Prototype Small Wheeled Shooter

Do you have Video? This info is great! We found that with a 10 3/8 gap it shoots farther, but we did not have non slip surface on angle. Will try adding that tomorrow. Here is our two wheel vid https://www.youtube.com/watch?feature=player_embedded&v=Jc8g9WMoQ2o

Would you mind sharing your shooting angle? We’re currently set up at 45 degrees, but I’m starting to think that perhaps it’s a little overkill.

  • Sunny G.

We haven’t measured any angles yet, we just have the prototype that we just change the angles until we make it. On the actual shooter we will test and then measure the angle so we can put it in code…If we get a chance today to test the proto then we will measure the angle.

I want to give you and your team big props. We’re using a similar design for our shooter and this has been a wonderful help!

Good luck at your regionals!

We got our prototype shooter running Sat night and hit 5 out of 6 3 pointers in following configuration;

20 ft
Shooter at 25 deg
Two RS550s on 1:1 versaplanetaries
2 7/8" blue banebot wheels
10.5 in compression with top plate
Stationary rail was a painted 2x4
The discs were still rising as they passed through the goals.

Couple of interesting observations;
On our first setup the plates the gearboxes were mounted to would flex. Made quite an improvement to hard mount the gearboxes.
The top plate made a noticable increase in performance when we reduced the compression distance to 10.5"
Tried some 3 7/8" wheels and there didn’t seem to be a noticeable difference in performance.

Three wheels, 1/4" apart, 10/3/8" compression, no non slip angle
Ratios of gear boxes go 5 to 1, 4 to 1, 1 to 1 order of motors is Bag, am, bag

We are getting flexing in the base, will improve in final design

Tried non slip surface on angle not much difference, Orange flat rubber, wheel tread, tape ect…

The farthest we can shoot is 27 feet

How is that 27 feet being measured. With just our two wheel shooter we were getting 30+ feet with the shooter mounted 2 feet off the ground and shooting parallel to the floor.

Sure would be interesting to see a bird’s eye view high-speed video in slo mo of the frisbee passing thru that third stage.

will get that on Sunday

Ok now we did 5, 3, 1 ratio

Shooting farther! Still have flex in base, will get more when we stop this

Very nicely done.

Think its due to our base flexing, it will not in the final model. We did shoot from around the Pyramid so it may be 30, 27 was in straight line

Got slow mo of two wheel

That tells me you had a lot of slipping in the 3rd stage. Maybe you still do. Try 2:1 for that second stage.

Just measured the latest distance in the hallway, from video last posted of three wheel shooter. 48feet! from 2 1/2 feet above floor

isn’t it illegal to trim the shaft of the motor down?
Well not illegal in Texas perhaps but illegal in FIRST?

R

4.1.7.2 R33-A

R33
The integral mechanical and electrical system of any motor may not be modified. Motors, servos, and electric solenoids used on the ROBOT shall not be modified in any way, except as follows:

The mounting brackets and/or output shaft/interface may be modified to facilitate the physical connection of the motor to the ROBOT and actuated part.
The electrical input leads may be trimmed to length as necessary.
The locking pins on the window motors (P/N: 262100-3030 and 262100-3040) may be removed.
The connector housings on the window motors (P/N: 262100-3030 and 262100-3040) may be modified to facilitate lead connections.
The Integrated Encoder Module (P/N: 276-1321) may be installed on the VEX 2-wire Motor 393 (P/N 276-2177).
The VEX 2-wire Motor 393 (P/N: 276-2177) gears may be changed or replaced per the Supplier instructions.

R33 give us permission to modify the output shaft otherwise tightening a set screw too hard would be illegal.

Thanks to Allen & Ether for posting the relevant rule. It is allowable per FRC Ultimate Ascent rules to modify a CIM shaft in this way.

I have contacted the Texas state legislature regarding your question, but have not heard back yet. My buddy is a cop, and he says he’s never had to arrest anyone for it, and thinks that if there is a law against it, it is probably one of those ones which isn’t strictly enforced. I think we can assume it is okay until we hear otherwise back from the TX lawmakers.

Luckily, Gov Rick Perry is a fan of robotics and FRC – if there is a problem in TX maybe he can help us resolve it?

-John

No we just turn robotics into an underground sport down here. Think of the wonderful and terrifying implications.

There is a special place in the afterlife down under (hint: not Australia) for people that crank down set screws into keyways.