Team 1625 Introduces their 2011 Robot: Mr. Cringerpants

Mr. Cringerpants

10 Wheel Timing Belt Driven Lobster Drive

Custom 2 speed gearbox with 3 motors

Single jointed, telescoping, 4 bar arm with a wrist

3 Position Roller Claw

Minibot and minibot deploy not shown (It’s a surprise;) )

Looks great guys! Another innovative drive-train implementation and once again I’m impressed. Care to elaborate or point me to somewhere to show me how it works?

Being reminded of why 1625 is my favorite team in FRC- priceless.

That drivetrain. You crazy.

Correct me if I’m wrong, but do you guys have TWO drivetrains? One for forward/back, and another for strafing?

I am at a loss for words due to awesomness.

I have no idea how it works and I’m not sure if I am better off keeping it that way or not.

How do the strafing wheels come into play?

Why telescope instead of a higher arm joint?

Why is your arm joint a four bar kind of thing I’m so confused


That’s pretty beastly, Good job guys.

Cant wait to see this thing in action great looking bot.


Any videos of this thing in action? I’m really curious about how well your drive works.

Seems to me like 1625’s “lobster” drive shown here, is a relative of 148/217’s Slide drive (Nonadrive) from 2010, at least in how it works. It looks to me like the strafing wheels are actuated up and down to lift the other 6 traction wheels off the carpet.

Looks ridiculously awesome as usual.

Telescoping arm + roller claw remind anyone else of 233 in 2007? If that’s any sign of things to come. . . well, watch out!

I get how the lobster actuation works (downright ingenious imo) – the front/rear wheels are the rotation axes for the lateral wheels. Yet what really blows my mind is how the belt running between the two lateral wheels (‘lobster wheels’ ?) doesn’t get eaten when the robot turns in place during normal operation. Is there a differential not shown?

Awesome work!

I’m hazarding a guess that the left gearbox is chained to the front wheels and the right gearbox is chained to the back, or something similar.

Ahh, that would do it.

Looking good 1625! Your robot definitely has a unique look and feel to it. I’m excited to see how you do in competition, and how fast that minibot makes it up the bar :wink:


Glad I’m not going against that anytime soon.

Basically, it is a normal 6 wheel west coast style drive, only with internal belt runs rather than chain. The gearbox transfers power through the center wheel which then runs belt to the outer wheels. From the outer wheels the axles are extended inward to act as a pivot for the “Lobster Tubes” to rotate around. On one side of the lobster tube it is merely a pivot for the tube to rotate around, but on the other side there is a set of bevel gears to transfer power to one of the lobster wheels. From that lobster wheel there is an axle going through one of the wheels and it extends to the back of the lobster tube. On the end of that axle there is a pulley which runs a belt down to the other side to power the other wheel.

It is one drivetrain, but not all wheels are touching the ground at all times.

Strafing wheels or come down via a pneumatic cylinder. Telescope rather than a higher arm joint was based on some strategic and control decisions. The arm has a 4 bar support system for structural integrity.

As explained above there is a set of bevel gears on two opposite corners of the robot. Essentially when you drop down the lobster tubes forward becomes left strafe and backwards becomes right strafe. Here is a picture of the bevel gears on a lobster tube:

It’s actually quite fun to watch drive around with no bumpers, because all wheels spin at all times. It can really mess with your mind sometimes.

Awesome work. Can’t wait to see it compete!

It’s much more similar to 190’s 2003 robot, which had a very similar (secondary drop-down drive train) arrangement.

Amazing as usual!

Your team took a 6-wheel swerve drive to Einstein last season, and I would have bet money that we would have seen it again in 2011 (with the flat field, it seems perfect). On paper, at least, 6-wheel swerve has advantages over this drive system (strafing while translating…e.g. diagonal movement). Both drive systems are much more complex than a skid-steer drive, but clearly within the means of your team.

What was your decision process that led you to the “lobster-drive” over doing 6-wheel swerve again? Complexity/weight? Some perceived advantage that is elluding me? The cool/doing something novel factor? Just curious!

6 wheel swerve is great and if properly put into use it definitely has advantages. The one obvious advantage is diagonal movement. We went back and rethought our entire season last year when going through this design process. We found that almost 100 percent of the time when the strafing capabilities were put to use it was only for lateral side to side movement. This led us to believe that the diagonal movement might not necessarily be worth the time, weight, complicated code, and maintenance that come with having a 6 wheel swerve. Another advantage of lobster is that as soon as you drop the lobster tubes you know that you can go straight side to side. With a 6 wheel swerve you have to worry about having modules aligned to properly do a perfect sideways strafe. Yet another advantage of lobster is the ability to put in a drift function. Beyond what all the capability differences may be this drivetrain offers something that the swerve can not. It is a much more direct link between driver input and robot motion. This drivetrain essentially offers us the same advantages that our 6 wheel swerve offered us last year and possibly has advantages even beyond that and we plan to push it to its limits.

Just curious about the reasoning behind the double fittings on all the pneumatic connections… (Mostly in reference to the claw pneumatics)