01-01-2016 18:06

asid61

Re: pic: 1540's new 3 cim dog shifting gearbox

Looks good, reminds me of some of the low-profile shifters I've seen on here.

The way you've done the lightening pattern seems nontraditional. I think if you added a few more struts you could greatly increase the strength of the gearbox.

What cylinder are you using to shift?

That low speed seems fine for 3 CIMs, but do you have a plan for if you brown out?

EDIT: Are the gearbox plates flippable? Interesting, I haven't seen that feature before.

01-01-2016 18:12

Ari423

Re: pic: 1540's new 3 cim dog shifting gearbox

How are you planning on attaching the gearbox to a chassis?

01-01-2016 19:14

Munchskull

Re: pic: 1540's new 3 cim dog shifting gearbox

Looks good. Obligatory warning: The roborio is at risk if browning out from the current load and subsequent voltage drop of a 6 CIM drive train.

01-01-2016 20:11

Adolfo Apolloni

Re: pic: 1540's new 3 cim dog shifting gearbox

We ran bolts through the tubed took of our frame and then through the bottom 4 standoffs of the transmission. While this cantilevered the gearbox a bit, we found that with 4 bolts, that attachment technique worked just fine on one of our off season robots.

The gearbox plates are flipable.

We used .5 inch stroke, .75 inch diameter bimba button cylinders for shifting.

As for brownouts, we found that they only occurred when we were in high gear and we plan to add software base current limiting in the future to account for this.

01-01-2016 20:48

Chak

Re: pic: 1540's new 3 cim dog shifting gearbox

Why did your team decide that this is necessary? If the flipable gearbox plates is not a requirement, you can save material and space by cutting out or lightening the corner of the gearbox that doesn't have a shaft in it.

01-01-2016 21:25

Dunngeon

Re: pic: 1540's new 3 cim dog shifting gearbox

Under what types of testing scenarios? How much did the robot weigh/battery condition?

02-01-2016 00:16

Adolfo Apolloni

Re: pic: 1540's new 3 cim dog shifting gearbox

The robot with a battery and bumpers weighed about 120 pounds. We were using 1 battery per match and we were using batteries that were purchased at the beginning of the 2014 and 2015 seasons. We tested this robot in the off-season competition called bunnybot that team 1540 hosts in December.

As for the flipable plates, we kept the section in the bottom corner so we had the ability to add a power takeoff if we wanted to later. It is an inconvenient spot for a power takeoff as it is on the bottom of the gearbox but we thought is was better than nothing.

Here is a link to a step file of the gearbox.

https://drive.google.com/file/d/0B40...ew?usp=sharing

02-01-2016 02:02

Munchskull

Re: pic: 1540's new 3 cim dog shifting gearbox

What about other mechanisms, what were their power draws?

02-01-2016 11:14

Adolfo Apolloni

Re: pic: 1540's new 3 cim dog shifting gearbox

I don't know exactly how much current the other mechanisms drew but we did have a football shooter driven by 2 cims and a football intake that was driven by a bag motor on that robot