Frisbee shooter

[BrendanB]

Probably most important is what resources do you have to build your shooter in 10 days with? If you could post a picture of your previous linear shooter and current shooter that would be great! What wheels do you have or have tried in the past? What gearboxes do you have sitting around your shop?

Our linear shooter was three bag motors through 1:1 versa planetaries with 2 7/8in banebots wheels. Opposite our shooter was a wall covered in wedgetop tread and compressed the discs about 1/2in. We noticed a huge difference in our shoot distance/consistency when we added more compression.

[protoserge]

You need compression on the frisbee to transfer enough kinetic energy to it. Some of the 3M grip tape or other friction material will be useful on the wall. For the wheel, the BaneBot, pneumatic, and AndyMark hi-traction kit of part wheels worked well.

You can make a very effective shooter out of plywood. The hard part is indexing your discs so that you don't jam the shooter.

[Ether]

The purpose of compression is mostly to reduce slipping between the frisbee and the wheel, and the frisbee and the fence, to impart spin. Without spin, the frisbee will not travel very far. That's why most teams add some sort of friction surface to the fence. You want the frisbee to roll on the fence, not slide.

[fr05ty27355]

Here's what our team's shooter looked like:
http://i.imgur.com/cTw6mas.jpg?1
http://i.imgur.com/KRfkpUV.jpg?1
We used two mini cims and I believe we geared them down slightly. The blue thing is a piece of foam similar to pool noodle material (I think what we actually bought was a yoga mat). This material gave us compression and and the wedgetop tread on our shooter wheel provided grip. Together these allowed for minimal slipping on the frisbee. We cut an angle into the foam to prevent the frisbee from walking up the side of the channel and we added teflon tape to the plexiglass rails that the frisbee rested on in order to reduce friction as much as possible.

[Gemmendorfer]

We used a linear design that got plenty of speed. We used two pneumatic wheels attached to a CIM and Mini CIM, with distance from the edges of the wheels to the other side of the track 1/2 an inch smaller than the frisbee diameter. (We cracked a piece of plywood with our shooter around 80% power).

http://www.youtube.com/watch?v=AfY-uYwHv50

[rhp3794]

Hi, here are some fotos of our shooter.
We have a mini CIM and a CIM connected directly to two wheels of 6" diameter; the shooter is linear so we have a space between the wall of acrylic and the wheels of about 27 cm. We try to shoot at 30 degrees then in 45, but we stell have problems geting the height (we only get like 1,70m ).
I don´t know were is the problem, maybe it could be the compression of the frisbee or the speed of the wheels (we connect both motors to the battery and I think we achieved good speed)

any help will be great

[xForceDee]

I have not seen many teams have much success with those wheels as shooting wheels. If you click on the link in my signature you can see how well they worked for us (not saying they can't but there certainly are better options). I would recommend these pneumatic wheels but it looks like you have a different concept in mind. So instead, I suggest using these wheels and play around with different compression and opposite wall surfaces (the goal as Ether pointed out is to get the disk to rotate).

[z_beeblebrox]

If you can get the packaging to work, CIMs direct-driving the 8" pneumatic wheels in a linear or circular shooter with some compression work great.

[orangemoore]

If the poly carbonate you are using for the shooter is flexible it may be wasting all of the compression you have tried to make.

[TOPHER097]

My team used a linear design, but the properties are the same for both linear and circular designs. The key is to have as much grip/friction on the wheel and the other plate the frisbee is riding on. With these two points of contact, the frisbee will get a good spin=longer distance and higher rise. Another main thing that you will want to focus on is the compression. The compression determines the friction between the two points of contact on the frisbee. My team never got our compression perfect, but after some trial and error, you will get it right. One last key is to have the frisbee travel through the shooter will little to no friction, this is to keep the spin and speed constant throughout the shot for an accurate ending location (use a material like delrin).

[rhp3794]

our offseason is this saturday, maybe we could ask for pneumatic wheels to a team close to us.
we are going to try changing the fence from acrylic to wood

[Qbot2640]

We had marginal success with a radiused shooter using similar speeds in the spring, but decided to attempt to recreate team 67's incredible shooter as an offseason development exercise for our new builders. The results were incredible. While it is obviously not the only way to do the job...it works.

Whatever you end up with - don't overlook compression of the discs...that was the biggest factor affecting the performance of our radiused shooter - but it was very difficult to adjust the compression in that configuration...in a linear shooter it's just a matter of moving the fence.

https://vimeo.com/75662715

[jspatz1]

Team 1986 shooter: 2 stage
1st stage - CIM direct drive, 2008 KOP wheel (6" w/ solid rubber tread), 50 degree arc of contact against bare solid wooden fence, 1/8" of compression.
2nd Stage - Mini-CIM direct drive, 2008 KOP wheel, straight path against bare aluminum fence, 1/8" of compression. Approx. 6" of close 3-sided guiding after the final wheel.

[Peyton Yeung]

In our first iteration of our shooter we had a bare polycarbonate side wall supported by aluminum. Our initial results were less than satisfactory (only a few meters). We added a tacky material to the side wall and the results were astounding. We were shooting a few meters before and with the added sidewall material we could shoot full court.

[Chris is me]

As a counterargument, our two wheeled linear shooter had plenty of shot consistency with a smooth polycarbonate wall on the opposite side. Our shooter was far from an optimized solution, but if you're trying to build a simple cycler, you don't need a perfectly optimized solution. You just need a consistent and effective solution.

Here's our shooter specs, if it helps you:
- Two Banebots 4 7/8" wheels plugged into two mini cims or a cim + mini-cim (honestly doesn't matter) using the AndyMark 8mm to hex adapters
- 10.5" between the tips of the wheels and the opposite wall of the shooter (so .5" disc compression)
- Polycarbonate on the opposite side of the shooter. I've heard from MANY teams that wedgetop tread or other grippy material works well, so consider that an option too, but you might not need it.
- Plastic strips above and / or below the shooter barrel such that frisbees sliding through are physically constrained in the shooter. Basically what this does is it forces the frisbee to contact both wheels rather than lifting up between the wheels and not getting full contact. This dramatically improves vertical consistency.

We used an aimable shooter so I can't tell you if this consistently fires the exact same height over 1,000 shots, but if everything was working all 4 discs would hit almost the exact same place every cycle. This definitely isn't the best way to build a shooter, but "done" is better than "perfect".