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View Full Version : pic: KING TeC Drivetrain Prototype - All Wired Up!

AKSoapy29
06-12-2014, 19:30
[cdm-description=photo]40994[/cdm-description]
Abhishek R
06-12-2014, 19:30
Any plans to put a bunch of weight on it when you drive it? It looks great, will we get to see video :) ?
Gregor
06-12-2014, 19:31
I really enjoy the invert CIM stickers.

I'm curious to see how the hex shaft collars on the axles hold up. I've never seen that done on a WCD before, but it seems like a nice way to reduce machining.
Arpan
06-12-2014, 22:36
I really enjoy the invert CIM stickers.

I'm curious to see how the hex shaft collars on the axles hold up. I've never seen that done on a WCD before, but it seems like a nice way to reduce machining.

Anecdote here, but we ran a virtually identical drive last year. They were okay, but we had to tighten them every few matches. We'll probably switch to clips or bolts this year.
AKSoapy29
07-12-2014, 00:41
Anecdote here, but we ran a virtually identical drive last year. They were okay, but we had to tighten them every few matches. We'll probably switch to clips or bolts this year.

We are just temporarily using the collars because we haven't had access yet to the machines in our school. We will eventually replace them though.


And yes, we will try and do a video on Monday :)
snoman
07-12-2014, 19:46
Looks sweet. What's the pneumatics do for you?
Abhishek R
07-12-2014, 20:24
Looks sweet. What's the pneumatics do for you?

I believe it's probably for shifting, since there's just the one tank.
AKSoapy29
07-12-2014, 21:34
I believe it's probably for shifting, since there's just the one tank.

Correct, all the pneumatics do is shifting.
Dukenator76
08-12-2014, 11:09
What is the weight of it with motors and electronics and no battery?
blazeflipper
08-12-2014, 12:36
Very cool Gear boxes! Just curious what are your gear ratios and expected fps when fully loaded with 135ish pounds?
nomad725
09-12-2014, 00:18
What material did you use to mount the electronics on?
llamadon
09-12-2014, 13:50
Very cool Gear boxes! Just curious what are your gear ratios and expected fps when fully loaded with 135ish pounds?

Thanks! They are from West Coast Products.

The Ratio spread currently is 2.06, with calculated FPS at 7 in low and 13.5 in high. The drivetrain is currently unloaded (50 lbs roughly,) so we can't really tell between low and high.... They are both stupidly fast. We also purchased two different gear sets, and also pinions. We can configure the drive to the following speeds: 5.5/15 7/18 5.5/18 7/20.5 5.5/11 7/13.5 (low/high)

We'll see how many we have time to actually test.

What material did you use to mount the electronics on?

It is a perforated polypropylene sheet. You can find them online. McMaster Carr has them in stock.
AKSoapy29
09-12-2014, 14:50
The Ratio spread currently is 2.06, with calculated FPS at 7 in low and 13.5 in high. They are both stupidly fast.

Yeah, and the programmers capped the power to 80%!
asid61
09-12-2014, 15:57
Yeah, and the programmers capped the power to 80%!

Why? You have 6 cims running at <14fps in high gear.
Thad House
09-12-2014, 18:49
What kind of drive method are you using to drive it? If you are using tank drive or standard arcade drive, it would make it seem like it is really fast and hard to control. I would recommend something similar to Chezy Drive. We've been using Chezy Drive for the past 3 years, and it makes faster robots much easier to control, as long as you put set the gains right. 13.5 fps is fast, but not stupidly fast, which I would consider being 17+. Still anything over 10 fps is hard to control with tank.
audietron
09-12-2014, 18:51
I would recommend something similar to Chezy Drive. We've been using Chezy Drive for the past 3 years.

What is Chezy drive?
Thad House
09-12-2014, 18:55
What is Chezy drive?

Its a modified arcade drive. They use 2 separate joysticks. One to control throttle, and one to control turning. Some math actually changes the turning ratio so the robot turns in smooth arcs instead of sharp corners like standard arcade drive would. This makes full speed sweeping turns much easier, which makes the robot more controllable.

Their implementation can be found here. (https://github.com/Team254/FRC-2014/blob/master/src/com/team254/frc2014/CheesyDriveHelper.java)
audietron
09-12-2014, 18:58
Its a modified arcade drive. They use 2 separate joysticks. One to control throttle, and one to control turning. Some math actually changes the turning ratio so the robot turns in smooth arcs instead of sharp corners like standard arcade drive would. This makes full speed sweeping turns much easier, which makes the robot more controllable.

Their implementation can be found here. (https://github.com/Team254/FRC-2014/blob/master/src/com/team254/frc2014/CheesyDriveHelper.java)

That is essentially what we use but I just called it halo drive. I might just implement the "smooth arc" changes to our drive though to see what that is like.
audietron
09-12-2014, 20:13
do you have video of the drive running?
AKSoapy29
10-12-2014, 21:47
do you have video of the drive running?

Of our prototype drive, yes. Our video guy won't be able to render it immediately though :/

And just a linear drive is a bit to uncontrollable, so we are going to try to test out some different math functions for the different gears and see what handles the best.
Jay Burnett
12-12-2014, 10:15
How do you guys hold the wheels on to the shafts at the end? I'm designing a WCD for our team and was curious how other teams accomplished this.
notmattlythgoe
12-12-2014, 11:33
How do you guys hold the wheels on to the shafts at the end? I'm designing a WCD for our team and was curious how other teams accomplished this.

Our team, and I'd imagine most teams, uses snap rings.
Jay Burnett
12-12-2014, 12:10
Really? That's what i have in the CAD now, but I was told that those might not hold up under the force of the wheel trying to push off the shaft. Any specific type? Thanks!
audietron
12-12-2014, 12:17
Really? That's what i have in the CAD now, but I was told that those might not hold up under the force of the wheel trying to push off the shaft. Any specific type? Thanks!

We use klip rings which are a brand name type ring. They are a special type of e-clip but easy to put on and take off with a screwdriver.
Here is the link to them:
www.mcmaster.com/#98420a138/=uzrf5a (http://www.mcmaster.com/#98420a138/=uzrf5a)
AdamHeard
12-12-2014, 13:12
Really? That's what i have in the CAD now, but I was told that those might not hold up under the force of the wheel trying to push off the shaft. Any specific type? Thanks!

They are rated for a lot of force, and unless the snap ring is damaged by deforming too much during installation (easy to avoid with proper snap ring pliers) they are plenty for the job.