BrachioGraph – a cheap, simple pen plotter • Hacker News Board

Re: BrachioGraph – a cheap, simple pen plotter

#11

Post by [deleted] » Thu, Oct 17, 2019, 1:43 PM UTC

diafygi wrote: post #7

It's my understanding that higher quality plotters/3d printers/mills' accuracy and precision come from higher quality motors (e.g. stepper motors instead of servos). Will it be possible to someday just put cameras on the plotter which watch the current print and self-correct as needed? That's basically what our eyes do when we write/sculpt/carve. Will cheap motors + cameras + software eventually meet or exceed the qu…

[deleted]

Re: BrachioGraph – a cheap, simple pen plotter

#12

Post by Ididntdothis » Thu, Oct 17, 2019, 2:04 PM UTC

I love pen plotters. When I worked with CAD we still had them. It was so much fun seeing it slowly working on a technical drawing. Laser printers are obviously much better and faster but much less fun to watch.

Re: BrachioGraph – a cheap, simple pen plotter

#13

Post by yakz » Thu, Oct 17, 2019, 2:06 PM UTC

diafygi wrote: post #7

It's my understanding that higher quality plotters/3d printers/mills' accuracy and precision come from higher quality motors (e.g. stepper motors instead of servos). Will it be possible to someday just put cameras on the plotter which watch the current print and self-correct as needed? That's basically what our eyes do when we write/sculpt/carve. Will cheap motors + cameras + software eventually meet or exceed the qu…

Rigidity is a major factor--if you inspect one you'll notice that high speed and high repeatability machines (e.g. a 6-axis +/- 0.020mm repeatability manipulator) are made from rigid (often high-mass) components with robust joints.

Re: BrachioGraph – a cheap, simple pen plotter

#14

Post by HeWhoLurksLate » Thu, Oct 17, 2019, 2:10 PM UTC

This is awesome! To the people that made this happen: Thank you so much!

I've been wanting something to demonstrate how the gap between hardware and software is fairly easy to bridge at this point- thank you for sharing something that demonstrates this well!

Re: BrachioGraph – a cheap, simple pen plotter

#15

Post by roland35 » Thu, Oct 17, 2019, 2:17 PM UTC

diafygi wrote: post #7

It's my understanding that higher quality plotters/3d printers/mills' accuracy and precision come from higher quality motors (e.g. stepper motors instead of servos). Will it be possible to someday just put cameras on the plotter which watch the current print and self-correct as needed? That's basically what our eyes do when we write/sculpt/carve. Will cheap motors + cameras + software eventually meet or exceed the qu…

I can see this helping with low-force motion such as a pen-plotter but I think with things like 3-d cutting there just isn't a replacement for rigidity and high-power motors that can maintain a consistent cutting feed rate for a quality finish.

Re: BrachioGraph – a cheap, simple pen plotter

#16

Post by Accujack » Thu, Oct 17, 2019, 2:19 PM UTC

frankwiles wrote: post #3

Daniele had it do my portrait at DjangoCon last month and it turned out pretty well despite the fact I'm so hairy! https://twitter.com/fwiles/status/1177018222987448321

Judging from the pic, I'd say "Hairy" is something this plotter does well.

It's a neat toy and a cool hack, but it's not useful for a lot except artistic sketches.

Re: BrachioGraph – a cheap, simple pen plotter

#17

Post by test1235 » Thu, Oct 17, 2019, 2:20 PM UTC

frankwiles wrote: post #3

Daniele had it do my portrait at DjangoCon last month and it turned out pretty well despite the fact I'm so hairy! https://twitter.com/fwiles/status/1177018222987448321

did you have a belt across your face?

Re: BrachioGraph – a cheap, simple pen plotter

#18

Post by cpach » Thu, Oct 17, 2019, 2:22 PM UTC

If you’re in to this kind of stuff, you might want to check out the hashtag #plotterwitter. Some really good stuff there.

https://twitter.com/hashtag/plottertwitter

Re: BrachioGraph – a cheap, simple pen plotter

#19

Post by hortense » Thu, Oct 17, 2019, 2:23 PM UTC

diafygi wrote: post #7

It's my understanding that higher quality plotters/3d printers/mills' accuracy and precision come from higher quality motors (e.g. stepper motors instead of servos). Will it be possible to someday just put cameras on the plotter which watch the current print and self-correct as needed? That's basically what our eyes do when we write/sculpt/carve. Will cheap motors + cameras + software eventually meet or exceed the qu…

You can improve the precision by using visual feedback, but there are movements that are impossible to do if you don't have precise enough motors.

Re: BrachioGraph – a cheap, simple pen plotter

#20

Post by mrandish » Thu, Oct 17, 2019, 2:26 PM UTC

diafygi wrote: post #7

It's my understanding that higher quality plotters/3d printers/mills' accuracy and precision come from higher quality motors (e.g. stepper motors instead of servos). Will it be possible to someday just put cameras on the plotter which watch the current print and self-correct as needed? That's basically what our eyes do when we write/sculpt/carve. Will cheap motors + cameras + software eventually meet or exceed the qu…

That's in interesting thought but instead of a camera what if it used an optical mouse sensor? Even cheap ones in $5 mice can do hiDPI now and track on most surfaces. Maybe it could slide on the paper next to the pen with a fixed offset telling the software exactly how far the pen has moved.