Recursive CNC (or 'Gerald's Bad Influence')

[mrdovey]

Last night I used my 'Bot cut parts from baltic birch for my new "J-Bot (http://www.iedu.com/DeSoto/JBot.html)", a 3-1/2 axis machine that I've been edging up to for joinery-specific tasks. I won't have my rails or linear bearings for a couple of days yet, so all I could do was lay out the parts for a "dry fit". Step size on this little critter is 1/4800" (0.00021") but, of course accuracy will depend on linear bearing precision.

The plan is to sell a "desktop" joinery machine with firmware for dovetails, box joints, mortise & tenon, etc...

Just kidding about the "bad influence".

[gerald_d]

My influence?...... built of wood???

[mrdovey]

Actually, yes. I liked what I saw on the HotBot forum; but don't have much in the way of metalworking skills (or tools) - and so decided to make the best of what I do have.

What I really wanted was the ability to tilt my Bot's spindle to horizontal; but there isn't enough room. I decided that it'd be easier to build a new machine (of wood) than to modify the (steel) one I have.

The only real challenge so far has been the driver software and, in particular, how to produce reliable microsecond delays. Once that problem was solved (the code can now do sub-microsecond delays), the rest fell into place fairly easily.

I think that if I ever get my hands on a CNC mill I might be dangerous.

[earld]

Morris-
If you get hold of a cnc mill, you will enter into a deeper world where you can become lost...
The outside world will wonder about you, when you walk into walls, trip over the obvious, stop talking in the middle of conversations and drive the wrong way down one way streets, puzzling over some project...
Much like the ShopBot experience...

[mrdovey]

Since I already do most of those things, I may not have much to lose.


The prospect of being able to shape metal like I do wood and plastic with the 'Bot has considerable appeal for me - but I think I probably have a very long way to go before I'll be able to afford a machine capable of doing the kind of projects I'd like to tackle...

Meanwhile I'm having a lot of fun discovering just how much can be done with softer materials...

[drodda]

Morris,
When I was reading Earl's post I was thinking this guy has met Morris? If not he describes you to the tee?

Glad to see that you are making progress on the J-BOT though.


Dave

[gerald_d]

Whence the name JBot?

[mikejohn]

for joinery-specific tasks?

[mrdovey]

Gerald...

I have three more special purpose machines on my to-do list. Since the first is just for joinery, I decided to call it a JBot (shortened form of Joinery Robot).

Dave...

I have no idea what you're talking abou.....what?

[gerald_d]

Guess I should have figured the Joinery-Bot, but the sun and heat on this Sunday beside the pool has made my brain slow down. It is a hard life....

[mikejohn]

The only thing that makes me not be impolite to you is that we are heading towards summer, whilst you are heading towards winter. (Not that you suffer through your winters!!)

[gerald_d]

Mike, 2 days ago it snowed 100km inland from here - and today we had a windless 38C! (The reason I was beside the pool was to clean the leaves out of the darn thing after one of our many summer gales. I'm hoping that the windy season is over now......)

[kerrazy]

Ah-ha Finally we have proof Gerald is really only a lowly Pool boy..... Finally we know what Gerald really does!!!!!

[gerald_d]

My real job is working on garbage trucks - and I am dead serious when I say that.

[mikejohn]

When he says he works on garbage trucks, he is being a little economic with the truth. This (http://www.mechlift.com/) is what he really means!
Snowing here as I write

..............Mike

[stickman]

You know, if I bought one of Gerald's ML150 dumpers, I could save myself alot of energy and muscle to unload my beer into the cooler... or to dump the shop trash cans into the larger dumpster... That is some neat stuff Gerald.. though I am a ranch kid from Western Nebraska.. and I like mechanical stuff...

[gerald_d]

Hey, this is Morris' JBot thread!

[mikejohn]

Now do you understand what is meant by "Geralds bad influence?"

[rhfurniture]

Morris,
How is your Jbot going?
I have had something similar at the back of my mind, and may even get round to it this year. I would use standard shopbot PRT parts and constructions, it would have a horizontal router, and basically be a slot morticer, borer and round ended tennoner all rolled into one, that would dovetail and pin as well. I was thinking of a moving Y carriage with about 900 travel, 150 X (in and out) and 150 Z (up and down). The Y carriage would be L shaped to machine both ends and sides of rails etc, probably an off the shelf shopbot Z. In fact a cross between my benchtop and a standard morticer. Don't know when I'll get roundtuit, but would be interested in your designed movements and capacities.

[mrdovey]

rh...

The machine progresses by fits and jerks.


Work area is roughly 12"x12"x4" (x,y,z) with a stepsize of 1/4800" on all three. The spindle can be manually rotated from vertical to horizontal.

...Morris