#linuxcnc Logs

Mar 27 2022

#linuxcnc Calendar

02:45 AM Deejay: moin
03:44 AM -!- #linuxcnc mode set to +v by ChanServ
04:17 AM Contract_Pilot: Howdy all
05:06 AM JT-Cave: morning
05:38 AM Tom_L: morning
07:02 AM t4nk_freenode: hi-di-hi
07:02 AM Deejay: yo-di-ho
07:03 AM t4nk_freenode: seems like we're all present here ;)
09:01 AM t4nk_freenode: well, 96 drilling operations into steel, by hand, sofar, .. and I only broke 1 drill and have ony one burnt finger.
09:01 AM t4nk_freenode: *making progress* ;)
09:01 AM Tom_L: the day is still young
09:02 AM t4nk_freenode: lol
09:02 AM t4nk_freenode: yeah, that got me worried... still need some 32 drillings ;)
09:02 AM t4nk_freenode: but I'm having coffee, while I still can
09:03 AM Tom_L: 96 is a plea for cnc
09:04 AM t4nk_freenode: I've decided to forego with the c-beams, on account of too expensive whilst too flimsy
09:04 AM t4nk_freenode: so I got some rectangular steel tubing from the hardware store
09:04 AM t4nk_freenode: and I'm now 'prototyping' some bearings on those
09:05 AM t4nk_freenode: 40x30mm tubing btw
09:05 AM Tom_L: i used thick wall square steel
09:05 AM Tom_L: seems solid enough for me
09:05 AM Tom_L: 2"
09:05 AM t4nk_freenode: only stuff I could get was 1.5mm thick.. but compared to what's currently on the cnc it's a phenomenal improvement
09:06 AM t4nk_freenode: and I'm using them at 50cms length, so that is probably just nice
09:08 AM t4nk_freenode: though I'm already dreaming ahead... making a next machine from 1m long beams
09:09 AM t4nk_freenode: but I still need to see how the bearings work out though, tbh
09:09 AM t4nk_freenode: having high hopes
09:09 AM t4nk_freenode: four smaller square tubes surrounding the big beam, with bearings inbetween
09:11 AM t4nk_freenode: euhh... so they're only 32 holes at the moment ;) lol
09:11 AM t4nk_freenode: I'm just drilling them in steps
09:11 AM t4nk_freenode: prblem is that I don't have any decent tools, so I printed some template to mark the holes
09:11 AM t4nk_freenode: 1.5mm drill at first
09:13 AM t4nk_freenode: precision is my greates flaw, and the lack of experience doing it by hand
09:14 AM t4nk_freenode: I've learnt a bit when cutting the smaller square tubes though; not scared of it anymore, and it's fairly straight
09:15 AM t4nk_freenode: but I don't trust myself marking the holes by hand, so I printed the templates... but it's still not perfect, but I knew that in advance
09:50 AM CloudEvil: https://www.youtube.com/watch?v=ip641WmY4pA Feel my haptic knob.
09:53 AM mrec_: can anyone recommend a 1.5kw motor & controller for a lathe?
09:53 AM mrec_: today threading nailed it... it worked but when the tool touched the stock the RPM went down from 500rpm to 300rpm
09:54 AM mrec_: lousy 750W controller..
09:54 AM mrec_: G76 while J was 0.03 only.
10:32 AM roycroft: is this on a mini-lathe, mrec_?
10:59 AM silopolis[m]: Afternoon mates 🙂
11:00 AM silopolis[m]: Can s/o help me identify the difference(s) between 7i47 and 7i52S except that on the first 2 encoders inputs have no index ? 🤔
11:07 AM t4nk_freenode: (well, I now burnt my foot too)
11:08 AM t4nk_freenode: (and I did something else too, but it's too embarrassing ;) )
11:08 AM t4nk_freenode: (fixed it though)
11:09 AM t4nk_freenode: dinner time, and then I just need to cut 8 pieces of threaded rod... WhaTCouLdGoWronG with that.
11:34 AM -!- #linuxcnc mode set to +v by ChanServ
11:55 AM mrec_: roycroft: yes
11:58 AM perry_j1987: mrec_ i hear a bunch of mini lathe guys are going to brushless sewing motors
11:59 AM -!- #linuxcnc mode set to +v by ChanServ
11:59 AM Tom_itx: mrec_, https://www.alibaba.com/product-detail/310V-1-2kw-electric-motor-1200w_60737993181.html?spm=a2700.7724857.videoBannerStyleB_top.9.32c7751dTHUvzS
12:02 PM Tom_L: the control on those sewing machine motors is kinda iffy
12:03 PM Tom_L: if you want program control of it
12:04 PM mrec_: Tom_L: did you buy that one?
12:05 PM Tom_L: i got one from glockcnc
12:05 PM Tom_L: same thing i'm pretty sure
12:06 PM Tom_L: mine was 110v though
12:07 PM mrec_: the 1.2kw looks okay I will check the maximum size tomorrow
12:07 PM mrec_: I'm using a transformer to get 230v here
12:07 PM Tom_L: for the mill, i'm happy with this one
12:08 PM mrec_: varying speed under load is an absolute no go
12:09 PM mrec_: I need to set the feed rate very conservative because of that
12:26 PM Tom_L: it has pid on the control and i'm using a pid loop with linuxcnc as well
12:40 PM t4nk_freenode: mmm it's going to take some doing to line up all these holes :|
12:41 PM t4nk_freenode: I can fit the four tubes together with 8 rods, but it's rather crooked :|
12:42 PM t4nk_freenode: that's not going to run the bearings too well hhehe
01:37 PM roguish[m]: Tom_itx: i've looked at a bunch of those type of motor/drive combos. some pretty good. it's the shipping that jacks the price, usually.
02:06 PM perry_j1987: hows it going
02:15 PM t4nk_freenode: mmmmmm I went ahead and took some bolts and bearings, put it together without fixing the fit of the holes...
02:15 PM t4nk_freenode: and been playing around a bit...
02:16 PM t4nk_freenode: mannnnn... this is looking really promising I say
02:16 PM t4nk_freenode: probably used way too many bearings, 16 for one side, in pairs of two
02:16 PM t4nk_freenode: but, *brr*.. no play
02:17 PM t4nk_freenode: seems so strong
02:17 PM t4nk_freenode: wow.
02:26 PM t4nk_freenode: I don't see how this v slot could ever compete with this
02:30 PM t4nk_freenode: well, the only thing is... how on earth am I going to get there using caveman-tools :(
02:34 PM Tom_L: i did
02:34 PM t4nk_freenode: I don't even have a drill press
02:36 PM Tom_L: i used hand tools for most of mine
02:36 PM Tom_L: did have an angle grinder
02:37 PM t4nk_freenode: well, cutting the tubes 'is no longer a problem', it's fairly straight if I cut each side separately
02:39 PM t4nk_freenode: but these holes for example.. if I want to attach a plate to the carriage, I need it to be flush of course, and that's going to be a problem
02:40 PM t4nk_freenode: I have m8 threaded rods, and I guess I can file the holes a bit larger, but I don't know if that's gonna do the trick
02:48 PM t4nk_freenode: 100euros for a 400W drill press, might buy it
02:52 PM t4nk_freenode: well, I'll continue tomorrow, see how it goes
02:53 PM t4nk_freenode: ;) it's looking nice so far
03:09 PM CaptHindsight[m]: t4nk_freenode: is 400w enough for you? Sounds pretty light for a drill press
03:12 PM t4nk_freenode: yeah, I know.. it's not much at all
03:12 PM t4nk_freenode: guess the main thought was to be able to drill straight
03:15 PM CaptHindsight[m]: t4nk_freenode: it's slightly better than nothing. I usually find used that is bigger and better but needs some repair for around that price.
03:17 PM t4nk_freenode: I believe my handdrill is about 650W.. and it's pretty useless ;)
03:18 PM t4nk_freenode: wanted to drill some holes into the walls and ceilings, didn't happen.
03:21 PM t4nk_freenode: apart from that it's shamefully out of balance
03:30 PM * Loetmichel is just cleaning up his hobby room. Should do that more often... Just packing a box with electric hand tools... *digging through the corners.. "ANOTHER one? How many Jigsaws DO i own??? #1 ... #2 ... #3 ... AAAAnd there is ANOTHER one.. maaaan..." :)
04:25 PM * JT-Shop listens to Kraftwerk
04:36 PM perry_j1987: *is tired of putting setscrews in products today
04:41 PM roycroft: i'm getting tired of having to fabricate parts for my dust collector
04:41 PM roycroft: i think i'm almost done with that, though
04:42 PM roycroft: i was planning on doing this job on friday
04:42 PM roycroft: now it's sunday, and i'm still working on it
05:49 PM robinsz: Tom_L, very happy with the hand controller now, so convenient!
05:50 PM robinsz: some of this small batch of relays I am going have slight height offsets, so easy now to release the quill clamp, send Z to zero, set the tool back on the work and re-clamp the Z ...
05:56 PM Tom_L: yay
05:56 PM Tom_L: everything is simple once you know how
06:28 PM JT-Shop: yup
08:17 PM mrec_: Tom_L: why are you using 2 pid loops for the motor?
08:19 PM Tom_L: for me, the linuxcnc loop helped the bottom end torque response
08:20 PM Tom_L: so the analog signal wasn't as linear
08:21 PM Tom_L: i first got it working with the vfd loop then added in the linuxcnc pid
08:21 PM mrec_: but that would mean that you would have to override the other pid no?
08:22 PM Tom_L: no
08:22 PM Tom_L: it uses the encoder feedback from the spindle
08:22 PM mrec_: which is the 3 segment encoder?
08:22 PM mrec_: or the high resolution encoder?
08:22 PM mrec_: 3 segment / hall encoder I mean
08:23 PM solarwind: https://www.youtube.com/watch?v=I1o5PNHLO_c
08:23 PM solarwind: How does this brass plating mechanism work?
08:23 PM solarwind: Is it actually melting a small amount of brass?
08:25 PM mrec_: Tom_L: ok so the main driver is just using the hall effect sensors, and the linuxcnc loop is using the highres encoder on your side?
08:25 PM Tom_L: yes
08:26 PM mrec_: how did you interface the driver, via voltage 0-5/10v?
08:26 PM Tom_L: 0-10
08:26 PM Tom_L: it will do pwm, 0-5 or 0-10
08:26 PM Tom_L: not sure how that works but....
08:27 PM solarwind: I have to plate some object with brass, and I have a whole bunch of bronze brazing rods, but oxy acetylene brazing will take a lot of time and I only need a very very thin plating
08:27 PM solarwind: brazing will waste a lot of the filler and make a very thick layer which is completely unnecessary and a total waste of expensive RBCuZn-C rods
08:28 PM mrec_: Tom_L: is that reliable or is there some overshooting sometimes?
08:28 PM solarwind: I'm almost contemplating grinding the rods into a fine powder somehow, mixing into a flux paste, then pasting it onto the metal before heating it up
08:29 PM solarwind: kind of like those plumbing fluxes which contain solder in them to make it clear when you reach soldering temperature
08:29 PM Tom_L: it's pretty accurate
08:29 PM Tom_L: it may overshoot slightly but recovers quick
08:29 PM Tom_L: overall it doesn't much
08:29 PM mrec_: it would almost be a solution for my current motor but the step response is too slow
08:30 PM mrec_: my motor is rated at 310V so I guess I can just re-use that one with a different driver
08:30 PM Tom_L: what wattage?
08:30 PM mrec_: 750w
08:30 PM mrec_: that should be okay for my applications
08:30 PM Tom_L: i thought you said that wasn't enough power
08:31 PM mrec_: I think the problem is the driver not the motor itself
08:31 PM Tom_L: i wanted to do it once and done so i got the 1.2kw over the 750w
08:32 PM Tom_L: it was my first vfd experience so i certainly don't have all the answers for it
08:32 PM Tom_L: i just fiddled with mine until it worked good
08:33 PM mrec_: did you part steel with your lathe?
08:33 PM Tom_L: i've got this on a mill
08:33 PM mrec_: oh ok
08:33 PM Tom_L: i can cut steel with it though
08:33 PM mrec_: I also don't have a problem with milling steel
08:34 PM mrec_: just the lathe is a problem
08:35 PM Tom_L: gear it down
08:35 PM Tom_L: if you plan to cut alot of steel
08:35 PM mrec_: I think I will need a similar setup like you have with the second pid loop
08:36 PM mrec_: I'll try to get a better driver first
08:37 PM Tom_L: get it as good as you can with the vfd before you add it in
08:37 PM Tom_L: i mean, if i hold the spindle at a low rpm (400ish) and let go it will overshoot
08:37 PM Tom_L: but it does recover quick
08:38 PM mrec_: better faster than slower, I can try to do that too
08:38 PM Tom_L: the thing about that is as it is being held, linuxcnc is adding more voltage to it's loop so eventually you have to let go
08:39 PM Tom_L: without it, it just stalls
08:40 PM mrec_: same here, ok I'll just get the driver first
08:45 PM Tom_L: my configs are all online if you wanna look at em
08:45 PM mrec_: I can still get the 1.2kw driver and use it with the 750w motor
08:45 PM mrec_: that would save me from re-installing the motor
08:45 PM mrec_: thanks for your hints!
08:45 PM Tom_L: i dunno if the settings are different if you do that or not
08:46 PM Tom_L: skunkworks is also working on a lathe setup
08:50 PM Tom_L: mrec_, what controller do you have on it now?
08:50 PM Tom_L: just curious why you think you need another one
08:59 PM mrec_: the current driver is completely coated
08:59 PM mrec_: I interfaced the potentiometer to control the speed in linuxcnc, however the step response is relatively slow
09:00 PM mrec_: I did some threading yesterday I set the RPMs to 500 ... when the tool touched the stock the RPM went down to 300
09:01 PM mrec_: a second pid loop would not help in my case because it will be too slow
09:01 PM mrec_: when I set the threading at 300rpm it almost stalled at a deeper pass
09:01 PM Tom_L: why do you say it wouldn't help?
09:02 PM mrec_: because the step response is too slow
09:02 PM Tom_L: mmm
09:02 PM mrec_: there's like a second delay until the speed would be there
09:03 PM Tom_L: i'm using a mesa 0-10v analog spindle driver on mine
09:03 PM Tom_L: well a 10v range...
09:03 PM mrec_: the original controller just acts too slow
09:03 PM Tom_L: what makes you think a new one will be better?
09:03 PM Tom_L: are you using the parallel port?
09:04 PM mrec_: it's not a problem of sending the data, the bldc controller just takes it too slow
09:04 PM mrec_: I'm using the parallel port yes
09:04 PM Tom_L: i've also got no experience using a parallel port
09:04 PM mrec_: the parallel port works fine here
09:05 PM Tom_L: that's fine, i just don't know it's limits
09:07 PM mrec_: https://streamable.com/znwidh
09:08 PM mrec_: the motor will catch up but very slow
09:09 PM mrec_: the controller looks like this one:
09:09 PM mrec_: https://ae01.alicdn.com/kf/H565ac69518994c31ab97bc0b04ba5bf7i/1-1KW-1100W-Controller-untuk-Brushless-Motor-Bubut-Papan-Kontrol-untuk-1100W-DC-Brushless-Motor.jpg_Q90.jpg_.webp
09:09 PM mrec_: not much you can do with it
09:10 PM Tom_L: no front pannel software settings...
09:10 PM mrec_: no there's nothing available
09:11 PM Tom_L: k
09:11 PM Tom_L: and it's a pwm interface?
09:11 PM Tom_L: not analog
09:11 PM mrec_: 0-5v (potentiometer)
09:11 PM Tom_L: oh so linuxcnc doesn't control it?
09:11 PM mrec_: but .. 0v = 50rpm
09:12 PM mrec_: I interfaced the 0-5v linuxcnc can control
09:12 PM mrec_: but as mentioned if I change the speed it will take some time until the controller does something
09:12 PM Tom_L: for the heck of it before you spend money try adding a pid loop to linuxcnc
09:12 PM Tom_L: do you have an encoder on the spindle?
09:12 PM mrec_: yes
09:13 PM Tom_L: try that first
09:13 PM Tom_L: it will take a little tuning but you might be surprised
09:13 PM Tom_L: got nothing to lose..
09:16 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/configs/NEW_MILL_SHOP_2.8.2/new_mill.hal
09:16 PM Tom_L: my spindle is pid.0 if you wanna look
09:17 PM Tom_L: file is kinda messy. i try testing different things once in a while
09:36 PM mrec_: Tom_L: it will not work for me, eg. if I change the speed via potentiometer it will take a second until the speed will really ramp up
09:37 PM Tom_L: ok
09:37 PM Tom_L: so you're still using the pot too?
09:44 PM mrec_: yes also, it doesn't matter if I apply the voltage via linuxcnc the bldc controller is slow
09:50 PM roycroft: you should lay off the pot
09:50 PM roycroft: it will make you spacy and give you the munchies
09:51 PM Tom_L: is that why you have pizza friday?
09:52 PM Tom_L: mrec_, yeah if the ramp times aren't adjustable there's not much point
10:01 PM roycroft: i just enjoy pizza
10:01 PM roycroft: and i enjoy the weekend
10:01 PM roycroft: pizza is a way to celebrate the beginning of the weekend
10:02 PM Tom_L: not a bad idea
10:05 PM mrec_: Tom_L: can you also put a position loop around the velocity loop?
10:05 PM mrec_: not that I need that but I'm just curious
10:17 PM Tom_L: i haven't tried