Drill motors

[dddriveman]

How many drill motor should we get next year?

[FotoPlasma]

Two more than we need.

[Kevin A]

I think that 2 is enough. 2 is enough for rookie teams to have a simple powerful robot. If you gave them 4 then there wouldn;t be a need for teams to make shifters and let the creativity really flow.

[sanddrag]

The need for shifting is not based on the motors you have or how many of them simply because everyone gets the same motors in the same quantity. The need for shifting comes from potentially having something better than many other teams.

[Kevin A]

yes, but the drills have built in shiftable gearboxes. And i didnt mean only shifters, i mean i made a gearbox for the chippys that didnt shift. That would not have been required if four drills were provided.

[Rob Colatutto]

How would just having 2 more motors make shifting gears not required? If you think about it then people could have 2 drills and an atwood per side on their drive. Now your saying that drive locked into 300rpm is just as strong as the same drive with a shifter capable of 300 or 100rpm? As was said...the main reason some teams make a shifter is to give them that edge over other teams who are locked into 1 speed. Not to mention shifing to a lower ratio reduces the current draw and lets you push against other robots without worry (most the time)

[Jeff Waegelin]

Well, 4 drills would make swerve drive a whole lot easier; perhaps too easy. If you have 4 identical motors, like the drills, you could just put one on each wheel, and not have to worry about matching speeds between two dissimilar motors.

[Matt Reiland]

Originally posted by Jeff Waegelin
Well, 4 drills would make swerve drive a whole lot easier; perhaps too easy. If you have 4 identical motors, like the drills, you could just put one on each wheel, and not have to worry about matching speeds between two dissimilar motors.

While I don't know if it would make it a 'whole' lot easier

(since you need to already make your own gearboxes for swerve anyway so changing the last stage to match the motors wouldn't be that hard) The FP and Atwoods are somewhat simple to match to the FP’s as described in many documents.

It does make the design much more common as you can have 4 (or 2 of L/R) identical interchangeable modules with the same motors. I think it would make a very nice powerful swerve robot. The hardest part to swerve in my mind is the control of 4 gearboxes both in steering, power levels, and the operator control system.

If we got 4 of the same drills……. I would probably put 2 of them together on each side with the Atwoods to make a monster shifter gearbox with incredible power and redundancy. But that’s just me.

[FotoPlasma]

Granted, designing and fabricating four of the same gearbox, instead of two each of two seperate designs, can be easier, but it depends on what a team's resources are. Either one could be trivial for a team with professional machine shop support, while a team without that support would probably want a standard design that they could copy for replacements.

I agree with Matt Reiland, however, in that the control system for a swerve drive is probably the more involved part of the design / manufacturing process. Speaking from experience (and I wasn't even the one programming the thing), testing and bugfixing and calibrating and recalibrating and compensating for hardware in software, etc., takes a lot of the time allotted to you for such a project as this.

[Adam Y.]

Well, 4 drills would make swerve drive a whole lot easier; perhaps too easy. If you have 4 identical motors, like the drills, you could just put one on each wheel, and not have to worry about matching speeds between two dissimilar motors.

Actually almost all designs can get through with using just a pair of similar motors for drive. You would just need another motor for steering.
Ackerman-Don't need a pair but it will improve power if you do use two of them for drivetrain.
Differntial-It will work with just a pair of drill motors.
Synchro Drive or Crab Steering-I have thought about it. You probably could make do with just two drill motors and have the others just free wheel.
The only one where you need more than two motors is the holonic or omni wheel deising.

[Ryan Foley]

Originally posted by Jeff Waegelin
Well, 4 drills would make swerve drive a whole lot easier; perhaps too easy. If you have 4 identical motors, like the drills, you could just put one on each wheel, and not have to worry about matching speeds between two dissimilar motors.

along the lines of what he said,
4 identical motors, on a standard tank drive, that would give you a lot more power, saves a lot of time with building coplicated drivetrains, alows more fancy/ complex designs for other things on the bots.
It would make drive train construction easier.
Or 2 extra drills wold give you more powerful mechanisms, other that drive.

[mtaman02]

just consider this the more motors you get, the less weight you'll have for other things b/c motors have weight and even though the speed controllers for them / wiring doesn't weigh that much that 1 ounce over could hurt your quailifications for a Comp. espicially if FIRST sticks to the 130lbs. 1 more motor would be a lil better 2 would make it to simple and designs for drive train would be near but not quite similar. 3 drillls for drive train would make things a lil more interesting and 2 drills would bring out some awesome designs. like it has done so in the past couple of years so either.


A: keep the amount of Motors the same
B: Add an additional motor
C: Add an additional 2 motors. and suffer possible weight constricting / restricting designs

[sanddrag]

Just because you get two more motors doesn't mean you have to use two more. It's just nice to have more options. And as for wiring weighing less than 1 ounce, I don't think so. Especially not with 8 guage to all 4 drive motors.

[Veselin Kolev]

I've said this in some other post, but adding another 2 motors of the same kind would make things too easy. Notice how only 4 motors are practical for drive trains? And they are 2 different types. Last year, you could have added the fischer prices and got about 2/3 more horsepower, but that's a challenge to do. Giving us 2 more drills gets the horsepower a little past 3, and it's pretty easy to modify last year's 4 motor to a 6 motor. FIRST wants to give us a challenge. If you want to make a better drive train, make one with 2 or more gears, or a swivel or whatever. If you are just going for more power and not complexity, ask yourself this: do you really want a battlebot? None of FIRST's games involve a robot that is only one big drive train. And if you are looking for an advantage while pushing another robot, you must remember the physics involved. A robot can only exert as much force on the ground as the wheels can permit. The equation is :

power on ground = traction of wheels x weight x power of motors

Since all robots are 130 lbs or close, it fully relies on traction and power. Most robots with 4 motors can drive up against a wall and burn out their tires, so it is the traction of the wheels that gives up first. Work on better traction, not more power. A robot with 2 drills and high traction will always beat a robot with 10 drills and medium traction. It's just a matter of how much of your motors' power you can deliver to the ground. But hey, I guess you can always dream about more motors

[Cory]

Originally posted by Veselin Kolev
None of FIRST's games involve a robot that is only one big drive train.

Actually, thats exactly what the last two year's games have involved

Cory