Chapter 11:

The poor Man's CNC, the 3D Pantograph


Once again, you don't have to be poor to build this, if you don't want to do much machining, or for any other reason, you can just build a 3D Pantograph.


Illustration 38 Remember this? Has an error I've corrected, see if you can find what on the next picture...


Why? What can it do for you'?

Well, imagine you can carve Wood, or even Roofmate, and want make a piece from that, you want to have made in Aluminum, or Steel;

Put the original and a metal block firmly set at the same distance that separates the Dremmel from the pointer.

Then turn the Dremmel on, with a milling bit, and pass the pointer over the original piece's surface, the Dremmel will mill away the empty volume around the piece's contour...

And leave the rest, that is, an exact replica of the original piece.

So any one with no patience to learn CNC, or for any other reason, can carve a mock up of the thing he wants, and then, after a few moment's time, proudly hold a metal whatsit that is only dependent of his/hers carving skills, but will hold a lot of abuse no Wood/Stirofoam/Roofmate piece would. 

So what's a 3D Pantograph, anyway?

It is an array of drawer slides, bars on holes, or whatever, that can make a pointer holder and a machine holder move synchronized, on movements where they move parallel in the X, Y an Z axis, or in plain English, they move from left to right, up and down, and to and fro, in-sinc.

Not to make light entertainment, but for the Dremmel milling bit to replicate the motions of the pointer, so as to replicate like a 2D Pantograph, but in this case, not a drawing, 3D means palpable objects!

Illustration 39 What the pointer does, so does the Dremmel!

In the case shown, the left to right blue bar set on the sides of the red box holds all the white moving parts, and so they move left to right.

Then the 2 vertical blue bars hold the remaining white parts, making those move left-right, up-down.

Then the last, 2 horizontal blue bars move the holding piece with the inherited X and Y parallel movements of the other parts, and add the depth movement, front-back, parallel in the Z axis.

So the red X original contour is being carved away on the green block!

Note that if you follow this model, the first horizontal bar is the strongest bar, then the 2 vertical, then the 2 horizontal bars, as the latter only holds the holding piece, but the first holds all of the moving parts.

Now, there's an easier way...

Just buy yourself one of those Milescraft Pantographs,

and make them REALLY work 3D with this, a Pantograph Raiser Platform, easy as pie:
Just think of it, you start from the top down, work your way down the piece, in steps that are set by rotating off those plaques, that are as high as the Milescraft's working height.

The Pantograph sits on the floating Platform, in blue, and gets down as the plaques are rotated.

The 4 guide pins, on which the platform moves up or down, without losing the Platform's alignment to both the original and replica.

And so you can replicate a lot of stuff, remember to make a 2-pass work on the most complicated jobs.