Unable to set via diameter larger than hole size in Kicad 8.0.5 - Page 1
Forum section: electronics / general

author: newtekuser
author_rank: Frequent Contributor
timestamp: October 26, 2024, 06:35:03 pm
content: I'd like to bump the via sizes of components passing high currents from 0.8mm diameter and 0.4mm hole size to 0.16mm diameter and 0.8mm hole size for larger current draw in my circuit but Kicad complains that the hole size needs to be smaller than the diameter which is.Is this a bug?

author: coppercone2
author_rank: Super Contributor
timestamp: October 26, 2024, 06:43:16 pm
content: you need to ask yourself a questionwhat is a subset of what herei think you might be trying to warp space with your chosen dimensions

author: Monkeh
author_rank: Super Contributor
timestamp: October 26, 2024, 06:44:40 pm
content: It's a bug, but not in Kicad. 0.16mm is 160μm. 0.8mm is 800μm.

author: coppercone2
author_rank: Super Contributor
timestamp: October 26, 2024, 06:52:02 pm
content: its not a bug, the hole in the doughnut cannot be larger then the diameter of the doughnut, under normal space time conditionsI checked your work, your current dimensions bring you Abydos

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 26, 2024, 07:51:20 pm
content: Quote from: newtekuser on October 26, 2024, 06:35:03 pmRead the message again.You have switched the numbers.0.8mm is yourDrilldiameter, while the 0.16mm is the diameter of theCopper of the via. And that does not work of course. For a drill of 0.8mm, a via diameter of 1.2mm would be suitable (which leaves 0.2mm for the annular ring. Not much but probably sufficient.

author: newtekuser
author_rank: Frequent Contributor
timestamp: October 26, 2024, 07:56:43 pm
content: Yup, didn’t consider the decimals but only the value after… <facepalm>

author: newtekuser
author_rank: Frequent Contributor
timestamp: October 26, 2024, 08:11:48 pm
content: Quote from: Doctorandus_P on October 26, 2024, 07:51:20 pmI think at that size I may be better off adding two smaller (standard size) vias per pad vs a single large one. What do you think?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 26, 2024, 08:43:35 pm
content: I've heard of a rule of thumb to use one via per amp of current, but I have no idea what that's based on.A more sensible rule would be to use the same copper cross section for the via, as for the tracks. KiCad has a built in calculator for copper track resistance and temperature rise. In general, copper thickness for tracks is 35um for the tracks, and around 17um for via plating. If your via's are clean (not plugged and with cutouts in the solder mask) you can also fill them with solder, which increased both their current handling and robustness.

author: floobydust
author_rank: Super Contributor
timestamp: October 26, 2024, 09:03:50 pm
content: Via barrel diameter as well as plating thickness affects the current handling capability. Less copper there means less current handling.So OP shrinking them could be a mistake.

author: SiliconWizard
author_rank: Super Contributor
timestamp: October 26, 2024, 09:18:23 pm
content: Quote from: newtekuser on October 26, 2024, 07:56:43 pmOh well, that happens!That'd be worse if that did happen on a Boeing's project.

author: TimFox
author_rank: Super Contributor
timestamp: October 26, 2024, 10:19:55 pm
content: Quote from: SiliconWizard on October 26, 2024, 09:18:23 pmOr if an AI app learns math from the post.

author: tooki
author_rank: Super Contributor
timestamp: October 26, 2024, 11:25:57 pm
content: Quote from: newtekuser on October 26, 2024, 06:35:03 pmYes, it’s a bug, but in your math, not in KiCad.0.8 × 2 ≠ 0.16

author: newtekuser
author_rank: Frequent Contributor
timestamp: October 27, 2024, 03:18:20 am
content: Quote from: TimFox on October 26, 2024, 10:19:55 pmYes, I'm a bot. BEEP! BOP!

author: Geoff-AU
author_rank: Frequent Contributor
timestamp: November 04, 2024, 10:25:11 pm
content: Quote from: newtekuser on October 27, 2024, 03:18:20 amWell you're also an American trying to use the metric system, so you get a "Bravo!" from me(just do what I do and blame your mistakes on a caffeine deficit)

author: TimFox
author_rank: Super Contributor
timestamp: November 04, 2024, 10:43:38 pm
content: Quote from: Geoff-AU on November 04, 2024, 10:25:11 pmThe US went metric in 1959, but didn’t bother to tell anyone.

author: coppercone2
author_rank: Super Contributor
timestamp: November 06, 2024, 02:52:32 am
content: maybe milimeters (and not related to wire). No one here wants centimeters or metersAND HONESTLY FOR REALLY SMALL OBJECTS that people of any engineering or science you want to hear THOUSANDTHS. No one wants to hear mm decimal.Fact is, 0.001 (1 thousanth) is a relatable figure. Very weak metal but its like physical thickness for most material. 0.01 mm is BASCIALLY noncorporeal and 0.001mm is basically atomic/vapid. So comprehension basically starts at 0.001 inches. If you start at 0.01 or 0.001 mm you are starting basically from non-physical to physical, while if you start at 0.001 inches you are starting at bearly physical. Makes more sense to me to start and end with something that is at least similar to a human.metric is OK to the 1-10mm range but using it for bigger thing is ridiculous because its like inflated for common objects. AND THAT would be like a special scale *useful in a magnifier glass readout plate*Like a tape measure with centimeters just looks dumb/confusing, total headache. How big would your eyes need to be to make comfortable use of a metric tape measure??? you would need eyes like a grey alien. pool balls. You can't pattern the divisions nice without going into non decimal fraction. 8 digit works on a ruler becuase it patterns good. you need 1/4 its like a ratio that works for us.like how freaking close do you need to be to a metric tape measure? What if its like on the floor far away from you. its just not practical and no one is ever gonna adopt it. Need 20/20 vision and binoculars to measure a structural material accurately. give me a break. And not to mention its dark and some numbers stand out more then other ones and their allbig.

author: Monkeh
author_rank: Super Contributor
timestamp: November 06, 2024, 03:19:46 am
content: Quote from: coppercone2 on November 06, 2024, 02:52:32 amNo one except most of the planet. My eyesight is crap, I can still read 1mm on a tape measure approximately as far away as 1/16 of an inch - certainly as far away as my feet.. Oh, you wanted 1/8? Well, 5mm is close enough to that, too (if you're 1/8 out on framing you'll hate it just as much as 5mm, measure better), and there's a bigger line for that. Might be nice to have them at 2mm increments, though.Unhinged ranting doesn't make for convincing arguments. Just admit you're not willing to put the effort into learning and move on.

author: coppercone2
author_rank: Super Contributor
timestamp: November 06, 2024, 05:21:59 am
content: nothing you can say will make those little lines any less annoying when there is alot of them.Also when shit gets real like rain, darkness and bad angles the inch always winsI can't stand people trying to push centimeters on like practical workers, its sillyI can't see how it would ever take over on something like a affordable construction site or renovation. Its like making people write in cursive.'The centimeter would need to be at least 50% longer for it to be a viable competition in marginal conditions but it would still lose in poor conditions and I personally would not mind a 'ruggedized' inch that is longer.It's already REALLY bad sometimes with inches.

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 06, 2024, 06:42:05 am
content: Like, everywhere outside of the US, almost pretty much?

author: tooki
author_rank: Super Contributor
timestamp: November 06, 2024, 08:18:52 am
content: Quote from: coppercone2 on November 06, 2024, 05:21:59 amI guess you’ve never used an inch steel rule? 1/32” is smaller than a mm. 1/64” smaller than the 1/2mm on metric steel rules.Anyhow, your argument just makes Americans look silly. As an American myself, I ask you to just stop.

author: Monkeh
author_rank: Super Contributor
timestamp: November 06, 2024, 11:13:54 am
content: Quote from: coppercone2 on November 06, 2024, 05:21:59 amNo, no argument will ever convince the irrational of anything, that's well known.You probably need to go get some glasses. Or just off our lawn, because we're not anywhere near yours.