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CNC Hexapod

Posted by Gene Hacker 
CNC Hexapod
April 03, 2008 05:18PM
I just found this interesting video of a Hexapod drawing with a pen, which the robot's creator intends to replace with a CNC routing head.
This is pretty much a subtractive reprap, considering that it draws one of its own parts in the video. Having a reprap capable of moving itself presents some interesting possibilities, namely that it is capable of having infinite tool heads without a complex tool head switching mechanism. Also, having six legs means that 2 of them can assist in assembly.

Because it can move, it might be able to make it capable of autonomously searching for resources needed for replication. Just imagine what a swarm of these things could do!
Re: CNC Hexapod
April 03, 2008 05:42PM
Wow I can imagine a machine like this in a workshop collecting raw materials and tools, making parts and assembling them. Complete self replication, just supply it with raw materials and come back later.

Re: CNC Hexapod
April 03, 2008 07:48PM
Or send them to a junkyard and periodically resupply microchips.
Re: CNC Hexapod
April 03, 2008 07:51PM
Its the American Grey Goo...


J Sweezy Sincerely
Re: CNC Hexapod
April 04, 2008 09:14AM
Damn! smiling bouncing smileysmiling bouncing smiley
Re: CNC Hexapod
April 21, 2008 03:49PM

I have nearly finished making the routing head for my CNC hexapod, and I have added the ability for the control software to read g-code, so 3D routing should be possible smiling smiley

I would like to find a collet chuck that I could fit to the 1/8" spindle shaft, anybody know of anything suitable?

Matt Denton
micromagic systems
Re: CNC Hexapod
April 21, 2008 03:58PM
Welcome to Reprap, Matt! Glad you could join us! smileys with beer
Re: CNC Hexapod
April 21, 2008 05:07PM
winchymatt Wrote:
> I would like to find a collet chuck that I could
> fit to the 1/8" spindle shaft, anybody know of
> anything suitable?
How about picking up a Dremel collet and collet nut set (part# 4485)? A piece of round stock, drilled and threaded, could be used to attach it to the spindle. Looks like this guy [9x20lathe.blogspot.com] managed to get one to fit.
Re: CNC Hexapod
April 21, 2008 05:27PM
I did buy a dremel collet, but don't think I can make the threaded bar on my lathe.. with my skills. I may see If I can find out what the thread is and pick up a thread piece of bar.

Re: CNC Hexapod
April 21, 2008 05:34PM

thanks for the link, this gives me all the information I need to give it a go! cheers smiling smiley
Re: CNC Hexapod
April 22, 2008 01:30AM
Well depending on the size of the bar and what thread you want you might be able to find a thread die for it at a hardware store that way you dont have to try and use the lathe to make a thread...which can get complicated.

Here is an example of a tap and die set...you don't have to get them as a set usually you can just get the "wrench" and the die you need for the job.

Re: CNC Hexapod
April 22, 2008 08:17AM
According to that blog page [9x20lathe.blogspot.com] , it's 7mm diameter and 40 threads per inch. It'd be tough to find a die for that.

Might be easier to buy just the collet and make your own nut by drilling a hole in an 3/8" acorn nut.

(thinks about it for a bit)

OK, try this:
- take a 3/8" carriage bolt, cut off the head but leaving plenty of unthreaded stock
- drill a 3/16" hole in the threaded end, at least 5/8" deep
- take a 3/8" acorn nut and drill a 3/16" hole in it

That should take a standard Dremel collet.

Edited 1 time(s). Last edit at 04/22/2008 08:35AM by Steve DeGroof.
Re: CNC Hexapod
April 22, 2008 08:28AM
Indeed finding a die at that size would be near impossible.. unless you work for dremel.

I think one of the guys at work s going to make one for me in exchange of some tech services smiling smiley

Re: CNC Hexapod
June 05, 2008 07:29AM
CNC hexapod cuts its first material!

Ok, so its only polystyrene, but its a start smiling smiley

A couple of improvements were made to the router since my last post, most significantly I had a colleague make me up an dremel collet adaptor to fit directly onto the motor shaft, much better than my brass grub screw style colet.

For these two videos I'm using a 1/16" two flute slot cutter, the router is running at approx 35,000 Rpm, the additional battery on the to of the hex is a 12V NiMh 4500mah pack just to run the router. DXF files are loaded in to artcam where G-code tool paths are created. Due to the 10mm thickness of the poly and the cutter only being 6mm long, I chose to do two passes on the workpiece, this also shows that although the resolution is low, repeatability is good enough for multiple passes. Material is held down by the weight of the hexapod, which is current;y 4.3Kg with the router and additional battery pack.

CNC Cut Poly Square

CNC Cut Poly Femure - 2 pass cut

You may notice in the picture of the poly femur with the hole left in the poly, the hole has a cleaner cut edge than the cut piece. This is due to the fcat that foam and poly cuts better in a reverse direction, however, I forgot and generated the tool paths for a normal cut direction.

I also tried to cut 2mm ABS, however, this caused too much vibration in the tool, which in turn loosened the colet allowing the tool to slip out and cut too deep into the ABS. A square was cut, but not terribly accurate, some work needed yet!

[email protected]

Re: CNC Hexapod
June 05, 2008 12:23PM
Just had a second go at the femur shape, I increased the size by 20% and reverse cut the piece.. much better!

Original and larger New part

Close up of the cut edge.

Re: CNC Hexapod
June 05, 2008 04:52PM
I love RepRap but i also love this where do i get one smiling smiley

I guessing it's not open source sad smiley

Re: CNC Hexapod
June 06, 2008 07:44AM
I had a go at 3D profiling today in high density foam. I have a few issues to sort out, mainly with my control software not having a puase or for that matter a stop button yawning smiley .. any who, I fed a 3D stl file into artcam and ran a couple of passes through the hexapod to get this:

I admit its not great, but you can kind of make out the eyes, nose and mouth.. kind of. The large 1/8" scar on the face was caused by operator error!

I will post a video of this process some time after the weekend, and try another test next week.

[email protected]

Re: CNC Hexapod
June 06, 2008 08:52AM
Hi Matt,

... very impressive!

I want to output cartesian 3D-data (X,Y,Z) with a vertically oriented tripod ( [builders.reprap.org] - look at "Assembling the Tripod"), so it's a similar problem.

Can you help me with the conversion?

Re: CNC Hexapod
June 09, 2008 03:07PM
Ok, attempt two at 3D cutting was much better.

I made a few improvements to the software that streams the data to the hexapod.. including a stop button! The cutter was the same, 1/8 ball nose. After a roughing cut, I did a raster pass with 1mm step, and a second raster pass in the opposite direction with 0.8mm step.

I could use a smaller ball nose cutter to get a finer finish, but I think I'm approaching the limitations of the robots resolution.

I will edit the video and upload when I have time.

[email protected]

Re: CNC Hexapod
June 11, 2008 07:21AM
I have just uploaded the 3D face video.

Cutting 3D face

To cut the face I did three passes:
1) roughing cut
2) X raster finish
3) Y raster finish.

The face took just under 30 minutes to produce.

Edited 1 time(s). Last edit at 06/11/2008 07:27AM by winchymatt.
Re: CNC Hexapod
June 11, 2008 09:30AM
I really think you ought to get your name added to the builders blog list and start publishing there rather than on this thread in the forums. Your work deserves a much wider readership which you'd get there.


Have you thought about hanging a Mk II extruder onto your hexapod and additively printing stuff rather than milling objects? I think it would be really cool to try that. smileys with beer
Re: CNC Hexapod
June 11, 2008 05:30PM
Just tried to log in with the invite from Adrian, but I'm having log in issues!
Re: CNC Hexapod
June 12, 2008 11:19AM
LOL I was just about to post this after seeing it in Make Magazine only to realize it was first posted here. Wow this is the most coolest thing since well Reprap.

Keep the videos coming.. and Forrest is right... Post in the Blog....

I want one of these my cat would love to play with it. If I had a cat that is.

Bruce W.
Re: CNC Hexapod
June 12, 2008 11:26AM
So the next thing you need is GPS and then you could make stuff with accuracy well if GPS was accurate enough. Humm?? Radio triangulation?
Re: CNC Hexapod
June 12, 2008 11:53AM
Cheers, I have stuck a post in the blog smiling smiley

[email protected]

[email protected]

Re: CNC Hexapod
November 01, 2010 08:02AM
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