Disk brakes

has anybody used disk brakes from a bike on their robot? if so how did they work?
and i did check the forms for this one i didnt find anything

Team 38, The Nonebots, used a disk brake on their arm in 2005. If you look in the linked photo, you’ll see if just below the middle student’s left wrist. IIRC, it worked pretty darn well, as they were a regional champion is Rochester (?) that year…

Team 38, 2005

BEN

We have been using disk brakes for 3 years now, and they are really good to have. We didnt use the ones from a bike though we went out and bought some from a go-kart shop.

1126 also used a brake in the 05 season. it was amazing and worked amazingly with the proper programming. i’ll try to find a picture of it.

How would you actuate a disc brake on a robot?

we used a little 1/2" bore 2-3" stroke piston. it was pretty cool.

thats what we wanted to do a piston to replace the lever on a bike brake system…

I have an omni drive proof-of-concept machine i’m working on right now, uses just 2 motors to do swerve drive and am using a solenoid to actuate the disc brake on a part of the machine.

Yes, yes i know that you can’t use solenoids, but if anybody ever needs to have a way to do it easily outside of first i’ve found it works very well.

We used got our disc brake and the caliper for it from Northern Tool at a great price. Also an awesome place to get big tires cheap too, among other things… its like harbor freight on steriods for some stuff :smiley:

-Q

Brakes are actually a really good idea. I can think of quite a few instances where 4 locked wheels on a robot with heavy traction wheels could put up quite a defence against another robot trying to push it!

as rees ponted out to me there rather expenseve the (bike ones) and many time it is the wheels tracktion that the weak point not the drive tran, at least on are robot
but also many are fluied filled and first will not be happy with that

I can think of a pretty easy and cheap way to fab up some disc brakes.

Get some sheet aluminum, or round aluminum, cut out discs, drill them on a press, then make some sort of rubberized pad and a caliber.

Probably would cost around $50 for 4 wheels depending on how you did it.

Darn, now I want to go try it!

Here are the ones we have been using for 3 years.

http://zacm.com/gocart/brake/brakassy.jpeg.gifhttp://zacm.com/gocart/brake/brakeparts.htm

Keep in mind that there are other, possibly cheaper, methods of braking, including one build into the Victor speed controllers (see what 111 and several others did last year). For a different physical method of braking, look at 25s drivetrain.

The victors use power to slow down the robot. If one were to use say a solenoid to open a precharged air loop, which in turn powered a disc, it would use virtually none.

I think a disk brake to control more than one mechanism would be interesting if used to control say…a differential like thing to separate power to two or more different mechanisms from one motor. I agree with Sean, they aren’t as useful in the drivetrain as a mechanical locking mechanism in the gearbox itself like 25 had this past season.

That isn’t how it works. In “brake” mode, a Victor speed controller isn’t supplying any power to the motor. It’s simply connecting both sides of the motor together, turning it into a dynamic brake.

another good source for brakes is here. The ones I would use are about halfway down the page. http://electricscooterparts.com/brakes.html

the 120mm is 4.72 in in diameter and with activation from a pneumatic cylinder they would be quite effective.

Hmm I wasnt aware of that, thanks for the info. However, a physical brake im sure can stop shaft movement much better than an electronic one.

Indeed it can–at the cost of extra weight and complexity. (Granted, they can be quite light if you design it right–look at 25’s robot this year–but they still have mass.)

Just another one of those times when you have to take into account what you want more. :slight_smile: