#robotics Logs

Mar 08 2017

12:00 AM Guest31598 is now known as CrazEd
12:02 AM CrazEd is now known as Guest41609
12:35 AM rue_house: I got some good stuff for another cnc mchine
12:35 AM rue_house: I'm still torn on how best to do sliders
12:35 AM rue_house: right now I'm using parallel independent bearings, but as that can lead to twist, I'd like someting else
12:36 AM rue_house: once upon a time I wanted to make a slider from a milled peice of I beam
12:36 AM rue_house: I have a mill now
12:47 AM rue_house: https://www.aliexpress.com/item/Photo-Studio-Accessories-LP-03-250mm-Movable-Range-2-Way-Macro-Focusing-Rail-Slider-For-DSLR/32335348510.html
12:47 AM rue_house: its interesting what you find cnc machine parts listed as
12:51 AM rue_house: https://www.aliexpress.com/item/Hot-Sale-Metal-Black-4-way-Macro-Shot-for-Focusing-Rail-Slider-1-4-Screw-F/32495995843.html.
12:51 AM rue_house: https://www.aliexpress.com/item/Hot-Sale-Metal-Black-4-way-Macro-Shot-for-Focusing-Rail-Slider-1-4-Screw-F/32495995843.html
01:01 AM Guest41609 is now known as CrazEd
01:02 AM CrazEd is now known as Guest18357
01:29 AM SpeedEvil: Massive granite surface plate with air bearings.
01:31 AM anniepoo_: 8cD
01:32 AM anniepoo_: rue, that's a slider for a camera. Probably not at all rigid.
01:32 AM SpeedEvil: http://www.ebay.co.uk/itm/STARRETT-GRANITE-SURFACE-PLATE-/182463031607 they can be remarkably inexpensive
01:33 AM anniepoo_: is that free shipping?
01:34 AM SpeedEvil: No, you collect
01:34 AM Jak_o_Shadows: How flat do you really need though.
01:34 AM Jak_o_Shadows: For the air-bearing thing I mean
01:34 AM SpeedEvil: Jak_o_Shadows: It depends.
01:35 AM SpeedEvil: Jak_o_Shadows: The bearing does average the surface to a degree, so high frequency low amplitude roughness may not matter at all.
01:36 AM SpeedEvil: Once you get too warped, the air bearing will lose stiffness.
01:36 AM SpeedEvil: And air consumption will go up.
01:37 AM SpeedEvil: I have idly wondered about a high performance air bearing lathe on wooden ways, primarily to annoy people with.
01:37 AM Jak_o_Shadows: I'ts more you want to avoid warping, rather than just random stuff
01:37 AM SpeedEvil: 'But you can't do that!'
01:38 AM SpeedEvil: Movement is fun.
01:38 AM SpeedEvil: I just noticed that my driveway IP camera moves up 20 pixels or so when the sun hits it
01:38 AM Jak_o_Shadows: From metal expansion?
01:39 AM Jak_o_Shadows: NASA just had a bit of flat concrete floor in this: https://www.youtube.com/watch?v=sbBQONITclk
01:39 AM Jak_o_Shadows: As a side note, I really want to see details on that robot
01:40 AM SpeedEvil: 'air bearing' in machine terms generally means bearings which actively control height.
01:40 AM SpeedEvil: rather than pure suspension
01:40 AM SpeedEvil: Jak_o_Shadows: It is mounted on a fibreglass roof over a shed
01:42 AM Jak_o_Shadows: OH? Ok. I've had some experience with a spherical air bearing - it needed tighter tolerances than what it was made with :(
01:42 AM Jak_o_Shadows: How the heck is it moving 20px?
01:44 AM SpeedEvil: The fibreglass roof expands a lot more than the steel building and flexes.
01:49 AM Jak_o_Shadows: The fibreglass itself? Didn't know that
02:02 AM Guest18357 is now known as CrazEd
02:03 AM CrazEd is now known as Guest98089
03:03 AM Guest98089 is now known as CrazEd
03:04 AM CrazEd is now known as Guest62150
04:04 AM Guest62150 is now known as CrazEd
04:05 AM CrazEd is now known as Guest90023
05:10 AM z64555: should make it floating
05:11 AM z64555: hmm... on second thought, might not be that great of an idea. you get astrongish wind gust and it'll blow the roof off
06:44 AM Poltergiest: dos anyone use C++ in their robotics projects?
06:45 AM veverak: o
06:45 AM veverak: o/
06:54 AM Poltergiest: ?
06:59 AM * veverak ses it
06:59 AM veverak: *uses
07:05 AM deshipu: pretty much anyone
07:34 AM veverak: gives me headache
07:34 AM veverak: SFINAE does not like me
07:49 AM Poltergiest: veverak, you use what ?
07:50 AM veverak: Poltergiest: C++
07:53 AM Poltergiest: nice
07:53 AM Poltergiest: i am learning it
07:53 AM Poltergiest: but just the basics when i get spare time and motivated
07:53 AM Poltergiest: lol
07:53 AM Poltergiest: but ive not done anything with robotics
08:32 AM Deacydal is now known as deacyde
09:48 AM rue_house: build a machine to make supper
09:49 AM rue_house: or cookies
09:50 AM robopal: debone a fish
05:32 PM mun: are there ways to recover lost steppers with stepper motors?
05:33 PM orlock: mun: what do you mean?
05:33 PM anniepoo_: you mean lost steps?
05:33 PM mun: oops
05:33 PM mun: yes
05:33 PM anniepoo_: 8cD do more steps?
05:34 PM orlock: Make it stop losing steps?
05:34 PM mun: orlock, yeah that's right
05:34 PM orlock: if you are going to start basing everyhting off encoder inputs, you may as well just use a plain old DC motor
05:34 PM mun: orlock, yeah, i know
05:35 PM mun: so i wonder if there's something smarter than reading off encoders
05:36 PM orlock: mun: yeah, set it up right so it doesnt miss steps
05:37 PM mun: hmm
06:21 PM z64555: steppers can lose steps if their not the only source of torque on the output shaft
06:21 PM z64555: *they're
07:11 PM rue_house: mun
07:12 PM rue_house: yes, if you have an encoder, you can detect skips and compensate for them
07:13 PM rue_house: mun, is it just paranoia, or do you have a problem with something?
09:13 PM Rez is now known as L
10:13 PM L is now known as Lo