Brokkr CNC 2.0

Update: Jan 3rd 2019: Teaser video



Here is the finished first project, a wooden variant of the 4400 year old 'Royal game of Ur' from Mesopotamian era:



2.0 version changes:
Extra thick wall C beam to support weight of spindle. Zero deflection under load measured.
Beefier joints.
Silenced steppers.
RF shielded power lines, both 220 and 110V.
Dedicated breaker box for 220V feed.
Dual torsion box CNC stand leveled to 1 thou over 48" distance.
Stand designed for disassembly for when I move.
Beefier level gauges modified to achieve that.
220Kv water cooled spindle.
Dual temp gauge for spindle and reservoir.
Tougher waster board/hold down slots.
Dedicated PC with SSD so no moving parts.
New dual monitor display.
UPS to filter out spindle ground plane noise and protect against brown outs and short outages.
Magnetic switch on 220 line.
Dedicated up front 220 dual breaker.
110V pump turns on with 220V Magnetic switch (third switched leg).
And lots of learning on my part and all credit due to building on the discoveries of others.
Thanks to them, my families dream of having a tough dependable CNC is a reality. Thank you all.

Update: Feb 18 2018: It lives!



Lots of progress. Control box built. Populated with 4 drivers (1 per stepper), 2 driver 36V power supplies, 1 heavy amperage contactor for EStop of both power supplies, 1 PC power supply for regulated 5 and 12V supply, 2 venting fans and one UNO with terminal shield.


Definitely started to get cramped in the PC case. Should have gone for a old 24" server case.

I made an effort to shield, twist, segregate (data from power) and ground all cabling inside and outside of the control box. Stepper lines are twisted 4 pair inside braid and foil shield. Each stepper coil lead twisted passed thru individual ferrite bead 4 times. All shields grounded at the case.



Shielded the router power line with braid and added toroidal ferrite bead.



Update Oct 16 2017:
Based on discussion on Openbuilds forum I have finally cut up my 1000 mm C-beam. I went with a 310mm length for the Z-axis, which left 347mm for the 2 gantry legs.







Inspired by 'C-beam Prefab Untitled', 'C-beam 1-M', and 'CRH C-Beam Router' builds.

Just mocking up parts just now and deciding how to cut up my 4th 1M C-beam for my gantry legs and Z-Axis.



I liked the idea of being able to 'choke up' on the gantry height for maximum rigidity. I hope to maximize the gantry leg material, while having a reasonable amount of c-beam left over for the z-axis.

While I could just split it into three 330mm pieces, I do not want the z-axis length to be so long (plus heavy-ish stepper motor at top) as to be 'wagging' when it moves.

Ultimately I would like to get into a 1.5 KW air-cooled spindle so am trying to build with that in mind as well.

Really trying to just build one CNC and maybe get it 'right' the first time. Ordering delays are brutal.





Why a mock up? I just got familiar with Sketchup. Now I am learning Fusion 360!