pic: Offseason Shooter CAD Project

[Sperkowsky]

loading photo ...

[Jay O'Donnell]

Looks pretty good. I see the cylinders connected to the back plate, I'm assuming that's for pushing the ball into the shooter wheels? Also what's holding the ball in place in the vertical dimension?

[Sperkowsky]

Originally Posted by Jay O'Donnell

Looks pretty good. I see the cylinders connected to the back plate, I'm assuming that's for pushing the ball into the shooter wheels? Also what's holding the ball in place in the vertical dimension?

Yea that is what the cylinders do.

As for the ball getting held in the vertical dimension. Currently the way it works is the ball compresses slightly against 2 of the hex shafts. It works in theory but in practice I'm not sure. Luckily those spacers are just 1/2 hex shafts so I could add rollers with 2 bearings and a tube on each side which should be more then enough to keep the ball in place. Worst comes to worse I could make resting points for the ball out of tubing and lexan sheets but I don't think that's necessary.

[S.P.A.M.er 17]

Is the pulley on the side for vertical aiming? Also, How thick are your blue plates, and what tap size did you use to secure the pulley plates? Do you see any potential problems with drilled out holes that are almost as big as the thickness? I've never done something like that, so I'm just curious.

[Ether]

What's your wheel diameter and expected operating wheel speed?

[Sperkowsky]

Originally Posted by S.P.A.M.er 17

Is the pulley on the side for vertical aiming? Also, How thick are your blue plates, and what tap size did you use to secure the pulley plates? Do you see any potential problems with drilled out holes that are almost as big as the thickness? I've never done something like that, so I'm just curious.

Yes, the pulleys on the sides are for tilting the shooter.

The plates are 1/4" thick. I am going to tap for 10-24 bolts which require a hole of .1495. A 10-24 screw is .190" in diameter. So, it does leave a decent amount of space left. Thinking of the failure mode I have a hard time seeing them fail but again I can not be 100% sure unless I tested it.

[Sperkowsky]

Originally Posted by Ether

What's your wheel diameter and expected operating wheel speed?

Math is not my strong suit so, forgive me if any of these numbers are incorrect.

The wheels are Colsons with a Diameter of 4"
Being its a 775pro which has a Free Speed of 18730 RPM the free speed after reduction (Technically a 2.08:1) is around 9005 RPM.

Typing the numbers into JVN's Calculator it says in reality it will be about 8990.4 RPM.

[Sperkowsky]

I added some 2x1 supports and modeled the shafts.

This GIF shows the motion path very well.

[Ether]

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[Cothron Theiss]

Any chance you could get longer belts and mount the motors on the other side of the pivot point? They'd act as a counterweight for the whole carriage and make everything a bit more balanced.

[Sperkowsky]

Originally Posted by Cothron Theiss

Any chance you could get longer belts and mount the motors on the other side of the pivot point? They'd act as a counterweight for the whole carriage and make everything a bit more balanced.

Yea, I totally could do that. Thanks for the idea.

I probably would have done that to start with but, this whole thing actually started as this.
http://i.imgur.com/EFDEC8s.jpg?1

I was just trying to learn how to model belts. And.... I got a little carried away.

Now... It has become this.
https://gyazo.com/b5cd294f84ccf905d3028937b3520f59

[EmileH]

Any plans for an intake? Or will your shooter be the intake?

[Cothron Theiss]

Originally Posted by Sperkowsky

Yea, I totally could do that. Thanks for the idea.

No problem. With the 775's, you can certainly get away with leaving the motors on the far end, but if you were running mini CIM's or had some type of gearbox as well, moving that to the back end becomes infinitely helpful.

Originally Posted by Sperkowsky

I was just trying to learn how to model belts.

Are you using the Belt/Chain Tool in SolidWorks 2016?

[Sperkowsky]

Originally Posted by Cothron Theiss

Are you using the Belt/Chain Tool in SolidWorks 2016?

I used the Belt/Chain Tool to actually model the belt but, I first did a sketch of everything.

I don't have a picture of the one from this particular project but, here is a picture of the sketch of the drive rail I am currently working on.
https://gyazo.com/aaef1a4585d9dbe3b34d1960f3728893

The thing to look at is the Path Length measurements. To get it I just put an arc around the pitch diameter of my pulley circle on opposing sides of both pulleys I am trying to link. I then drew lines to connect the 2 arcs and selected all 4 of the sketch marks and assigned a path length measurement which can be found under the drop down of smart dimension. From there I can just assign a belt length that I can find from a vendor and I know for sure the spacing will work.

You may know all of that but, I figured Id tell you what I did anyway.

[Sperkowsky]

Originally Posted by EmileH

Any plans for an intake? Or will your shooter be the intake?

There are plans for an intake on this not likely to be real robot. I am probably going to do a small beaver tail that is pneumatically actuated. If that appears to be heavy or not worth the effort I will do something similar to what 5172 did.

The robot getting built is entirely dependent on whether We can raise somewhere around 12 - 15 thousand before September. But, if we do get the money we will definitely build this for a local off-season or two. I am aiming to make everything as cheap as possible. Doing stuff like reusing wheels and pulleys for the drive train. So, maybe even if we do not raise that much money I can get our team to do a few extra fundraisers early in the year.

I am going to get to work finishing the CAD and then raising some money .