Prototype Small Wheeled Shooter

[sdcantrell56]

Originally Posted by Ether

Better yet:

a) remove wheels 2 and 3, and adjust the speed of wheel 1 until you get the fastest exit speed (call it s1), then

b) keeping wheel 1 at speed s1, add wheel 2 and adjust its speed until you get the fastest exit speed (call it s2), then

c) keeping wheels 1 and 2 at speeds s1 and s2, add wheel 3 and adjust its speed until you get the fastest exit speed.

Most logical process for dialing in the shooter that I have seen yet.

[billbo911]

Originally Posted by Ether

Better yet:

a) remove wheels 2 and 3, and adjust the speed of wheel 1 until you get the fastest exit speed (call it s1), then

b) keeping wheel 1 at speed s1, add wheel 2 and adjust its speed until you get the fastest exit speed (call it s2), then

c) keeping wheels 1 and 2 at speeds s1 and s2, add wheel 3 and adjust its speed until you get the fastest exit speed.

This is where a Chronograph will come in really handy!
Whether you use of a single sensor or dual sensor doesn't matter, either will take out the subjectivity of the measurement and just give you solid measurements.

[Bob Steele]

Originally Posted by JVN

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

While you are talking to them ask them about this law from Texas.....

If two trains going in opposite directions on the same track meet each other, one can't move until the other does.



Thanks for the clarification on the FIRST rule ...

[Andy Brockway]

Thanks to all have posted to this thread. We tested our version last night.

We had been running two CIMs at 1:1 with 6" wheels with mediocre results. We could score in the high goal but only if we were close to the wall.

Last night we ran the 2-7/8" Bane Bot wheels. Our set up is BB550 motors at a 19:46 reduction. Two wheels 4" apart. The disk is loaded at about 12" off the floor with an angle of about 40 degrees. Running the motors at 50% shot the disks over the top of the high goal from about 17' away. Higher speeds did not change the performance much.

We started with 10-3/4" spacing but were not happy so we added a piece of 1/4" poycarbonate. Current spacing is 10-1/2". No additional friction material.

[Kevin Sevcik]

Originally Posted by Andy Brockway

Thanks to all have posted to this thread. We tested our version last night.

We had been running two CIMs at 1:1 with 6" wheels with mediocre results. We could score in the high goal but only if we were close to the wall.

Last night we ran the 2-7/8" Bane Bot wheels. Our set up is BB550 motors at a 19:46 reduction. Two wheels 4" apart. The disk is loaded at about 12" off the floor with an angle of about 40 degrees. Running the motors at 50% shot the disks over the top of the high goal from about 17' away. Higher speeds did not change the performance much.

You forgot the other critical variable. What compression are you running?

[dbonar]

Thanks for all the discussion!

New shooter last night. Slow wheel is a CIM with a 2.5" soft neoprene wheel (1:1). Fast wheel is a mini-CIM with a 4" soft neoprene wheel (1:1). Compression and the spacing between the wheels are not optimized yet. We've ordered a taller 4" wheel and installing a top shield as the frisbee is definitely rising as it goes through. While we don't have the rotational speed that some teams are getting we managed a 53" distance (parallel to the floor start) before optimization.

[Madison]

Here's some video of us testing our own variation of this idea. I'm not yet thrilled with how it's working out. We're not getting a lot of distance out of it.

http://www.youtube.com/watch?v=FR7ppSZ7VS0

The video shows a few different tests spliced together. I didn't edit out anything bad -- including language, thus the dumb music -- so what you see is what we saw.

In each subsequent test, we're dialing back power to the wheels.

The details:
Input wheel -- Banebots RS550 motor through a 3:1 Versaplanetary transmission driving 2 .8" thick, green Banebots wheels.
Output wheel -- BAG Motor through a 1:1 Versaplanetary transmission driving 4 .4" thick, orange Banebots wheels.
Bottom surface -- 1/4" delrin sheet
Wall -- 1x1x.063" Aluminum tube with 1" wide urethane flat belting double-sided taped to the inside face.
Compression -- 3/4" compression, I believe.
Loader -- 6" stroke, 3/4" bore pneumatic cylinder
Angle -- 30 degrees
Exit Height -- 22"

Any thoughts?

[falconmaster]

Originally Posted by Andy Brockway

Thanks to all have posted to this thread. We tested our version last night.

We had been running two CIMs at 1:1 with 6" wheels with mediocre results. We could score in the high goal but only if we were close to the wall.

Last night we ran the 2-7/8" Bane Bot wheels. Our set up is BB550 motors at a 19:46 reduction. Two wheels 4" apart. The disk is loaded at about 12" off the floor with an angle of about 40 degrees. Running the motors at 50% shot the disks over the top of the high goal from about 17' away. Higher speeds did not change the performance much.

We started with 10-3/4" spacing but were not happy so we added a piece of 1/4" poycarbonate. Current spacing is 10-1/2". No additional friction material.

We found the spacing to be very sensitive, we see best results at 10 and 3/8" with the banebot wheels.

[Bob Steele]

Is anyone seeing any statistical/quantifiable difference between results when you compare the different banebot wheels (orange/green/blue)?

[AllenGregoryIV]

Originally Posted by Bob Steele

Is anyone seeing any statistical/quantifiable difference between results when you compare the different banebot wheels (orange/green/blue)?

I don't have the data but we were measuring better distances with the green wheels but they were getting damaged by the discs to quickly for us. The blue wheels weren't that of a much difference in distance.

[Bob Steele]

Originally Posted by AllenGregoryIV

I don't have the data but we were measuring better distances with the green wheels but they were getting damaged by the discs to quickly for us. The blue wheels weren't that of a much difference in distance.

thanks for the information!
One other thing.
Do you find that the Versaplanetary gear boxes get hot while you are doing your shooting testing?

We set up two tonight and it seemed that they were pretty hot after a relatively short time.

thanks

[CalTran]

Originally Posted by Bob Steele

thanks for the information!
One other thing.
Do you find that the Versaplanetary gear boxes get hot while you are doing your shooting testing?

We set up two tonight and it seemed that they were pretty hot after a relatively short time.

thanks

We're running BAG motors through VERSAPlanetary gearboxes at 3:1 entry and 1:1 exit, both driving 2.875" blue banebot wheels off a .5" hex shaft. The 3:1 doesn't change temperature too terribly. The 1:1 gets fairly warm rather quickly. Not sure if it's something to be concerned about or not right now. Still have yet to put our shooter prototype through it's paces. Will do extensive testing tomorrow and Thursday.

[Bob Steele]

Originally Posted by CalTran

We're running BAG motors through VERSAPlanetary gearboxes at 3:1 entry and 1:1 exit, both driving 2.875" blue banebot wheels off a .5" hex shaft. The 3:1 doesn't change temperature too terribly. The 1:1 gets fairly warm rather quickly. Not sure if it's something to be concerned about or not right now. Still have yet to put our shooter prototype through it's paces. Will do extensive testing tomorrow and Thursday.

We set up two to run on the BB 550 motors (a 5:1 and a 1:1) and both seemed to get hot very quickly. We followed the directions on attaching the motors ... but it didn't feel quite right for either one... a little too much binding when we clamped down the screws...

We followed the directions on how to assemble from the website..

We are doing the same thing you are with the same size banebot wheels and the hex shafts... we will try more tomorrow night.
thanks for the help!!

[Dale]

Bob,
It might also have to do with how the gearboxes were lubricated. Too much grease can cause of a lot of internal resistance and, of course, too little isn't a pretty sight unless you like metal dust. We use about a pea sized amount of grease per stage, either Superlube or Lithium is what we use but everyone has their favorite. Ours get warm but certainly not crazy hot.

[Botwoon]

Originally Posted by Bob Steele

thanks for the information!
One other thing.
Do you find that the Versaplanetary gear boxes get hot while you are doing your shooting testing?

We set up two tonight and it seemed that they were pretty hot after a relatively short time.

thanks

Our 1:1 boxes get uncomfortably hot after about 30 seconds or so. We definitely won't be running them full time.