pic: 319 Octagonal Drive Isometric

[BrendanB]

Originally Posted by Ty Tremblay

Here's the result. Weight is now about 36lbs.

This looks really nice. It also looks like you can pick up some more space in the center by shortening your side extensions now that you've moved the chains to the backside of the 2x1.

We haven't use the WCP gearboxes but we were really happy with our 3 CIM ball shifters this year. Something our mechanical guys really liked is the flexibility when removing them from the robot. We designed our chassis with a slot in the side plate as well as a large pocket in the bellypan so we could remove the whole assembly (gearbox, wheel, axle, etc) through the bottom of the robot. They found it was much faster and simpler to just separate the main gearbox from the third stage assembly when we had to replace the encoder gears for the updated version.

[TD78]

Originally Posted by Ty Tremblay

Here you go.

Note that the cantilever could be reduced further by the use of wheels other than Colsons.

Thanks so much.

Less cantilever is nice, but those Colson wheels are just so robust. No need to replace them throughout the year. When I was on 121, we used them from 2005 through 2008 without issue (and we had to make our own hubs then!).

I know a lot of teams like to use 7075 for the shafts to be lightweight, but for the little extra weight, I would try and go with steel (granted, as stated previously, that the steel hex shaft lines up well with the hex bearings). I saw a few teams last year shear some 7075 shafts (including gearbox direct drive shafts) and replacing those did not look like fun...

[mwtidd]

Originally Posted by BrendanB

This looks really nice. It also looks like you can pick up some more space in the center by shortening your side extensions now that you've moved the chains to the backside of the 2x1.

We haven't use the WCP gearboxes but we were really happy with our 3 CIM ball shifters this year. Something our mechanical guys really liked is the flexibility when removing them from the robot. We designed our chassis with a slot in the side plate as well as a large pocket in the bellypan so we could remove the whole assembly (gearbox, wheel, axle, etc) through the bottom of the robot. They found it was much faster and simpler to just separate the main gearbox from the third stage assembly when we had to replace the encoder gears for the updated version.

Brendan, I'm curious, did you guys opt for manual or automatic shifting? Did you find any pros/cons with your chosen approach?

[BrendanB]

Originally Posted by lineskier

Brendan, I'm curious, did you guys opt for manual or automatic shifting? Did you find any pros/cons with your chosen approach?

We've discussed developing an auto shifting program but the conversations usually end with us deciding that the programming effort should be focused on our manipulators and keep our driver in control of the robot so he isn't working against the robot if he feels the need to stay in low gear while an auto shifting program would quickly shift up on him. The biggest downside is we could be pushing a robot while in high gear but our driver was practiced and got into the routine of downshifting just before contacting an opponent so we didn't ram them hard. Both the operator and myself would verbally remind him to be be in low gear while pushing as a precaution.

[notmattlythgoe]

Originally Posted by BrendanB

We've discussed developing an auto shifting program but the conversations usually end with us deciding that the programming effort should be focused on our manipulators and keep our driver in control of the robot so he isn't working against the robot if he feels the need to stay in low gear while an auto shifting program would quickly shift up on him. The biggest downside is we could be pushing a robot while in high gear but our driver was practiced and got into the routine of downshifting just before contacting an opponent so we didn't ram them hard. Both the operator and myself would verbally remind him to be be in low gear while pushing as a precaution.

We've talked about it too, our solution to staying in low gear is when we're in high gear to do the autoshifting, but switching to low gear will stay in low gear. So you basically have an autoshifiting setting and a low gear setting.