#garfield Logs

Feb 21 2025

01:24 AM rue_mohr: ok, I got esp8266 ADC via pwm working
01:52 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1330851.jpg
01:52 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1330853.jpg
01:52 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1330857.jpg
01:52 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1330858.jpg
01:53 AM rue_mohr: new cnc doing slotting,
01:53 AM rue_mohr: the esp8266 boards I made up
01:53 AM rue_mohr: and using a VFD screen with an esp8266 (wifi enabled controllers) to read some PWM to an 8 bit value
02:03 AM Tom_L: slot come out better on the new cnc?
02:04 AM rue_mohr: well, without the chatter I had to do a spiral path to get the slot a bit wider
01:46 PM rue_mohr: Hmm
01:46 PM rue_mohr: if I wanted to drill a hole in the end of 300 pipes
01:47 PM rue_mohr: and I set up a jig to hold 10 in the cnc
01:47 PM rue_mohr: I wonder if I could just loop it so as it drilled them I could change out the pipes for undrilled ones
01:47 PM rue_mohr: both ends of 30 pipes
01:47 PM rue_mohr: hmmm
01:48 PM rue_mohr: would GOTO be a M or G command...
01:52 PM Tom_L: umm, maybe leave out the M2? and put an M0 there instead
01:52 PM Tom_L: i'm not sure
01:52 PM Tom_L: or call a subroutine x times with an M0 in front of the call
02:56 PM Tom_L: does grbl support subroutines?
02:56 PM Tom_L: no
02:57 PM Tom_L: https://community.carbide3d.com/t/grbl-command-to-call-sub-routine/72704
02:57 PM Tom_L: maybe
02:58 PM Tom_L: doubtful
03:21 PM rue_mohr: no
03:21 PM rue_mohr: BUT
03:21 PM rue_mohr: what does my spooler software support!
03:21 PM rue_mohr: (nothing)
03:21 PM rue_mohr: (yet)
05:06 PM rue_shop2: ok, etching a pcb...
05:06 PM rue_shop2: not done this in a while
05:24 PM rue_shop2: have to install parallel port card, brb
05:59 PM rifraf: morning all
06:00 PM rifraf: arrived home to confirm i ordered wrong springs :( but they sure have some spring force, standing on one does not compress it much at all
06:04 PM rifraf: 70mm OD bellville washer very strong, can get about 3mm travel with 2 washers getting squashed in vice , still a fair bit but will need more
06:05 PM rifraf: needs more than 100kg force to squeeze, standing on these does nothing much to them
06:07 PM rifraf: a way to measure spring forces?
06:12 PM rifraf: force meter is only good for 50N, bathroom scales in the vice with spring?
06:15 PM rue_shop2: jugs of water?
06:15 PM rue_shop2: 1kg/L
06:15 PM rifraf: gonna be a few jugs
06:15 PM rifraf: need 100kg to start i think\
06:16 PM rifraf: trying the scales in vice things
06:29 PM rifraf: rather linear spring rate of 5kg/mm
06:30 PM rifraf: now need to decide how much force to keep a collet locked, and that will be the rest point, maybe 50kg?
06:32 PM rifraf: and then 5mm travel from the pneumatics will add another 25kg, plus any extra to break the collet grip, all doable i reckon
06:47 PM rifraf: belleville are measure 160kg/mm spring force
06:47 PM rifraf: bit of a difference
06:48 PM rifraf: but have some numbers to work with now at least
07:26 PM rue_shop2: hmm
07:26 PM rue_shop2: trying to etch a board
07:26 PM rue_shop2: NOTHING works anymore
07:26 PM rue_shop2: lots of work to just get set up
07:27 PM Tom_L: rifraf, i think they're likely stronger than the average coil spring
07:28 PM Tom_L: rue_shop2, etchang goin bad?
07:29 PM Tom_L: rifraf, https://calcdevice.com/belleville-spring-id12.html#:~:text=BASIC%20FORMULAS%20Spring%20load%20at%20sequential%20arrangement:,arrangement:%20CI%20=%20FI%20/%20YI%20.
07:30 PM rue_shop2: I had to unburry the printer
07:30 PM rue_shop2: the mouse on the pcb station didn't work anymore
07:30 PM rue_shop2: the spooler program didn't work
07:30 PM rue_shop2: the computer that sent to the printer was upgraded and had no parallel port
07:30 PM rue_shop2: the thermostat on the tank heater broke
07:31 PM rue_shop2: almost none of the plotter pens work
07:33 PM Tom_L: https://www.bellevillesprings.com/stacking-disc-springs/
07:35 PM Tom_L: https://www.design-engineering.com/how-to-determine-the-proper-disc-spring-stack-configuration-1004038694/
07:36 PM Tom_L: https://www.engineersedge.com/belleville_spring.htm
07:36 PM Tom_L: rifraf, one of em is bound to help
07:38 PM rifraf: Tom_L yeah a good deal stronger
07:41 PM rifraf: no idea on youngs modulus or poissons ratio, cannot use calculator
07:42 PM rifraf: only have the 2 belleville tom, stacked opposing
07:42 PM rifraf: more will increase the range, but is it worth $100 of washers, i really think these 5mm spings are more like the forces i am after
07:42 PM Tom_L: cost per washer?
07:43 PM Tom_L: the washers are too stiff?
07:43 PM rifraf: about $9 a pair i think
07:45 PM rifraf: no they are just very stiff, if i need those force i will try them, but we are talking a few kN at least, i would like to do testing with the spring forces i tested earlier, much safer and well if it does slip and unlocks, then the battle is won
07:45 PM rifraf: spent the evening drinkin beers with oxsta rue_mohr
07:46 PM rifraf: we pulled the whole headstock apart and he reckons it should all work
07:46 PM rifraf: we still could not find a better solution, sure a few things to try down the track if needed
07:52 PM rifraf: was able to home the radius cutter a little with needle files a little, enough to make a difference and take away a couple of ridges i could see under microscope, 400 grit cleaning them up well
07:54 PM Tom_L: sounds like you're making good progress
07:55 PM rifraf: i know, shame that work is gonna get in the way again in a couple of days
07:56 PM rifraf: got a couple of weeks for parts to get here now
07:57 PM Tom_L: work always seems to get in the way of fun
08:00 PM Tom_L: you know i was just thinking what about car valve springs?
08:00 PM rifraf: yep, was discussing them a bit last night, what thoughts did you have?
08:01 PM Tom_L: some from a performance shop might be stiff enough
08:01 PM Tom_L: and
08:01 PM rifraf: and he talk me some if how car clutch works
08:01 PM rifraf: but is not gonna be better in this application
08:01 PM Tom_L: some have 2 springs one inside the other
08:01 PM rifraf: diameter never very large though
08:01 PM Tom_L: clutch springs are weaker but more of them i would imagine
08:02 PM rifraf: i wonder if they are ans strong as the 5mm thick springs i just got though?
08:02 PM Tom_L: where did you plan to mount the springs? around the tube?
08:02 PM Tom_L: doubtful
08:02 PM rifraf: they take alot of force
08:02 PM rifraf: yes
08:03 PM Tom_L: they'd be more like 3mm
08:03 PM Tom_L: or thereabouts
08:03 PM Tom_L: maybe 4
08:03 PM rifraf: ok, well i don't think i want less than 5mm, they are giving me about 50N/mm
08:04 PM rifraf: depends if i can hold the collet in with say 50kg of force, the spring compressed 10mm
08:04 PM Tom_L: https://www.ferrea.com/valve-springs/c76
08:04 PM Tom_L: but then you'd have to know what vehicle has the big ones
08:04 PM rifraf: and then need to compress 75kg of force + collet locking force to release the collet
08:05 PM Tom_L: A typical racecar valve spring might have an outer diameter of around 1.550 inches, an installed height of 2.000 inches, and a spring rate of 644 lbs/in
08:05 PM rifraf: yep physicall these springs look like those valve springs, theses are bit larger though
08:05 PM rifraf: hrm, thats actually pretty close
08:06 PM Tom_L: they have single dual and triple spring setups
08:06 PM rifraf: 36mm = ~1.4"
08:06 PM rifraf: i can make a double when i get the new springs
08:07 PM rifraf: because i ordered these as OD instead of ID, the they will just fit inside the replacements
08:07 PM Tom_L: https://www.researchgate.net/figure/Dimensions-of-the-automotive-engine-valve-spring_fig6_366067576
08:08 PM rifraf: ok i need to remember how to calculate spring index
08:08 PM rifraf: arg no wonder i forgot it
08:09 PM rifraf: ah they have the spring rate, 10N/mm , BOUT 20% OF THESE ONES
08:09 PM rifraf: didn\t mean to shout
08:09 PM Tom_L: those looked like smaller ones too
08:11 PM rifraf: ok, so i reckon what i have is equiv to large valve springs from what i have seen
08:12 PM rifraf: so on similar track
08:15 PM rifraf: will take pic for context
08:19 PM rifraf: https://desire3d.com/images/public/springs.jpg
08:20 PM Tom_L: the washers look pretty hefty
08:20 PM Tom_L: i think those springs should work fine
08:20 PM rifraf: yeah cheers, same
08:20 PM Tom_L: and
08:21 PM Tom_L: you can always have them in compression for a bit more tension can't you?
08:21 PM rifraf: they will be constantly compressed
08:22 PM Tom_L: how stiff are those small washers?
08:22 PM rifraf: i need the free running state to be enough spring force to hold collet in but still allow enough compression for exjection of the drawtube
08:22 PM rifraf: did not measure, but can do a bit later, need spavver
08:23 PM rifraf: spanner
08:23 PM Tom_L: doesn't matter much really
08:23 PM rifraf: i have 3 sizes of smaller belleville, the sammel are about 0.7mm thick, the large are 2mm thick
08:24 PM rifraf: nope, but i like the num bers when you are trying to calculate the forces and make sure its being made strong enough etc
08:24 PM Tom_L: the small ones were a test though right?
08:24 PM rifraf: yep just tpo prove concept
08:25 PM rifraf: and it did with that setup, if i tighten springs a little more than they are cannot slide stock on collet
08:25 PM rifraf: in that phote they are not loaded much at all
08:32 PM Tom_L: gonno go get some R & R in...
10:40 PM rifraf: always unplug electromagnetic vice when not in use
10:40 PM rifraf: could not work out what the smell was, had bumped footpetal about an hour earlier
10:41 PM rifraf: had brass sitting on top of vice, went to get a piece and wondered why it was so hot
10:41 PM aandrew: heh
11:32 PM rue_mohr: rifraf, remeber the air regenerated cupric chloride etchant?
11:32 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1330888.jpg
11:33 PM rue_mohr: a few years ago I made some. I was never able to work out the tests on it
11:33 PM rue_mohr: I tried etching one side off some clad and it worked, but I think it would have taken any resist off before it finished
11:39 PM rifraf: rue_mohr sorry am not remembering, mine was always blue
11:42 PM rifraf: http://www.roboreprap.com/robotics/boardmaking/DSCF1287.jpg