Plain and simple: cable attaches to leg and pulls back against the surgical tubing holding the leg. A 1/2"-stroke pneumatic pulls two gears apart, thereby releasing the full fury of our leg.
*Note: the mechanism pictures is in advanced prototype stage. AKA: the final will be prettier looking.
Sweet idea! Are you having any problems with the gear teeth breaking under the increased forces as they engage/disengage? How fast does it pull back/whats your kickers range? Show this baby on the final bot too please
Can you share the gear ratio of the gearbox? Standard Toughbox or custom?
It is a modified toughbox, containing only a 14 tooth CIM gear (attached to the window motor) and a 50 tooth output gear. The cylinder disengages the gear, allowing a 6" IFI wheel attached to the output shaft (not shown) to spin freely.
We added more structure than what you seen in this picture to prevent the bottom plate from bending when the cylinder extends.
We will probably increase the cylinder bore size to 2", since the current one cannot hold the load we desire.
Holy bending angle bracket batman! You might want to consider cross-bracing on that bracket?
I like the idea though! What ensures that the gears re-mesh after a shot?
Only half the winch is shown in this picture; Believe me, we have a cross bracing on it now.
The bearing holes are slotted in the toughbox casing. So far, by just using that slot to guide the gear and extending the cylinder, we have had no problem keeping the gears engaged. The only issue we have is when a large force is applied, the gear sometimes skips.
We have not yet had teeth-breaking problems, but we are going to watch that closely.
We can load the kicker to its full strength in less than 5 seconds; hard numbers will come later. Our range is currently approximately 18’ with a height of 2’. However, we are testing foot designs/angles to see what works best.
Will do. Come to BMR, Buckeye, or Atlanta and see for yourself!
Very interesting take on a clutch mechanism. I’d like to see some video of it in action if you have any.
For anybody having issues with kicker winches, these little window motors work great;) Of course they don’t back drive unless you really pull on them.
The little window motors don’t do much work, compared to a CIM, so you might need to wait around a while for it to winch up your cable
Agreed, we used the CIMs and Fishers on ther things, so I had a choice of pneumatics, the 555 or the window. The 555 is pathetic. On our system the window motor is directly coupled to the shaft, and takes 3 seconds to winch back 70 pounds. Ball is going 40 feet at 9 feet at it’s highest point. Of course we just go off half cocked to shoot closer to the goal.
What is the length of your pneumatic cylinder? What is the bore measurement?
Be careful of calculating the frictional forces on the gear you are pulling.
Are you pulling a dog gear ??
We are using a similar system but using 2 pneumatics … the dog gear winds the capstan and the tension is held by a ratchet and pawl… we then pull the dog gear with a pneumatic and release the kick with the 2nd pneumatic which releases the pawl.
Our design engineer thought that the friction in the dog gear would be too great to pull effectively with a short throw pneumatic.
We are winding with a Banebot transmission and a FP motor.
No, we are just disengaging a 50-tooth gear. We used parts from an old AM Gen 2 and an off-the-shelf ratchet to test the dog gear-ratchet approach, but like you said, the friction forces prevented the dog gear from disengaging. After trying a number of things (like beveling down the “teeth” of the dog gear), we switched to this idea.
It is a 1.5" bore cylinder with a 1/2" throw.
It’s been a little while since I’ve seen a mesh-shifter in FIRST, and this is about as close as I’ve seen recently. Definitely cool, used to be a lot more stuff like this in FRC.