14-06-2006 01:06

sanddrag

Re: pic: Saving weight (and rotational mass)

Wow, that looks really nice. CNc mill I presume? I've never really seen anybody lighten it quite like that before. What are the specs on that gear?

14-06-2006 01:43

Gabe

Re: pic: Saving weight (and rotational mass)

What was the weight originally before milling? 3/4 of a pound off of how much?
I have to say, that is some really nice machining. You guys (or girls?) have skills.

14-06-2006 08:57

Tim Baird

Re: pic: Saving weight (and rotational mass)

Yeah, we had to do that to most/all of our gears and sprockets. We decided to put almost every idea we had onto the one robot, so, it's the price to pay!

14-06-2006 09:58

KenWittlief

Re: pic: Saving weight (and rotational mass)

interesting. How did you choose the pattern? Was some analysis done on the rotational torque, and radial forces that would be encountered, and the amount of material required to perform the desired function.

14-06-2006 10:17

Francis-134

Re: pic: Saving weight (and rotational mass)

Wow, I'm glad my team isnt the only one that does that to all their gears (what can i say, 40 just loves to swiss-cheese everything). For our drivetrain, we brought the gears down even more than that and we haven't experienced any probelms, just in case you needed that extra .1 lb.

14-06-2006 12:36

Kevin Sevcik

Re: pic: Saving weight (and rotational mass)

Does anyone remember getting a free copy of ANSYS software with Mechanical Desktop way back in the ancient past? It would be rather useful for this sort of thing. Or a copy of solidworks with cosmosworks. Granted that both are much more useful with a working knowledge of the limitations of FEA.

14-06-2006 13:19

sanddrag

Re: pic: Saving weight (and rotational mass)

Inventor 11 Pro has ANSYS if anyone was wondering.

14-06-2006 13:56

M4 Sherman

Re: pic: Saving weight (and rotational mass)

Yes, we did use CNC milling and a little bit of lathe work. Its a .5" face gear, with about a 4.125" diameter. The webs are .25" thick and .5" wide.

14-06-2006 13:59

M4 Sherman

Re: pic: Saving weight (and rotational mass)

I dont know the exact weight of the gear, but before I started machining I weighed the entire transmission and it weighed 13.5 lbs.. After I was done machining the tranny weighed 12.75 lbs.

14-06-2006 14:07

M4 Sherman

Re: pic: Saving weight (and rotational mass)

We stayed .125" way from the bottom of the gear teeth. This ensures us that the gear will not deform or "crush" under its suggested maximum torque.

09-08-2006 00:20

P38 Lightning

Re: pic: Saving weight (and rotational mass)

Hey, that looks familiar