2073 Two wheel Boulder chucked prototype

[billbo911]

In the past, 2073 has been very open with sharing our prototyping and testing. Last year we deviated from that approach. This year we are returning to that approach once again.

Although there are a large varieties of ways to throw the boulder into the castle, we decided to prototype just a couple. This two-wheel style is one of our prototypes. In this video you can clearly see some of the advantages and disadvantages of this particular style of Boulder chucker. Can you say wobble?
If running both wheels at the same rpm, the boulder will come out just like a knuckleball. No spin, little stability. This can be overcome by running the wheels at different rpms. If you intend to put backspin on the ball, you will need to run these in a vertical position not horizontal.

[Ty Tremblay]

Originally Posted by billbo911

Can you say wobble?
If running both wheels at the same rpm, the boulder will come out just like a knuckleball. No spin, little stability.

I wonder how long of a shot needs to be taken for the lack of spin to actually make a difference.

[Starwarsguy2]

Originally Posted by billbo911

Although there are a large varieties of ways to throw the boulder into the castle, we decided to prototype just a couple. This two-wheel style is one of our prototypes.

Thanks! I feel like a lot of times will take this approach but hey, if it wasn't good then a lot of teams wouldn't use it.

[billbo911]

Originally Posted by Starwarsguy2

Thanks! I feel like a lot of times will take this approach but hey, if it wasn't good then a lot of teams wouldn't use it.

Whether we use this or another style will depend on several variables.
Mostly we chose to post this particular video because it contains so much valuable info on dynamics that occur during a shot.
By no means are we suggesting any one style or another...... yet.

[MARS_James]

I know some may see this as off topic, but everyone around the prototype should be wearing safety glasses, not just the one dealing with inserting the boulder.

[PowerfulKitty]

We made a setup almost exactly like that! Did you have issues with the BAG motors getting too hot? Ours were smoking in no time at all, so we switched to 775Pro motors and we have had much better results on that front.

[billbo911]

Originally Posted by MARS_James

I know some may see this as off topic, but everyone around the prototype should be wearing safety glasses, not just the one dealing with inserting the boulder.

James, you are 100% correct. THANK YOU for pointing that out. We need to do better.

[Monochron]

Do you have any data to share on approximate accuracy over different shot distances or heights? Maybe just something simple like the area of hit at a given distance? We are working on a similar prototype to this one, but it might be a couple days until we get results.

[billbo911]

Originally Posted by Monochron

Do you have any data to share on approximate accuracy over different shot distances or heights? Maybe just something simple like the area of hit at a given distance? We are working on a similar prototype to this one, but it might be a couple days until we get results.

At this point, we have no gathed data. We are still prototyping. What we use as a benchmark is approximately 7 foot apex when shooting from 5 inches above the floor, at a distance of 4 feet out. Those are our current minimum values.

[bEdhEd]

Originally Posted by billbo911

If running both wheels at the same rpm, the boulder will come out just like a knuckleball. No spin, little stability.

With all due respect, I beg to differ Mr. Bill

[billbo911]

Originally Posted by Ty Tremblay

I wonder how long of a shot needs to be taken for the lack of spin to actually make a difference.

Originally Posted by bEdhEd

With all due respect, I beg to differ Mr. Bill

It looks like you just answered Ty's question.
I'm guessing the symmetry of your shooter combined with the smoothness of the outer surface of the boulder, unlike a baseball, is allowing you to shoot very consistently.

[kprzewodek]

One thing to note is that you are putting a good amount of side loading on these gearboxes when you cantilever the wheel as shown. This is both adding extra resistance which could be why their smoking at the end. If you watch the video closely this flex in the system is also introducing an upward component on the launch. I would suggest possibly supporting the shaft end to reduce side loading and improve efficiency of launch.