#robotics Logs
Mar 28 2017
#robotics Calendar
12:36 AM pokmo: for small plastic gears, could a 40T and a 16T run smoothly if the pressure angle of one was 14.5 deg and one 20 deg?
12:39 AM pokmo: like module 0.5
12:46 AM mrdata: pokmo, are you making these gears?
12:46 AM pokmo: no, i'm just buying them
12:49 AM mrdata: ok, so what power are you transferring with them?
12:50 AM mrdata: https://en.wikipedia.org/wiki/Pressure_angle
12:52 AM mrdata: "To run gears together properly their pressure angles must be matched"
12:52 AM pokmo: mrdata, not a lot. the torque will just be around 200g.cm
12:52 AM pokmo: mrdata, yeah i know. but what happens if they're slightly off
12:52 AM pokmo: and the power isn't too high
12:53 AM mrdata: not sure; will there be slip and backlash if they dont match?
12:53 AM mrdata: could they get stuck?
12:54 AM pokmo: yeah i know
12:55 AM mrdata: will there be friction / wear?
12:55 AM mrdata: i am not the expert; just brainstorming here
12:59 AM rue_house: the gears should match
01:16 AM pokmo: well, there shouldn't be much friction
01:17 AM pokmo: the teeth on a 14.5 and those on a 20 look distinctly different
01:19 AM mun: i'm trying to mount a rod on a micro servo's horn. the horn has 1mm through holes in it. should i be using M1 screws?
01:20 AM mun: but M1 screws are designed for holes tighter than 1mm, right?
01:22 AM mun: is M1 even standard?
01:26 AM rue_bed: no itsmetric
01:31 AM mun: well, standard metric?
01:35 AM mun: if the throughhole is 1mm wide, should I use bigger screws?
01:35 AM mun: like M1.2?
09:03 AM rue_bed: for sizes M3 and up,its usually a 0.5 mm difference
09:03 AM rue_bed: for a while anyhow
09:11 AM deshipu: you mean screws or bolts?
09:34 AM rue_house: machine screws
09:36 AM robotustra: http://fullerfasteners.com/tech/basic-metric-thread-chart-m1-m100-2/
09:37 AM robotustra: 3, 3.5. 4, 5, 6, 7, 8, ...
09:37 AM rue_house: http://eds.dyndns.org
09:38 AM rue_house: hahah
09:38 AM rue_house: no
09:38 AM rue_house: http://ruemohr.org
09:38 AM rue_house: sometimes I forget
09:38 AM robotustra: did a gate to you PC?
09:38 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/mech/tapchart2.jpg
09:39 AM rue_house: only goes down to M1.6
09:40 AM robotustra: I used to have this set of taps http://www.ebay.com/itm/30-PCS-Mini-Tap-and-Die-Wrench-Set-M1-M1-1-M1-2-M1-4-M1-6-M1-8-M2-M2-2-M2-5-Set-/322285780896?hash=item4b09babfa0:g:Vt4AAOSwLF1X93cE
09:41 AM rue_house: hah, adapter for tapping
09:42 AM rue_house: and a downsize adater, ever thought of that
09:43 AM rue_house: http://www.ebay.com/itm/1mm-x-0-25-Metric-Taper-and-Plug-Tap-M1-x-0-25mm-Pitch-/291870849590
09:44 AM rue_house: huh
09:45 AM robotustra: http://www.ebay.com/itm/M2-5x0-45-D3-HIGH-SPEED-STEEL-2-FLUTE-TiN-COATED-SPIRAL-POINT-PLUG-TAP-/222147894980?hash=item33b90bdec4:g:mw8AAOSwvg9XWhKz
09:45 AM robotustra: the best M2.5 I ever had
09:45 AM robotustra: but it's fragile
09:45 AM rue_house: hah $24
09:46 AM robotustra: 2 flutes does better job than 3 flutes
09:46 AM rue_house: I got a bunch latley
09:46 AM robotustra: yeah, too expensive even for me
09:46 AM rue_house: I didn't even notice for a while, I looked carefully and was !???!!??!?!
09:46 AM rue_house: I got 10, there was an error with one, it was M3 instead of #4
09:46 AM rue_house: and it was lasered wrong too!
09:47 AM robotustra: I used M1.0 once when I repared my glasses
09:47 AM rue_house: http://www.ebay.com/itm/6pc-Drill-Tap-Countersink-Deburr-Set-Metric-Combination-Drill-Tap-Bit-M3-M10-Hss-/141862907588
09:47 AM rue_house: nice for thin tap/drill ops
09:48 AM robotustra: may be
09:48 AM rue_house: funny enough, I cant get metric in canada
09:48 AM robotustra: but it's for machining
09:48 AM rue_house: they work fine in a hand drill
09:48 AM robotustra: feck, Canada IS METRIC
09:49 AM robotustra: :)
09:49 AM rue_house: try to buy a metric wood spade bit
09:49 AM rue_house: they aren't even available in canada
09:49 AM rue_house: even tho they are avialable from brands we have
09:49 AM robotustra: when Canada concour Southen Canada - we will do metric everywhere
09:50 AM robotustra: or Trump will build northen wall and we become metric too
09:52 AM rue_house: the hardware store was surprised when I walked in with a bit, packaged from a brand they carry with a size they couldn't even prove existed
09:53 AM rue_house: just like those combo bits, greenlee makes metric ones, but they aren't even listed in canadian catalogs
09:54 AM robotustra: http://www.ebay.com/itm/7pc-HSS-Metric-Plug-Tap-Set-Machine-M3-4-5-6-8-10-12-Right-Hand-Thread-Drill-Bit-/172438585732
09:54 AM rue_house: http://www.greenlee.com/products/DRILL%2540FTAP-KIT%2540c-METRIC-%28POP%29.html?product_id=19200
09:55 AM rue_house: pretty sure, 10-24 isn't a metric size...
09:56 AM rue_house: https://www.grainger.com/product/GREENLEE-Drill-Tap-Countersink-Set-1ANZ3
09:56 AM rue_house: aha, $66
09:57 AM rue_house: http://www.ebay.com/itm/6pc-Drill-Tap-Countersink-Deburr-Set-Metric-Combination-Drill-Tap-Bit-M3-M10-Hss-/141862907588
09:57 AM rue_house: $6
11:02 AM akaWolf1 is now known as akaWolf
01:44 PM abstresma: What would I need to know about a radio controller for rc cars to pair it with a radio receiver for an arduino?
01:55 PM deshipu: how to pair it, probably
07:48 PM rue_house: well, diagnosing system failure is a good part of repair
07:48 PM rue_house: matter a fact, working out what the problem is, is the most important part
07:48 PM rue_house: done wrong, you can end up with a 100% replaced device
07:49 PM rue_house: done really wrong, you can end up with a device thats had everything replaced, and still dosn't work
07:49 PM rue_house: first, know how the device is supposed to operate
07:50 PM Snert__: that's the problem....not knowing what good looks like when it's the only one of it's kind and 1st time in.
07:50 PM rue_house: then, obtain an understanding of how it achives its operation
07:50 PM rue_house: then, test each part of the system that can affect the incorrect operation, from the base of the dependency tree, to the leaves
07:51 PM rue_house: when you know what system is not working properly, analize its components
07:51 PM rue_house: when you find the component thats not working properly, replace it
07:51 PM rue_house: remember that any good problem is made of more than one issue
07:52 PM rue_house: so, your likley to find a few things gone wrong, even tho it may be statistically impossable
07:52 PM rue_house: and then its fixed and works
07:52 PM rue_house: enjoy
07:52 PM rue_house: !bookmark how to fix stuff
07:53 PM orlock: rue_house: yeah it's like that here
07:53 PM orlock: i have about 30 Nema23's at home
07:53 PM orlock: i'm guessing most will appear to work fine
07:53 PM orlock: but they don't meet up to the by-the-book verified specs
07:54 PM rue_house: you by a motor factory?
07:54 PM rue_house: or buying from china
07:54 PM Snert__: rue_house: you're citing certain skills that often take years to develop. Not many noobs can use a voltmeter and draw a valid conclusion, and then perform an inverse proof of whether or not the conclusion is correct or not.
07:54 PM orlock: nah -scrap metal bin at work
07:54 PM orlock: rue_house: work owns a few motor factories
07:55 PM rue_house: its hard to be a level 8 electronerd
07:55 PM orlock: Well, did. They went out along with Fluke and Tak
07:55 PM orlock: Tek, even
07:55 PM rue_house: wow, coool
07:55 PM Snert__: rue_house: lol...yes. many facets there.
07:55 PM orlock: Portescap, Thomson, etc
07:55 PM rue_house: so, your a fine supplier for 3d printer motors?
07:55 PM orlock: Nah. Too expenive
07:57 PM orlock: rue_house: i should have grabbed a picture of the stepper driver they made here
07:57 PM orlock: it's a full length PCI card
07:57 PM orlock: 4 axis, 48v
08:45 PM rue_house: how do you take up a full length pci card on a step driveR?
08:46 PM rue_house: unipolar? bipolar?
08:46 PM Snert: cause if it's not full length..half of the card flops in the breeze.
08:47 PM Snert: it need to slot into the front chassis.
08:47 PM orlock: it was covered in mosfets and a fpga and stuff
08:47 PM orlock: four bipolar steppers i guess
10:32 PM rue_house: I hasve some 5 phase bipolar motors
10:32 PM rue_house: those take quite an array of drivers