How accurate could something like this be? I've seen the homemade CNC stuff and that's a bit cost prohibitive. Does it make anyone else shudder seeing he used wood for the frame?

Dremel Carver/Duplicator like a Human Powered CNC Router

(Click for more detailed pics)





From the site:
For the last few years I have seen all these cool CNC projects from
affordable rapid-prototyping machines, to laser cutters, to hacked
together CNC routers.  One of these days when I have the funds, I will
build one of these CNC machines but till then I thought I would do
something more on my budget.
I have a Dremel and have been buying various router bits for it lately.
I was thinking that I could buy one of those Dremel Router tables but,
that would be kind of limiting. So then I thought what about building a
Dremel Duplicator. It would have three axes and could be utilized much
like a CNC Router with the added advantage of copying an existing
object.
This is my exploration into building a Dremel Duplicator.

http://www.youtube.com/watch?v=ZyDlo8fW0dY&feature=player_embedded












XHuMHYPhFi0&hl=en_US&feature=player_embedded

step 1Design Intent

My original design intent was to create a Dremel duplicator/carver from
readily available and inexpensive materials. This machine should be able
to duplicate simple operations such as holes, channels, and outlines.
Ideally this machine would also be able to manufacture complicated 3D
objects. Future versions may include synchronized turntables and a
mounting plate to hold items in place.
I had this all planned out: draft a simple CAD model to figure out
dimensions, print out pieces to use as a template, cut and drill parts,
assemble, document, post to contest and brag about how this machine cost
less than $20 to build, was modular and reconfigurable. Seems pretty
easy but it was anything but&
The main stumbling block in Rev 1.1 was that I did not have access to a
drill press. The holes in this project need to be exactly aligned, which
is really hard to do with a hand drill.

step 2Rev 1.1 - Materials

You may have asked yourself, does this work?
And the answer is that it's a work in progress.
The biggest problem was that I used a hand drill because I did not have
drill press. All of the holes were crooked and none of the axes aligned.
So would this work if you had a drill press? Maybe, but I think you
would still need to come up with an ingenious to increase the
performance of the sliding axes. This may be achieved by adding ball
bearings or using UHMDPE plastic.
At any rate I am going to include the printouts and construction
documents in case you want build/modify this design. If you build one or
have any suggestions please email me and/or attach a picture.
You can fast-forward to Rev 1.2 to see a working prototype if you like.

Rev. 1.1
Materials:





+ (1) Dremel




+ (1) Phillips screw driver to be used as a Stylus




+ 20ft of 1x2 hemlock (mdf or plywood may be better because it will be
less affected my expansion and contraction of natural wood)




+ 5' 11 3/8 of .5 Stainless steel pipe (electrical conduit would be
fine)




+ (1)  3/4" or smaller pipe clamp ($0.79Hardware Sales
)




+ (1) 1.25" pipe clamp ($1.29 Hardware Sales)




+ (1) 2.5-3" pipe clamp ($1.29Hardware Sales)




+ (16) 2.5"  wood screws




+ (34) 1.5" wood screws




+ (7) .5" wood screws




+ (6) 8-32 x 1" screws (this is to lock the Dremel and stylus in place.)
Useful Tools:




+Safety glasses and ear plugs: Safetly First, attempt project at
 your own risk! I will not be held liable for any injury, medical
 expense or death as a result of think about, building or using the
 project once completed.''

+ Hand drill




+ Miter Saw (hand saw could also be used)




+ Drill press




+ Pipe cutter




+ Various drill bits including 1/8, 1/4, .5 or slightly larger




+ Tape measure




+ Ruler




+ Router bits for a Dremel


Router Duplicator Template.pdf(792x1224) 21 KB

step 5Rev 1.1 - Metal Pieces

step 6Rev 1.2

Finally some success! As you can tell from the videos, all of the axes
are working properly.
Now I just need to work on the accuracy. The x axis (left and right
motion) is quite choppy at the moment. Im going make the arm the entire
length of the vertical support so that it can only move up and down. The
new x axis will be the pipe that the Dremel is attached to. Another
improvement will be the addition of skate board bearings on the rails
which should improve tool fluency. So stay tuned!





 
 
 



 

Try it by fluting a barrel.

It's a duplicator, so I'd need borrow your most expensive fluted barrel to try it out.



 

I watched the videos, that gizmo has so much flex in it, both laterally and vertically, that it would be useless for duplicating anything.

Conceptually though would it be a worthwhile endeavor if you used welded steel as the frame and improved pivots/hinges/bearings?



 

Certainly making the thing out of better materials than 1x2s and zip ties is a start.  Still, I would think a used pantograph off of ebay would be tons better in every way.