#linuxcnc Logs

Oct 04 2021

#linuxcnc Calendar

01:21 AM Deejay: moin
01:52 AM randy: morning
02:12 AM CaptHindsight[m]: solarwind: we used to be able to get 100KW - 500KW diesel generators for the cost of removing them
02:13 AM CaptHindsight[m]: every ~5 years they replace the backup gens at telephone switch locations
04:34 AM t4nk_freenode: I just ordered that pi4, CaptHindsight[m] ... should arrive later today
04:34 AM t4nk_freenode: 8G version, I hope that should be enough
04:35 AM t4nk_freenode: so I'll be having a look at installing linuxcnc
04:37 AM t4nk_freenode: and that remora-thing
04:38 AM t4nk_freenode: also going to buy a 128G sd card
04:58 AM JT-Cave: morning
04:58 AM XXCoder: yo
05:27 AM alex_joni: morning
05:36 AM JT-Cave: hey alex_joni
06:21 AM alex_joni: hey JT
07:28 AM Loetmichel: CaptHindsight[m]: i can remember that the highrise (160 appartments) i grew up in had a ~300kw diesel genset in the cellar. Every year it was started for a few hours to make sure it would still run. ... blackening the whole entrance area to the building with soot for a while. ;)
08:40 AM JavaBean: that had to have been fun, having a building roll coal as you walk up
08:48 AM enleth: Loetmichel: makes sense, it probably needed its own water pumps to maintain pressure at the top floors
09:10 AM enleth: Loetmichel: I'm not saying the thing wouldn't re-power stairway and hallway lighting as soon as it starts up, it definitely would, but you want the lights to work *immediately* with zero interruption when power goes out and it takes a moment or two to start up a generator
09:12 AM enleth: a 300kW genset takes a few minutes to start the engine, stabilize it, perform self-tests and go online
09:26 AM Loetmichel: its actually preheated as and has electric oil pumps as far as i know. it needs less than 10 seconds to repower the complete house minus the electric stoves
09:26 AM Loetmichel: but yes, in case of power loss it takes a few seconds before the power comes back
09:27 AM Loetmichel: dsoesent mean it coughs up a reasonable amount of soot every time it starts.
09:28 AM Loetmichel: and whoever made the exhaus come out right in front of the entrance to the building in a small corner of greens....
09:28 AM Loetmichel: :)
10:31 AM Eric_ is now known as unterhausen
10:31 AM unterhausen: the stuff from my lab finally made it to salvage
10:42 AM unterhausen: we were supposed to get 5 days of rain in a row. turns out it rained last night and I don't think we'll get any the rest of the week
10:57 AM roycroft: typically by this time of year it rains almost every day, and will continue doing so until june, but we're getting a few days of sunshine at a time, followed by a brief rainy period
11:16 AM snakedGT is now known as snaked
11:23 AM unterhausen: facebook is down, pretty funny
11:24 AM roycroft: may it stay that way forever
11:29 AM roycroft: does anyone here know much about metric timing gears and belts?
11:30 AM roycroft: i was going to use the timing gear from my current mill motor on the new one, boring it out and cutting a new keyway
11:30 AM roycroft: but when i disassembled it, i found that it would be a problem - it's a 3 piece gear, with the main gear cog surrounded by two plates
11:31 AM roycroft: and instead of being held in by a set screw, there are two grooves in the motor shaft, and it's held in place using c clips in those grooves
11:31 AM roycroft: i do not want to even think about doing that with the new motor
11:32 AM roycroft: so i'd like to get a different gear, but i can't figure out what to get
11:32 AM roycroft: when i measure both the belt and the gear, it looks like a 6mm pitch
11:33 AM roycroft: i cannot find timing gears or belts with a 6mm pitch though - 5mm is common, i've found a very few 7mm pitch, and 8mm pitch is very common
11:33 AM roycroft: is an m6 pitch a real thing?
11:33 AM roguish[m]1: roycroft: can you put up a picture of the 3 piece gear ???
11:33 AM roycroft: sure - it will take me a couple minutes
11:42 AM unterhausen: yeah, mcmaster doesn't have 6mm pitch, must not be a standard
11:46 AM roycroft: roycroft.us/Gear
11:46 AM roycroft: i can probably figure out how to mount the existing one on the new motor shaft
11:46 AM roycroft: but then i would have to find a timing belt that fits
11:47 AM roycroft: and the non-standard pitch thing would come into play again
11:52 AM roycroft: the belt is also ~14.5mm wide, which is non-standard
11:52 AM roycroft: but it would probably work fine with a 12mm belt
11:58 AM unterhausen: that's not a very good tooth profile
11:58 AM roycroft: no, it's not
11:58 AM roycroft: but it works
11:58 AM unterhausen: somebody's nephew designed it
11:59 AM roycroft: it's pretty typical for this kind of machine
11:59 AM unterhausen: how hard is it to change the other pulley
11:59 AM roycroft: very hard, i think
11:59 AM roycroft: which is why i want to use this one
12:00 PM roycroft: but that may be the only reasonable option if i can't track down this particular one
12:00 PM unterhausen: I guess you are going to have to add set screws
12:00 PM roycroft: that would not work
12:00 PM roycroft: i would have to add a collar above and below it
12:00 PM roycroft: with set screws in the colars
12:00 PM roycroft: collars
12:00 PM unterhausen: if you say so
12:01 PM roycroft: but regardless of what i end up doing with the gear itself, i'm still left with the problem of finding a belt forit
12:02 PM roycroft: the new motor is bigger than the old one, and the motor shaft will have to be located further away from the spindle, so i'll need a longer belt
12:08 PM roycroft: i wonder if the gear is actually 1/4" pitch, with metric bores for the shafts
12:08 PM roycroft: there's a lot of frankenstein gear in the world
12:11 PM unterhausen: I was wondering if it was 1/4" too. Measure between a lot of teeth
12:12 PM unterhausen: you can also reverse engineer it from the pulley diameter and number of teeth
12:13 PM roycroft: between the teeth i measure just under 6mm
12:13 PM roycroft: the belt is almost brand new, and i've done most of the pitch measuring with it
12:14 PM unterhausen: yes, you need to measure between 20 teeth and then divide by 20
12:14 PM roycroft: and it measures right about at 6mm, but since it's rubber, it would be pretty easy to be off by 0.3mm
12:15 PM roycroft: after work today i'll determine exactly how difficult it would be to replace the other timing gear
12:15 PM roycroft: i'd actually like to replace them both if feasible
12:15 PM roycroft: i think i'd like to adjust the gear ratio to get a little more top end speed
12:17 PM roycroft: as it is, it tops out at 2000rpm
12:17 PM roycroft: 2500rpm, at least, would be nice
12:17 PM roycroft: i know i can get a bit more speed by increasing the frequency of the vfd output
12:18 PM unterhausen: I missed it when you decided to replace the motor
12:31 PM roycroft: yeah, i think i need to do that
12:32 PM roycroft: last spring the mill died after i completed a light cut
12:32 PM roycroft: i had the controller board repaired a month ago
12:32 PM roycroft: the guy who repaired it was concerned that the motor may be damaged, but it worked for a month doing light cuts
12:33 PM roycroft: then it failed again while i was doing a plunge cut with an end mill
12:33 PM roycroft: a replacement motor of the same type is expensive, and i can't control the spindle with linuxcnc using the current controller board
12:34 PM roycroft: i have a nice motor in stock that should work fine, with a few modifications to the motor mount, and it's a standard 3 phase motor that i can control with a vfd that linuxcnc knows about
12:37 PM unterhausen: I guess it makes sense that the problem was the motor
12:37 PM unterhausen: what model mill is it?
12:38 PM roycroft: grizzly g0463 - it's a sieg x3
12:41 PM unterhausen: fb was reportedly taken down by a mirai botnet
12:42 PM unterhausen: it's a bit annoying those iot devices are still out there
12:44 PM cradek_: also annoying facebook is still out there, so it's even
12:44 PM unterhausen: sometimes the enemy of my enemy is not my friend
12:45 PM cradek_: true
12:45 PM unterhausen: anyone can turn one of those botnets on any target
12:45 PM unterhausen: source code is available
12:45 PM cradek_: maybe the problem will get some attention for a minute now
12:46 PM unterhausen: I forget what the vulnerability on our side was, but someone turned one of our lab computers into a ddos bot
12:46 PM unterhausen: the university shut it down because of the extra traffic
12:47 PM unterhausen: roycroft, it looks like it might not be too hard to switch that other pulley out since it's at the end of a geartrain
12:48 PM unterhausen: the other pulley has flanges that bolt together
12:49 PM roycroft: roycroft.us/Gear/MillGears.png
12:50 PM roycroft: the gear on the right is the one that would be difficult to replace
12:51 PM roycroft: the facebook problem gets lots of attention, but nobody does anything aboutit
12:52 PM roycroft: "i know facebook are evil and are destroying the world, but they make it so easy for my daughter to share pics of my grandchildren, so i don't care"
12:54 PM unterhausen: it would be difficult to tell if facebook was getting bot traffic from one of your customers
12:54 PM unterhausen: although ISP's could scan for open telnet ports just like the bot software does. code is already written
12:56 PM roycroft: is the isp in macedonia going to do that?
12:56 PM roycroft: are you going to be able to contact them if they don't?
12:56 PM unterhausen: my guess is that all the traffic is coming from comcast
12:56 PM roycroft: it's likely not
12:56 PM roycroft: it's likely coming from asia and eastern europe mostly
12:58 PM roycroft: cnn are starting to try to make a connection between the 60 minutes segment from last night and the outage today
01:02 PM unterhausen: It's not too hard to make that connection, all someone has to do is d/l the code, switch the target, and let it loose into the wild. It self-replicates
01:04 PM roycroft: what's kind of shocking to me is that all the information that came out of that segment has been well-known for quite some time
01:05 PM roycroft: but the majority of people are just now learning it
01:05 PM JT-Shop: USPS suspended all package service to New Zealand on 10-1
01:06 PM roycroft: the prime minister is really locking down the country
01:06 PM roycroft: i'm sure it's extremely difficult to get parcels and letters through customs now
01:07 PM unterhausen: there are rumors that fb screwed up a network change.
01:07 PM roycroft: that's possible, but a ddos is more likely
01:09 PM JT-Shop: UPS does not have a problem at all
01:10 PM JT-Shop: no commercial flights means no USPS, UPS has their own planes
01:11 PM LuminaxWk is now known as Luminax
01:12 PM roycroft: i don't get the lockdowns on mail
01:12 PM roycroft: this happened in japan last year in april or may
01:13 PM roycroft: i had a shipment coming from there, and it was actually on the plane and about to leave when japan post cancelled all foreign shipments
01:13 PM roycroft: the us was not blocking them
01:13 PM roycroft: it was japan post who did it
01:14 PM roycroft: i know we did not know as much about sars-cov-19 at the time, but i think we knew enough to know that it would not be transmitted by shipping packages
01:15 PM roycroft: none of the sars family of viruses can be transmitted that way - as pernicious as they can be, they can't survive outside a host for a long time
01:17 PM roycroft: there are actually "concerns" that one of the common seasonal flu strains may become extinct because i wasn't passed around very much last year
01:18 PM roguish[m]1: holy shit..... the world's going to come to a screeching stop..........
01:20 PM roycroft: i don't know if it will be screeching
01:20 PM roycroft: but the world is going to end
01:20 PM roycroft: it's not a matter of if, but when
01:21 PM roycroft: our sun will turn into a red dwarf in a few billion years, and then we'll all be doomed
01:24 PM * roycroft would try to move to titan then
01:30 PM JT-Shop: I should punch back in and do some CAD work
01:32 PM CaptHindsight[m]: ever pronounce macedonia as mastadonia and then think that is where mastadons were from?
01:35 PM Tom_L: roycroft, i went with the GT2 series 5mm pitch on mine GT3 is a little better profile but a little harder to find
01:35 PM Tom_L: 15mm wide
01:35 PM CaptHindsight[m]: enjoy it while it lasts
01:45 PM roycroft: i need to figure out what to do about the gear on the transmission
01:45 PM roycroft: that's going to be difficult to replace
01:46 PM roycroft: once i get that sorted, then i can start figuring out the replacements
01:47 PM roycroft: some folks bypass the transmission completely and just put a new timing gear directly on the spindle
01:50 PM CaptHindsight[m]: @joco how are you getting your packages now?
01:51 PM CaptHindsight[m]: Joco: ^^
01:55 PM CaptHindsight[m]: https://www.latimes.com/archives/la-xpm-1985-04-03-me-28522-story.html
01:56 PM Tom_L: roycroft, with that big a spindle motor i'd say going direct to the spindle would be a good idea
01:56 PM Tom_L: mine is 1.2kw and i'm 1:1 direct
01:57 PM Tom_L: but i am glad i went with a wider belt that i previously had
01:58 PM roycroft: it's lunch time, so i'll go look at the spindle gear
01:59 PM roycroft: that may be easier to replace than the transmission gear
01:59 PM CaptHindsight[m]: losing Facebook is like ending PID's
01:59 PM roycroft: and eliminating the transmission will make the mill quieter, amongst other advantages
01:59 PM roycroft: for me, there's nothing to lose
01:59 PM Tom_L: yeah i doubt you need it really
02:00 PM Tom_L: is it reduction or overdrive?
02:00 PM roycroft: i don't consider myself particularly prescient, but i predicted the evils of facebook when it was first launched, and have avoided it since day one
02:00 PM roycroft: it's reduction
02:00 PM roycroft: the motor top speed is 4000 rpm
02:00 PM roycroft: the top spindle speed is 2000rpm
02:00 PM roycroft: the transmission does 1:1 and 1:2
02:01 PM roycroft: to the motor
02:01 PM roycroft: and then to the spindle it's 1:2
02:01 PM Tom_L: mine tops out ~5500 but i generally don't run it that fast
02:01 PM roycroft: er, i think i have that backwards
02:01 PM roycroft: 1:2 to the motor, i believe
02:01 PM roycroft: and either 1:1 or 1:2 to the spindle
02:02 PM roycroft: anyway, with so much more power, and a vfd that can provide decent low end torque, i think elminating the transmission should be fine
02:02 PM roycroft: the new motor is 3750rpm @60hz,but i can probably bump it up to 80Hz without issue
02:02 PM Tom_L: sounds like the setup would be simpler
02:03 PM roycroft: yes, simpler, more reliable, more efficient, and quieter
02:03 PM roycroft: and i would not have to configure linuxcnc for both the high and low range
02:03 PM Tom_L: GT2 GT3 have the best contact area i think
02:06 PM Tom_L: so i went from this with the sherline motor: http://tom-itx.no-ip.biz:81/~webpage/cnc/new_pulleys/timing_pulley1.jpg to this with the new motor: http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Spindle/Motor_Mounted2.jpg
02:09 PM roycroft: the spindle gear has a 35mm bore
02:09 PM roycroft: that might be challenging to find
02:10 PM Tom_L: yeah
02:10 PM roycroft: it has 34 teeth, and the motor 16 teeth, so almost a 1:2 ratio if i went directly to the spindle
02:10 PM roycroft: with the existing gearing
02:10 PM Tom_L: i bored at least one of mine each time
02:11 PM roycroft: well if i do it this way, i'll probably try to find something off-the-shelf that fits the motor shaft (5/8"), and then bore the spindle gear to size
02:11 PM roycroft: your web server is not responding
02:12 PM roycroft: oh, now it is
02:12 PM Tom_L: i've been having isp issues it may be slow
02:12 PM roycroft: it timed out the first time
02:12 PM roycroft: but it's ok now
02:12 PM roycroft: there will be quite a bit more space between my motor shaft and the spindle than on yours
02:13 PM roycroft: but that should be fine - those belts aren't too strechy, in my experience
02:13 PM Tom_L: i could have moved it further out
02:13 PM roycroft: as long as i have a tension adjuster on the motor mounting plate
02:17 PM CaptHindsight[m]: https://i.imgur.com/doqNxr6.png
02:19 PM CaptHindsight[m]: https://www.tube-tradefair.com/cgi-bin/md_wiretube/lib/pub/tt.cgi?oid=2381261&lang=2&ticket=g_u_e_s_t
02:20 PM Tom_L: that one didn't load
02:20 PM Tom_L: well the first pic anyway
02:23 PM roycroft: i'm finding gears that almost work
02:24 PM roycroft: but typically they have a hub diameter of 38mm or so
02:24 PM roycroft: and that won't work at all
02:24 PM roycroft: i really need the hub diameter to be 55mm or so to leave room for the 35mm bore with keyway, and to have a bit of meat left on the hub
02:27 PM Tom_L: did you try sdp-si?
02:28 PM roycroft: i just found one that's suitable for boring to 35mm, but it's $1393.93
02:28 PM roycroft: yes, i just left that site
02:28 PM roycroft: 38mm is the biggest hub size i found
02:33 PM roycroft: i found one that might work
02:34 PM roycroft: https://www.bbman.com/catalog/?page=product&id=36L075-6FS7
02:35 PM Tom_L: what series is that?
02:36 PM roycroft: it's tooth style l
02:36 PM roycroft: it says type 6f
02:36 PM Tom_L: doesn't ring a bell
02:36 PM roycroft: i don't know much about timing pulleys, so that's not making a lot of sense to me
02:37 PM Tom_L: L might
02:37 PM Tom_L: the rounded profile of GT series is a little more efficient
02:37 PM roycroft: but two of those would do the trick, giving me a 1:1 ratio and a spindle speed of 3750rpm
02:37 PM Tom_L: instead of the squareish teeth of those
02:37 PM Tom_L: but it will still work
02:37 PM roycroft: yes, but if this is all i can find it's the one to get
02:37 PM Tom_L: yup
02:38 PM roycroft: i'm just happy i've found something that might work
02:38 PM roycroft: i don't think i would purchase a broach for that
02:38 PM Tom_L: you have a belt?
02:39 PM roycroft: no, but i can't shop for belts until i know what gears i'll be using
02:39 PM roycroft: and i'm thinking maybe 24 teeth on the motor, not 36
02:40 PM roycroft: that would get me 2600rpm at the spindle at 60Hz
02:40 PM roycroft: which is right about where i want to be
02:42 PM roycroft: type l timing belts are easy to find
02:43 PM CaptHindsight[m]: https://d2n4wb9orp1vta.cloudfront.net/cms/GP0315_Grinding_6.jpg;width=860;format=webp
02:44 PM roycroft: i've seen videos of folks cutting keyways using a lathe, and making a cutter that mounts on the carriage and works like a scraper
02:44 PM roycroft: does that actually work well in the real world?
02:46 PM roycroft: i like that the spindle gear from that outfit is ductle iron - it would be easy to bore out
03:01 PM Tom_L: i tried it once on the mill with less than stellar results
03:01 PM roguish[m]1: capt_hindsight[m]: it's real....... https://www.bleepingcomputer.com/news/technology/facebook-whatsapp-and-instagram-down-due-to-dns-outage/
03:02 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/rotary/Broach/broaching2.jpg
03:02 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/rotary/Broach/Test_Keyway6.jpg
03:02 PM Tom_L: i wound up buying a broach
03:03 PM roycroft: for a 35mm bore i would likely never use it again
03:03 PM Tom_L: and that was in aluminum not steel
03:03 PM roycroft: i bought a broach a while back for a machine handle i had bored out, but it was m12 or m14, and there's a decent chance i'll use it again
03:03 PM Tom_L: maybe you could find a shop to do it cheaper than a broach
03:04 PM roycroft: this is one-off, so i don't think i want to invest $100 in a broach and a collar
03:04 PM roycroft: that's something i'm considering
03:04 PM Tom_L: doubtful but maybe
03:04 PM roycroft: it would actually be easier to just have the machine shop do the bore and the keyway
03:04 PM Tom_L: yup
03:04 PM roycroft: since my lathe is already a little wonky, and i only have a 3 jaw chuck to use
03:05 PM roycroft: getting the gear centered perfectly would be a hassle
03:05 PM roycroft: shims under a 3 jaw are not fun, because it takes a long time to dial in
03:06 PM roycroft: i'd probably be better off making a collet to hold the gear
03:06 PM roycroft: but that's a lot of work to do properly
03:07 PM roycroft: and i should think that getting that bore perfectly concentric is important
03:07 PM roycroft: if it's a tiny bit off i could get some vibration/oscillation
03:09 PM enleth: https://i.imgur.com/kr2age1.jpg
03:09 PM roycroft: i have some more measuring to do to see if i can even use that gear - i may have to go down to one for a 1/2" belt
03:10 PM enleth: just finished a KUKA robot calibration tool
03:10 PM roycroft: the spindle gear is also held in place with c-clips
03:40 PM Tom_L: odd
03:52 PM t4nk_freenode: heh... they just delivered my pi4 ... it's 22:40, had a long day, literally only have the energy left to shove the package onto a shelf ;)
03:53 PM t4nk_freenode: judging by the box... it must be a very small device
03:54 PM t4nk_freenode: they'd probably need a couple of office buildings to house the same power back in the days
03:55 PM enleth: roycroft: as for broaching with the lathe: yes, it works
03:55 PM roguish[m]1: capt_hindsight[m]: Westinghouse Marine division in Sunnyvale had a 200" gear hob in a environment controlled room, at least back in the early '80s.
03:55 PM enleth: roycroft: slow and annoying, but works if you have to
03:56 PM roguish[m]1: could hold a few thou over the 200"
03:56 PM enleth: roycroft: not so bad in brass or aluminum, a bitch in steel
03:56 PM enleth: experience with shaper bit grinding is a huge plus
03:56 PM roguish[m]1: made gears for nuc subs. the navy likes very quiet transmissions.
03:58 PM roguish[m]1: also had a twin cutter vertical lathe, in the floor, about a 30' diameter table
03:59 PM roguish[m]1: shoulda seen the line boring machine for the transmission housings.....huge......impressive.
04:08 PM roycroft: i only have to do it once, enleth
04:08 PM roycroft: and it would be ductile iron
04:09 PM roycroft: so kind of in between aluminium and steel
04:09 PM enleth: oh, that should broach relatively nicely
04:10 PM enleth: what you need is one of those old style boring bars with a transverse square hole near the end and a screw holding a bit in the hole
04:11 PM enleth: and a HSS blank that fits in there
04:12 PM enleth: roycroft: https://cdn11.bigcommerce.com/s-c9l4hm6h/images/stencil/1280x1280/products/4095/8138/borin1__43544.1574217924.jpg?c=2
04:12 PM enleth: like the left end on that thing
04:14 PM enleth: the bit gets one cutting edge as wide as the keyway, quite a bit of negative top rake, a bit of side relief and a bit of bottom relief
04:14 PM enleth: the top rake is important
04:16 PM enleth: this thing needs to *dig* *in* by itself, with no bushing to keep it engaged with the work it'll slide and deflect the bar instead if the rake is too gentle
04:16 PM roycroft: i've seen it done using a parting tool on its side
04:16 PM roycroft: that gives plenty of clearance on the sides
04:16 PM roycroft: if i have a parting tool that's wide enough
04:17 PM enleth: that might work
04:17 PM roycroft: i'll have to measure, but it looks like about 5mm
04:17 PM enleth: or you might need to modify it a bit
04:17 PM enleth: a normal parting tool might not have enough rake angle
04:18 PM roycroft: top rake?
04:19 PM enleth: yes
04:19 PM roycroft: that can be adjusted by the angle in the tool holder
04:20 PM roycroft: i could also carefully grind a hss tool
04:20 PM enleth: if the gear is thin enough and the bore large enough that the tool being at an angle won't interfere - yeah
04:20 PM roycroft: the bore needs to be 35mm
04:20 PM roycroft: i'll have like a giant chasm to work in
04:20 PM enleth: I had to broach some pretty long stuff where that wouldn't do, so I used the boring bar method
04:21 PM enleth: actually, I now realized I'll need to do that again, in steel, and I'm not looking forward to it
04:21 PM roycroft: the keyway needs to be about 35mm long as well
04:21 PM enleth: I have to re-make the brake disc carrier for the bridgeport
04:21 PM roycroft: but i still don't know if that gear will even work
04:21 PM roycroft: i get off work in less than an hour, and i'll go measure then
04:22 PM enleth: oh, BTW, set it up on the mill and plunge a 5mm endmill in there first, to remove as much material as you possibly can before broaching
04:22 PM enleth: so you'll only have two corners to broach
04:23 PM roycroft: the gear is for the mill spindle
04:23 PM roycroft: so that's not going to work
04:23 PM roycroft: i have no mill until i install the new motor
04:23 PM enleth: drill press? could work with a plunge cut
04:23 PM roycroft: i could use a drill press
04:24 PM roycroft: but honestly, ductile iron should cut like butter
04:24 PM roycroft: if i'm taking 0.05mm passes or so it should be pretty easy
04:24 PM roycroft: it will just take a while
04:24 PM enleth: another trick is using a jigsaw with a metal blade to remove the bulk of material
04:25 PM enleth: like, a regular woodworking jigsaw
04:25 PM roycroft: i really think that if this is what i'm going to do, getting the gear concentric in the chuck is my biggest concern
04:25 PM roycroft: because it will be in a 3 jaw that's old and worn
04:25 PM enleth: it doesn't even have to be, you're not going to be rotating it
04:26 PM enleth: what you do need to get right is tool height
04:26 PM roycroft: i'm talking about for the bore itself
04:26 PM enleth: your toolpost's tool height adjustment becomes one of the axes
04:26 PM enleth: ah, ok
04:26 PM roycroft: and i think i do want that to be as spot on as possible
04:27 PM enleth: is there a hole in the gear now, or is that a solid blank?
04:27 PM roycroft: as far as tool height, i'd just throw a piece of scrap rod in the chuck, turn it to a point, and line that up with the center of the broach
04:27 PM roycroft: the one i'm looking at purchasing will have a 5/8" hole bored in it
04:27 PM roycroft: so i'll have something to indicate
04:27 PM enleth: then use a dead center to press it against the chuck face
04:27 PM roycroft: https://www.bbman.com/catalog/?page=product&id=36L075-6FS7
04:28 PM enleth: it'll align the hole on the lathe centerline
04:28 PM roycroft: that's what i'm looking at
04:28 PM enleth: then try chucking and shim if needed
04:28 PM roycroft: but i need to bore it to 35mm and cut a keyway
04:28 PM roycroft: yeah, i can shim it
04:28 PM roycroft: but it's really fiddly shimming jaws of a 3 jaw
04:28 PM enleth: oh, that even has a nice chamfer on the hole
04:28 PM enleth: definitely center it with the tailstock
04:28 PM roycroft: because the shim doesn't move the part the opposite direction
04:29 PM roycroft: well it does, but what i mean is i can't indicate the opposite side and shim accordingly
04:29 PM roycroft: because the axes are not 90 degres to each other
04:30 PM roycroft: i've done it before, and it can be really fiddly
04:30 PM enleth: I did something like this once by slowly tightening the chuck and using feeler gauges to check the gap at each jaw
04:30 PM enleth: so I had a rough idea of where and how to shim
04:30 PM roycroft: and i could possibly make a collet for the gear, but it's big enough and shallow enough that it would probably take me a very long time to make a good collet
04:30 PM enleth: while the tailstock held the part on axis
04:31 PM roycroft: using the tail stock to hold it on axis might work out well
04:31 PM roycroft: i'll ponder that, and perhaps give it a go with the existing gear to see how fiddly it turns out to be
04:32 PM roycroft: i'm not going to blame my sloppy lathe for not being able to turn this properly, because i'm fairly confident i can
04:32 PM roycroft: i just have to weigh the time it takes me do it vs. paying someone else to do it
04:32 PM solarwind: CaptHindsight[m] what would I search for if I just want to buy the "alternator" part? "Alternator" just gives you automotive 12V alternators. I don't really care if it's brushed or brushless, but 3 phase would be a requirement. I guess I could always use any alternator and feed the power into an inverter
04:32 PM solarwind: 100kW would be nice
04:33 PM roycroft: this is an unbudgeted repair that i need to do right as i'm pumping all my spare cash into my router project, so keeping the cost down as much as possible is what i want to do
04:33 PM solarwind: Can always stick a smaller engine onto it
04:33 PM enleth: solarwind: look for a genset with a completely buggered engine?
04:33 PM roycroft: which is one reason i'm using a motor that is way bigger than i need on the machine
04:33 PM enleth: solarwind: that sounds like it might be cheap and available if you know where to ask
04:33 PM enleth: like, companies that service generators
04:33 PM solarwind: enleth yeah that's what I'm leaning towards
04:34 PM roycroft: boring from 5/8" to 35mm is going to take some time too
04:34 PM roycroft: even if i use twist drills for part of the bore
04:36 PM roycroft: an annular cutter might be a good idea
04:36 PM enleth: roycroft: tool and equipment rental companies usually rent out generators, too - I wouldn't be surprised if they ended up with a broken one to throw away from time to time
04:37 PM roycroft: i think that was probably for solarwind?
04:37 PM enleth: roycroft: annular cutter with a guide would be perfect
04:37 PM enleth: oh, yes
04:37 PM enleth: solarwind: : tool and equipment rental companies usually rent out generators, too - I wouldn't be surprised if they ended up with a broken one to throw away from time to time
04:37 PM solarwind: Thanks, I'll look around
04:38 PM roycroft: 1-3/8" is just under 35mm
04:39 PM roycroft: i am finding 1-3/8" annular drills that are 1" long
04:39 PM roycroft: the gear is 1.5" long
04:39 PM roycroft: and i don't think i want to flip it around to complete the cut - i would not have much wiggle room (about 0.002")
04:41 PM roycroft: if i used a smaller annular drill i suppose i could do that
04:41 PM roycroft: do the back side first, flip it around, indicate it since i'd still have the factory bore on the front, drill it, and complete the bore with a boring bar
04:47 PM Tom_L: i don't think i'd flip it once it's set in place
04:47 PM roycroft: for the final bore, no
04:48 PM roycroft: if i did it as described above, a bit undersize, it would not be that big a deal
04:48 PM roycroft: when i drill the back half i would not even need to indicate it - i could just chuck it up and go
04:48 PM roycroft: as long as i indicate the front half carefully, and do not move it once it's indicated
04:49 PM enleth: sounds like a decent plan
04:49 PM roycroft: and i found that they have the same gears, but for a 1/2" belt, so that may be an option of the 3/4" belt size won't work
04:49 PM roycroft: and the 1/2" belt gears are a fair amount less expensiv
04:49 PM Tom_L: also maybe ask that company you're buying it from if they offer that service
04:50 PM roycroft: i'd rather use the wide belt if possible
04:50 PM roycroft: yeah, i'll ask that
04:51 PM Tom_L: that would be ideal
04:51 PM roycroft: time to check on ebay to see if i can get the parts for a song, before i do anything else
04:54 PM roycroft: fixturing the gear could be interesting, because i'd only be able to hold onto the flanges with the vise jaws
04:54 PM Tom_L: they're not held on that well either
04:54 PM enleth: roycroft: three equal blocks of aluminum or brass can fix that
04:55 PM enleth: the flanges are most likely not suitable for holding and will get ripped off easily
04:55 PM enleth: three blocks and some rubber bands, to be exact
04:55 PM enleth: unless you fancy using three hands to chuck something
04:57 PM roycroft: yeah, i could make some soft jaws for the lathe that are narrow enough to grab the gear itself
04:57 PM roycroft: actually that might be a good way to center it as well - i could scrape tiny bits off a jaw instead of messing with shims
05:08 PM CaptHindsight[m]: are there any off the shelf server cooling systems for 1-4 racks? Where you don't want to cool the whole room, just a rack or two.
05:12 PM roycroft: you'll want to cool the whole room
05:13 PM roycroft: the rack coolers would just dump the heat into the room
05:13 PM roycroft: if it's a really huge room, consider some portable ac units that you can duct to the outside
05:14 PM roycroft: if you have four racks, add a fifth rack
05:14 PM roycroft: remove the walls between them all
05:14 PM roycroft: and seal them up really well
05:14 PM roycroft: stick the portable ac unit in the 5th rack
05:14 PM roycroft: and duct it outside
05:14 PM CaptHindsight[m]: roycroft: " IF it's coming from the USA then there are issue. US Post has stopped shipping to countries with COVID delays. NZ being one. I understand NZ Post is looking at how they can get around that."
05:15 PM CaptHindsight[m]: from China to NZ is not a problem, so drop ship :)
05:15 PM roycroft: i'm not looking to ship anything to new zealand
05:15 PM roycroft: except perhaps myself, if this country doesn't get its act together :)
05:18 PM roycroft: so i just read that when the drive center distance is eight times the diameter of the small pulley or when the drive is operating on vertical shafts, the timing pulleys should be flanged
05:18 PM roycroft: that answers that definitively
05:18 PM roycroft: the drive center distance may be close to eight times the diameter of the small pulley, but even if it's not, it will be a vertical mount
05:20 PM Tom_L: i would flange one anyway
05:20 PM macgalempsy: evening gents
05:21 PM roycroft: i was planning on doing that
05:21 PM roycroft: someone here indicated that it is not necessary
05:21 PM Tom_L: theoretically maybe
05:22 PM roycroft: i just got an offer from paypal
05:22 PM roycroft: if i spend $25 on crypto currency using paypal they will give me a $25 credit
05:23 PM roycroft: that sounds like a wash
05:23 PM roycroft: and if the crypto currency value goes down to zero it's still a wash
05:23 PM roycroft: so now i have to find the hidden fees
05:24 PM macgalempsy: its been a while, but getting back onto the CNC project. a general question. I have created a voltage divider circuit with a couple of big caps and a small one. VIN is 48v and VOUT when not connected to anything is 24v. After connecting the servo drives, the voltage dives to ~3.5V.
05:24 PM macgalempsy: does this seem normal?
05:41 PM CaptHindsight[m]: https://xindaenergy.en.made-in-china.com/product/INCmTyiEZwVY/China-100kw-700rpm-Inner-Rotor-Axial-Flux-Pancake-Sychronous-Magnet-Generator-Alternator.html
05:42 PM CaptHindsight[m]: also wind turbines
05:43 PM XXCoder: lol weird error in pricing
05:43 PM XXCoder: 250 each for 1-999. more than that, 5000 usd each
05:43 PM XXCoder: might be a way to limit numbers
05:44 PM CaptHindsight[m]: solarwind: http://www.xindaenergy.com/100kw-30rpm-permanent-magnet-generator-p358.html
05:46 PM CaptHindsight[m]: https://www.magnax.com/magnax-blog/axial-flux-motors-and-generators-shrink-size-weight
05:47 PM CloudEvil: CaptHindsight[m]: that is damn near topologically identical to thin wide brushless of the conventional form
05:49 PM CloudEvil: Actually, no, on reflection. Coils, yes, flux in the rotor not
05:58 PM roycroft: that pulley is way too big
05:58 PM roycroft: oh well, i'll find something else
06:04 PM CaptHindsight[m]: roycroft: it's not my room
06:09 PM roycroft: well i don't know of any rack coolers such as you're asking about
06:09 PM roycroft: if the room has climate control, there are fan banks that mount in racks - i have a setup like that at home right now
06:09 PM roycroft: my rack cabinet has some exhaust fans at the top
06:09 PM CaptHindsight[m]: roycroft: how many portable AC's can you link serially? can you go 100ft from server to outdoor air? Will this require a damper for when the outside temp is low and the humidity is high?
06:10 PM roycroft: and i have some fans in the bottom of the rack that suck air up through the bottom
06:10 PM CaptHindsight[m]: if the servers are on wheels can't they just move them around to cool areas? the internet is wireless anyway
06:11 PM roycroft: the portable ac units i'm talking about should be able to exhaust 100' if you use 6" rigid duct
06:11 PM unterhausen: the internet is wireless? Now you tell me, I'm pulling an ethernet cable to my office
06:11 PM CaptHindsight[m]: how about immersion cooling using fluorinert and an old above ground pool?
06:12 PM roycroft: if the servers are on wheels you can just roll them up to greenland and carve out an ice cave to stick them in
06:12 PM CaptHindsight[m]: or a used walk in cooler and those 6ft big ass fans
06:13 PM roycroft: those can be had cheap on cl
06:17 PM CaptHindsight[m]: "but this is a pancake"
06:17 PM CaptHindsight[m]: that goes to 11
06:30 PM CaptHindsight[m]: unterhausen: saw it on the IT Crowd
06:31 PM CaptHindsight[m]: https://www.youtube.com/watch?v=Vywf48Dhyns
06:31 PM roycroft: another option would be to get a bunch of giant weather balloons and float the racks up to 30,000 feet
06:31 PM roycroft: wifi should work fine from there
06:32 PM roycroft: i have found gears that will work, and they're half the price of what i was looking at
06:33 PM roycroft: the overall length of the spindle gear is 0.003" too long
06:33 PM roycroft: i think i can deal with that
06:36 PM CloudEvil: If using press-fit gearing, remember to add high pressure lube to the gearbox.
06:37 PM CaptHindsight[m]: the air might be too thin to cool the racks
06:37 PM roycroft: it's not press fit
06:39 PM roycroft: and the bore is not even really 35mm - i'll need to mike it to dial it in exactly, but my calipers say the shaft is 34.87mm, and the old gear bore is 34.89mm
06:39 PM roycroft: which is closer to 1.375" than 35mm
06:39 PM roycroft: this could be another frankenstein part
06:40 PM roycroft: the keyway is 8.00mm wide
06:53 PM XXCoder: https://www.youtube.com/watch?v=_ZFi7F_rtJ4
06:53 PM XXCoder: interesting lathe tecique
06:54 PM XXCoder: cnc but yeah
07:07 PM XXCoder: that guy must have really tiny shop
07:07 PM XXCoder: he uses only gathe
07:08 PM XXCoder: he uses it for buffering and sand disks too
07:09 PM XXCoder: oh guy has a drill press
07:17 PM XXCoder: bandsaw too
07:17 PM XXCoder: https://youtu.be/W3n6pEVp3Fo
07:17 PM XXCoder: amazing project
07:17 PM XXCoder: roycroft: you might like that guy dunno
07:20 PM XXCoder: other video hes making something like wood case for iphone? with hughe speakers
07:27 PM snakedGT is now known as snaked
07:33 PM XXCoder: im loving that channel so far
07:47 PM XXCoder: cuckoo clock is insane
11:02 PM solarwind: CaptHindsight[m] I was wondering if the 30 RPM was a ty po
11:02 PM solarwind: But nope, meant to be connected to a water wheel
11:04 PM solarwind: What the hell, 4,900kg?
11:07 PM solarwind: http://www.xindaenergy.com/200kw-150rpm-Permanent-water-power-generator-60hz-p315.html
11:08 PM solarwind: 600kW, 450 RPM, 12,733N•m, 5,200kg
11:08 PM solarwind: I wonder how much that costs
11:22 PM XXCoder: crazy. https://youtu.be/B2IMASYxrAs
11:23 PM XXCoder: guy makes toothbrush the hard way