Build a cheap, SIMPLE, CnC foam cutter.

[moreil]

I've just started building my CNC foam cutter.

Step-by-step progress is being recorded at http://www.homecnc.org/index.php/Cheap_Foam_Cutter

My objective here is to build a fairly cheap machine that's buildable with the tools I have (meaning, no drill press, no lathe )

Hopefully, the page above will be useable as a step-by-step guide for easily building a cutter.

My background is in software, so this real world stuff is a bit of novelty at the moment

I have all the electronics, and have cut the wood so the next step is to start assembly....

My cost to date is around $USD330, most of which is the stepper controller board.

Many pictures at the wiki page above.

[moreil]

Fully finished building one frame (didn't have enough Al tubing to do the other one end).

Now just need to add the motors and it will be working! yay!

[moreil]

dup

[moreil]

My M8 threaded rod is galvanised (or corroded). Which makes it too thick for my M8 nuts.

I started re-threaded it with a hand die, but it's hard going (it's removing quite a bit of metal) and the thought of re-threading 2000mm of rod isn't much fun.

Anyone know of a good supplier of metalwork materials in Sydney, Australia? That's open on a saturday morning...?

[fkaCarel]

Try stainless rod (304). Cost a little more, but there is no galvanising, nor will there be corrosion.

Carel

[moreil]

Sounds like a good idea. I've found a metal supplier that's open on a saturday, so here's hoping they've got M8 threaded rod.

I'm currently using 12mm Al tubing for the rails. I think I might replace that with 12mm stainless steel if I can. (Assuming that the metal suppler will cut it for me. No way am I going to try cutting stainless steel by hand

[fkaCarel]

The problems in handling stainless are a little overrated. You get used to it. The keywords are tools and patience (as in work progress is not linear with adrenaline level)

Carel

[moreil]

What would you normally use to cut it? I'm assuming a hacksaw isn't going to do the trick. Would a cutoff wheel from a dremal make any impact? I suspect an angle grinder would do something but that's probably overkill.

[fkaCarel]

A hacksaw for metal does the trick. Use a quality sawblade from your local industrial supplier. A consumer hardware store only sells tools that have the appearance of tools. Think off the bits they sell for electric screwdriving. If you look very carefully you see them disintegrate if they come within a distance of 5cm of the screw they have to drive

Carel

[moreil]

We went out this morning, in principle to meet a friend for breakfast. We 'accidently' detoured along the way to go to Edcon Steel in brookvale.

Very nice shop! I bought 4 meters of 12mm stainless steel rod. They nicely used their electric hacksaw to cut it into 500mm lengths. They directed me next door to another place to buy the 1000mm stainless steel threaded 8mm rod. Total cost was about $AUD65 which I thought reasonable.

The 12mm stainless steel is unsuprisingly much heavier than the Al tubing, but it's incredibly stiff. I can visibly bend the Al tubing in my hands, but I can't make a dent on the steel rod. It's also got a better surface than the Aluminium tubing (smoother and harder).

I spent a couple of hours putting the other frame together, and then added threaded rod and motors to be first one.

Just connected it up to the computer and yay! it moves!

Moves very nicely actually. No missed steps on the motor, silent and smooth. There's no detectable lash that I can see, but I'll need to measure that properly later on.

Am feeling very chuffed with myself at the moment.

[moreil]

I've extensively updated the step-by-step guide at http://www.homecnc.org/index.php/Cheap_Foam_Cutter with more photos. I've also move the bulk of the photos off into sub-pages so it isn't quite so bad to load (previously, it was loading more than 4 megabytes of pictures

[fkaCarel]

Congratulations! I know the feeling when an effort turns into a result. Bath in it and have a beer. Were you able to totally avoid sawing?

Carel