pic: 48 Kicker Winch

This was designed by one of our alumni collegiate mentors, who got tired of me assigning him human winch duties for our prototype kicker.

Window motor with 3:1 gear reduction and Andy-Mark pneumatic dog clutch.

Two of our awesome local sponsors, Gilanyi Engineering and Manufacturing Services and Ajax TOCCO, contributed their CNC and waterjet services to this mechanism.

Now to test it on the robot and see if JVN’s spreadsheet is telling the truth… :slight_smile:

Looks great.
Nice design work.

Have you already confirmed a 3/4" bore cylinder will be able to disengage the dog gear? We tried a 3/4" bore on ours, and it wouldn’t pull out. To be safe, we switched it out with a 2" bore, 1/2" stroke cylinder. Very slick gearbox, can’t wait to see final pics of the bot!

We’ll find out today. :slight_smile: How much of a load were you applying to your system?

Can’t give you a numerical number, but we are stretching back about 12 strands of surgical tubing 6-8 inches, with the winch fighting that force directly. Its quite a bit to pull, but we get a pretty sweet kick out of it :slight_smile:

Darn, the first dry run didn’t quite work. We are having issues with a set screw holding the drive gear on the shaft. As the gear rotates under load the set screw is digging into the inside wall of the spool. I am thinking of taking another note from AM on this one and using a star retainer over the shaft instead of the set screw.

We haven’t set up the pneumatics yet to see if the pressure on the cylinder will pull the dog but using a screw driver to do the job we found the friction on the clutch to be quite extreme.

Tomorrow will hold our answers.

–A. Reed
~The Designer~

We’re doing the window motor too. We don’t do the 3:1 reduction, just direct drive. We were able to pull about 70 pounds with the motor, and do it quickly. We too had some trial and error on the pneumatics. We finally went with about a 6:1 lever arm to leave any doubt out of it shifting.

We had to go with a bigger cylinder and also go with a lever design to get mechanical advantage to disengage. There is too much force required to disengage with mounting the cylinder straight in line with the shaft.

Another viable solution is to reduce the diameter of your pulley. The smaller the pulley the lower the torque on your shaft, and thus a lower force to overcome when disengaging the dog. Our pulley is 1/2" diameter, aka its just the super shifter output shaft. :stuck_out_tongue:

Could you give us more information about the dog clutch you used?

Standard AndyMark dog into a plate cut (waterjet) to the same geometry as the inside of an andymark shifting gear. One word of warning though, use a much larger cylinder at least 1.5" bore to pull the dog out of the spool. The force provded by a 3/4" bore cylinder is not enough to overcome the friction of the system and dislodge the dog.

The Ri3D team used a lever arm, which can overcome the 3/4" bore size.

it looks some thing nice, it will be nice if you can tel me what the use of the cylinder.