#linuxcnc Logs

Feb 25 2021

12:12 AM unreal is now known as Guest13042
01:00 AM abetusk is now known as Guest83515
01:11 AM Deejay: moin
04:22 AM dan3wik is now known as dan2wik
05:02 AM JT-Cave: morning
06:51 AM Loetmichel: *aaaaahhh!* Shielding glass pane broke. 350 eur down the drain. And it takes 8 weeks to get a new one (made to order, size)... and boss thought 2 would be enough for two prototype monitors due at the customer next monday :(
07:51 AM enleth: Loetmichel: what is it shielding against and what managed to break it
07:51 AM enleth: *?
08:11 AM unterhaus_: ebay not working for me, can't search
08:52 AM JavaBean|new|2 is now known as JavaBean
08:57 AM roycroft: wrap it with cling film and ship it out, loetmichel
09:50 AM rs[m]: enleth: they are re-housing common computer stuff for military applications, so i suppose it should shield invisible EM radiation. probably some kind of metallized glass.
10:29 AM plndra is now known as plundra
11:10 AM veegee: My custom charging algorithm for flooded lead acid goes against conventional charging advice and looks like it's actually improving the capacity and performance of the battery under test
11:10 AM veegee: Several research papers using a similar algorithm show similar results
11:11 AM veegee: I'm charging at _very_ high currents, like at 0.5C - 1C rate as opposed to the usual 0.15C rate
11:11 AM veegee: Pumping in as much power as it can take below the gassing voltage. Looks like it's helping stir the electrolyte too. Battery isn't getting warm at all
11:12 AM veegee: Then doing a constant current overcharge at very low current and terminating when dV/dt is 0 or very close to 0
11:12 AM veegee: That seems to bring the specific gravity of the electrolyte to its maximum for all cells
11:13 AM Loetmichel: enleth: shieding against van eck attacks
11:14 AM veegee: Then a subsequent high power discharge with the lab power supply shows very good capacity, like more than 10%. Hopefully this is not still in the "forming" phase of the battery. Reverting to a conventional charge algorithm or using a shitty NOCO genius charger shows worse capacity and inconsistent/low electrolyte specific gravity
11:14 AM veegee: This is a standard group 31 deep cycle battery, nothing special
11:16 AM veegee: I wonder if lead-calcium vs lead-antimony makes a difference here
11:19 AM enleth: veegee: isn't that similar to what you'd do to revive a dead lead-acid battery?
11:22 AM veegee: enleth definitely not the high power charge part. That'll just make it overheat and gas like crazy
11:22 AM veegee: The low constant current part may work. But hard sulfation is difficult to fix. Personally I wouldn't bother. I'd just get a new battery and take care of it
11:23 AM veegee: In my experience, as long as you keep it fully charged, don't do super deep discharges, and keep the electrolyte from stratifying, they'll last a very very long time
11:24 AM veegee: Cell monitoring goes a long way. Traditional cell balancing doesn't work and may actually cause imbalance. Only way is to top balance by overcharging very carefully. Too much causes positive plate corrosion
11:51 AM _builtin is now known as __builtin
12:52 PM MrHindsight is now known as CaptHindsight
02:11 PM chris_99: Hi, i'm wondering if anyone could possibly point me in the right direction, i bought 2x of these - https://www.amazon.co.uk/gp/product/B0897MWRTG/ (200mm Linear Rail Slide), to make a simple xy machine, so i need to mount one linear rail on top of the moveable platform of the other, the moveable platform has nuts in a different size, to the nuts in the other aluminum extrusion, so at the moment i can only think of
02:11 PM chris_99: using a screw adapter, to convert say M4 to M3 or whatnot, but maybe there's a better solution? ( thinking of making it roughly like https://www.youtube.com/watch?v=NhX79Fdpfas where there's just the 2 linear rails, without additional support)
02:16 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Y_Axis_Plate1.jpg
02:16 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Assembly/X_Axis_Plate.jpg
02:16 PM Tom_L: chris_99,
02:19 PM chris_99: oh doh, hadn't thought of that, that looks a good idea, cheers
02:50 PM unreal is now known as Guest79597
02:50 PM arachnist is now known as ar
02:52 PM enleth_ is now known as enleth
02:52 PM tumdedum_ is now known as tumdedum
04:11 PM Tom_L: 4% positive test rate here now
04:13 PM gloops: 350 per 100k here
04:15 PM gloops: R- 7 or 8 but they arent lifting the lockdown straight off this time, going to stage it
04:15 PM Tom_L: yeah, taking it slow here
04:24 PM JT-Shop: blank gripper came out nice
04:32 PM snakedGT is now known as snaked
04:33 PM JT-Shop: https://gnipsel.com/images/customers/Foxy/Top%20Cutter/
04:35 PM JT-Shop: Tom_L, that's one holy plate
04:35 PM Tom_L: :)
04:35 PM Tom_L: i see what you mean now.. for the spoke machine
04:36 PM Tom_L: yeah, the plate that holds the X & Y axis together
04:39 PM JT-Shop: tested the gripper and it holds the blank real tight so I'm a happy guy
04:39 PM Tom_L: so the piston pulls
04:41 PM JT-Shop: aye
04:41 PM Tom_L: does that whole thing rotate then to load the blank?
04:41 PM JT-Shop: once the blank is being held by the dogs the gripper drops out of the way so it can retract
04:42 PM JT-Shop: that part is mounted to a slide that moves the blank from the magazine to the dogs
04:42 PM Tom_L: i'm sure it will become clear as you build
04:42 PM JT-Shop: yep
04:43 PM Tom_L: so this assembly slides instead of rotating
04:44 PM Tom_L: when it reaches the dogs, the arm swings down to release it
04:44 PM JT-Shop: yea when the slide is out the dogs grab the blank then the arm releases it and the slide retracts out of the way of the top cutter
04:48 PM Tom_L: is that tubing nylon?
04:50 PM JT-Shop: https://gnipsel.com/images/customers/Foxy/Top%20Cutter/Top%20Cutter.JPG
04:50 PM JT-Shop: hmm I forget the material
04:54 PM JT-Shop: polyurethane
05:53 PM roycroft: i'm about to power up my mostly-assembled bandsaw today
05:53 PM roycroft: so that i can use it to make a couple parts for it
05:53 PM roycroft: i haven't had it under power with a blade installed since i started working on it
05:55 PM * roycroft sees light at the end of the bandsaw rebuild tunnel
07:06 PM roycroft: i just got my weekly update from the county health department
07:07 PM roycroft: phase 1b, group 5, wave 4 will be eligible for vaccination on monday
07:07 PM roycroft: i should be in the next group after that, and they've been adding a group every week for the past six weeks, so hopefully i'll be eligible on 7 march
07:07 PM roycroft: or 8 march
07:11 PM roycroft: my bandsaw appears to be ready to go, btw
07:11 PM roycroft: i'll have a few tweaks to do still, and i have to make some guards and mounts for the power switch and hour meter, but it seems to work fine, so that's good
07:12 PM roycroft: i'm ready to get back to making stuff, not rebuilding machines, although i shall actually need a cnc mill very soon, so i'll have to finally get that project done, whether i want to or not