#linuxcnc Logs

Jul 28 2020

#linuxcnc Calendar

08:36 PM Tom_L: .
08:36 PM Tom_L: ok
08:36 PM Tom_L: that's better
09:11 PM Wolf__: jymmmm: I was sleeping last night when you linked them ESC, ebay one sounds off, says pwm then relay controlled, only one motor channel, the hobby king ones are brushless motor ESC
09:12 PM jymmmm: Wolf__: ok, so the HK are good for this stuff?
09:13 PM Wolf__: totally worthless
09:14 PM Wolf__: go to the HK speed controllers>brushed ESC
09:16 PM Wolf__: keep in mind looking at those 60A brushed ESC is mated to a motor that is 14v ni-cad drill sized
09:19 PM Wolf__: jymmmm: diy approach https://prototyperobotics.com/projects/triple-8-h-bridge
09:26 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/3995_hbridge/hip4081_hbridge.png
09:27 PM jymmmm: Wolf__: I was looking at the brushless stuff though on HK
09:27 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/3995_hbridge/hip4081_hbridge_board.png
09:27 PM Tom_L: never actually built one of those
09:27 PM Tom_L: 40A ? mosfets
09:28 PM jymmmm: Tom_L: you can parallel mosfets
09:28 PM jymmmm: I think I actually have a couple 400A mosfets around here somewhere
09:29 PM Tom_L: what do traffic lights use?
09:29 PM Tom_L: those are big
09:29 PM jymmmm: no clue, 24V?
09:29 PM Tom_L: i doubt it, probably 120v
09:30 PM veegee: So yeah true blue pipe dope and brass nipple fixed my leak problem
09:30 PM veegee: Two variables changed so can't be sure which one
09:31 PM veegee: I also didn't need to torque it insanely tight. I used an 18" pipe wrench and tightened it "normally"
09:31 PM skunkworks: CaptHindsight: no hydraulics on ours
09:31 PM Tom_L: probably crappy threads on the other fitting
09:31 PM veegee: yeah that might have been it
09:31 PM jymmmm: Tom_L: 12-24V or AC https://www.trafficlights.com/led-signals/hp200-series-single-led-signal/
09:31 PM skunkworks: the tool unclamp is air also
09:32 PM Tom_L: jymmmm, led yeah but what about the old ones?
09:32 PM veegee: but also brass is super ductile and forms really nicely against something hard like cast iron threads
09:32 PM jymmmm: Tom_L: you would want/use an old one?
09:32 PM Tom_L: no we were comparing mosfets
09:33 PM veegee: I wish I could just get a single big pipe of brass so I can cut and make my own nipples and such
09:33 PM jymmmm: Tom_L: I thught triacs were for AC, not fets
09:33 PM Tom_L: probably so
09:33 PM Tom_L: carry on...
09:33 PM veegee: don't know where I can get that. I have all the taps and dies
09:33 PM Tom_L: veegee, get a brass bar
09:33 PM veegee: jymmmm MOSFETS can be put back to back to make a solid state relay
09:33 PM Tom_L: i made thousands of barb fittings
09:33 PM Tom_L: hex or round
09:34 PM veegee: you need a floating gate though, they usually do it with a phototransistor to get the gate to source voltage needed]
09:34 PM veegee: Tom_L solid? Don't you mean hollow tube?
09:34 PM jymmmm: veegee: ah
09:34 PM Tom_L: veegee, but then you would need a lathe
09:34 PM veegee: I have a lathe
09:34 PM Tom_L: no solid bar
09:34 PM skunkworks: make sure you calculate the power from the drain to source..
09:34 PM veegee: and that's a lot of waste of brass
09:35 PM Tom_L: we made all sorts of brass fittings from solid stock
09:35 PM skunkworks: of the on resistance
09:35 PM Tom_L: resell it
09:35 PM jymmmm: Tom_L: I got one of these for free, just want to turn it in RC https://www.monsterscooterparts.com/media/catalog/category/1379.jpg
09:35 PM veegee: other ways to do it is use a charge pump gate driver
09:35 PM Tom_L: jymmmm, motorcycle engine
09:35 PM veegee: that isolates the gate to source bias so you can drive them high side, etc.
09:36 PM Tom_L: jymmmm, recall the street outlaws episode where farmtruck made one?
09:36 PM jymmmm: Tom_L: Nah, eeelectric,
09:36 PM veegee: no idea what you guys are talking about but yeah mosfets
09:36 PM jymmmm: Tom_L: never saw it, link?
09:36 PM veegee: also you can get huge ass SCRs
09:36 PM veegee: like rated for many thousands of amps
09:36 PM Tom_L: jymmmm, https://www.youtube.com/watch?v=LjIBM0_9znw
09:40 PM jymmmm: Tom_L: lol
09:40 PM jymmmm: wheely bars
09:41 PM jymmmm: Tom_L: I just need snow tires and a robotic arm for it
09:42 PM XXCoder: that video man it cant show a segement without cutting it into < 1 sec parts
09:47 PM Tom_L: jymmmm, you ever take apart one of the gimballs on those?
09:47 PM Tom_L: the directional knob
09:47 PM jymmmm: Tom_L: on what now?
09:47 PM Tom_L: the chair
09:48 PM Tom_L: hall effect directional control
09:48 PM jymmmm: oh, it has a programmable controller, but I don't have the programmer for it
09:48 PM jymmmm: The controller itself it probably worth more than the whole thing on ebay
09:49 PM Tom_L: motor might make a good spindle motor
09:50 PM jymmmm: MAybe, but it's got a good solid welded frame and might be more fun with my own controller and buffed up battery
09:50 PM jymmmm: beefed
09:51 PM jymmmm: Tom_L: These cell I just got are capable of 200A continuously
09:52 PM Tom_L: so you could weld with em
09:52 PM jymmmm: Hmmm.....
09:53 PM jymmmm: I know they use them for a spot welder
10:50 PM _unreal_: OK the last major part is done
10:51 PM _unreal_: and it looks JUST like my cad drawing :)
11:26 PM CaptHindsight: makerspace near me got a Tormach
11:26 PM CaptHindsight: https://wiki.pumpingstationone.org/Tormach_1100_series_CNC_mill