#linuxcnc Logs
Aug 08 2020
#linuxcnc Calendar
04:59 AM JT-Cave: morning
05:05 AM XXCoder: hey
05:58 AM Tom_L: morning
05:58 AM XXCoder: hey
08:54 AM unterhaus_: there is no cheap way to get gpib, is there?
09:36 AM _unreal_: good lord I have been gassing it up hard the past day or two
09:52 AM jymmmm: hola
09:54 AM jymmmm: Buenos Tacos
11:11 AM sync: unterhaus_: no
11:11 AM sync: just buy one of those agilent usb gpib things, they go for around $200 on ebay
11:20 AM jymmmm: $129 free shipping/returns on amazon... https://www.amazon.com/Agilent-82357B-HIGH-Speed-Interface-High-Speed/dp/B0828THF3P/
11:21 AM unterhaus_: that's what I'm seeing, trying to decide if installing linux on a computer with ISA slots is worth it. Have an ISA card
11:22 AM jymmmm: unterhaus_: NO!!!! Bad unterhaus_ (smacks nose with rolled up newspaper) DO NOT USE ISA.... BAD GEEK!!!
11:23 AM unterhaus_: it's just to mod my o'scope, not permanently
11:24 AM unterhaus_: actually, I have an msdos install disk
11:24 AM jymmmm: unterhaus_: Ok, fiiiiiiiiiiiine
11:25 AM jymmmm: unterhaus_: and how do you plan on getting data/control from dos?
11:25 AM unterhaus_: isa is the last hacker-friendly interface, that's why they got rid of it
11:26 AM jymmmm: unterhaus_: I think is has more todo with 8,16, or 32 bit
11:26 AM roycroft: time to do the last milling operations on my bench timbers
11:27 AM roycroft: i think my neighbors will be happy when that's all done
11:27 AM roycroft: i'll be able to work inside the shop again, and there won't be constant noise from machinery
11:28 AM unterhaus_: any computer with a parport probably has an isa bus on it, just not broken out
11:29 AM SpeedEvil: unterhaus_: Not true.
11:29 AM SpeedEvil: Unless you are including LPC bus in ISA
11:38 AM _unreal_: I am liking my dust/shoe-water block more and more
11:38 AM _unreal_: looks like both parts are going to be MULTI two sided builds
11:41 AM _unreal_: !!!! and I should add LED lighting this time to the inside of the dust shoe. so I can see what is going on
11:42 AM Thorhian: dust/shoe-water block?
11:47 AM Thorhian: Also, it seems ebay's website is broken on my end. It's like all of the css disappeared.
11:47 AM * SpeedEvil wishes that various sites would just give a metadata API and get the fuck out of the way.
11:48 AM SpeedEvil: See, for example, ebays breaking wildcards.
11:48 AM Thorhian: Metadata API?
11:50 AM SpeedEvil: Means for automating scraping of their offerings so you don't have to rely on terrible, terrible integrated search.
11:50 AM Thorhian: Ah, that's what you mean.
11:51 AM SpeedEvil: For example, if you are searching on ebay, you cannot search for nn334a and nn334b as other than an enumerated list of all the possibilities
01:03 PM _unreal_: yes water block
01:05 PM _unreal_: https://drive.google.com/file/d/1GSiiMR9_JYhca81QY2FJqnnFBOsyHAsp/view?usp=sharing
01:05 PM _unreal_: That is what it looks like will look like
01:06 PM _unreal_: https://drive.google.com/file/d/1rZ_uWIyJqas2Pd5ph2OAzxlPHdhZAdJc/view?usp=sharing
02:03 PM Deejay: hi
02:03 PM Thorhian: Hello!
02:03 PM _unreal_: ok.... just finished taking apart my spdinel motor
02:03 PM _unreal_: spindle
02:04 PM _unreal_: the lower bearing was CLEARLY out of place
02:04 PM _unreal_: or bearing closested to the tooling end
02:04 PM Tom_L: screwed up?
02:04 PM Tom_L: send it back
02:04 PM _unreal_: was pushed way up... only about 1/3 of it was captured in the end cap
02:05 PM _unreal_: so I used my bearing puller and dropped it back down to where it should be
02:05 PM _unreal_: decent spring tension on the washer-spring
02:05 PM _unreal_: err spring washer
02:05 PM _unreal_: also there were some coil wires touching the washer so I pushed those down. very poorly wound
02:06 PM _unreal_: I didnt take the motor apart being a bldc dont know if it will fuck up the magnet
02:34 PM roycroft: milling is finally done!
02:34 PM roycroft: 65 hours into the project
02:59 PM Deejay: gn8
03:59 PM veegee: One of you guys linked me to a pneumatic venturi vacuum thing that produces a very strong vacuum
03:59 PM veegee: I can't seem to find the link anymore
04:06 PM JT-Cave: what country?
04:07 PM veegee: I'm in Canada but I don't ordering from the land of the oppressed, home of the pussies
04:07 PM veegee: I don't mind* ordering from [...]
04:07 PM JT-Cave: https://www.vortec.com/
04:08 PM JT-Cave: come around my neck of the country and you would get shot talking like that...
04:09 PM veegee: I have bullet proof vests
04:09 PM veegee: and they'd get a very large prison sentence
04:10 PM veegee: I'm a licensed pilot and UAV operator and someone shot my quadcopter, which is a federal crime
04:10 PM veegee: Got him arrested on the spot
04:11 PM veegee: trash talk is ok. Violence and putting people in actual danger is never ok
04:11 PM XXCoder: shot by saying what?
04:11 PM veegee: "land of the oppressed, home of the pussies"
04:12 PM veegee: no one in Canada would care if you made fun of the country. I've been all over the USA many times in my life. They have shitty flags _everywhere_
04:12 PM veegee: In Toronto, you see like one or two flags in the entire city lol
04:12 PM veegee: no one hangs that shit on their house like a douche
04:12 PM XXCoder: ahh ok
04:13 PM veegee: But damn that was fun getting the idiot arrested
04:13 PM XXCoder: yeah bullets dont magically disappear
04:14 PM XXCoder: it could arc down and kill someone
04:14 PM veegee: he thought he was being clever when I warned him it was a federal crime equivalent to shooting a regular airplane
04:14 PM veegee: legally
04:14 PM veegee: Well that too, but mainly the offence is shooting a registered aircraft
04:14 PM veegee: doesn't matter if it's a quadcopter or a 2 seater Cessna, the penalty is just as severe
04:14 PM XXCoder: yah just commenting that its really dumb to shoot into air
04:15 PM XXCoder: i once read about group of people who went to harricine and shot into it
04:15 PM veegee: and he was right in front of me. he just didn't like that I was flying it (fully legally)
04:15 PM veegee: XXCoder american I bet
04:16 PM XXCoder: wow you guessed right on first try, i;d think that impossible heh
04:16 PM veegee: THe guy thought I was bluffing when I called 911
04:18 PM XXCoder: theres nothing "little" about shooting off
04:18 PM veegee: A bunch of kids were trying to hit it with a baseball. They missed of course because it's hard to do and they suck, but at least they got scared when I told them it's a federal crime and stopped being little shits about it
04:19 PM veegee: Benefits of being fully licensed, don't need to take shit from anyone, especially when operating fully legally
04:19 PM XXCoder: you fly for work or enterainment?
04:19 PM veegee: just for fun, always had a passion for flight of any kind
04:20 PM veegee: Working on my private pilot licence now
04:20 PM veegee: Friend has a Cessna, so logging my flight hours using his plane
04:20 PM XXCoder: cool :)
04:20 PM veegee: But for UAV, I'm already fully licensed at the highest level, so I can legally fly even in dense cities, over people, even at airports and talk to air traffic control if I have a radio
04:21 PM veegee: I didn't get a radio yet, never needed to fly near an airport, but the point is I can if I wanted to which is cool that Canada takes drones very seriously and lets you do anything you want if you're licensed
04:22 PM XXCoder: isnt there quite good paying jobs for drone operators like you
04:22 PM XXCoder: like for fire survey and so on
04:22 PM veegee: So I've heard, but never bothered to look into it, so many other hobbies and a backlog of project ideas. Add to that regular work for my company and there goes all my time
04:23 PM XXCoder: lol ok
04:23 PM veegee: Spent all last night welding a broken brake calliper on my friend's car. TIG welded it, can't believe it worked
04:24 PM XXCoder: why not replace?
04:24 PM veegee: it was hard to clean it and very hard to maneuver in a tight spot so it ruined my pyrex cup and gas lens, but got a solid weld
04:24 PM XXCoder: discountined model?
04:24 PM veegee: no, he's just tight on cash and I help anyone who asks for it
04:33 PM XXCoder: nice
04:50 PM _unreal_: There the BUCKING driveway has been cleaned
04:50 PM _unreal_: hate the BUCKING HOA
05:02 PM skunkworks: dkfa;l\
05:02 PM skunkworks: heh
05:44 PM veegee: JT-Cave can't seem to find their venturi vacuum pumps
05:45 PM veegee: But this is really cool: https://www.vortec.com/vortex-tubes-1/overview
05:57 PM roycroft: i don't know what kind of ventury vacuum pump you're looking for, but i got the parts for mine from veneersupplies.com
05:59 PM roycroft: https://www.roycroft.us/Vacuum_Pump.jpeg
05:59 PM roycroft: and that's the vacuum pump i made
05:59 PM roycroft: it works brilliantly
06:01 PM roycroft: https://www.roycroft.us/Vacuum_Bag.jpeg
06:01 PM roycroft: there's a panel being glued up in the vacuum bag
06:40 PM skunkworks: finally got parts in for the garage bandsaw.. http://electronicsam.com/images/greenmachine/IMG_20200808_174832.jpg
06:44 PM XXCoder: yo
06:44 PM roycroft: that looks like an old craftsman 12" band saw
06:47 PM Tom_L: skunkworks, http://tom-itx.no-ip.biz:81/~webpage/cnc/rotary/Broach/Broach_holder1.jpg
06:47 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/rotary/Broach/Broach_holder3.jpg
06:47 PM Tom_L: i clamped the front but i think i'm gonna drill another hole or dowel pin it
06:50 PM skunkworks: andypugh: cool!
06:50 PM skunkworks: I mean
06:50 PM skunkworks: Tom_L: Cool!
06:50 PM skunkworks: wth
06:50 PM skunkworks: I read it as rotary broach ;)
06:52 PM jymmmm: IF a connector only has an AC rating of 120VAC@20A, what might be the DC amperage rating?
06:52 PM jymmmm: guestimate
06:53 PM roycroft: 0A
06:53 PM jymmmm: realistically
06:54 PM roycroft: if it's not been tested/rated for dc i would not use it unless i had no other choice
06:54 PM roycroft: but if i had no other choice i'd derate it by at least 1/2
06:54 PM roycroft: and keep eye on it even at that
06:55 PM roycroft: so in a pinch, 10A if you watch it
06:55 PM skunkworks: it is mainly the break might not break.. (arc)
06:55 PM skunkworks: so they lower the current..
06:55 PM andypugh: skunkworks <wakes up> Huh?
06:56 PM jymmmm: skunkworks: ah
06:56 PM skunkworks: Sorry - I don't know why I called you instead of tom..
06:56 PM skunkworks: andypugh: ^
06:57 PM skunkworks: although I think I almost have the math figured out to add a radius to the corner of the polygon...
06:57 PM skunkworks: To help with the direction change.
06:57 PM jymmmm: skunkworks: I REALLY want to use those nupon connectors, but ZERO dc ratings
06:58 PM andypugh: nupon?
06:58 PM jymmmm: hang on
06:58 PM roycroft: i'd contact the manufacturer and ask if they have a recommendation for using their products in a direct current application
06:59 PM jymmmm: Sotty, neutrik https://www.amazon.com/dp/B002EDM9AU/
06:59 PM jymmmm: Sorry*
06:59 PM jymmmm: roycroft: Yeah, XLR
06:59 PM jymmmm: I don't want to use xlr's though
07:00 PM jymmmm: andypugh: https://www.amazon.com/dp/B002EDM9AU/
07:01 PM andypugh: Right, Neutrik
07:01 PM andypugh: I am using the Speakons for DC. It’s fine :-)
07:01 PM jymmmm: andypugh: what amperage?
07:02 PM andypugh: Several?
07:02 PM andypugh: No idea.
07:02 PM andypugh: The 8i20s max out at 20A, so about that.
07:02 PM jymmmm: andypugh: 40A ?
07:02 PM jymmmm: ah
07:03 PM andypugh: Here is what Neutrik said when I asked them about PowerCON and DC:
07:03 PM andypugh: Morning Andy
07:03 PM andypugh: Thanks for your email
07:03 PM andypugh: The powerCON connector is an AC connector and all its approvals are related to this.
07:03 PM andypugh: The thing is with connectors they are used in many different applications for which they were never dreamt of being used, I know speakON connectors being used in diesel engine management design!
07:03 PM andypugh: If a connector is part of a system and it passes safety tests then the system becomes approved not the connector!
07:03 PM andypugh: All the best and thanks for using our connectors
07:03 PM roycroft: so they punted
07:03 PM roycroft: which is to be expected, i suppose
07:04 PM andypugh: They have been absolutely fine for about 8 years.
07:04 PM andypugh: But: You absolutely can’t disconnect them at 300V DC.
07:05 PM andypugh: But at £8 for a new set of socket and plug, that was just a learning experience.
07:06 PM andypugh: (I only found this because a fault had caused my crowbar resistor to explode. So when I was unplugging to investigate the loud bang and dark brown smell, I inadvertantly disconnected a 300V live PowerCON
07:07 PM andypugh: Because the crowbar curcuit had not discharged the caps/
07:10 PM jymmmm: Eh, I guess I'll use these instead... https://powerwerx.com/anderson-sb-connectors-sb50-50amp
07:14 PM veegee: jymmmm hey those look cool
07:14 PM veegee: I was going to place an order for powercon but this looks like another option
07:14 PM jymmmm: veegee: they go larger, 175A
07:14 PM jymmmm: veegee: And they are actually DC rated
07:15 PM veegee: If I can get them in a 4 wire configuration for 3 phase, I can standardise on that for my equipment
07:15 PM jymmmm: veegee: amperage?
07:15 PM veegee: less than 50
07:16 PM veegee: but I have 600V equipment and 240V equipment so it's great that they're keyed and colour coded
07:16 PM veegee: NEMA L14-30 sockets and plugs are expensive
07:17 PM jymmmm: 75A https://powerwerx.com/anderson-pp75-loose-piece-housing
07:17 PM jymmmm: veegee: Woth those ones, you can interlock into any configuration you want 1x2, 1x3, 2x2, 3x2, etc
07:19 PM jymmmm: I use the 30A version for all my stuff
07:19 PM veegee: Damn that sounds perfect
07:19 PM veegee: I think that's the solution I was looking for
07:19 PM veegee: One configuration for 600V 3 phase, another for 240V 3 phase, another for 240V single phase
07:19 PM veegee: And cheap enough such that I can have many outlets
07:20 PM veegee: Something that my friend can't accidentally plug a 240V tool into a 600V outlet
07:21 PM veegee: jymmmm I don't see how the interlocking mechanism works though
07:21 PM veegee: How would I make a 2x2 or a 1x4?
07:21 PM jymmmm: veegee: https://powerwerx.azureedge.net/productattachments/ds-pp75.pdf
07:22 PM _unreal_: I'm getting closer...
07:22 PM _unreal_: I am rather sure the HEAT production is from the bearing
07:22 PM _unreal_: btw
07:22 PM _unreal_: on the new spindle
07:22 PM veegee: Excellent. Their panel mount is cheaper than a single NEMA receptacle
07:23 PM veegee: Glad I waited. I didn't want to spend $50 per 600V receptacle
07:24 PM veegee: Dielectric withstanding voltage is rated for 2,200V AC, nice
07:24 PM jymmmm: veegee: https://www.picclickimg.com/d/l400/pict/202306130231_/4-way-6-way-30A-45A-Splitters-fit-ANDERSON-POWERPOLE.jpg
07:24 PM veegee: Yeah that's exactly what I need
07:24 PM jymmmm: veegee: there is a toungue and grove on them
07:25 PM veegee: If they don't screw me on the shipping, I'm sold
07:25 PM jymmmm: ebay, amazon, etc
07:26 PM jymmmm: veegee: USe the proper crimper, the barrel MUST stay round to fit into the housing.
07:27 PM veegee: Yeah I don't mind buying their crimper because I have so many connections to crimp and their pricing on the connectors is excellent
07:27 PM jymmmm: I think the crimper is like $35
07:28 PM jymmmm: veegee: buy extra connectors to test with first. You CAN remove the connector from the housing if you need to
07:29 PM veegee: yeah
07:29 PM jymmmm: just need a thin blade screwdrive to pry with
07:31 PM jymmmm: veegee: You can use rollpins to keep the hsouing together, or a drop of crazyglue/epoxy
07:31 PM jymmmm: the rollpin sometimes falls out
07:33 PM jymmmm: veegee: The is NO LOCKING tab on these connectors, but I use these to secure two connectors together https://www.amazon.com/Cambridge-Cable-Releasable-Reusable-Standard/dp/B00YARIYL6?
07:35 PM jymmmm: get the size you need accordingly
08:31 PM _unreal_: OH WOWOWOWOWOWOW
08:31 PM _unreal_: ok just started doing my first cut building my new "water block
08:31 PM _unreal_: DUST SHOE
08:31 PM _unreal_: going to be a TOTAL waste of time
08:31 PM Tom_L: how so?
08:31 PM _unreal_: remember I was working on the spindle today
08:31 PM _unreal_: I just started doing the cut and there was an ODD quick screach sound
08:32 PM _unreal_: then the spindle started running REALLLLY quiet
08:32 PM _unreal_: and the lower end cap bearing mount just cooled off instantly
08:32 PM Tom_L: doesn't sound promising
08:32 PM _unreal_: something was fucked up with that bearing and it just fixed its self fingers crossed
08:32 PM Tom_L: things like that don't just happen
08:33 PM _unreal_: its been running for about 10min now quiet VERY quiet
08:33 PM _unreal_: and no real heat to speak of
08:33 PM Tom_L: maybe you got powdered bearing now
08:33 PM _unreal_: or there was a flake in side the bearing?
08:33 PM Tom_L: could be
08:34 PM Tom_L: if it's shielded, it's still in there
08:34 PM _unreal_: all i know is its now cool
08:34 PM _unreal_: ya I KNOW
08:34 PM _unreal_: and yes large and shielded
08:34 PM _unreal_: if it fails I'll just replace it. there is no way I can FIX it
08:34 PM _unreal_: its a sealed large bearing
08:35 PM _unreal_: oh man what a relief
08:35 PM _unreal_: still a vibration when running
08:36 PM _unreal_: but thats poor balance in the perm mag
08:38 PM _unreal_: I can hear some ticks now and then maybe 5-10 times a min....
08:38 PM _unreal_: so I can assume one or both bearings are CRAP in my new spindle :(
08:39 PM _unreal_: it did take 4 months to get to me
08:39 PM _unreal_: sigh
08:39 PM _unreal_: well regardless WHAT a difference so I was milling aluminum
08:39 PM _unreal_: milling aluminum with a 1/8th bit at a depth of 1/8th at 26mm/min like a champ
08:39 PM _unreal_: the new rebild on my machine has made a HUGE difference
08:41 PM Tom_L: hss or carbide?
08:41 PM _unreal_: I would be lucky to get a 1/16th per pass at 26mm with out massive deflection.
08:41 PM _unreal_: the bit?
08:41 PM Tom_L: yeah
08:41 PM Tom_L: that's pushing that little cutter
08:42 PM _unreal_: https://www.amazon.com/gp/product/B078MJCZFK/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
08:42 PM _unreal_: my new spindle runs at 16k rpm
08:42 PM _unreal_: so says the display
08:43 PM Tom_L: any imbalance is gonna blow that thing all over
08:44 PM _unreal_: ya there is clearly imbalance but the shaft does not seem to be out... but the body clearly has a vibration
08:45 PM _unreal_: going to set up my guage see how much runout I have
08:45 PM Tom_L: be careful
08:45 PM _unreal_: the frame is sooo much more rigid now
08:45 PM _unreal_: just amazing how much play my old Z had
08:45 PM _unreal_: just amazing how much play my old Z had
08:46 PM _unreal_: that was odd
08:46 PM _unreal_: OHH... hehe I hit the UP key on the keyboard
08:46 PM _unreal_: up and shift are side by side
08:47 PM _unreal_: sigh.... all that work I did with the water cooling block was for nothing
08:47 PM _unreal_: its running cool now. so BACK to making the parts from star board
08:47 PM _unreal_: simple and easy
08:47 PM Tom_L: if it's a water cooled motor you should water cool it
08:48 PM _unreal_: its not a water cooled
08:48 PM _unreal_: its air cooled with an internal fan
08:48 PM Tom_L: how were you planning to water cool it then?
08:48 PM _unreal_: the bottom or tooling end of the spindle was in the wrong location
08:48 PM _unreal_: so I fucked with it in the morning. and using my bearing puller got it to where it should be
08:49 PM _unreal_: also corrected some of the coil wires at the bearing end that were touching the bearing
08:49 PM _unreal_: poor winding job
08:49 PM _unreal_: china
08:49 PM _unreal_: GOD I AM SOOOO glad it stopped making heat
09:23 PM _unreal_: Tom_L, its an amazing difference
09:23 PM _unreal_: I'm now milling in starboard HDPE the same part and the spindle is litteraly cold
09:23 PM Tom_L: good news
09:24 PM XXCoder: you won lottery??
09:24 PM Tom_L: i did?
09:24 PM _unreal_: spindle lottery
09:25 PM _unreal_: I fixed my new spindle
09:25 PM _unreal_: had a bearing issue
09:25 PM _unreal_: appears to have been corrected
09:26 PM XXCoder: ah thought you said so ;)
09:28 PM _unreal_: I love it more power and no heat
09:29 PM _unreal_: the DC spindle did me well even for a tiny little 200watt but boy it got hot
09:44 PM flyback: I wasted the last 2 weeks fighting with mom's dying phone
09:44 PM flyback: rather would have dealt with a overheating spindle
09:44 PM _unreal_: been running for an hour now nice and cool
09:45 PM XXCoder: fun
09:45 PM _unreal_: YEP can not wait for this to be done
09:45 PM _unreal_: nothing like making DUST
09:45 PM _unreal_: will be VERY nice to have a dust shoe again
09:49 PM roycroft: i have the front legs of my bench glued up
09:49 PM roycroft: i'll glue up the back legs in the morning, and then start gluing up the bench top
09:50 PM roycroft: i should be able to start doing joinery by next weekend
09:55 PM skunkworks: was gone for a week - the work bench was still standing. I think I am good
09:59 PM jymmmm: skunkworks: But is the building the bench was in still standing?
10:02 PM skunkworks: didn't notice...
10:02 PM jymmmm: lol
10:05 PM _unreal_: My fucking word I just do not understand what is going on with this computer. meaning the one driving the machine
10:05 PM _unreal_: rebooting it rigth now and naturally windows update
10:06 PM _unreal_: every time it makes a Z move its loosing it location
10:06 PM _unreal_: go from 0 to -12.7 ends up at -15mm and counting and trips out the limit switch
10:06 PM _unreal_: my fucking word
10:06 PM _unreal_: I have 5 holes and the part to cut out and the first one is done
10:06 PM _unreal_: shoot me
10:07 PM Tom_L: BOOM! --->
10:07 PM _unreal_: now as to the tooling quality with the new spindle z setup.... itdsssssss aaaaaa niceeeeeeeee..............
10:08 PM Tom_L: getting noise from it?
10:08 PM Tom_L: got things grounded properly?
10:08 PM _unreal_: as in elec grounding?
10:08 PM _unreal_: yes
10:08 PM _unreal_: I have the 3 BLDC wires fully covered with stainless mesh and that is grounded
10:09 PM _unreal_: to earth ground
10:09 PM _unreal_: the positioning is a computer issue by its self
10:10 PM _unreal_: the software has been crashing a lot as well
10:10 PM _unreal_: I'm rather sure its more to do with the computer driving it then anything else
10:10 PM _unreal_: little netbook on win10
10:11 PM _unreal_: once I get my dust shoe built Ineed to get the mount for the rpm LCD cut so I can plug it in and mount it
10:11 PM _unreal_: will be nice to have RPM feed back :)
10:29 PM _unreal_: damn it only 13% updated
10:31 PM norias: hi
11:02 PM roycroft: hi folks
11:02 PM roycroft: i need some eccentric drift punches
11:02 PM roycroft: purchasing them is expensive
11:02 PM roycroft: so i'm thinking about modifying some concentric ones
11:03 PM roycroft: i have a couple of these:
11:03 PM roycroft: https://www.amazon.com/dp/B00JG3KSUO
11:03 PM roycroft: i don't have the 4 jaw ready to mount on my lathe yet
11:03 PM roycroft: so what i'm thinking about doing is this:
11:04 PM roycroft: mount the drift in the 3-jaw with a spacer on one side to offset it
11:04 PM roycroft: cut off the tip and redrill on the eccentric center
11:04 PM roycroft: then turn the taper with it off-center like that
11:04 PM roycroft: it seems doable to me
11:04 PM roycroft: am i missing something?
11:05 PM roycroft: the exact amount of eccentricity is not important
11:05 PM roycroft: i just need a bit of cam action as i twist it
11:05 PM norias: hypothetically, that should work
11:06 PM roycroft: so what i'm proposing makes sense?
11:06 PM roycroft: they cost between $50 and $75 each to purchase
11:06 PM norias: i mean, the thing you are making doesn't make sense to me
11:07 PM norias: but it doesn't have to
11:07 PM roycroft: i paid $10.65 each for the drifts i linked to
11:07 PM Tom_L: why do you need an offcenter punch?
11:07 PM roycroft: not puch
11:07 PM roycroft: punch
11:07 PM roycroft: drift
11:07 PM roycroft: i need these for installing draw pins in mortise and tenon joints
11:08 PM roycroft: assuming you know what a mortise and tenon joint is in woodowrking, the premise is that you drill through the side of the mortise
11:08 PM roycroft: insert the tenon
11:08 PM roycroft: mark the center of the hold
11:08 PM roycroft: hole
11:09 PM roycroft: offset that mark a slight amount in the direction of the tenon cheek
11:09 PM Tom_L: i'm aware what the joint is
11:09 PM roycroft: then bore a hole in the tenon at that offset mark
11:09 PM roycroft: then reinsert the tenon, and drive a dowel through the entire joint
11:09 PM roycroft: the offset hole in the tenon will pull it in tightly to the mortise
11:10 PM roycroft: the problem is that dowels don't like to bend like that
11:10 PM roycroft: so after drilling the offset hole, one reinserts the tenon, and then inserts the eccentric drift
11:10 PM roycroft: push it in until it's fairly tight, then twist it a bit
11:11 PM roycroft: that smooths out the hole and makes it easier to insert the dowel
11:11 PM Tom_L: why not just taper the end of the dowel and cut it off after you drive it in?
11:12 PM roycroft: the eccentricity allows one to put a bit more pressure on the offset tenon hole than the mortise hole
11:12 PM roycroft: making for a slightly smoother transition
11:12 PM roycroft: that is also part of the technique, tom_l
11:12 PM roycroft: the safest way (safe = minimising breaking the dowel) is ot do both
11:13 PM roycroft: these eccentric drifts have been used for hundreds of years
11:14 PM roycroft: draw bores have been used since before glue was invented/discovered
11:16 PM roycroft: a standard concentric drift helps, but an eccentric drift is even better
11:21 PM roycroft: i've broken dowels in drawbores before
11:21 PM roycroft: and i'm about to do some fairly large ones
11:21 PM roycroft: so i thought it was time to get some eccentric drifts