20-02-2014 12:16

nxtmonkeys

Re: pic: Team 696 Teaser #2

Are those Pneumatic cylinders or shafts or what?

20-02-2014 12:18

D_Price

Re: pic: Team 696 Teaser #2

They look like a shaft of some sorts? And that is some intricate machining on the parts.

20-02-2014 12:21

O'Sancheski

Re: pic: Team 696 Teaser #2

They are shafts for Transmissions. The slot towards the rear is to accommodated the dog gear to allow shifting.

20-02-2014 12:49

Chris is me

Re: pic: Team 696 Teaser #2

I take it these are your transmission axles, and the step hexing allows for round bearings everywhere while using COTS sprockets.

Impressive work - how was it made?

20-02-2014 12:51

nxtmonkeys

Re: pic: Team 696 Teaser #2

So there could be two gears or more spun by the motor, and there could also be some free-spinning gears in the middle, as well.

20-02-2014 13:10

sanddrag

Re: pic: Team 696 Teaser #2

We actually make our sprockets as well, from 7075 bar stock, but they're basically a copy of the AndyMark or VexPro ones. We do use all round bearings in the drive system. That's the benefit of going down to 7/16" hex at the wheels and front and back sprockets. Also, we have no keys anywhere in the robot other than the 2mm key on the CIM motors, but we do use hex bearings (unfortunately) on the choo-ch.....uhh, other gearbox for a few reasons we couldn't easily avoid.

Machining this was a bit of a pain, primarily due to the length of the shaft and number of setups required. The machine shop that did these for us tells me that it was two CNC lathe and two CNC mill setups, with a 4th axis in a vertical machining center. The chatter marks on the 7/16" hex are because they didn't have a tailstock for their 4th axis, so it was sticking way out there.

The right way to do this would be with a live tooled Y axis lathe, or even better, a swiss screw machine. But, we don't (yet) have a sponsor with these types of machines.

20-02-2014 13:12

Thad House

Re: pic: Team 696 Teaser #2

They are shifting drive shafts, very similar to what 254 and 968 use. The 5/8 round are for the dog gears. The 5/8 Hex is for the shifting dog. Then the 1/2 Hex is for the Drive sprockets. The 1/2 Round then goes through the frame using standard 1/2 inch round bearings instead of Hex. Then the wheel attaches to the 7/16 Hex.

20-02-2014 13:26

nxtmonkeys

Re: pic: Team 696 Teaser #2

Sounds cool.

20-02-2014 13:46

paul_v

Re: pic: Team 696 Teaser #2

Deja-vu

http://www.chiefdelphi.com/media/photos/29636

20-02-2014 14:17

sanddrag

Re: pic: Team 696 Teaser #2

Yep, that's what we were going for. Our photography student went from almost zero experience with camera settings, to the photo I posted, in just a couple weeks time. The 968 one still is my favorite though, but we're getting better.

20-02-2014 17:00

waialua359

Re: pic: Team 696 Teaser #2

Its funny how you thank 968.
Being that you were part of that team, arent you thanking yourself?


Kidding.....looks great!

21-02-2014 15:59

Lil' Lavery

Re: pic: Team 696 Teaser #2

My goodness. I do not envy the machinist who had to make those. Though I envy their capability to do so.

21-02-2014 16:07

AdamHeard

Re: pic: Team 696 Teaser #2

Manual mill and lathe can make these parts without an insane amount of time.

21-02-2014 18:25

DampRobot

Re: pic: Team 696 Teaser #2

You would need some sort of clever jig for machining the hexes on a manual mill though.

21-02-2014 18:31

R.C.

Re: pic: Team 696 Teaser #2

You could use a 5c indexer or a 5c collet block.

21-02-2014 18:36

Re: pic: Team 696 Teaser #2

Put round shaft on mill, flatten one side, turn 120 degrees, repeat.

21-02-2014 18:58

Cory

Re: pic: Team 696 Teaser #2

http://www.amazon.com/5C-CB-5C-Colle.../dp/B0007Q1Q50

21-02-2014 20:03

Chris is me

Re: pic: Team 696 Teaser #2

Yeah, making a 120 degree turn without aforementioned "clever jig" isn't exactly easy to do precisely? You need the 5C collet to do it right.

21-02-2014 21:16

sanddrag

Re: pic: Team 696 Teaser #2

The part is definitely possible with a manual mill and lathe. It would just take some time, a decent machine, and someone who knows what they're doing.

22-02-2014 00:38

AdamHeard

Re: pic: Team 696 Teaser #2

If you really wanted to get around that it wouldn't be that crazy to tilt the head for one pass to get the process rolling.

Buying the $20 collet holder or using a dividing head (which is a fairly standard piece of manual equipment) is certainly easier though.

A basic milling machine w/ no extras can do a lot of things many people assume aren't possible if some basic math is used (which people often overlook and consider cleverness).