#robotics Logs

Apr 14 2013

04:37 rue_house hmm
04:37 rue_house I wonder if any of the digital equip protectors have any
04:43 hackkitten :o
11:59 rue_house switched to 2 20" monitors... wow
11:59 Tom_itx don't need bifocals yet then?
12:00 rue_house Ihave to play with the video card to get it up to 1600x1200
12:00 Tom_itx nice
12:01 rue_house see about switching to a usb sound card so I can get in the video card for the 3rd monitor
12:01 rue_house linux has a few issues with identifying usb audio things
12:01 rue_house (when you have more than one plugged in)
16:42 MrCurious woo hoo got a free atom 1.6ghz mini machien with 4g ram and 340g disk
16:42 Tom_itx nice
16:42 Tom_itx i like those atom boards
16:45 MrCurious Zotac
16:45 MrCurious put windows on the other i have, and it was able to play skyrim. long story short, guess i am taking a 1 year break from robots to play that
18:22 eadthem hey kat you here?
18:25 Tom_itx she doesn't want to come here
18:59 eadthem ok what im working on is the table for my table saw
19:00 eadthem the saw is a 1940s atlas 16x19 inches table top tilt table
19:00 GuShH eadthem: wait, if it's already a tablesaw why does it need a table
19:00 ShH is looking for an "inverter" bipolar ~10A switch for a l
19:00 eadthem Planning to imbed it in a 4x8 foot table and make it in to a tilt arbor saw
19:01 eadthem For the fence i wanted to use a rack and pinon to keep it paralell
19:01 eadthem but they are not cheep so im planning on useing a pinion and all thread for the rack
19:01 eadthem My issue is im not sure what the pressure angle shuld be for the pinion for all thread
19:02 GuShH all-thread is too soft for most things
19:02 eadthem im dealing with 3/8 allthread 24 threads per inch
19:02 GuShH I've found the hard way
19:02 eadthem Im using grade 8 allthread
19:02 GuShH here they mix them all up as the same thing, must be the lowest grade available
19:03 GuShH -lowest in quality-
19:03 eadthem http://www.mcmaster.com/#
19:03 GuShH speaking of which, got a cheap bench grinder... I'm already hating it
19:03 GuShH should've got one with the reduction box for sharpening tools instead
19:04 eadthem where you located at?
19:04 GuShH but maybe I could swap the stones for wire brush and get another grinder for sharpening
19:04 eadthem My dad got a 1450 RPM slow grinder for tools a while back
19:04 GuShH the one I was going to get is more or less 200RPM or so at the output of the reduction box but over 1000RPM on the regular stone
19:05 GuShH they come with a water "bucket"
19:05 GuShH don't know why I bought the regular one instead
19:05 eadthem you could build your own
19:05 GuShH 550W
19:05 GuShH but it's low duty.... 30 minutes
19:06 eadthem i mean ust use shafting for the grinding weels pillow block berings and a chrismas tree pully set for the shaft and the motor (In the center)
19:06 GuShH but I could still use it with a wire brush and a buffing wheel, and get another one for sharpening like I said
19:06 eadthem Then a standard induction motor would be sufficant for you
19:06 GuShH eadthem: it's cheaper to buy one than to construct anything like what you just mentioned.
19:06 GuShH they are all induction.
19:06 GuShH I've never seen a brushed bench grinder, but perhaps they exist
19:07 eadthem shaft 10$ pillow block bearings 20$ each ebay
19:07 GuShH if only this one had a variable speed
19:07 eadthem chrismas tree pully probably 20$ ebay for a set of 2
19:07 eadthem and then any old induction motor you happen to have
19:07 GuShH eadthem: a new unit costs under 50 usd, I said cheapie not name brand.
19:07 GuShH well, medium grade. I've seen cheaper
19:08 eadthem well the advantage there is you have a chrismas tree pully
19:08 eadthem so you could go alot slower
19:08 GuShH with this reasoning I could also build a lathe from scratch
19:08 GuShH and why not, every other tool I need
19:08 eadthem ya shuldnt be to hard ither
19:08 eadthem :p
19:08 GuShH but in practice it doesn't work very well.
19:08 GuShH to make precision tools you need precision tools
19:09 eadthem no clue how much grinder cost but givin how simple they are if quailty cost then its probably rather easy to build
19:09 GuShH I've used an induction motor from an old washing machine as a wood lathe
19:09 GuShH let's just say without a chuck or tailstock it's not a very safe deal.
19:09 eadthem Lathe would be harder, i would probably buy a replacement arbor for a powermatic
19:10 GuShH I compared the DeWalt one with the Chink ones... same thing, different colour of paint.
19:10 GuShH Shame on you dewalt.
19:10 eadthem Not sure what i would do for the bed and tailstock or toolrest
19:10 GuShH it had minute differences, I'm willing to bet they come from the same factory
19:10 eadthem i bet it could be had at accuracy without much issues
19:10 GuShH eadthem: gingery lathe
19:10 GuShH if you dare work with molten alu
19:10 GuShH I've only cast tiny cylinders of alu, never anything big or complicated.
19:11 GuShH eadthem: in theory you can convert a medium range wood lathe to turn soft metals
19:11 GuShH precision would come from your external measuring tools then
19:12 GuShH all of this at the expense of cutting speed (very low feed as to not stress the lathe)
19:12 eadthem well for a lathe aligning the headstock to tailstock and bed is all that matters
19:12 GuShH I did some research on the "hobby" grade metal lathes and... it's more or less a waste of money
19:12 GuShH specially since they go for $1000 and up here
19:12 eadthem and that can be done with test cuts to a resonable accuracy using a tailstock drill bit
19:12 GuShH the bearings are very important
19:13 eadthem yep
19:13 GuShH since you don't always cut with a tailstock, a chuck is also a must
19:13 eadthem tahts why i said buy a powermatic replacement arbor
19:13 GuShH I could use steel for the bed and make my own pulleys, true them up on a makeshift adapter on the shaft of the motor
19:13 GuShH and so forth. but, it's not that much cheaper than buying the lathe in my case
19:14 eadthem well if you need a 4 foot swing or something
19:14 GuShH also I don't have enough scrap aluminum
19:14 eadthem or some other mesure of absurdity in use
19:14 GuShH not really
19:14 GuShH that sounds like 3-phase, light dimming power right there, unless you can live with very low RPMs
19:15 eadthem I didnt build my tablesaw but i am signifcantly improving it
19:15 GuShH I'm mostly interested in wood right now, but I would love to turn soft metals.
19:15 eadthem Naw my dads powermatic runs on 20A 240V
19:15 GuShH -_-
19:15 eadthem the motor is 3 phase but uses a phase converter for full varable speed
19:15 GuShH that's another thing, power consumption
19:15 eadthem 80 to 5000 RPM
19:16 GuShH neat
19:16 GuShH used lathes here are sold for a reason.... bankrupcy, owner died or... they're in very, very bad shape.
19:16 GuShH usually a combination of all 3
19:17 GuShH I wouldn't spend 4-5k on one unless it had literally no play and no missing parts
19:17 GuShH but then it would cost a lot more.
19:18 GuShH so a cheapie wood lathe with a 250 bucks chuck should do for now
19:18 GuShH (why are chucks so expensive?)
19:18 GuShH 4 jaw, removable, reversable, can't recall the diameter...
19:19 GuShH I know they're machined to pretty tight tolerances and they use high grade steel in most cases but jeez.
19:19 GuShH You'd think they produce one every minute or less, so why are they expensive
19:22 eadthem I think he spent 3K on that powermatic on ebay it was new but fell off its pallet and was damaged
19:23 eadthem the metal cabnet for the electronics had to be rebent some paint damage needed a new estop button and reversing switch otherwise perfect condition
19:23 GuShH :/
19:23 GuShH and what's the "new" price?
19:23 eadthem 7000 ish
19:24 GuShH that's an awesome deal
19:24 eadthem His tarus wagon didnt think so
19:24 GuShH lol
19:24 GuShH almost a ton?
19:24 eadthem he had to put the headstock and tailstock in the passenger seat so the rear end wouldnt bottom out
19:24 GuShH the cheapies I've seen are all under half a ton, which makes you wonder a lot.
19:25 eadthem It probably was 1/2 ton
19:25 GuShH I couldn't house anything over half a ton anyway
19:26 GuShH the high end RPMs are gained due to the VFD?
19:26 GuShH usually they won't get past 2k rpm
19:26 GuShH unless it's for wood
19:26 eadthem 960 LB
19:26 eadthem Its for wood
19:27 eadthem i did some metal on it freehand however
19:27 GuShH can you tilt the headstock?
19:27 eadthem no its double ended
19:27 GuShH that's a great feature only the big lathes seem to have
19:27 eadthem and thats why it has a reverse switch
19:27 GuShH allows you to turn a bowl to the side
19:27 GuShH well apart from sanding why else would you need a reverse?
19:27 GuShH I'm not too experimented with that
19:28 GuShH Also speaking of which that's why I'm looking for a bipolar reverse switch, in case I get the cheapie I can convert it to have a reverse
19:28 GuShH Some of the "expensive lathe" features are very cheap to implement yourself
19:29 GuShH rpm indicator, reverse, sometimes even a brake.
19:30 GuShH I wonder if the best lathes allow you to define the diameter of the work piece to show you the feet or meter per minute at the current RPM setting.
19:34 eadthem Turning it to the side thats pritty much it
21:40 GuShH eadthem: I guess it depends on the lathe then, the best reason I know for reversing is sanding
21:41 eadthem The reason why you turn to the side is if you have something larger than the swing over your bed
21:42 eadthem the powermatic my dad uses can do like 48 Inch swing on the side
21:42 eadthem mmm ya guess you wouldnt need reverse even for that :p
21:45 GuShH depends to which side it turns the head and to which side you want to be, assuming the stand can go both ways
21:46 GuShH anti clockwise is the norm either way so I don't know if there are special tooling that requires reverse or what else.
21:46 GuShH saw a neat spiralling tool also a threading tool, but couldn't find them anywhere local
21:46 GuShH doesn't make sense to pay the S&N to Argentina either.
21:46 GuShH S&H
21:47 GuShH I guess the N would've stood for Neglecting, since that's what they do.
22:29 rue_house I just thought of how to do bumpers, baloons and pressure sensors!
22:30 rue_house then I can zone it however I want
22:30 rue_house need a protextive coating of course, but yea