#robotics Logs

Oct 05 2012

17:52 eadthem So how much force dose a drawbar on a CAT40 or BT40 or ISO 30 type tool system pull on the tools pullstud?
17:53 LoRez idk, but a friend does. has a gauge that can check a machine's pull
17:54 eadthem betting when katsmeow comes back she will know
17:54 eadthem ive been given the impression that its a hell of a lot more than i thought
18:32 katsmeow on a hard surface that the tracks can bite to, a tracked machine can pull almost as much as it weighs
18:32 katsmeow so if it weighs 20 tons, it can pull 20 tons steady
18:32 katsmeow intermittant loading, like jerking , will be much higher
18:33 katsmeow and depends also ont heload
18:33 eadthem no i mean just the tool holder to the spindle
18:33 eadthem how hard dose the drawbar pull on the pullstud on the tool holder
18:33 eadthem i mean i was thinking ok its just like maby 20 pounds
18:33 tsmeow looks conf
18:34 eadthem but reading im starting to think it might be a fue hundred pounds
18:34 eadthem k you know a cat40 tool holder for cnc
18:34 katsmeow somehow i was thinking a CAT dozer, i just woke from a nap
18:34 eadthem np
18:35 katsmeow i don't know, but it's enough to break the tools
18:36 eadthem i figured the mechiancial advantage of the taper was enough with even minimal pull force
18:36 tsmeow should shut up till she w
18:36 eadthem but i just saw a device for mesuring it that goes up to 10,000 PSI
18:36 katsmeow you mean the pull rod that clamps the tool?
18:36 eadthem ya
18:37 katsmeow 10,000 psi is stupid, it is for a very small pull piston
18:38 eadthem http://cnc-specialty-store.com/maintenance-tools/drawbar-force-gage-cat-bt-spindle-clamp-force-tester
18:38 katsmeow 2000 lbs is all you need, enough to stretch 1/4 rod
18:39 katsmeow make 1/2 stuf hollow for ol flow
18:39 katsmeow oil
18:39 katsmeow or water, etc
18:39 eadthem never imagend it exerted that much force on the tool
18:40 katsmeow it hasto overcome the friction in the tapering
18:40 katsmeow and you want as much metal-metal contact as possible
18:41 eadthem so thers a coupler inside like a airhose quick connect
18:41 eadthem the balls go in around the pullstud and then the spring releases and pulls the stud clamping the tool
18:41 eadthem ?
18:42 katsmeow i haven't seen them inside for decades, i don't use them
18:44 eadthem http://www.clamprite.com/Assets/Drawbar.jpg
18:44 eadthem found it
18:44 eadthem that helps alot
18:45 katsmeow welllllllllllllll,, that's not the only way things work
18:45 eadthem no i expect not
18:47 tsmeow uses a 5C and just twists the
18:50 eadthem http://en.wikipedia.org/wiki/Belleville_washer
18:51 tsmeow
18:51 katsmeow they are ideal for transistor bolting to heatsinks also
20:55 eadthem katsmeow-afk, you mentioned there was a simpler way to hang on to a CAT40 tool holder?
20:55 eadthem or were you just meaning a collet style setup like a dremel or router but larger
20:59 Tom_itx retention knobs
20:59 Tom_itx is the most common
20:59 eadthem at the top?
21:00 Tom_itx yes
21:00 eadthem so realy the same as a drawrod setup
21:00 eadthem but no spring
21:00 eadthem and a screw
21:00 Tom_itx we used them all the time
21:00 Tom_itx a gripper grabs the retention knob with an air cylinder
21:00 Tom_itx some are multiple stage
21:03 eadthem so its still automatic but not requireing a spring setup
21:03 Tom_itx https://picasaweb.google.com/lh/photo/Tad4D5FLiM1goCdswmXtddMTjNZETYmyPJy0liipFm0?feat=directlink
21:06 eadthem that looks like a normal drawbar using bellevill springs
21:08 Tom_itx it's a 3 stage air cylinder
21:08 Tom_itx i presume the spring retracts the cylinder
21:09 eadthem the pink section are bellevill washers/springs
21:10 eadthem the cylinder at the end gray colored like the housing is i would belevle the piston
21:10 eadthem it pushes on the green rod compressing the bellevill spring stack relasing the tool
21:11 eadthem purple i think is a berring that keeps it from flopping
21:58 katsmeow-afk oh this look like FAIL before it's even downloaded : ACL09-Annoataion Guidelines.pdf
22:38 rue_house I have a 1200A spot welder, how many amps do you think it takes to spot welt tabbs on batteries?
22:39 rue_house it looks like an air brake cylinder
22:40 katsmeow-afk i doesn't know
22:40 katsmeow-afk be sure you have the kind that does not pass weld current thru the battery itself
22:41 eadthem rue_house, id expect more than most and for shorter than normal pulses
22:41 eadthem i saw a video of someone who made a battery spotwelder on youtube
22:42 eadthem no clue where it is now
22:42 eadthem IIRC they used a rewound MOT
22:43 katsmeow-afk 2v at 400amps?
22:43 katsmeow-afk cheapest way to do it is a modest sized psu and a oversized capacitor
22:44 eadthem that might do it to
22:44 katsmeow-afk charge the cap at a couple amps and discharge it at 1000 amps (or less)
22:44 eadthem the problem is i think most battery setups apply the current via 2 prods spaced about 2 to 8 mm from each other
22:44 katsmeow-afk you don't want a lot of energy in the tab weld, the heat can hurt the battery seals
22:44 eadthem and thus must go thrue the tab in to the battery material and back thrue the tab agan
22:45 eadthem a cap makes more sense
22:45 katsmeow-afk Sears Craftman C and D cells can be broken if you rap them with a screwdriver on the + end
22:45 eadthem the + cap falls off right?
22:46 katsmeow-afk no, the center rod breaks connection tho
22:46 katsmeow-afk it's as if a 10k resistor got inserted , you cannotpull enough current to light an led
22:47 eadthem thats odd
22:48 eadthem ive seen duracell D loose there + cap wich was just a punched peice of metal
22:48 katsmeow-afk yeas, i know, i dropped a flashlite, the *battery* broke (internally)
22:48 eadthem still works
22:49 eadthem if you take the shrinkwrap off it will fall off thats all thats holding it on to the body
22:49 katsmeow-afk so i replaced it with anoteh brand, put the last Sears cell up at the top of the stack, and dropped it again, that Sears cell quit putting out power too
22:49 eadthem must crush something
22:49 eadthem or crack something
22:50 katsmeow-afk breaks the connecton
23:08 tsmeow-afk ponders not putting the 115vac ups in the same box as the battery char
23:09 katsmeow-afk mostly because if the charger developes a problem, i don't want to lose the ups functioning when i open up the charger circuits
23:10 katsmeow-afk and vice versa
23:11 rue_house its getting colder
23:11 rue_house kat are you awake this time?
23:11 katsmeow-afk i am atm
23:12 katsmeow-afk .. 11 pm Friday 10/5/2012 ..
23:12 rue_house ok between 3 items
23:13 rue_house http://www.ebay.ca/itm/NEW-10-X-8-8-micro-switch-6pin-non-self-lock-/220819711631?pt=LH_DefaultDomain_0&hash=item3369e1668f
23:13 rue_house those,
23:13 rue_house or
23:13 rue_house http://www.ebay.ca/itm/2-x-DC-Power-Jack-2-1mm-Enclosed-Frame-Switch-/250857611600?pt=LH_DefaultDomain_0&hash=item3a68476150
23:13 rue_house those , or
23:13 rue_house http://www.ebay.ca/itm/1x-MINI-Micro-Roller-Lever-Switch-Normal-Open-Close-5A-/170696178107?pt=LH_DefaultDomain_0&hash=item27be48f9bb
23:13 rue_house that
23:13 rue_house whats the coolest
23:14 katsmeow-afk what is the first one?
23:14 rue_house higher grade pushbuttons
23:15 rue_house lots of peices, nice action
23:15 katsmeow-afk forget #3, you can get those outa nukeboxes
23:15 katsmeow-afk not rolelrs, butthe same switch with lever
23:15 rue_house WITH a roller!?
23:15 rue_house its cool cause it HAS the roller tho
23:15 rue_house I could make a programmable drum switch
23:15 katsmeow-afk #2 is nice because you can float the psu off the metal chassis box
23:16 rue_house not htat I make a lot of them
23:16 rue_house so #2 then!
23:16 katsmeow-afk you can make programmable drums without the roller, all Tek 7000 plugins have drums, and none has a roller
23:16 rue_house no min,d buying barrel jacks
23:17 katsmeow-afk ok
23:17 katsmeow-afk tayda is in my fav sellers list too
23:17 rue_house oh, I was just wondering who I just bought that from
23:17 katsmeow-afk cn-resource is too
23:17 rue_house taishopetc is another good one
23:18 tsmeow-afk
23:19 rue_house taishopetc gave me a 10% off card, but I have to buy $10 of stuffs before oct 31
23:19 rue_house but I dont need anything
23:19 rue_house if I dont need it, I cant put more than $1/day
23:19 rue_house maybe I could find parts for the mecha
23:24 katsmeow-afk i still like the idea of using a 10mpg 4cyl as the "boiler" for a steam engine, only problem is the still needs to be an auz boost boiler for times you will need the steam power in 2 minutes but cannot cram all that fuel thru the 4cly right now
23:24 katsmeow-afk maybe for a stationary and steady load it would work ok
23:27 katsmeow-afk Home Depot has a 16awg 100ft 3-wire extension cord for $16