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!
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.
> 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.
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.
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 05:35AM by Steve DeGroof.
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.
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!
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 .. any who, I fed a 3D stl file into artcam and ran a couple of passes through the hexapod to get this:
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 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.