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 We're not here to build robots. We're here to build students. - GreyingJay [more] |
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By: Travis Covington
New: 25-01-2007 02:30
Updated: 25-01-2007 02:30
Views: 1479 times
I don't think these are hard to distinguish at all, so I won't even bother making you guys guess. I wanted to show a finished delrin side plate and one of the 7075 gears with dog cutouts. The 'numbers' say the delrin should hold up just fine... we'll see.
The caliper is there to show the plates relative size... somehow it got a lot smaller than last year!
Discussion
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25-01-2007 03:17
Jeff K.
Re: pic: 968 - Even more unfinished parts!!
That is niceee. I wouldn't expect anything less from 968 and 254.
25-01-2007 03:24
NMR
Re: pic: 968 - Even more unfinished parts!!
Grats Travis to yet another shiny piece of metal (seriously, 968 rawks)!
25-01-2007 03:35
Gabe
Re: pic: 968 - Even more unfinished parts!!
Wow, 968 and 254 are going all out this year with their robots. 7075, 7068, Delrin. Is your frame made from welded 2024 by chance? 
25-01-2007 03:50
AdamHeard
Re: pic: 968 - Even more unfinished parts!!
are you running two CIMS or one and a FP? I think you guys said you'd never run the FPs again, is that true?
25-01-2007 03:51
Travis Covington
Re: pic: 968 - Even more unfinished parts!!
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Originally Posted by AdamHeard
are you running two CIMS or one and a FP? I think you guys said you'd never run the FPs again, is that true?
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25-01-2007 13:48
sanddrag
Re: pic: 968 - Even more unfinished parts!!
Hrrm, I've seen this somewhere before. Oh yes, last night when I was holding my breath making sure we didn't crash the CNC. 
Anyhow, this particular plate has something special that you can't see. 
thank goodness
26-01-2007 01:08
David Guzman
Re: pic: 968 - Even more unfinished parts!!
Looks very nice,
I just have a couple of questions.
How are you guys cutting the teeth?
Whats gonna be the pitch on those aluminum gears?
Those plates are very nice and I bet this gearbox is gonna be supper light.
26-01-2007 11:56
Cory
Re: pic: 968 - Even more unfinished parts!!
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Originally Posted by David Guzman
Looks very nice,
I just have a couple of questions. How are you guys cutting the teeth? Whats gonna be the pitch on those aluminum gears? Those plates are very nice and I bet this gearbox is gonna be supper light. |
That gear will be 20 DP. The initial reduction is 32 DP.
26-01-2007 12:02
Pat Fairbank
Re: pic: 968 - Even more unfinished parts!!
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Originally Posted by Cory
They will be hobbed.
That gear will be 20 DP. The initial reduction is 32 DP. |
The only experience I have with hobbing is with the half-million dollar CNC hobbing machines they use at GM where I work.
26-01-2007 15:15
Travis Covington
Re: pic: 968 - Even more unfinished parts!!
These will be hobbed on generic hobbing machines whose sole purpose is cutting gear teeth. They are relatively simple machines - purely mechanical.
26-01-2007 21:15
Alan Ing
Re: pic: 968 - Even more unfinished parts!!
This past year, I made a gear hobbing attachment for a generic bridgeport milling machine. So far we have cut type 35 and type 25 aluminum sprockets from 6061 and 7068 as well as cut a few 20 DP and 32 DP gears in both steel and aluminum.
Unlike an indexing method where you cut one tooth at a time and reindex, a hobber spins the gear blank and proceeds to cut all the teeth as they revolve under the cutter.
Sorry, I don't know how to post pictures, but there are a couple on our website showing the hobbing attachment making a 25 DP cluster sprocket and a type 35 sprocket.
http://www.mckinleyrobotics.org/2007...es/0120-01.jpg
http://www.mckinleyrobotics.org/2007...es/0119-02.jpg
http://www.mckinleyrobotics.org/2007...es/0118-06.jpg
Basically, I put an optical encoder on the spindle of the mill which runs through an adjustable divider circuit which in turn provides step and direction pulses to a servo driver which turns the gear/sprocket blank at the exact speed to cut whatever number of teeth we want. The gear or spocket blank needs to turn at the spindle speed divided by the number of teeth you want to cut. Whats nice about this set up is that I can stop the mill midway, check measurements and start it up again without losing sync.
Unfortunately the pictures do not show the servo drive on the 5c collet spindle. Maybe the next time I set it up we will take some better pictures.
If there is enough interest, I might write up a white paper or something at the end of the season.
27-01-2007 01:54
sanddrag
Re: pic: 968 - Even more unfinished parts!!
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Originally Posted by Alan Ing
If there is enough interest, I might write up a white paper or something at the end of the season.
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27-01-2007 01:57
Gabe
Re: pic: 968 - Even more unfinished parts!!
Wait a minute, you made your own hob? Please explain, because that would also would be a very worthy white paper too!
08-02-2007 03:06
TKM.368
Re: pic: 968 - Even more unfinished parts!!
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Originally Posted by Alan Ing
If there is enough interest, I might write up a white paper or something at the end of the season.
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http://mckinleyrobotics.org/2007/vid...rocket_med.htm
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