#robotics Logs

Jun 21 2020

03:01 AM rue_mohr: heh, ok, I can do 21:1 in one gear step, but thats a damn big gear
03:07 AM rue_mohr: maybe if I do something to the effect of 5:1 and 4.2:1
03:10 AM veverak: seems better?
03:10 AM veverak: unless worm drive
03:10 AM veverak: wait
03:10 AM veverak: rue_mohr: isn't there like 4am at your side of the planet?
04:11 AM deshipu: which planet would that be?
05:03 AM rue_shop2: 4am?
05:03 AM rue_shop2: sure, its 3am just now
05:04 AM rue_shop2: hmm
05:04 AM rue_shop2: worm drive
05:04 AM veverak: close enough
05:05 AM rue_shop2: I suppose 21:1 isn't really backdrivable anyhow
07:09 AM squirrel1 is now known as veverak
11:39 AM rue_bed: that said, 21:1 isn't much of a worm drive, small output gear
11:45 AM veverak: I wonder if there is a place for 40:1 worm drive with 1:2 gear reduction
11:46 AM rue_mohr: how aboiut a cycloid drive
12:33 PM Tom_itx is now known as Tom_L
01:36 PM ThomasEgi: why not a harmonic drive gear?
01:36 PM rue_mohr: material fatiuge
01:37 PM rue_mohr: cycloid is harmonic without the material stress
01:39 PM Tom_L: seems to 'pulse' more too
01:40 PM ThomasEgi: why would it fatigue if you correctly dimension it?
01:40 PM ThomasEgi: it flexes but so does every spring. just a matter of designing it correctly
01:40 PM Tom_L: springs fatigue too but it takes quite a while
01:41 PM rue_mohr: neither should pulse?
01:41 PM rue_mohr: I just dont have to worry about material as much with cycloid
01:41 PM Tom_L: https://www.youtube.com/watch?v=KCLrzAtq3j4
01:41 PM Tom_L: looks like the outer ring isn't constant
01:42 PM Tom_L: aka wankel engine
01:42 PM rue_mohr: erm, isn't wankle different?
01:42 PM Tom_L: somewhat but not that much
01:43 PM Tom_L: it's opposite that video
01:43 PM rue_mohr: oo neat video, its just the way he's cranking it
01:43 PM Tom_L: the outer turns the inner
01:43 PM ThomasEgi: i thought it was about getting high gear ratios in one stage.
01:43 PM Tom_L: yeah
01:44 PM rue_mohr: he has that set up odd, I like it
01:44 PM rue_mohr: I need 21:1
01:44 PM rue_mohr: I dont want to make a project out of it, I did find normal gears
01:44 PM Tom_L: how do you calculate the ratio on those?
01:45 PM rue_mohr: I made a C program
01:45 PM Tom_L: https://us.sumitomodrive.com/en/page/how-calculate-cyclo-gear-drive-ratio
01:45 PM rue_mohr: when the outter is 22 and the inner is 21, its 21:1
01:48 PM rue_mohr: Tom_L, maybe there is a pulse effect from the way he set that up
01:50 PM rue_mohr: ok, why does youtube want me to get youtube premium
01:50 PM rue_mohr: would I be paying for it?
01:50 PM rue_mohr: would I be paying more than they get from the ads?
02:08 PM Tom_L: just say no
02:15 PM rue_mohr: hmm playing, 10 line encoder from 3d printer looks ok
02:18 PM rue_mohr: youtube cant put in enough ads to make up for what their storage is costing them
02:18 PM rue_mohr: heh
02:18 PM rue_mohr: ok, off to work