pic: FTC Custom Drive Train

[hectorcastillo]

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[cbale2000]

You might want to consider offsetting one of the motors on each gearbox up a bit to allow the gearboxes to be removed more easily if needed (might also help with wire access to the motors). We've had issues in the past where we didn't allow enough clearance to do maintenance on our gearboxes and it proved problematic.

Otherwise it's a very nice looking drive, I initially mistook it for an FRC bot. =)

[Gregor]

It's hard to tell from the AM page if the motor leads stick out straight back or if they come out the side, but if they stick out straight back your motors may need to be further apart.

[GarrettF2395]

What an awesome render!
I noticed the 90deg gussets you've got on top, but how are you planning on attaching the bottom 1x1 tubes to the drive modules?
The way it's set up now looks like you plan on welding it.

[hectorcastillo]

Thanks for the feedback! It hasn't occurred to me to offset the motors to make it easier to remove the gearbox and give room for the wires. Thanks. As far as how the bottom tubes are attached, they are riveted onto small plates with tabs that fit into small notches in the larger side plates. These small plates are installed during the assembly of the module.

Here's a closer look:
https://drive.google.com/file/d/0B8z...ew?usp=sharing

[MattRain]

Originally Posted by Gregor

It's hard to tell from the AM page if the motor leads stick out straight back or if they come out the side, but if they stick out straight back your motors may need to be further apart.

They stick out the side. The encoder cable sticks out the back slightly but can be bent up right away.

[FTC5110]

Nice. Do you have a weight estimate?

[carpedav000]

Those white wheels are illegal for FTC. AM designed stealth wheels to take their place

[Jeremy Germita]

Looks great! I love how flexible the FTC rules are getting and I'm excited to see how teams are taking advantage of those rules.

Remember that FTC fields are 12' square(thus far), 6-7 feet per second would clear the field in about 2 seconds. That's ridiculously fast for this scale. Scaling that up to FRC field sizes, it's like gearing for 30+fps free speed.

Here is a custom FTC drivetrain I built a couple of years ago. I clocked it at just under 3 feet per second without any mechanisms on the robot, but it ended up being about 2.5 f/s during competition. I found it was on the cusp of controllability on an FTC field. When 72 made v2 of that drivetrain last season, they geared it for 4fps and the NXT loop execution rate was definitely too slow to control the drivetrain without lag. It would travel about 4-6" between motor controller updates.

Just a warning. These may or may not be valid concerns for the 2015-16 game and control system .

[hectorcastillo]

Do you have a weight estimate?

As of right now it weighs around 13.25 lbs.

Those white wheels are illegal for FTC.

Those are actually 4" VersaWheels from VexPro. Although the color and tread pattern does look similar.

Remember that FTC fields are 12' square(thus far), 6-7 feet per second would clear the field in about 2 seconds. That's ridiculously fast for this scale. Scaling that up to FRC field sizes, it's like gearing for 30+fps free speed.

Thanks. When I was deciding on my gear ratios I knew I wanted something fast, but I wasn't exactly sure how fast was fast and how fast was too fast. But I figured that someone here could point me in the right direction so that I can make the right adjustments.

[ehochstein]

First off - I love the look of this chassis. My students put something together something that looks similar to this last year. I'll see if one of them can send me a photo and I'll post it.

How do you plan on attaching the motors to the gearboxes? I would assume the 6 mounting holes on the face, loctited?

[Fusion_Clint]

I love it, we are going to try incorporating the FRC Texas tubes this summer on the FTC scale.

I have a question, FTC normally requires the robot to pick up something, how to you plan on this drive-train allowing that? I would suggest leaving the "front" somewhat open.

[hectorcastillo]

Originally Posted by ehochstein

How do you plan on attaching the motors to the gearboxes? I would assume the 6 mounting holes on the face, loctited?

There are holes in the gearbox plate that line up with two of the 6 mounting holes on the motor, and yes, I would probably use a little loctite, but not too much in case I need to remove a motor later.

[hectorcastillo]

Originally Posted by Fusion_Clint

I have a question, FTC normally requires the robot to pick up something, how to you plan on this drive-train allowing that? I would suggest leaving the "front" somewhat open.

I originally had the front left open without the front tube. I made it so that you can open up the front and back to fit the needs of the game. Removing the top tubes would make it a little less sturdy, but there are plenty holes along the top of the drive modules to mount whatever structure you need to provide stability and not be in the way. I wanted this design to be as dynamic as possible since we don't know what the next game is going to be.

[Nemo]

Two things:
1) Very cool looking design. I hope you folks end up building something like this.
2) Thanks for bringing my attention to those BaneBots 6mm adapter hubs! That removes a pretty significant barrier to some of the FTC ideas we've tossed around on our teams.