#linuxcnc Logs
Mar 13 2021
#linuxcnc Calendar
02:10 AM Deejay: moin
02:17 AM sensille: morning
03:23 AM -!- #linuxcnc mode set to +v by ChanServ
04:51 AM JT-Cave: morning
04:51 AM gloops: howdy
05:33 AM sensille: i wonder how much torque i need to drive the leadscrew of my mini lathe with a stepper
05:34 AM sensille: the stepper i have has 3Nm. the question is if i should add a further reduction to it
05:34 AM gloops: whats it like to turn by hand?
05:35 AM sensille: unloaded?
05:35 AM gloops: well, a question that came to mind when i was thinking of converting a manual lathe - do you want to keep the option of manual control as well
05:35 AM gloops: yeah
05:36 AM sensille: i want to keep the manual control, yes. just want to replace the gear drive by a stepper
05:37 AM gloops: if you did use pulleys to connect the motor you could always slip the belt off and you have normal manual control back
05:38 AM ar: /22
05:39 AM gloops: ive got something like a 280oz stepper on my z that pulls about 8kg vertical on a 5mm pitch ballscrew
05:40 AM gloops: i think the 425oz should drive a mini lathe saddle
05:44 AM gloops: the matter of holding toque isnt so important with leadscrews, they hold position anyway
05:51 AM sensille: i'll try to measure the unloaded force
06:29 AM sensille: can't really measure it with my torque meter
06:29 AM sensille: so, low
06:30 AM gloops: will fly with 3nm my guess
06:31 AM sensille: so i'll get a 1:1 belt set, no reduction
06:33 AM sensille: 10mm XL belt
06:34 AM gloops: 10mm wide? mine arent much more i dont think, probably should have used wider though
06:40 AM sensille: there's not much room for more
06:41 AM sensille: the gears are 8.5mm thick, so 17mm to work with
06:41 AM sensille: the pulley for a 10mm belt is already 15mm thick
06:43 AM gloops: well you can only do what you can do, i dont notice backlash with mine at all but im not measuring most things i make closely
06:44 AM sensille: but i can get larger pulleys to reduce to load on the belt
06:44 AM sensille: the backlash in the leadscrew is horrible
06:44 AM gloops: yeah makes sense to have more teeth engaged
06:44 AM gloops: backlash probably not an issue with a lathe anyway for 1 directional turning
06:44 AM sensille: also less force
06:45 AM sensille: i also have a glass scale lying around which i want to try to add
08:41 AM gloops: 3d roughing started 14.28
09:15 AM gregcnc: 425oz-in on a mini lathe? why so big?
09:15 AM gloops: because hes already got that motor
09:18 AM gregcnc: I was checking the lathe yesterday I have about about 0.033 backlash in Z. not sure I want to take it apart to see what's going on. Z axis is hard to get to
09:27 AM gloops: got to be some backlash with a leadscrew?
09:39 AM perry_j1987: morning
09:41 AM gregcnc: preloaded ball screw, but I'll have to look at the papers i think the tech I had inspect the machine said it needed a Z screw
09:41 AM gregcnc: before i bought it
09:44 AM gregcnc: perry_j1987 how is the lathe working?
09:44 AM perry_j1987: pretty good
09:48 AM perry_j1987: i got a lot of work to do still
09:58 AM sensille: ok, so i'll got for a 1:1 belt. the stepper should be good for roughly 400RPM before losing torque
09:58 AM gregcnc: fast is that in axis speed?
09:59 AM sensille: 800mm/min
10:00 AM gloops: x screw pitch
10:00 AM sensille: screw pitch is 2mm
10:03 AM gregcnc: rapids don't need much torque
10:04 AM gregcnc: that's a lot of thrust though. lead or ball screw?
10:06 AM gloops: the conversion kits usually use nema 17 motors i think, a third the torque or less
10:06 AM gloops: with 2mm screws
10:06 AM gregcnc: yeah no reason for 9kN of thrust
10:07 AM gloops: could gear it up for speed
10:07 AM gloops: alhough not sure 2mm leadscrews are made for speed lol
10:15 AM sensille: the spindle can go up to 2500RPM, and the highest gear ratio is 3mm/rotation. so that would be a theoretical max of 7500mm/min of the machine :)
10:15 AM sensille: so maybe i'll go for a 1:2 ratio
10:16 AM gloops: https://www.ebay.co.uk/itm/Giordano-CNC-router-motors/143970200186? cheap spindles there
10:16 AM gregcnc: I'd like to see manual threading on a mini lathe at 2500RPM and 3mm/rev
10:19 AM perry_j1987: someone converting a mini lathe or something it sounds like?
10:20 AM gloops: yeah sensille
10:22 AM perry_j1987: whats the budget
10:23 AM sensille: perry_j1987: just the leadscrew first
10:23 AM perry_j1987: i highly suggest serious consideration for picking up one of those ballscrew kits for the mini lathes
10:25 AM sensille: might take quite some effort to fit it in there, not sure
10:26 AM sensille: i'll take it in baby steps
10:26 AM perry_j1987: which mini lathe is it
10:30 AM gregcnc: perry_j1987 what kind of features did you need milling for?
10:30 AM perry_j1987: what do you mean gregcnc ?
10:30 AM perry_j1987: continuation of previous conversation?
10:30 AM gregcnc: yesterday
10:31 AM perry_j1987: ah yes
10:32 AM perry_j1987: one of my parts i cut slugs out of barstock and then face em all to size and then machine features once i have properly sized slugs
10:33 AM perry_j1987: im curious if i could just chuck a length of barstock in the 4th axis and mill turn a bunch of them at once all in line between 4th axis and tailstock
10:33 AM perry_j1987: then cut em apart
10:33 AM perry_j1987: but i need to be able to do eccentric cam but i havnt been able to with fusion 360 cam
10:34 AM gregcnc: that's still not available?
10:35 AM sensille: perry_j1987: https://www.paulimot.de/drehbank-/-drehmaschine-pm190-v-mit-230-volt-motor-und-frequenzumrichter
10:35 AM gregcnc: can you hold in in the lathe and turn your eccentric?
10:36 AM perry_j1987: would be best done in 4th axis on mill
10:36 AM gregcnc: multiple parts ina 4th axis is very common. just depends if you can make it work for the parts
10:37 AM perry_j1987: some eccentric milling, some holes and threadmilling etc
10:37 AM perry_j1987: maybe im thinking about it wrong..
10:38 AM gregcnc: if by eccentric you mean a turned circular feature, that could be some work
10:38 AM perry_j1987: maybe if i maybe if i offset the barstock in the 4th axis so the centerline was on the boss then it wouldnt be eccentric then
10:39 AM perry_j1987: i'd have to key it somehow to make the barstock faces repeatably held so it'd be able to access the sides for drilling etc
10:40 AM perry_j1987: sensille that looks an awful lot like the same setup on a lot of these other seig based mini lathes.
10:40 AM gregcnc: aren't they all?
10:40 AM perry_j1987: https://www.bdtoolsusa.com/sieg-7x10-12-14-ballscrew-kit
10:40 AM sensille: they claim that machine is not from sieg, though they also sell sieg in their shop
10:41 AM gregcnc: it may not be, there are clones of clones of clones by now
10:41 AM sensille: hm. driving it from the other side is an interesting idea
10:48 AM perry_j1987: could always just https://www.thingiverse.com/thing:2955025
10:48 AM perry_j1987: print 100% infill
10:50 AM gloops: finish path started at 16.30..hope im up late enough for it to finish...
10:52 AM -!- #linuxcnc mode set to +v by ChanServ
11:13 AM perry_j1987: so i was given my first pair of noise canceling headphones recently
11:13 AM perry_j1987: i have to say... pretty darn nice
11:23 AM sensille: perry_j1987: i think this is a nice setup https://youtu.be/do85xUquFVg?t=532
11:24 AM sensille: keeps the handle
11:26 AM gloops: damn sounds like a crunchy ball developed just into the cut
11:38 AM perry_j1987: you can keep the handle on any of em if you get double ended steppers :)
11:48 AM sensille: sure. but i already hurt my hand on the handle as it is from time when passing
12:18 PM gloops: roughing..it certainly was https://ibb.co/qMB7HKD
12:18 PM gloops: finish underway https://ibb.co/ncSDJNJ
01:22 PM roycroft: i just ordered a new gun for my blasting cabinet
01:23 PM roycroft: i want to finish that project up soon
01:23 PM roycroft: it will make so many other projects go faster
01:24 PM * roycroft ponders running a hard piped air line to his fabrication shop today
02:24 PM XXCoder1: JT-Cave: ever figured how to cut holes on pans?
02:46 PM JT-Shop: no
02:46 PM XXCoder1: oh well
03:38 PM JT-Shop: dust collector is cleaned out I'm calling an audible and say it's beer thirty here
03:44 PM XXCoder1: :)
03:47 PM roycroft: i decided to compromise today
03:48 PM roycroft: i'm making an air manifold for my fabrication shop, with the inlet going through the wall with a quick-disconnect
03:48 PM roycroft: i can hard plumb the air line and tie it in there later
03:49 PM roycroft: finding air quick-disconnects is suddenly challenging, though - i had to go to five stores to get what i needed
03:49 PM roycroft: in the before times any of those five stores would have had ample stock
03:51 PM JT-Shop: I just wish quick connects didn't leak so much
03:52 PM JT-Shop: I ran a 1/2" black iron pipe around the top of my machine shop with Tee's every 10' for drops
03:52 PM JT-Shop: I take that back Tee's every 5'
03:53 PM JT-Shop: in the corners I put an Ell pointing up with a bit of flex to make the corner so no stress on anything
04:00 PM CaptHindsight: cheaply made quick fittings are getting so poorly made I got a few that would hold any air or not connect
04:00 PM CaptHindsight: not hold any air
04:04 PM JT-Shop: that's pretty bad
04:05 PM * JT-Shop is loving the dust collection manifold
04:23 PM CaptHindsight: stay away from the brass HF quick fittings
04:23 PM XXCoder1: or "brass"?
04:24 PM CaptHindsight: grabbed handful on sale for $1ea, tossed most of them away
04:24 PM XXCoder1: remelt em to make better? try salvage some of money
04:25 PM CaptHindsight: yeah good idea
04:26 PM CaptHindsight: not
04:26 PM XXCoder1: whats wrong with it
04:33 PM -!- #linuxcnc mode set to +v by ChanServ
04:36 PM gregcnc: https://rockford.craigslist.org/sys/d/gilberts-custom-kennedy-tool-box/7273768947.html
04:40 PM XXCoder1: lolo
04:40 PM XXCoder1: that thing'd cost $50000 new ;)
04:40 PM XXCoder1: not really but kennedy is expensive
04:53 PM roycroft: that's nice
04:53 PM roycroft: kind of stealthy for the shop
04:54 PM andypugh: It’s quite nicely done, but I have no idea why it was done.
05:00 PM CaptHindsight: andypugh: is the latest RTAi (Nov-20) working well enough?
05:02 PM andypugh: I haven’t really looked at it. I am using it. But not testing hard. I lost motivation to carry on banging my head agiainst that particular brick wall.
05:23 PM veegee_: LOL I'm doing this from now on: https://i.redd.it/j6dve7icetm61.jpg
05:23 PM veegee_ is now known as veegee
05:23 PM veegee: flyback https://i.redd.it/j6dve7icetm61.jpg just for you
05:44 PM veegee: How do you guys hold a center drill? In a chuck? Or in a collet?
05:50 PM andypugh: Yes,
05:50 PM andypugh: I have the one that I use most held in an ER16 MT2 collet adaptor. But for any other sizes I put them in the drill chuck.
05:52 PM andypugh: Something like https://www.ebay.co.uk/itm/153439646938
05:54 PM veegee: andypugh thanks. I have a really nice llambrich MT2 chuck, but my tailstock is MT3. Anything wrong with going with a cheap MT2 to MT3 sleeve adapter?
05:54 PM * JT-Cave has culled all the firewood from the pile of white oak boards... now to restack them with the fresh cut on the bottom
05:55 PM andypugh: I don’t see a problem with it, if that is what it takes to make the chucj useful.
05:55 PM andypugh: Os it definitely an integral shank chuck?
05:55 PM * JT-Cave does not buy much at horrible frieght
05:56 PM andypugh: veegee: https://www.ebay.co.uk/itm/154359885719 is definitely not integral-shank…
05:56 PM veegee: andypugh it's an integral shank chuck: https://www.amazon.ca/Llambrich-Precision-Keyless-integrated-Diameter/dp/B007R62OAO/
05:57 PM veegee: Expensive, but really nice
05:57 PM veegee: If it has any runout, I can't measure it
05:57 PM andypugh: I actually thought that they were _more_ expensive than that.
05:57 PM veegee: They usually are, sometimes amazon has decent pricing for the odd thing
05:58 PM veegee: Now I have to figure out where to get a follow rest for my lathe. It only came with a steady rest
06:01 PM andypugh: veegee: Which lathe?
06:01 PM andypugh: You might just have to make one.
06:02 PM andypugh: (I made a steady rest for my lathe, I have never needed a travelling steady, but that might change next week)
06:05 PM veegee: andypugh https://www.aceronline.net/productDetail.php?id=311
06:06 PM veegee: I bought it used in good condition, everything works
06:07 PM andypugh: Have a look on eBay for something about the right size. There isn’t much to them, you can probably persuade one from a similar ize lathe to work.
06:07 PM andypugh: Or, 3D print a patten and have one cast.
06:09 PM andypugh: That’s what I did: https://photos.app.goo.gl/sfr4jA3PVbyw5Wq5A
06:10 PM veegee: I have the steady rest for it
06:10 PM veegee: So I can use that as a template if anything
06:11 PM veegee: And the taiwanese lathes in this class are sometimes identical
06:11 PM veegee: mine is very very standard
06:11 PM veegee: kind of like how Sharp, First, etc. are Bridgeport clones to the point where most parts are interchangeable
06:13 PM sorki is now known as srk
06:15 PM veegee: Actually I could probably just contact the manufacturer to buy one directly from them
06:52 PM _unreal_: TRYING TO fix my optical limit switches
06:52 PM _unreal_: kind of working
06:52 PM _unreal_: trying to invert the signals right now
06:52 PM _unreal_: just finshed the adapter. now I have to build adapter wires UGH...
08:05 PM _unreal_: I think there is some strange business going on with this GRBL board for the laser etcher
08:05 PM _unreal_: the ARDUINO just does not seem to function
08:05 PM _unreal_: some of the features
08:05 PM _unreal_: I cant for the @#%@#$%!@#$452 life of me get limits to work
08:06 PM _unreal_: I dont know if its the motor HAT or if its the arduino
08:08 PM JavaBean: probably both...
08:26 PM veegee: andypugh I was just cleaning up around the lathe and I found the follow rest LOL
08:27 PM veegee: what a relief
08:27 PM veegee: swapping the brass tips to ball bearings is a lot more fun than making a whole follow rest from scratch
08:27 PM XXCoder1: :)
08:30 PM veegee: took a triple dose of adderall, time to clean up the whole damn workshop
08:31 PM XXCoder1: yay more hidden gifts
08:31 PM veegee: (no, I'm not a junkie, it's prescription and I legitimately have ADD)
08:33 PM skunkworks: You sound defensive.. :)
08:35 PM skunkworks: http://electronicsam.com/images/greenmachine/IMG_20210313_201227.jpg\
08:36 PM XXCoder1: not loading
08:37 PM skunkworks: my site seems to be slow today
08:38 PM XXCoder1: oh finally load
08:38 PM XXCoder1: looks more finished
08:38 PM skunkworks: getting there.. Face plate just needs a bunch of holes in it.. I have to grind the wheel bearing so it has preload.
09:47 PM ve7it: http://electronicsam.com/images/greenmachine/IMG_20210313_201227.jpg is the correct link
09:47 PM ve7it: looks good
09:48 PM skunkworks: site is slow.. sorry