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BrachioGraph – a cheap, simple pen plotter

brachiograph.readthedocs.io

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Re: BrachioGraph – a cheap, simple pen plotter

#81

Post by penagwin »

semi-extrinsic wrote: post #78
penagwin wrote: post #48

Earlier quoted context omitted.

I haven't looked to far into this project, you might be able to gain a decent amount of stability with better materials like 3d printed plates instead of cardboard. (This is a place where CF filament actually makes sense, it's one of the most rigid printable plastics)

Or you could just laminate that cardboard with some fiberglass and epoxy, on both sides. A roll of 5cm x 3000 cm fiberglass woven cloth is $9 incl shipping on ebay. Buy some two component epoxy at the local hardware store, like 10 fl. oz. for $15. Cut your cardboard and fiberglass to whatever size and shape you like. You're going to make a sandwich: fiberglass, cardboard, fiberglass. Wear disposable gloves. Cover you…

I'm a huge fan of Peter Brown on youtube, I've been wanting to get into using epoxies for various projects, it's just that I live in a small apartment, I'm not sure where to start, and I know I'll need ventilation.

I'm biased towards 3D printing simply because I already have my own printer, so it's simply the fastest method for me (not including print time, but epoxies have to cure anyway).

Re: BrachioGraph – a cheap, simple pen plotter

#82

Post by dekhn »

DanieleProcida wrote: post #25
makotoNagano wrote: post #22

Nice stuff. Raspberry Pis are generally pretty terrible at running servo's though. Adding an intermediate Arduino would work wonders (I appreciate the complexity would jump significantly though)

Turns, out, it's actually very reliable in practice. I'm trying to work out at the moment just how far I can go with more powerful servos: https://raspberrypi.stackexchange.com/a/104662/42583 . There are limits, but they seem to be greater than I expected, especially when the only power to the Raspberry Pi is provided by a MacBook.

we live in a world where a macbook can power a raspberry pi which powers servos.

Re: BrachioGraph – a cheap, simple pen plotter

#84

Post by jessaustin »

penagwin wrote: post #81
semi-extrinsic wrote: post #78

Earlier quoted context omitted.

Or you could just laminate that cardboard with some fiberglass and epoxy, on both sides. A roll of 5cm x 3000 cm fiberglass woven cloth is $9 incl shipping on ebay. Buy some two component epoxy at the local hardware store, like 10 fl. oz. for $15. Cut your cardboard and fiberglass to whatever size and shape you like. You're going to make a sandwich: fiberglass, cardboard, fiberglass. Wear disposable gloves. Cover you…

I'm a huge fan of Peter Brown on youtube, I've been wanting to get into using epoxies for various projects, it's just that I live in a small apartment, I'm not sure where to start, and I know I'll need ventilation. I'm biased towards 3D printing simply because I already have my own printer, so it's simply the fastest method for me (not including print time, but epoxies have to cure anyway).

If ventilation is challenging, use less epoxy at one time. Also there's nothing wrong with leaving the room and waiting for the vapors to clear out.

Re: BrachioGraph – a cheap, simple pen plotter

#85

Post by mkl »

hrnnnnnn wrote: post #23

This looks like great fun, but I'd prefer to make something where the output is a little more precise. Does anyone know of a DIY plotter that's a step up quality wise from this one? Or maybe a site or community that lists similar projects?

Well, depending on your definition of "DIY" and "make"...

I have a Roland DXY-1100 from ~1990, an A3 flatbed design that is very precise. To make it go I had to build a weird serial adaptor and a weirder two-voltage DC power supply, so I count it as DIY! Because old plotters like this were originally designed for commercial use (design, architecture, engineering, etc.) they're often very well designed and well made, so still good despite their age.

Chiplotle (note the extra "l") is a handy Python library for controlling plotters like this.

Unfortunately I managed to short out my power supply and fry one of the voltage converters, so I need to remake the power supply and make an actual case for it so I don't do that again!

I also have a much bigger Roland plotter (not flatbed), but I haven't got that going yet.

Re: BrachioGraph – a cheap, simple pen plotter

#86

Post by ashish01 »

I am a complete n00b at this but very interested in making a CoreXY plotter. I get struct at how to get parts like linear guides and servos needed for this. What is the best way to educate oneself about this. Is there something like sparkfun how mechanical hardware. Thanks!

Re: BrachioGraph – a cheap, simple pen plotter

#88

Post by all2 »

ashish01 wrote: post #86

I am a complete n00b at this but very interested in making a CoreXY plotter. I get struct at how to get parts like linear guides and servos needed for this. What is the best way to educate oneself about this. Is there something like sparkfun how mechanical hardware. Thanks!

My goto while building a 3D printer is this:

https://hackaday.com/2018/08/03/classy-corexy-build-breaks-d...

Re: BrachioGraph – a cheap, simple pen plotter

#89

Post by aurbano »

gknoy wrote: post #49

This documentation is very impressive. I like that the author included a link to "Why is the documentation structured this way?" [0]. 0: https://www.divio.com/blog/documentation

That’s extremely well written!

I’ve been struggling to document an open source platform I’ve built with some friends and colleagues [1] and this is finally giving me hope!

[1] https://play.socialgorithm.org

Re: BrachioGraph – a cheap, simple pen plotter

#90

Post by joshu »

mkl wrote: post #85
hrnnnnnn wrote: post #23

This looks like great fun, but I'd prefer to make something where the output is a little more precise. Does anyone know of a DIY plotter that's a step up quality wise from this one? Or maybe a site or community that lists similar projects?

Well, depending on your definition of "DIY" and "make"... I have a Roland DXY-1100 from ~1990, an A3 flatbed design that is very precise. To make it go I had to build a weird serial adaptor and a weirder two-voltage DC power supply, so I count it as DIY! Because old plotters like this were originally designed for commercial use (design, architecture, engineering, etc.) they're often very well designed and well made,…

i found one of the power supplies on ebay fairly easily. i’ve thought about replacing their voltage regulator stuff internally as well.
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