a possibility.
just an idea
-Pat
Heh. Our drills didn’t even last until they were out of their box in the kit!
When we took them out of their boxes, the transmissions fell apart all over the floor. All we did was lift it out of the box. It’s no wonder we didn’t use them in our drive this year :rolleyes:
Actually, I think I’ve underestimated the drills a bit.
Anyway, If used correctly the drills/transmissions should last you a while…hopefully
There were so many teams that broke the motors or stripped out the gears etc. at VCU last year. They brought out buckets at the end of the regional of parts people had turned in broken. People could take the parts to keep. Both buckets were full of drills and drill transmissions. One BIG problem with the motors is if they overheat, the plastic connectors at the base will melt. Well, those plastic pieces happen to be the only thing holding the motor’s brushes into place. Or if you take a hit and it breaks off, bye-bye drill motor.
I think if they perfected the drills so they weren’t so flimsy (all the plastic housing) people would feel better about using them. It takes work and perseverance to preserve them well.
As far as your motors are concerned I think most of it has been covered in the previous posts.
In response to the suppositions that rust is the cause of the problem, our robot was (apparently) stored outdoors, in the rain, between ship date and the Silicon Valley Regional, in 2003. When we opened our crate, which was noticeably damp, there were two inches of standing water (so I was told, I cannot be absolutely certain about this fact), and all of the (non stainless) steel on our robot had rusted. Wetzel posted this image shortly after the discovery. You can’t see either of the two drill motors in that picture, so here are a couple of good pictures. As you can see, they were caked with oxidization. We were all deathly afraid that our drivetrain was completely ruined (the geartrains were rusted, as well), but when we carefully started the system, there were absolutely no problems. The drill motors worked (as far as we could tell) perfectly.
This isn’t to say that rust is absolutely not the problem in your situation, but it’s some experimental data.
They probably got overheated too much and it just can’t take that kind of stress. Drills usually don’t cool exceptionally well, and over the course of a match, especially when the motor changes forward and reverse, they get darn hot. Especially if they aren’t heatsinked. (I wish they’d include aluminum heatsinks in the kit…) Overheating and inadiquate cool-down time most likely killed your motors. At least that’s my take on the issue. I could, as always, be completely off-base here.
I have found the motors themselves surprisingly resilient. The motors from last year run today, despite an absurd amount of rust for a machine that was stored inside our autoshop under a cover, being abused during preseason, competition, and post-season fundraisers, and simply thrown around in general. I cannot say the same for the transmissions… I long ago lost count of the number of transmissions that crapped out despite any measures we took to hold them. (The reinforcements for the mounting seemed to grow steadily throughout the build, we tried running at reduced power for a while, we built mounts to hold the system together in directions where there was no feasable way for force to be applied…) Well, our team now has a robot with one working motor transmission, and no spares, and nobody feels like expending the effort to repair that stupid transmission, if such a thing is feasable.
Mike,
I am willing to bet that the pullouts were not stored very well before ship. If you look closely, it is likely that the brush assembly has been damaged and the brushes are either not touching the commutator or are shorting to the case of the motor. This year’s drills do not have a long life outside of a box or mounting bracket. The motor was designed to be protected by the drill housing and not to be tossed into the bottom of a tool box.
Yeah, what Al said. 
Did you check and make sure the shifter on the drill transmission is firmly engaged? They can often get stuck in the middle if they arent hold down, and the drill can’t turn unless its completely in high or low. Also the leads to the brushes might be broken, and yes that is fixable, but difficult. Short of damaage or possibly severe rust they should not die on a shelf. The only other thing I could imagine is if it was subject to extreme temperatures at some point it might have caused the lube in the gearbox to seize up (pure speculation).