So we are planning to do a stable shooter stystem on the 2022 rapid react challenge and we decided to put a 6 inch wheel/flywheel which will shoot the ball. But I cannot find a good wheel which we can use. Can u guys give me some ideas? About the wheel or the type
What specific objectives and constraints do you have? I would suppose being outside the U.S. so buying from the usual FRC suppliers would be more difficult than most of the people on this forum.
Yes Our team is located at turkey which is outside the us
If you have extra of the kop drive wheels that’s enough for the low goal
We aim for the high tho
The KOP wheels would be good for high goal as well
I would flip the question around - what wheels do you have access to, and how can you design around one of those wheels?
We have limited access to frc products and we usually buy it from deküp which is turkeys Andymark distributor.
This can mean suppliers that serve other audiences. Pneumatic wheels are often used on garden equipment. Some of the spoked wheels are like those used on some wheelchairs. There are probably industrial suppliers in Turkey similar to Grainger and McMaster Carr that sell suitable wheels.
AndyMark has a great line of wheels available in all sizes. My team is using 4" compliant wheels from AndyMark for our shooter this year, and our prototype worked great. So, instead of limiting yourself to 6" wheels, do some testing with the wheels you have available to see what works best - you may find a 4" wheel or a 7" wheel or something that works great, and adjust your design to accommodate the different diameter.
We wanted to use Colsons last year but could not find any that would work with our constraints. We used two KOP wheels, and they were perfect. The cargo is different this year, we have not begun prototyping our shooter yet, but we were going to begin with those, and test all the other wheels we have (including the colsons that we did eventually acquire).
8 in. Pneumatic Wheel Kit - AndyMark, Inc?
We are using this, and it sounds like we have a very similar system. I believe that we have a 6in wheel however. We use this wheel completely deflated FYI.
That is a wonderful idea.
Edit: I see someone marked this as thumbs down. I guess I may want to elaborate.
I have no idea if it would work, but I am excited about the idea (and we will try it as well) as frequently, they say with a solid object you want soft wheels, and with a soft object, you want hard ones. These pieces are in-between, so the pneumatic wheels could allow you the adjustability to be somewhere in the middle.
I totally understand that
a) They be inconsistent, and
b) The adjustability may hurt more than they help
but I do think the experimentation is a cool idea that I would never have considered.
We are using two 6" polyurethane wheels from Fairlane. If you want polyurethane on the outside you might look at cart and caster wheels locally.
On a 6" wheel shooter, the wheels have a significant moment of inertia, and spooling them up takes some time and energy. With 4" wheels the MOI is much lower and you may find you want to add MOI to your system so that the shot to shot time is lower. By storing more energy, the ratio of stored energy to energy leaving in the ball is higher. You still have to re-fill your energy budget… However, with enough stored energy you can just blow two balls through and have the velocity of the two balls be pretty close. With one, 4" wheel you will see the shooter slow down significantly when it launches a ball.
Some teams couple 4" shooter wheel(s) with a separate flywheel running at higher speed than the shooter wheels. This gives you more storage capacity per pound… MOI is a strong function of radius AND stored energy is a squared function of speed.
Smaller wheels have significantly lower stresses than large ones for the same speed.
Lots of trade offs to play with! Best wishes!
So thank you for the idea and I think that it is very smart, but I did some research today and found out these 4 in. Stealth Wheel, 1/2 in. Hex Bore, 60A Durometer | Deküp Robotics which could be really good at the job what are your thoughts
The Stealth wheels have been used on many shooters with success. We are planning to use them and they worked well in prototyping.
Honestly, with these balls, it is more the motor that you drive them with that will make or break your shooter. I would suggest 2 to 3 moderately sticky wheels side by side with a good high speed motor. You want to have plenty of extra high end on the motor, so that your normal shooting speed is not over 70%, if possible. But be prepared to add a true flywheel to your shooter so that it maintains speed throughout the shoot (don’t know for sure you will need it but it happens).
We are using 6 inch kop wheels and shooting high. They had good grip with these balls and were very consistent and we have a ton of them.