Mini 3-Axis CNC v0.29

by MakerBlock Dec 11, 2013
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Can this be run without the Z servo?

Definitely. If you look for prior versions, I did exactly that.

What's the dimensions of the largest part? (the base plate with the horizontal teeth, it looks like)

I have a relatively small 3D printer with a 12cm x 12cm x 12cm build volume and I'm curious if the largest part can be printed out properly?

I did mine, splitting in half the ones long. To glue the pieces , I used super glue with baking soda and sanded carefully.

Neat! Did you post a picture?!

Yep. Check the makes section. I cut in the middle the x and y pieces.

I'm not done with the print yet, but the base is ~15cm long... I think it's the biggest part...

can you post links to the software for this? I love the project, I think it whould be neat to add small stepper to the z axis and us it as a cnc exacto knife mill for paper:)

Okay, I posted a link to the Github repo!

Comments deleted.

where i can buy the 8 plastics parts?

Shoot me a message through my blog at makerblock.com

Cool project! Any plans to port this into a mini CNC Mill/3D Printer?

It's not rigid, powerful, or accurate enough to really work as a printer or mill. It can draw and possibly operate an exacto blade. Though, I'd love to see someone do more with it.

Afina can't print this. If it is rescaled the servos won't fit. 5.5inch cube.

Hi There, Great project! Can you please post the openSCAD or Solidworks source files? When I try to edit the design, all I see are vertices, which are not good for editing. Thanks!!

You really need to put a mount for a mini servo, much like the eggbot uses to lift/place the tool. http://egg-bot.com/uploads/images/AnatomyShot_600.jpghttp://egg-bot.com/uploads/ima... you can see it lifts the board the pen is attached to... or you could just make it lift the pen by tilting it back 30 degrees...

This 'bot has something even better than a pen lift - an actual working no foolin' Z axis.

With a pen lashed to the Z axis as show in the picture and video, you can raise and lower the pen within the Z axis range (I think about 15mm). That's enough to lift a pen out of the way or to push it into the drawing surface for more contact.

I used some Mighty Putty to help fix the gears to the Servos. The Servos are only $2.5 so I don't care not getting it undone. https://www.youtube.com/watch?v=kyA1Viugxjwhttps://www.youtube.com/watch?... RIP Billy Mays

Here is a short video of everything moving: http://youtu.be/rGSBhuBcDHAhttp://youtu.be/rGSBhuBcDHA

I think if the z axis gear rim would be a little bit smaller and the teeth a little bit longer that may improve this axis. My Servo is working really hard to move the z and it look a little bit cricket.

I'm very please how good the X/Y axis work. For me the X rack could be a little bit higher because the mighty putty and the screw add some additional height and now the screw drags on the table...

Anyway, good work and thanks for this nice toy!

@Alpharesearch: I agree about the flange on the Z axis gear - it does need to be smaller. It kinda pushes the Z rack out of place. Also, I'm trying to figure out a better way to solve the X set screw so it doesn't hit the table. This may sound funny - but I'm glad that you're having the same problems I'm having. These are the exact same problems I'm looking to solve with the next iteration.

I casted rubber feet with silputty from the hole in the x gear. They fit perfectly in the holes in the y rack. This lifts it about 5 millimeters. Stopping any drag and snagging from the screw.

@Inhed1: That's a great solution! I'm working on a new design and I've added a little extra height to the X rack to prevent the dragging problem. I love the idea of rubber feet anyhow since it will help keep the robot in place. By the way, the one you printed looks great in the gray/orange.

As someone trying to keep up with your lightning-fast progress, would be nice to have a changelog that at minimum maps version number -> which parts changed. Just so that I don't need to print the entire thing every time you change a single part. Great project! Thanks for doing that.

Great ! Thank you. I just print the v0.18 and, as discussed on your blog, I wrote some Gcode interpreter that I will share tomorrow.
I was thinking about how to add the z axis and why are you lifting the pen with gears for a translation ? I am wondering if sticking the pen directly to the servo can do the trick :)
Also share a scad version of the gears should be helpfull : my servo can't fit inside both bears so I had to drill them...
Corona : I use cheap no name 9g servo and it works fine !

="thingiverse-128267006fa0f5554d155ff28a81fe3a:disqus" href="http://disqus.com/thingiverse-128267006fa0f5554d155ff28a81fe3a/Oliv4945: Sticking the pen directly to a servo arm would allow me to reduce the part count by 1, but would also mean the robot is only a 2 axis plotter with pen lifts. This way, it is a no foolin' 3 axis CNC machine that works pretty well as a pen plotter. :) The SCAD files are seriously a horrible mess - I'll post all the SCAD files as soon as I work out a few more kinks. But, if you want to email me, I'll create a set of gears for you.

Ok, for now I will not have enough time to try the Z version, but I'll let you know, thank you.

Also, I uploaded the code :)

Arduino Gcode interpreter for Mini-CNC

I understand that big gears are needed since you're limited to less than 360 degrees of rotation on a stock servo, but this will substantially weaken the force it can push with. And a micro servo doesn't have a lot to start with.

:) The servos I'm using (Batan 2122's) seem to have more than enough power. Give it a whirl - you'll be surprised.

Can you let us know where you get your servos from ? My googling skill is failing for Batan's 2122... Thx.

I just ordered a BUNCH of micro servos (TowerPro SG90) that are far easier to find. I got my servos from Make, but I don't see these anywhere for sale on their site. I expect the servos to arrive in about a week. When they do, I'll redesign this version to better fit these more common servos.

In your blog you mention the scad files...are you going to post those anywhere?

For now, no - but I will. Long story short, when I've posted OpenSCAD files for unfinished projects I end up getting questions about problems in those files for years. At the moment my files are poorly commented and in pretty bad shape. I'll be cleaning them up and posting them with a better version soon. Still lots of room for improvement!

HI MakerBlock, I love this project and want to contribute. Its been 4 years ... would you be willing to share the openscad files now :)

The blog is HIGHLY recommended reading. Thanks for you fine work!

Thanks Cerberus333!

to minimise backlash, how about adding two small 'posts' for a simple rubber band to attach. thus keeping the gear teeth gently pulled together? assuming the pen on the paper doesn't give much resistance to movement :)

I like that idea. I'll see if I can incorporate it into the next version. :)
I got the robot to make some marks on a piece of paper, but nothing photo worthy at the moment. I don't think there's too much resistance yet?