CoreXY CNC - 2W Laser cutter for paper

Projects
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I am planning on making a small 30cm x 22cm (11" x 8.5") CoreXY CNC table using MakerBeam and a 500mW-2W laser diode.

Making it myself is NOT the cheapest or easiest or even the smartest solution. There are plenty of cheaper solutions that already exist and are available for sale on aliexpress/Kickstarter/Ebay/etc… There are also a huge selection of other DIY CNC cutters our there with full instructions and large communities built around them. If I just wanted all my problems to disappear, for a reasonable amount of money, I would just get a X-CARVE (from inventables) with a laser diode attachment. (X-CARVE is an amazing tool by the way, VHS should get one)

I want to learn more about CNC from the guts outwards. I want to know why people made the choices that made and I want to experience first hand the problems that exist. I am in no rush. I have most of the BoM already from other projects.

BoM

I decided to use the Maker Beam as the frame because I already has a full set of Maker Beam that I got from the creator when I visited him in SF at Maker Faire. Great guy. In exchange for delivering a few demo kits to a bunch of different hackspaces in a few other cities, that I was already going to, he gave me a full kit.

Software,
I am planning on using http://www.linuxcnc.org/, its open source, free, and is what many other projects seem to be using. It supports DFX and SVG.

The other option is to use just the Arduino running the motor shield that can intemperate GCode sent via serial USB. Again there are lots of examples of other projects that do this too. Then use a SVG or DFX to GCode converter. I don’t like this idea as much as I want the software stack to be as simple as possible.

Why:
VHS’s laser cutter shouldn’t be used for production projects. I have been making a bunch of laser cut paper craft for the last year. I have put some of the once off prototypes on Etsy.com. I would like to start doing production runs of some of the paper craft that I have been doing. I don’t want to abuse VHS’s laser cutter, and paying for $1 a min for laser time at Maker Labs +100 a month for membership, is too expensive for me. Since I live in a small apartment, I can’t store a full size laser cutter. They are also over kill for what I am doing. Instead I have decided to make a small portable one that I can use on my balcony.

Always open to suggests and feedback.

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Arduino code to interpret gcode and another to send gcode to the gcodecncdemo

same again with a gui and image conversion options. Choose “COREXY” from the firmware config.

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I am also building a CoreXY table.

This particular one will probably be turned into a low power laser cutter,
too. Ideally, I should have practice on building these, and be able to
knock together another one in a few hours, for whenever I need a new CNC
platform. CNC everything!
My use-case for a low-power laser is to cut thin vinyl. Obviously I can’t
do that on ours, because the chlorine gas damages the equipment, and
damages your lungs. For my personal one, I don’t care about the equipment,
and I can run it in my back yard, outside, so I’m not worried about the
poisonous gases.

So far I have spent:

  • $10 on GT2 belt + 2 pulleys for motors
  • $10 on extra pulleys
  • $10 on idler posts

I provided all of the links above, so they should be the same as
@funvill’s. Somehow we ended up with different idler posts, though, and
mine do not fit my pulleys. I have laser cut some shims, and that seems to
work.

Another $10-20 is expected in frame materials, but I should be able to
scavenge the motors, precision rod, and bushings from my stash and from old
printers.

For the frame, I will laser cut acrylic, or plywood, or both and sandwich
them to prevent warping. They provide the waterjet files here:
CoreXY | Cartesian Motion Platform so it should take very little effort
to adapt them to my system.

I’ll need to double-check dimensions to match my motor mounts, rod
diameter, material thickness, laser kerf, and the table size I decide on.

Unless something comes up, I will be working on this later this week and
Sunday maybe.

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Would be a nice application for your CRAMPS board.

If you want to go really hard core and build your own, I have pcbs for Adafruit Motor/Stepper/Servo Shield for Arduino v2 Kit [v2.3] : ID 1438 : $19.95 : Adafruit Industries, Unique & fun DIY electronics and kits

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Obligatory OT balcony fire photo. It turns out the exterior cladding of this building is (now) classified as flammable. It’s the Al alloy cladding that is burning…

image

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I will be one of the interested parties who wants a look see when you get it done. I’m following everyone’s work on lasers machines as of course I have plans to follow on the work done by others.

After I picked up that makeblock kit I came across this on there website

http://www.makeblock.cc/xy-plotter-robot-kit/

I think I have the pieces here to do a 1/2 size plotter. And I would definitely want a more powerful laser.

One thing I did want to mention is that after talking with a few people who already have there’s running, I believe an air jet might be a good idea to add the the laser end. Not sure if that’s true but its something I’ll put to the test.

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→ I believe an air jet might be a good idea to add the the laser end

Wouldn’t an air jet make it easier for whatever you’re cutting to catch
fire?

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Most lasers (including ours) have an air-assist to push out the slag as
it’s cutting. I think ours is air, and MakerLabs has an argon one?

Their’s has a lot less charring, anyway. Like, no charring compared to our
cinderblocks.

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Argon? Wow wonder what the cost is on that. I’ll ask next time I’m down there…
Yeah VHS’s is just air.
Wonder if we could add nitrogen option to ours… Go nice with the liquid nitrogen can we’ve talked about getting.

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Speaking of laser cutters, Glowforge (a new Seattle laser cutter company) is releasing their new laser cutter soon. It’s probably going to be a lot more expensive, as it’s a legit wood-cutting laser cutter, but I’m mainly interested in seeing what price it comes out at and whether they’ve made half-decent software/firmware for a laser cutter for once. Unfortunately they’re holding most of the details for another 4 days.

Referral: http://refer.glowforge.com/?kolid=6XRPA

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Hmm, that does seem easier then making my own frame… even if I already have all the parts for my own frame when that laser cut acrylic one just works.

All the items with “XX” for the price I already have. I already have all the steppers, Adafruit stepper motor shield, and a raspberry pi.

Its a REQUIREMENT for laser cutters. Not optional.
The air assist prevents fires and clears away the carbon that is burnt by the laser. without it, you will not be able to burn though anything and you will just start fires.

They use air assist, not argon, or nitrogen

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I tried this out as I need one for the powder printer

http://www.canadiantire.ca/en/pdp/motomaster-heavy-duty-inflator-with-case-0095032p.html

I has no tank but Its a very nice size and actually has an acceptable air flow for what I need and quiet enough (for a compressor)

But its 12 bolts only and only has battery clamps. I did have the necessary power supply to make it work but quite the hassle. So I’m looking for something more suitable.

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Just ordered two sets of these Linear-Bushing
http://www.aliexpress.com/item/12pcs-LM8UU-8mm-linear-ball-bearing-bearings-Linear-Bushing-Bearing-8mm-linear-shaft-3d-printer-parts/32547439658.html

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Ordered this motor controller board
http://www.aliexpress.com/item/3D-Printer-1pcs-Mega-2560-R3-1pcs-RAMPS-1-4-control-panel-5pcs-DRV8825-Stepper-Motor/32499496112.html

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Bought these linear rods

Free shipping 4pcs 3D Printer rod 8mm linear shaft L 400mm hardened Chrome axis match use 8 mm bearing carving machine part
http://s.aliexpress.com/UZnaqY7f
(from AliExpress Android)

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So I installed Fusion 360 yesterday, and I am suitably impressed. Their parameterization engine is excellent, in particular.

Using the CoreXY waterjet version as reference, I’ve designed a version that is almost entirely parametric. That means that there are no hardcoded dimensions, the model is built entirely out of formulas based on the linear rod lengths, motor size, hardware type, etc.

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Here are all of the variables required to make a CoreXY table:

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(I have not finished the X axis yet, expect that to grow slightly)

The advantage of this system is that I can find old components around VHS, my storage locker, the Hackery, etc, and punch their dimensions into Fusion 360’s parametric solver. It will then magically reconfigure the platform for me. Like if I had shorter precision rod, for example.
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Likewise if I had larger motors. It’s a little bit difficult right now, because Fusion 360 only keeps track of parameters local to models, so I have to copy changes to each one when the values get changed.

That’s made easier by using an Add-In called ParameterIO. It doesn’t work out of the box, there is a bug because of the dimensionless quantities in linear patterns.

I had to edit line 219 of:
C:\Users\Jarrett\AppData\Roaming\Autodesk\ApplicationPlugins\ParameterIO.bundle\ContentsParameterIO.py

To say this:

        unit = ' '
        try:
             unit = _param.unit
        except:
            unit = 'FUCK'
        result = result + _param.name +  "," + unit +  "," + _param.expression + "," + _param.comment + "\n"
        ```

(The swears weren't necessary for correct operation, but they sure made me feel better)

To import, the same problem exists, but it was easier to just delete the model parameters in the CSV file, because they're unique to each model and don't carry over.

There are a couple more issues with the assembly, mostly down to my inexperience with Fusion 360. I don't know how to mate surfaces together, for example. I also intend to add in a laserKerf variable that will widen or narrow edges appropriately. And a couple measurements that can be tightened up a little to save some space. Nothing insurmountable. I'll fix all that in, like, half an hour when I come back to this.

Cloud stuff confuses and frightens me, but I think this a link to the file:
http://a360.co/20lCWgG

Stuff will be tweaked, fixed, and added to over time.
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Nice work Jarrett. Now for you to dive into the CAM portion!

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In Autodesk Inventor (the commercial desktop equivalent of 360), you could link parameters between parts, so I would end up creating a dummy part to store all my variables in, and linking to it from every other part. If that feature doesn’t exist yet in 360, I’m sure it’ll come eventually. That’s quite a pain if one of your parameters is your material thickness, or kerf, like you said!

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This looks really close to what I am trying to make. They are using the same laser diode that I am planning on using
https://www.kickstarter.com/projects/1537608281/lazerblade-the-affordable-laser-cutter-engraver/description

Their assembly instructions are behind a login screen. Too bad i would expect they would have a great amount of information in them.

I have everything for this build except the rods. Hopefully they will arrive sometime this week.

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Got all of the parts.

Started modeling the hardware in fusion 360. I plan to print these parts out tonight.

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Source code
https://github.com/funvill/LaserCNC

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