#linuxcnc Logs

Jul 17 2022

#linuxcnc Calendar

02:28 AM Deejay: moin
04:31 AM Tom_L: morning
04:55 AM JT-Cave: morning\
04:55 AM XXCoder: heys
05:26 AM Tom_L: 81F & few scattered sprinkles
05:50 AM JT-Cave: same
07:05 AM satiowadahc[m]: https://github.com/replaysMike/Binner
07:05 AM satiowadahc[m]: Many drawers are hard to keep track of. Even with labels
07:06 AM XXCoder: thats cool
07:07 AM satiowadahc[m]: Super useful for electronics. Takes a little more effort for other things. But Roy's drawers look like it could be useful for
09:24 AM -!- #linuxcnc mode set to +v by ChanServ
09:45 AM funkenjaeger[m]: I have a use case where I'd like to modify my soft limits during my tool change routine only - basically to mitigate any remaining risk of crashing the spindle assembly into the ATC tool rack during normal operation. Anyone done something like that?
10:01 AM funkenjaeger[m]: At a glance it looks like I can accomplish that by setting the `ini.y.max_limit` pin, and then I should be able to use `#<_ini[AXIS_Y]MAX_LIMIT>` to retrieve the original default to set it back to (and I probably need to do it for the joint(s) of the axis as well?). Just wondering if anyone's had success doing the same, and whether it's really that simple or if there are any 'gotchas' to be aware of.
10:02 AM JT-Shop: where are my parts brushes?
10:06 AM JT-Shop: looks like pncconf is the clear choice of newbees...
10:09 AM JT-Shop: I'm not greedy I just need one parts brush...
11:03 AM JT-Shop: a while true loop in python seems so wrong...
11:35 AM roguish[m]: JT-Shop: just posted another question on the forum...........
11:36 AM c101horse[m]: since im not finding much help in the qtpyvcp channel im asking once more here, does anyone have a tutorial on how to set up probe basic? i've followed the install and had the sim version running on the new machine, now how do i set it up so i can run my machine with it? since that is the part im hanging up on. in the meantime, the sim version doenst seem to wanna run since i've moved the pc from the kitchen to the shop and connected it
11:36 AM c101horse[m]: with the mesa.
11:39 AM roguish[m]: _discord_181695718124290048[m]: not sure if there is a turorial, but look here (it's a bit old, but may still help) http://www.qtpyvcp.com/
11:46 AM Tom_L: JT-Shop, in fairness, pncconf _is_ packaged with lcnc
11:46 AM Tom_L: i personally think yours is the better tool
11:46 AM Tom_L: c101horse[m], ask hazzy[m]
11:48 AM roguish[m]: Tom_L: ditto
11:49 AM Tom_L: spread the word!
11:50 AM Tom_L: some noobs will be trying parallel port though
11:53 AM roguish[m]: people really need to get away from this ancient parallel port stuff..... and old, useless computers.
11:55 AM roycroft: an rip4 and a mesa ethernet board (when available) cost about the same as a pc with enclosure
11:56 AM roycroft: i guess that "when available" applies to the rpi4 as well as the mesa gear
11:56 AM * roycroft still flashes back to the before times occasionally
12:00 PM -!- #linuxcnc mode set to +v by ChanServ
12:00 PM JT-Shop: and that _is_ the big problem if it's not part of LinuxCNC it's not going to be used
12:01 PM roguish[m]: JT-Shop: make it part of Linuxcnc
12:02 PM JT-Shop: I don't want to step on Chris's toes and compete with pncconf
12:04 PM JT-Shop: roguish[m], not sure what you mean by starting emccalib in the ini file? Do you mean you want to embed it in Axis?
12:05 PM * JT-Shop gives up searching for the 3 parts brushes and moves on to something else
12:05 PM roycroft: there are mulitple user interfaces in linuxcnc, including multiple ones that address essentially the same thing
12:05 PM roycroft: i'm not sure there's anything wrong with having multiple configuration tools as well
12:06 PM roguish[m]: no, I would like it to start up when lcnc starts up. the others can be started in the [APPLICATIONSS] section in an .ini file
12:07 PM roguish[m]: it's a .tcl not a .hal
12:08 PM Tom_L: JT-Shop, there are multiple GUI
12:08 PM Tom_L: there _could_ be multiple config tools
12:08 PM Tom_L: but i hear what you're saying
12:09 PM JT-Shop: I thought mine was better too
12:09 PM Tom_L: but
12:09 PM Tom_L: you don't support pp
12:09 PM Tom_L: push it as _the_ mesa config tool
12:09 PM JT-Shop: I actually had a pp tool too
12:09 PM Tom_L: oh
12:10 PM Tom_L: shopping for a better cable modem..
12:10 PM Tom_L: any thoughts?
12:10 PM Tom_itx: Arris Surfboard S33 or Motorola MB8600 were a couple candidates
12:10 PM roycroft: i bought what comcast suggested would be good
12:10 PM roycroft: i have an arris something
12:11 PM roycroft: get one that supports higher speeds than your service provider currently offers
12:11 PM Tom_L: i think both will
12:11 PM Tom_L: you can 2x the ethernet on the moto
12:11 PM Tom_L: the arris has the 2.x gb port already
12:14 PM JT-Shop: roguish[m], I don't see emccalib anywhere installed so it must be called by some other program
12:15 PM roguish[m]: it's called in the gui's
12:16 PM roycroft: i haven't used a motorola cablemodem, but the arris that i have has been in service for serveral years now without incident
12:16 PM roycroft: for whatever that's worth
12:17 PM JT-Shop: roguish[m], I know that but I don't know how it's loaded, emccalib is not in /usr/bin
12:17 PM Tom_L: i just clicked on the arris
12:17 PM roguish[m]: no, it's in tcl/bin
12:18 PM roguish[m]: oh, that's in source...... not sure where it is in an install. let me check
12:18 PM JT-Shop: usr/lib/tcl?
12:19 PM JT-Shop: ah usr/lib/tcltk/linuxcnc/bin
12:19 PM JT-Shop: hmm so you have to call it as a script somehow
12:20 PM Tom_L: roycroft, any suggestions for a wifi router/switch
12:20 PM roguish[m]: i looked at the axis source and could not see it. maybe just don't know what to look for.
12:23 PM JT-Shop: tclsh /usr/lib/tcltk/linuxcnc/bin/emccalib.tc
12:23 PM JT-Shop: seems to start it but something is missing even if you have axis running I get an error
12:24 PM JT-Shop: so the easy button says press a couple of buttons in axis to start it
12:25 PM JT-Shop: QtPyVCP has a menu item to launch it, you would have to see what Kurt did
12:28 PM Tom_L: so what type of cable for 2.5gb etherenet? cat6 or is there something better now?
12:42 PM roguish[m]: JT-Shop: that's why I posted the question. I figure someone, like Chris, could whip out the answer.
12:48 PM roycroft: cat 6 should work
12:48 PM roycroft: beyond that speed you'll need fiber, i think
12:50 PM Tom_L: i'll wait on the fiber for the next upgrade
01:02 PM c101horse[m]: i think i might need some fans in the control cabinet. its getting rather toasty in there
01:03 PM Tom_L: flow thru the whole thing
01:19 PM JT-Shop: well the splitter is out of gas thankfully
01:21 PM roguish[m]: JT-Shop: get the ax
01:27 PM * roycroft ponders working on a resaw outfeed table for his band saw, so he can cut the long veneers for his cabinet top counter
01:35 PM * JT-Shop has an X27 but doesn't use it anymore
02:25 PM * JT-Shop finally found the parts brushes after days of searching
02:31 PM roycroft: seems like years
02:31 PM roycroft: i hope you put them in the "parts brushes" drawer when you're done with them :)
02:38 PM JT-Shop: well they are in a tubby with my solvex gloves but I will put it somewhere where it won't get covered up again
02:40 PM gywilo[m]: I have zero experience with linuxCNC and am considering using it for a machine controller/firmware for a 5 axis (modified stewart kins) 3D printer.... (full message at https://libera.ems.host/_matrix/media/r0/download/libera.chat/bbf0098735a9ec475f839f4e85371854a784cad7)
02:43 PM gywilo[m]: Any concern running machine with Intel Celeron N5105 processor?
02:45 PM ZincBoy[CAON][m]: LinuxCNC can be good for a 5 axis setup and people have used it for 3d printers. The big requirement for the controller is having low and low jitter latency. The only way to find that out is to test it using the tools in LinuxCNC. Processor matters much less than the power management present in the motherboard/bios.
02:45 PM roycroft: boot off the livecd image and run the latency test if you are planning on using a parallel port
02:46 PM ZincBoy[CAON][m]: I would recommend using the Mesa interface hardware for a 5 axis setup. You will have issues trying to get enough IO with a parallel port.
02:46 PM roycroft: i would recommend the mesa hardware anyway :)
02:56 PM gywilo[m]: okay, thanks, that's helpful. I've got a small single board fanless computer here that I bought for this purpose. I'd like to test that for low jitter and latency first.
02:56 PM gywilo[m]: Does the livecd image have tools to run jitter and latency test, even if I'm planning on using mesa hardware instead of parallel port?
02:59 PM gywilo[m]: I'll start here
02:59 PM gywilo[m]: http://linuxcnc.org/docs/html/getting-started/getting-linuxcnc.html
02:59 PM gywilo[m]: looks like this is for latency test:
02:59 PM gywilo[m]: http://linuxcnc.org/docs/html/install/latency-test.html
03:00 PM gywilo[m]: it looks like that will cover both jitter and latency?
03:08 PM JT-Shop: for Mesa cards run latency-histogram --nobase
03:10 PM JT-Shop: jitter is latency
03:12 PM * JT-Shop watches chicken TV
03:19 PM c101horse[m]: wait, is there a different latency test for mesa's?
03:23 PM gywilo[m]: Ah, so the mesa board has to be installed for the latency and jitter test then?
03:30 PM jpa-: the --nobase just disables the high frequency "base" thread which is only needed for direct stepper driving
03:31 PM jpa-: it can improve your results, but on the other hand pretty much any computer is fast enough for 1 ms servo thread
03:37 PM roguish[m]: JT-Shop: a while back where you looking for a cam viewing program? see Blue Iris https://blueirissoftware.com/
03:51 PM JT-Shop: looking for something on my local lan not a cloud based anything
03:52 PM JT-Shop: $70 per PC is a bit steep for one year
03:53 PM roguish[m]: it's not cloud and will run on Rpi
03:53 PM roguish[m]: i don't know about that $70 year.....
03:54 PM JT-Shop: it's remote not local
03:55 PM roguish[m]: ok check this https://zoneminder.com/
03:55 PM JT-Shop: I have a Python3 PyQt5 program that displays 6 cameras for free... it needs some debugging. Sounds like a good project for me to work on now
03:55 PM roguish[m]: oh, you coder, you.....
03:56 PM JT-Shop: I've done zoneminder and eye something
03:56 PM JT-Shop: they all have issues
03:56 PM JT-Shop: motion eye
03:57 PM JT-Shop: I looked for a c++ Qt5 example but never found any...
03:58 PM roguish[m]: hey, whatever works for you.....is cool.
03:58 PM XXCoder: blue iris requires cloud?
03:59 PM roguish[m]: I don't think it does, but I would not swear to it.....never installed it.
04:00 PM roguish[m]: I'm seriously thinking of a few cameras around the outside of my house.
04:00 PM XXCoder: its nice to have
04:01 PM JT-Shop: https://github.com/jethornton/pyqt5-ip-camera
04:01 PM JT-Shop: that will display up to 6 cameras and a double click will zoom in
04:04 PM roycroft: what kind of cameras do you have?
04:04 PM * roycroft has been thinking about some surveillance cameras to put around the property, due to the neighbors and the transients who frequent the area
04:08 PM JT-Shop: POE IP cameras
04:09 PM JT-Shop: 6 Amcrest and one HikVision
04:18 PM roycroft: poe cams make sense to me - especially since i have a lot of poe injectors
04:18 PM roycroft: i have a couple poe gig3 switches, but they don't put out enough power to run several cameras
04:18 PM JT-Shop: the big boy MS391 saw is clean, sharp and full of gas and oil and ready for the next adventure
04:19 PM roycroft: https://www.amazon.com//dp/B081753HHH
04:19 PM roycroft: that doesn't look bad, and it's a resonable price
04:20 PM roguish[m]: I like Amcrest too. only problem is they are not US made, but I don't know any that are, too bad.
04:21 PM roguish[m]: but they are good units
04:21 PM roycroft: my firewall can keep it from sending pictures to china :)
04:21 PM roguish[m]: good value
04:22 PM JT-Shop: PTZ can be a problem if your not using their plugin and windblows
04:22 PM roguish[m]: same here. I block lots of stuff, like my cams, sprinkler controllers, NAS, etc. not allowed to go outside
04:22 PM JT-Shop: https://www.amazon.com/Amcrest-Security-Waterproof-5-Megapixel-IP5M-B1186EW-28MM/dp/B08K1M34ZQ/ mine are similar to that one
04:22 PM roycroft: i think i'd be fine with fixed cameras
04:23 PM roycroft: i only want to monitor some traffic zones
04:23 PM roycroft: such as the approach to my driveway, front door, and the shop doors
04:23 PM JT-Shop: maybe have one mounted to the water cannon for snotty kids
04:25 PM XXCoder: stunk spray :P
04:25 PM JT-Shop: I think the MS291 only needs gas and oil and a bit of filing on the chain
04:26 PM XXCoder: (kidding, pretty sure it counts as assult to stray stink oil)
04:34 PM * JT-Shop takes 5 with the Doobie Brothers before servicing the 021
04:35 PM JT-Shop: roycroft, VLC does a real nice job showing 1 rtsp camera with great detail
04:38 PM Tom_L: JT-Shop, i keep spare chains on hand in case i'm not in the mood for the oregon sharpener
04:39 PM Tom_L: i _think_ the pole saw takes the same ones as the little one i showed you the other day
04:45 PM JT-Shop: I keep a spare chain for each saw and the pole saw, if I didn't do something dumb like hit a rock usually the file works for 4-5 times before going to the oregon sharpener
04:47 PM JT-Shop: I was lucky with the MS391 and hit a rock on the last round on the big one... time to switch to the MS291 for the smaller side as it's a bit lighter
04:47 PM JT-Shop: Tom_L, got a lead on a Stihl 066 that needs rebuilding... that would be perfect for my Alaskan Sawmill
04:59 PM JT-Shop: MS391 is 64cc the 066 is 92cc should make a big difference
05:01 PM JT-Shop: I have an 021
05:02 PM Tom_L: i love the top handle
05:02 PM Tom_L: well balanced
05:03 PM Tom_L: guess you don't need to collect too many..
05:05 PM -!- #linuxcnc mode set to +v by ChanServ
05:07 PM JT-Shop: aye the 021 works great as a limb saw and I don't climb any more... the tree has to come to me
05:34 PM funkenjaeger[m]: I have a use case where I'd like to modify my soft limits during my tool change routine only - basically to mitigate any remaining risk of crashing the spindle assembly into the ATC tool rack during normal operation. Anyone done something like that? At a glance it looks like I can accomplish that by setting the ini.y.max_limit pin, and then I should be able to use #<_ini[AXIS_Y]MAX_LIMIT> to retrieve the original default to set it
05:34 PM funkenjaeger[m]: back to (and I probably need to do it for the joint(s) of the axis as well?). Just wondering if anyone's had success doing the same, and whether it's really that simple or if there are any 'gotchas' to be aware of.
06:12 PM _unreal_: god endless EFFING rain
06:18 PM _unreal_: t4nk_fn, just ordered 2 of these WeMos D1 R32 - ESP32 WROOM-32 - UNO Form Factor they have a strong support for GRBL. and should be a drop in replacement for my laser etcher :)
06:18 PM _unreal_: so I can finally pump up the feed rate
06:20 PM XXCoder: funkenjaeger[m]: is there gcode to change soft limit?
06:20 PM _unreal_: IF I can pump up the FEED rate finally. then I have a reason to redesign it a bit. and I'll get 12mm rails for it all the way around.
06:20 PM XXCoder: if so, you probably can put it in toolchange to first move soft limit outwards then do stuff then move it back inwards
06:20 PM _unreal_: XXCoder, ahh I dont believe LCNC has that option
06:21 PM XXCoder: any option to bypass soft limit?
06:21 PM _unreal_: I could be wrong. But I dont see how it would be able?
06:22 PM * roycroft hands _unreal_ a hammer
06:22 PM roycroft: there's always a way to do it, given an appropriate tool
06:22 PM _unreal_: grbl you can change soft limits in gcode. mainly because you can PASS settings code in the gcode i.e. ($21 XXX#)
06:23 PM _unreal_: XXCoder, if there is an option. It would have to be a script based setup.
06:24 PM XXCoder: yeah thats why I menioned toolchanging script :)
06:24 PM _unreal_: soft limits are set in the config.
06:24 PM unterhaus: no riots during arts fest
06:24 PM _unreal_: unterhaus, what a let down :(
06:24 PM _unreal_: ;)
06:24 PM unterhaus: disappointed about no horrible rainstorms during arts fest either
06:25 PM _unreal_: XXCoder, I just ordered two of these WeMos D1 R32 - ESP32 WROOM-32 - UNO Form Factor
06:25 PM _unreal_: I cant believe I've never been able to find them
06:25 PM XXCoder: computer board eh
06:25 PM _unreal_: no esp32
06:26 PM XXCoder: whats your plan of usage for it?
06:27 PM _unreal_: after I get GRBL onto it after I get it. and get it setup. its a drop in replacement for the uno driving my laser etcher
06:27 PM _unreal_: the only thing I have to deal with is some level shifting
06:27 PM _unreal_: 3.3v to 5v
06:28 PM XXCoder: interesting. ok
06:29 PM _unreal_: from what I have found its a drop in in regards to the standard stepper motor shield for arduino uno
06:30 PM _unreal_: that supports 4 stepper motors
07:09 PM _unreal_: https://www.youtube.com/watch?v=H9_zK7b9rRs&t=28s HAHAHAHAHAHA the first min of this video cracked me up
07:11 PM XXCoder: "want cnc?" "get mill first"
07:11 PM _unreal_: ?
07:11 PM _unreal_: https://youtu.be/H9_zK7b9rRs
07:12 PM XXCoder: unreal person trying to cheaply source and build cnc machine probably dont have mill :)
07:13 PM XXCoder: I can see few ways to make it not required however.
07:13 PM _unreal_: as I said the first min is funny
07:13 PM _unreal_: I didnt get far past that watching it
07:13 PM XXCoder: dont get me wrong, it seems excellent build video
07:14 PM _unreal_: I didnt watch the whole thing. I just watched the first min
07:14 PM XXCoder: at 5 min is funny also
07:18 PM _unreal_: !#@$%!@#$ my right pinter finger is killing me. to much cad work
07:18 PM XXCoder: lol
07:18 PM XXCoder: dont worry, you will have swole finger soon
07:19 PM _unreal_: I'm in my mid 40's everything is starting to say F-U
07:19 PM XXCoder: just starting? man youre lucky
07:20 PM _unreal_: guys in my fam. are built like a brick house. and very poor flex ablity. VERY poor. I dont break easy
07:21 PM _unreal_: but for as fast as I can type. only my right pointer is annoying me
07:21 PM _unreal_: man what a shit weekend. nothing but rain
07:23 PM XXCoder: unreal yeah you should watch whole video lol
07:23 PM _unreal_: I dont have any other known health issues.
07:23 PM _unreal_: aside from my eyes. but thats been an issue my whole life
07:44 PM solarwind: Curious, why don't machine coolant reservoirs use UV LEDs to stop microbial growth?
07:47 PM _unreal_: coolants typically have oils in them
07:47 PM _unreal_: and anti growth additives.
07:48 PM _unreal_: misters on the other hand are pure clean water "typically"
07:48 PM _unreal_: misters dont recycle
07:49 PM solarwind: Why is microbial growth such a problem for machine tools? I've never had any issue in my TIG torch water coolers and I just use "RV antifreeze" propylene glycol
07:49 PM _unreal_: mainly clogging filters
07:50 PM solarwind: https://www.youtube.com/watch?v=Gw9qzEMwpDw this looks absolutely disgusting and I have no idea why he's worried about the dangers of UVC when he can just fully enclose it
07:50 PM _unreal_: smell, can be a halth
07:50 PM _unreal_: health
07:50 PM _unreal_: I've installed UV units for water systems on yachts before
07:50 PM solarwind: I mean why does it occur in machine tool reservoirs so often and not TIG torch coolers or car radiator reservoirs?
07:50 PM _unreal_: hell infact I have an AIR duct UV unit brand new
07:50 PM _unreal_: forgot all about it
07:51 PM _unreal_: some where up in the attic
07:51 PM solarwind: Well I get that car radiators heat it up to almost 100ยบ, so that solves that problem
07:51 PM _unreal_: HEAT
07:51 PM solarwind: But I don't think TIG torch coolants get anywhere near that temperature at any point
07:51 PM solarwind: and especially not CPU water cooling systems
07:51 PM _unreal_: you'll never get coolants in a mill to BOILING the entire vat
07:51 PM XXCoder: dont TIG generate uv as it welds
07:52 PM _unreal_: yes
07:52 PM solarwind: Yeah but that never reaches the coolant
07:52 PM solarwind: the coolant is fully sealed against any kind of light, at least at the torch end
07:52 PM solarwind: And the flow rate is so high that the coolant never gets very warm
07:53 PM solarwind: I'm just wondering how machine tool coolant reservoirs are always so disgusting but never any other system I've seen
07:53 PM _unreal_: becuase they use oil
07:53 PM _unreal_: there are things that eat/break down oils
07:54 PM _unreal_: when you break down the oil. other things can eat the byproducts
07:54 PM solarwind: Ok if that's the reason, that makes sense
07:54 PM _unreal_: and you get a growth culture
07:54 PM _unreal_: enzimes or somehing like that.
07:55 PM XXCoder: that uv thing, probably didnt work because uv didnt go all way in
07:55 PM XXCoder: maybe it would work if there was couple fish tank air bubblers
07:55 PM XXCoder: keep it moving around and exposing bictera to uv? dunno
07:56 PM XXCoder: or have pipe to spray it down though uv light and return to tank
07:57 PM _unreal_: for UV to work on water. it must pass with in a narrow gap tube to the UV source to maximize the UV exposure
07:57 PM XXCoder: do it fast enough to have turnover high enough speed, and long enough light parhway to kill any germ
07:57 PM _unreal_: its not speed its time and intensity
07:59 PM solarwind: Yeah, I was thinking of making such a circulating pump with a tube lined with UVC LEDs
08:00 PM solarwind: Hopefully UVC doesn't affect the corrosion inhibitors and other things in the coolant
08:01 PM XXCoder: no idea. keep in mind ither stuff that can wear under uvc also
08:01 PM solarwind: It would be a copper tube
08:01 PM _unreal_: UVC requires glass tubes
08:02 PM t4nk_fn: where did you get the boards, _unreal_
08:02 PM _unreal_: ebay
08:03 PM t4nk_fn: should be a piece of cake then ey ;)
08:04 PM _unreal_: solarwind speaking of I have a mister pump
08:04 PM _unreal_: 12v. came from a boat. Goes to a tube as long as you want with mister ports.
08:05 PM _unreal_: and has a water tank :)
08:08 PM _unreal_: I have no plans for it as of this moment.
08:09 PM _unreal_: when I get out of here. I'm tempted to set it up as a back yard thing. who knows maybe I'll buy a boat. OR I could use it on the next big cnc
08:16 PM t4nk_fn: ah, that reminds me... let's check on your stocks ;)
08:17 PM t4nk_fn: rdbx first
08:17 PM t4nk_fn: OOPS
08:17 PM t4nk_fn: lol
08:17 PM t4nk_fn: 4.37
08:17 PM _unreal_: ?
08:17 PM t4nk_fn: you got them at 11, right
08:17 PM _unreal_: I'm not holding RDBX any more. I made $600 well 582
08:18 PM t4nk_fn: ??!? that's impossible, I've been monitoring, you got them at 11, and then never got back to 11
08:19 PM t4nk_fn: moreover.. that was the cash-cow for you, supposed to make you trillions :)
08:19 PM _unreal_: LOL. I got in at $13 sold at 18 at first
08:19 PM t4nk_fn: made you get the trembles, rememner?
08:19 PM _unreal_: then got back in and made a second play and got out
08:20 PM _unreal_: I thought about holding for some time then said F it. averaged down and the last bump. I got out with a tiny profit.
08:20 PM t4nk_fn: so then amc is the only one left
08:20 PM -!- #linuxcnc mode set to +v by ChanServ
08:20 PM -!- #linuxcnc mode set to +v by ChanServ
08:21 PM _unreal_: amc I'm only down what .2%
08:21 PM t4nk_fn: better sell now mate... really ;)
08:21 PM _unreal_: I'm not selling till it hits my price target
08:21 PM _unreal_: same with SNDL
08:49 PM roycroft: here it is, sunday night
08:50 PM roycroft: i've spent my spare time this weekend research rack and pinion systems again, and i've gotten no farther than i did the last time
08:50 PM roycroft: it was basically a weekend of memory refreshing
08:50 PM _unreal_: just pick one
08:50 PM roycroft: perhaps i can move forward now, before i forget everything again
08:50 PM _unreal_: or go with ballscrew
08:50 PM _unreal_: or belt drive
08:50 PM roycroft: i need over 2m of motion
08:51 PM roycroft: which is why i was looking at rack and pinion before
08:51 PM roycroft: i can't afford ball screws that are big enough to not whip around on rapids
08:52 PM roycroft: actually, i might only need just under 2m of motion
08:52 PM roycroft: but still, that makes for some long ball screws
08:58 PM roycroft: folks have suggested that i can do a belt drive system on my router, but i'd really rather avoid tat
08:59 PM roycroft: that
09:04 PM XXCoder: researched any anti-backlash on rick and pinion system?
09:06 PM roycroft: yes, and there are four main methods of achieving it
09:07 PM roycroft: how effective each one is, and what it would actually cost for me to implement each one, is what i still don't know
09:08 PM XXCoder: ok
09:25 PM XXCoder: one with 2 gears, one pushing other way seems cheapest, but then im not sure how that one works so it might be expensive speciality or something
09:30 PM roycroft: 1. high precision gears that mesh almost perfectly
09:30 PM roycroft: 2. split pinion
09:30 PM roycroft: 3. dual pinion
09:30 PM roycroft: 4. spring-loaded pinion
09:30 PM roycroft: a single spring-loaded pinion would be the cheapest
09:31 PM roycroft: but i don't know how well it eliminates backlash
09:31 PM XXCoder: you can sort of cheat with #1, using brass very slightly oversize gear
09:31 PM XXCoder: assuming pinion is well done
09:33 PM roycroft: that would be a high maintenance solution
09:34 PM XXCoder: I suppose
09:34 PM roycroft: it would lose accuracy over time, as the brass pinion wears, and the pinion would need to be replaced periodically
09:35 PM XXCoder: pinion should stay well since its much harder than brass but I take your point
09:36 PM XXCoder: dual pinion one with 2 drivers?
09:36 PM XXCoder: that one im not certain how it elimates backlash, does one drive go back when motion is done or what
09:37 PM roycroft: the pinions tension in opposite directions
09:37 PM roycroft: i'm not certain how to build that
09:37 PM roycroft: if i get that sorted it may be the option i prefer
09:37 PM XXCoder: so you just them in opposite directions, and it maintains that by just moving same distance?
09:38 PM XXCoder: I wonder if it tensions itself by power up process and maintans it
09:38 PM roycroft: yes, you spread them apart to eliminate backlash and mantain that spread
09:38 PM XXCoder: but power down would cause gears to rotate and loosen
09:39 PM roycroft: i think it's kind of like a split nut on a lead screw
09:40 PM XXCoder: so basically springs betweem motors?
09:41 PM XXCoder: it would rotate gears and go put to max spring (or max it can push out) so i wonder if first step is simply rotate both opposite directions to get slightly closer to each other
09:41 PM XXCoder: and spring takes out backlash
09:42 PM XXCoder: ie at power down, its "relaxed" and spread out fully as spring can push. power on, and enabledpower on procure gets it say, 2 mm or whatever closer to each other, putting spring in more tension, so gears is pushed apart, elimating backlash
09:43 PM * XXCoder wonders if picture is anywhere near reality)
09:45 PM roycroft: with a dual pinion system i think one of the pinions can be an idler
09:45 PM roycroft: only one needs to be driven
09:46 PM ZincBoy[CAON][m]: Split pinion is just a torsion spring between the two halves. Dual pinon usually means two motors that are fighting each other to take up the backlash. More often seen in hydraulic motor systems.
09:46 PM XXCoder: but since gear can rotate, wouldnt it just push out and lose it
09:46 PM XXCoder: lose tension
09:47 PM roycroft: split pinion is what i think i'd prefer, but i haven't seen any stand-alone split pinion gears
09:47 PM ZincBoy[CAON][m]: Dual pinion needs to be active as you are changing direction. There is no way to load an idler to take up the slack.
09:47 PM roycroft: only expensive mechansims with reduction gears
09:47 PM roycroft: yeah, i just figured that out
09:47 PM roycroft: an idler would not work if you're going to reverse
09:48 PM XXCoder: zinc was my discription anywhere near reality
09:48 PM ZincBoy[CAON][m]: That is because they are seldom required. A spring loaded pinion works fine for most of the applications where a non-precision rack and pinion is needed.
09:48 PM roycroft: and i do not want to have to deal with four motors on the y axis
09:49 PM roycroft: i know that several commercial cnc routers use spring-loaded pinions on the long axis
09:50 PM roycroft: it seems to me that it's the least accurate of the for main methods, but it might be good enough
09:51 PM ZincBoy[CAON][m]: I don't think so. The motors/pinions are fixed relative to each other and the take up force is by the motors turning in opposite directions. To move, you just reduce the torque on one motor.
09:51 PM roycroft: a spring loaded pinion does have the advantage of being able to deflect if a chip gets in the way, with less of a chance of damage than the other systems
09:52 PM XXCoder: how do spring loaded pinion work anyway
09:52 PM ZincBoy[CAON][m]: Yes, I have only seen spilt pinion or dual motor type designs in very large steel working gantry mills.
09:52 PM roycroft: the pinion shaft is pressed towards the rack with a spring
09:53 PM ZincBoy[CAON][m]: Instead of having the pinion at a fixed distance from the rack, it is forced into the rack with a spring.
09:53 PM XXCoder: aha so gears contact pinion, on both sides, at all time
09:53 PM roycroft: well
09:53 PM XXCoder: even with slight error in sizes
09:53 PM ZincBoy[CAON][m]: This means that you can have much less backlash as you don't need running clearance betweenb the rack and pinion.
09:53 PM roycroft: the pinion gear contacts the rack at least one point all the time
09:54 PM XXCoder: ok
09:54 PM roycroft: how much contact area is a functon of how accurately the pinion and rack gears are made
09:55 PM roycroft: that again creates a maintenance issue, but a different kind than using an oversize gear
09:55 PM ZincBoy[CAON][m]: That is also why the helical racks are better as you have more points of contact at a given angle. Better chance to have more than one contact point.
09:56 PM roycroft: there would not be significant wear over time and a loss of accuracy over time, but regular lubrication would be required
09:56 PM XXCoder: so helical rack and pinion would work well with spring loaded
09:56 PM XXCoder: roy can always put in a oil dropper
09:57 PM roycroft: but is an accurate straight gear better than a sloppy helical gear?
09:57 PM ZincBoy[CAON][m]: Yes. But there are side thrust requirements for helical and they are more $$
09:57 PM XXCoder: with small reservor. would last quite a while, so while it dont elimate maintance it is less often
09:57 PM ZincBoy[CAON][m]: Accurate always beats sloppy.
09:58 PM * roycroft still thinks that a split pinion would be the most elegant mechanism, but is converging on some kind of spring-loaded pinion as the most practical and doable method
10:00 PM ZincBoy[CAON][m]: Maintenance is lowest on the spring loaded pinion design. It is self compensating to a point and doesn't appreciably increase wear over a fixed pinion.
10:01 PM roycroft: and that is a very important consideration
10:02 PM ZincBoy[CAON][m]: Split pinion is the best but is either expensive or difficult to make. I don't know of an easy way to get a decent amount of spring force in a small pinion like would be used on your router.
10:03 PM roycroft: i would not try to make a split pinion myself
10:03 PM roycroft: that is beyond my current skill/patience level
10:03 PM roycroft: and i cannot afford any of the commercial offerings
10:05 PM roycroft: if you haven't figured this out yet, zincboy, i tend to overthink things and take a long time to come to the obvious solution
10:05 PM XXCoder: dual is interesting, you would have to make two, and have them get themselves closer at initial start (if im correct)
10:05 PM XXCoder: other than doubling cost its pretty easy?
10:06 PM XXCoder: spring is easiest I think
10:06 PM ZincBoy[CAON][m]: I suffer from the same aliment ๐Ÿ™‚ Sometimes I just have to force myself to start building...
10:06 PM roycroft: well if i did that i'd have to deal with a 4 joint axis in linuxcnc
10:06 PM XXCoder: adhoc is bit risky but works out pretty good. roy yeah
10:06 PM roycroft: and that would probably complicate things there a bit
10:07 PM ZincBoy[CAON][m]: Dual would work best with torque mode servos. The control would be bit tricky.
10:07 PM roycroft: that's what i'm thinking
10:07 PM ZincBoy[CAON][m]: Would not work at all with steppers.
10:07 PM roycroft: perhaps the easiest and best method would be to use high precision racks and pinions
10:08 PM roycroft: but that would be very expensive
10:08 PM roycroft: and would leave zero room for error in the build
10:08 PM XXCoder: easiest and cheapest, just rack and pinion. second easiest is spring loaded I guess
10:09 PM ZincBoy[CAON][m]: You need to keep your design target in mind. If you need 0.005" precision, then 0.001" backlash is not really an issue. 0.005" is overkill for a wood router as the material is not dimensionally stable to that level.
10:10 PM roycroft: i disagree
10:10 PM roycroft: 0.005" has actually been my target precision all along
10:10 PM roycroft: and while wood is not as dimensionally stable as metals, accurate joinery is still important
10:12 PM Tom_L: https://www.servotak.eu/sites/default/files/styles/w350/public/servotak_rackpinion_system_m6__3000.png?itok=EBFWZQbi
10:12 PM roycroft: when i am doing joinery in high end furniture quality projects, i take shavings of 0.001" or so when doing final fitment
10:12 PM ZincBoy[CAON][m]: True but do you need 0.005" accuracy as well? You will be able to get that level of precision fairly easily but that accuracy will be more difficult.
10:12 PM Tom_L: https://www.atlantadrives.com/images/products/Split-Pinions.jpg
10:12 PM XXCoder: tom is that stepper type?
10:13 PM Tom_L: http://rayharvey.org/wp-content/uploads/2010/03/splitpinion.jpg
10:14 PM roycroft: i need precision and consistency
10:14 PM roycroft: but not accuracy
10:14 PM ZincBoy[CAON][m]: Steppers won't work. They are position devices any you need a torque control for opposing forces.
10:14 PM roycroft: consistency meaning repeatability
10:15 PM ZincBoy[CAON][m]: Perfect. You can use lower quality components then as long as you can control the backlash. You don't need precision R&P as it won't help the precision. It helps with accuracy.
10:16 PM Tom_L: if you're not using steppers then you will need a gearbox or reduction of some sort
10:16 PM ZincBoy[CAON][m]: I know that sounds silly now that I read it back
10:16 PM Tom_L: and that will introduce more backlash
10:16 PM Tom_L: linear steppers
10:16 PM Tom_L: with glass scales
10:17 PM Tom_L: if i were... i'd do the belt thing i think
10:17 PM ZincBoy[CAON][m]: You can't use steppers for dual pinion even without a gearbox. You can't torque bias steppers like you can a servo. You need a servo system
10:17 PM roycroft: when i make things out of wood i get the best results when i measure things as seldom as possible
10:17 PM Tom_L: but... i weren't
10:18 PM roycroft: so i do think i'm making progress tonight
10:19 PM roycroft: i've all but eliminated every rack and pinion anti-backlash system except a spring-loaded pinion
10:19 PM roycroft: i'm about 90% convinced that will work for me
10:20 PM ZincBoy[CAON][m]: One thing to keep in mind is that pretty much any of the cheap ballscrew systems will have the same or worse backlash than a spring loaded pinion.
10:20 PM roycroft: i would have used a double nut ball screw system
10:21 PM ZincBoy[CAON][m]: With a rolled C7 screw you will still have issues. I have been there. They are cheap for a reason.
10:22 PM roycroft: there is such a disadvantage to a long ball screw that i've been really looking for another mechanism
10:22 PM Tom_L: consider moving the nut not the screw
10:23 PM roycroft: it's why my router design from six months ago had a complete z axis, a fairly comlete x axis, and no motion control on the y axis
10:23 PM roycroft: that's a neat idea, tom_l
10:23 PM XXCoder: Tom_L: I recall that. wasnt sure how it would work
10:23 PM roycroft: you mentioned it yesterday
10:23 PM roycroft: a practical method of spinning the nut has not come to me yet
10:23 PM XXCoder: same issue I thought of also
10:24 PM Tom_L: https://www.linearmotiontips.com/what-are-the-benefits-of-a-rotating-ball-nut-aka-driven-nut/
10:24 PM roycroft: i assume i'd have to put some kind of gear system around the outside of the nut
10:25 PM Tom_L: https://www.amannesmann.de/en/products/ball-screws/with-driven-nuts/
10:26 PM roycroft: i think that a spring-loaded pinion would be more compact than a ball screw with a driven nut
10:26 PM Tom_L: https://www.youtube.com/watch?v=GfvgFEHPTrk
10:26 PM XXCoder: interesting. wonder if can use 2 of em with strong spring to remove backlash
10:26 PM Tom_L: or just one _good_ one
10:27 PM XXCoder: i recall zinc commentary about P rated ones yeah
10:27 PM roycroft: ground ball screws are not in a $5k budget by any means
10:27 PM Tom_L: i'm showing viable solutions
10:27 PM XXCoder: didnt say otherwise :)
10:29 PM Tom_L: https://www.ebay.com/itm/164915175569
10:30 PM XXCoder: C7 rating
10:30 PM Tom_L: concept
10:30 PM XXCoder: ok
10:30 PM XXCoder: funny hopw its all metric except for length lol
10:30 PM XXCoder: *how
10:31 PM roycroft: that's actually not too badly priced
10:32 PM ZincBoy[CAON][m]: That is the first time I have seen a rotating ball nut solution for a hobbyist budget.
10:32 PM roycroft: still about 2x as much as a rack and pinion system
10:32 PM roycroft: but it's definitely an option
10:32 PM Tom_L: gnite
10:33 PM ZincBoy[CAON][m]: And I have questions about the three screws being used to hold the bearing in place.
10:33 PM roycroft: it's 1:1 gearing to the motor
10:34 PM XXCoder: Tom_L: night
10:38 PM roycroft: i think tom_l is trying to get me to talk about this router forever and never get it built :)
10:39 PM XXCoder: lol
10:40 PM XXCoder: I was pondering about 2 nuts using similiar design as leadscrew anti-bacllash but not sure how it would work as it'd be driven
10:45 PM XXCoder: if you attach flanges to the "loose nut" then have slots on gantry sides maybe
10:46 PM XXCoder: I guess would always need to rotate both at all times otherwise it will be left beyond
10:56 PM roycroft: i'm about ready to model a spring-loaded pinion setup
10:56 PM roycroft: i see two problems that i have to figure out
10:56 PM roycroft: 1. how much spring tension is needed
10:56 PM XXCoder: roy just had fun short sketch. gray is ballscrew. red is rotating ballscrew nuts. bordered green is plate alum. one nut has locking plate installed on it. dark green is spring. its not assembled yet essentally. black is belts. https://imgur.com/ZAHH7hi.png
10:56 PM roycroft: 2. how to build it so that i maintain consntant tension on the drive belt while the pinion moves in and out from the rack
10:57 PM roycroft: i think avid cnc use spring-loaded pinions
10:57 PM roycroft: and i'm sure there are heaps of pictures of their routers around
10:57 PM XXCoder: hope you enjoy my rapid modeling lol
10:58 PM roycroft: it looks like a lego ball nut
10:59 PM XXCoder: expensive option would be another pinion and gear on other side (as counter force to spring) but dont think its workable. not too sure how you would have movable counter to springs pushing down to pinion
11:00 PM XXCoder: framing fixed distance from rail, stepper and gear on it on springs?
11:02 PM XXCoder: I guess need something to allow up and down on spring, but disallow side to side
11:05 PM roycroft: i don't think the spring-loaded pinion will move much
11:05 PM roycroft: so perhaps belt tension is not an issue
11:06 PM XXCoder: yeah though side to side would intro some backlash
11:06 PM XXCoder: so good rods and stepper spring module assembly has good bores?
11:46 PM roycroft: avid cnc sell rack and pinion kits
11:46 PM roycroft: https://www.avidcnc.com/pro-rack-and-pinion-drive-nema-23-p-227.html
11:47 PM roycroft: that would save me a lot of time in both design work and machining work
11:48 PM XXCoder: interesting
11:48 PM XXCoder: not too expensive
11:48 PM roycroft: about $700 for everything
11:49 PM roycroft: i already have the motors
11:49 PM roycroft: my goal is not to build a cnc router completely from scratch
11:49 PM roycroft: my goal is to have a cnc router to my specifications
11:50 PM XXCoder: yeah thats what i thought