How to generate regular hole pattern - Page 1
Forum section: electronics / general

author: GregDunn
author_rank: Frequent Contributor
timestamp: August 17, 2018, 03:37:38 am
content: I did a search here but nothing useful came up. It's really a pretty basic thing, so hopefully someone has come up with a quick solution around here. I suspect some of the open source PCB layout tools like kicad might be able to do what I need, so that's why I put it in here to start...All I need is to generate a template/pattern for a bunch of regularly spaced holes (maybe 30-35) that I want to drill in a piece of scrap plastic. I think they're going to be on about 0.07" center, and maybe .02" diameter holes - but I won't be 100% sure till I place the template in the project space and verify it. They need to pass 30ga insulated wire, which has a slight tolerance so I may need to adjust after generating a test template. If they'd been 0.1" center, I could have used a piece of perfboard, but noooooo...Yeah, I could lay it out with a ruler, but then if I calculated wrong with my initial estimate, I'll have to do it all over again. Faster if there's something semi-automated so I can print out updates quickly.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 17, 2018, 07:20:13 am
content: Draw dots in Paint, and print to scale.If you have any better editing tool, use that.Tim

author: NivagSwerdna
author_rank: Super Contributor
timestamp: August 17, 2018, 07:29:08 am
content: This really depends on how much time you want to spend and how often you are going to do this sort of thing...Personally I use LibreCAD for 2D and Fusion360 for 3D.(and DipTrace for Schematic and PCB Layout)Any of those would do what you want.... and a lot more!(Make sure you check that your software is scaling for the printer correctly by checking with a ruler the first time; any decent software should get it right first time)

author: sokoloff
author_rank: Super Contributor
timestamp: August 17, 2018, 10:11:42 am
content: KiCAD files are plain text and fairly human-readable/editable (for simple things like this).I’d be inclined to lay out a file with 3 holes carefully spaced (so I knew the file format/pattern) and then write the file with a small program (or text editor and calculator nearby).If you really can’t manage this yourself, I’m sure someone on here is willing to one-off it for you (including me).

author: tpowell1830
author_rank: Frequent Contributor
timestamp: August 17, 2018, 05:24:42 pm
content: A couple of links to view. Remember to calibrate your printer as someone else stated.https://www.3ds.com/products-services/draftsight-cad-software/free-download/Hope this helps...

author: GregDunn
author_rank: Frequent Contributor
timestamp: August 17, 2018, 05:51:38 pm
content: Yeah, using a scaled drawing program works fine; it just took longer than I thought it should to generate repeating rows and they're not easily scalable, which is why I thought of a CAD or PCB program. Back in 1983 when we found that an easy way to buy a computer without weeks of admin paperwork was to mark it as a "schematic drawing tool"we had a very rudimentary piece of software which allowed you to generate repeating patterns with a couple of mouse clicks. That was also the first computer we'd ever had in the department with a mouse... Anyway, one of the problems there was that it required custom driver software for a pen plotter (!) to output a print which was to scale. Laser printer? What's that?I fooled around with kicad for a bit and couldn't find the proper commands, though no doubt it'll do it somewhere. I've used it many times for simulations, but never for PCBs, and the layout program is a bit different. I haven't tried LibreCAD yet, though I use LibreOffice for cross-platform stuff all the time; it was next on my list of things to try. Since the hope was to save time I thought I'd first try a basic drawing program and attempt to put something together to find out if it was possible to do what I wanted. It wasn't (couldn't extend the pattern to multiple objects directly) but luckily my original measurement was accurate and the first pattern I generated by cut-and-paste was good.Now that I've got something useful I'll look at trying to make kicad behave; since I use it for simulations, having mastery over the PCB portion will probably get used a lot in the future anyway...

author: Rerouter
author_rank: Super Contributor
timestamp: August 17, 2018, 09:18:48 pm
content: In kicad, the feature you want to use is "User Grid",You set it up under veiw/grid settings, then select user grid. this way you can have custom X/Y spacing, so you only need to draw 1 hole, then duplicate along the grid.Your 0.2" diameter seemed like it was meant to be 0.02" so I scaled accordingly, attached is a pdf from kicad using a custom grid of Y = 1.778, X = 0.254mm this is just because I am a metric person, if your using imperial, then you just set it in imperial.

author: GregDunn
author_rank: Frequent Contributor
timestamp: August 17, 2018, 10:15:17 pm
content: Yeah, that'll work - thanks! Next time I'll be able to be a bit quicker in setting up a pattern.

author: langwadt
author_rank: Super Contributor
timestamp: August 17, 2018, 10:42:30 pm
content: Quote from: Rerouter on August 17, 2018, 09:18:48 pmeven simpler use the create array feature