Anyone know why the technokats had so much trouble this year with their transmissions or whatever was preventing them from moving to well, so often?
Heh quite an amusing story,
We were running great until one match the victor attached to our left side drill motor blew because metal shavings from the gearbox shot up into it and yeah, it stopped working. We replace it and go to our next match were the same darn thing happened on the right side to the drill motor BAH!
Saturday we had no problems until we got to the finals and we had a major collision during auton mode and we never had full voltage for the rest of the match. Afterwards we pulled the bot off to the side and checked it out and from that collision the nut on the fuse pannel for the main breaker ground wire came loose and the crimp basically never was fully connected…doh! It wasnt my fault, but it was my responsibility so I am fully taking the blame for it. Oh well.
here’s another technocat-related albeit slightly off-topic question:
why did the technocats switch from a six-motor drive assembly (drills/chips/fisher-price) last year, to a four-motor drive assembly this year?
What it basically boils down to is that my team is looking into a six-motor drive four next year, and I’m trying to do some homework as to wether or not it is feasible/useful, or simply overkill.
Why you ask?
heh its because we pulled way too much current last year and frequently tripped our 60 amp breaker. Plus this year we used 9 motors and we needed the two FP’s for our arms 
Im not trying to discourage you from doing it…more power to you
*Originally posted by D.J. Fluck *
**Why you ask?heh its because we pulled way too much current last year and frequently tripped our 60 amp breaker. Plus this year we used 9 motors and we needed the two FP’s for our arms
Im not trying to discourage you from doing it…more power to you **
Also, it was because it was simply overkill and we didn’t need it…actually we took off two of the motors last year too b/c of the overkill and breaker trippage thing, so we only had a 6 mtr drive base for a short while. 
so, from what I’m hearing, the general consensus is that its not a good idea?
*Originally posted by Solace *
**so, from what I’m hearing, the general consensus is that its not a good idea? **
No, not necessarily…
Jake, use your resources wisely…dont sacrifice a motor to your drivetrain if you could find other usage for them that would be better…the way we did it was overkill, but heck who knows what you guys could design
another reason i could think of…
This years drill motors are alot more powerful than last and that will help make up for the power loss associated when dropping out the 2 FP motors.
I think the 4 motors they used this year were probably just as powerful as the 6 motors they used last year.
what i want to know is how much advantage do you get by adding motors beyond 2 per side (if you’re doing tank drive)? It seems to me that no matter how carefully you calculate your gearing there’ll still be some variance in the actual motors (especially after a few rounds of competition) so won’t they either wind up fighting each other, or one motor wind up pulling all the others behind it?
The gearbox this year was actually ready for the addition of the Fisher Price motor as you can see in the picture. We decided against it because we needed the motors for the wings.
http://www.pictars.com/0412003/03-45-gearbox.JPG
(copy & paste link)
do you think that your three motor design would have continued to trip stuff even with the new 120a breaker?
Before you do that i would work out the power you could achieve with just the CIM and the Drill’s. Those 4 can pull 160 amps which theoretically is enough to trip the breaker(it really won’t). Secondly you need to find really high traction wheels if you really want to use that power. i think the technokats tore up the carpet once with that 6 motor system at nats(they had those metal treads). It might have been a different team, but either way they had more power than they could use.
If you’re working on it now. You have time to really calculate it all. Thats what i’m doing. But i’m going for something slightly different. My plan
*Originally posted by Ianworld *
Secondly you need to find really high traction wheels if you really want to use that power.
With 130 lbs. It would be hard to transfer the power to the wheels anyway. It would be overkill.
*Originally posted by Ianworld *
Before you do that i would work out the power you could achieve with just the CIM and the Drill’s. Those 4 can pull 160 amps which theoretically is enough to trip the breaker(it really won’t). Secondly you need to find really high traction wheels if you really want to use that power. i think the technokats tore up the carpet once with that 6 motor system at nats(they had those metal treads). It might have been a different team, but either way they had more power than they could use.
Heck we ripped carpet all the time…but anyway at certain points during matches last year we pulled over 200 amps with the old drill motors, cims and FP motors…and that was on a 60amp breaker…
basically right now with the motors and assemblies we have delt with, 6 has been overkill…keep working on it though, maybe FIRST will give out new motors next year (this isnt a confirmed fact nor a rumor.)
i hope they don’t put out new motors. I find it pretty annoying. We have to design new mounts and interfaces for them. Instead of improving old ones.
Just as a note though, that 60 amp breaker could do up to and sometimes over 200 amps for some period of time. It could consistantly do 120 amps easily(the matches are only 2 minutes). Thats why i was slightly worried that the new breaker would actually be tougher to use because it would be more accurate. Turns out its just good/bad. My team probably pulled about 160 consistantly this year and our breaker never tripped(our robot did… but thats different).
i hope they don’t put out new motors. I find it pretty annoying. We have to design new mounts and interfaces for them. Instead of improving old ones.
Just as a note though, that 60 amp breaker could do up to and sometimes over 200 amps for some period of time. It could consistantly do 120 amps easily(the matches are only 2 minutes). Thats why i was slightly worried that the new breaker would actually be tougher to use because it would be more accurate. Turns out its just good/bad. My team probably pulled about 160 consistantly this year and our breaker never tripped(our robot did… but thats different).
*Originally posted by Solace *
**do you think that your three motor design would have continued to trip stuff even with the new 120a breaker? **
The three motors/side probably wouldn’t trip the 120A breaker, but tripping the 60A wasn’t the only issue last year. We also could easily pull the battery voltage down low enough to cause the RF link to shut down, resulting in a “lurching oscillation” when starting at full throttle in high gear. With two motors/side, this didn’t happen as easily. On a few occasions, we also had “run errors” in the robot controller which might have been the result of very the high current pulls with six drive motors. Maybe some kind of automatic current limiting would be a good thing if running six drive motors and tallish gearing.
you are working on a six motor design for next year
?!
how do you know what the game is going to be next year - what the ‘problem’ is that your design must solve?
for all we know, there could be all new motors next year - or no motors at all!
wheels, treads, propellers… ?!
who knows what evil schemes lurk in the minds of Dean and Woody?
:c)
For all the problems you guys were having i was extremely impressed with how well you handled it, and i was honored to be beaten by a broken bot as long as it was yous guys:)
I cant wait till we set our purdue kids loose on the idea of a switching transmission:) weee!
Well, after our first year with the TechnoKat modified shifter, I can only say I am impressed with the design. No failures in two regionals, and nationals, and actually almost no signs of stress in the entire drivetrain. Tons of power and tons of speed!
Next year we will take a similar design and see how far it can be shrunk and lightened and still provide this awesome robustness of the original design.
Our only problem early on was that the boxes were ever so slightly narrow that allowed the three finger dog to be in both high and low at the same time, just ever so slightly. For two weeks it worked perfectly, then one day (Just before the first ship date) we shifted and BAM locked both of them in high & low and actually the shock through the box blew the pinions off the Drill motors and bent some teeth on the 0.7 mod mating gear. What a depressing day I must say. We modified the design to use all standard gears. On the CIM was a 48tooth 0.7 Mod and 16 tooth 20 pitch 20 dpa gear cluster welded together and pressed onto the CIM. The main drive was then a 50tooth:50 tooth 20 pitch for high and a 80 tooth:20 tooth 20 pitch for low. Probably a little overkill but worked fantastic. Again Team 45 fantastic design!