DIY CNC Milling Machine From Scratch

[totts]

Hello everyone, well after making my first router type cnc machine on a budget ive decided to push the boat out and make a milling machine based of a sieg x3 machine.

The machine is going to be a bit larger than an x3 and hopefully far more rigid.

linear rails on all axis
DQ860MA 80V Drivers
yet to decide on powersupply
3.0Nm on X and Y nema 23
4.5Nm on z nema 34
2.2kw spindle to start with and hopefully BT30 spindle with ATC in the future.

Pictures to follow:

[totts]

Hopefully this is what it will look like: Nearly fully Drawn


Ears welded up to support the z axis



Z axis sides, 20mm thick:



The z axis fully built ready to be surface ground:




Surface ground and holes drilled and tapped for the ears:



Just checking the squareness: looks pretty good although this is adjustable on final assembly:




Mock up:




Steps machined for linear rails and ball screw supports and nut:




All holes drilled for linear rails, ball screw supports and the screws which will push them towards the parallel edges:




Y axis plate machined and holes drilled ready to mount the rails and then surface ground:

[totts]

This is just a test piece to check how well the taper locks up: was pretty good with just letting it drop in under its own weight, it would stay in when held upside down, and with a tap of a mallet i wasn't able to pull it apart by hand :)







Adjustable gas strut to help with the weight of the heavy z axis:




That's all for now apart from the rails and ball screws that everyone has seen before, material for the bed has been ordered and hopefully will be starting this soon :)

Hopefully everyone likes the build so far!

[Washout]

Very nice and definitely will be following this build.

[Lee Roberts]

There I was at lunch time today browsing through google images at other peoples mill type builds (shortly after reading through JBs x3 conversion thread), i'm keen to have a go at my own mill type, is it obvious yet?

Then I jump on tonight and I find this gem of a thread! Yea! Perfect timing, cant wait for the rest totts !?!

.Me

[GEOFFREY]

Starting to look very purposeful. Well done. G.

[totts]

Thankyou, lots still to do, everytime i think about it theres more to do! :(

[Lee Roberts]

Thankyou, lots still to do, everytime i think about it theres more to do! :(

Hehe always the way, are you going to fill the z axis column with anything to help with resonance or do you plan for something else, what are you going to use for the base of the machine, my thoughts are a nice slab of steel?

.Me

[totts]

I have a nice solid slab of aluminium as shown in the drawing, about 500mm x700mm by 76mm thick so i hope this will be solid enough.

I was going to fit some of the electronics into the colomn but i am now going to make a stand to house the spindle cooler, electronics, pc and coolant pump, so will probably think about filling the column with something after the z stepper and y stepper is mounted so i know where to fill.

Trouble is the cost keeps mounting up :( best not to take note and hide the reciepts from the missus hahah

[Jonathan]

Good start - almost getting jealous!

A few general observations...

Have you seen the BT30 ATC spindles on Aliexpress? If you're happy with 6000rpm then they're not excessively expensive:
http://www.aliexpress.com/wholesale?...initiative_id=

PSU - why no decision? A toroidal transformer of around 500VA would be ideal.

What is the mass of the Z-axis (head, spindle etc) and what are the dimensions of the Z-axis ballscrew? I've made a script to calculate it more accurately, so if you post that information we can make sure the motor you've chosen is the best option. I suspect you may be OK with one of the 3-4Nm Nema 24 motors. The gas strut makes surprisingly little difference if you try to get a reasonable acceleration...

Correct me if I'm wrong, but it looks like you're leaving the back of the Z column open, so it's a C-shape section not a box? If so then you should defiantly put another plate on the back, as the torsional stiffness of a C-section is very low compared to a box. That's one of the big advantages of putting the ballscrew on the front of the column, not inside - you can have a closed section.