A few ideas for tuesday, just parking here so I can freaking get to work (goddam ADHD):
Yeah - good ideas!
We did the same job on the small CNC with the same tool / material - came out fine…
We are thinking the calibration of the big one - or holding it with clamps is not strong enough to take the lateral forces…
Collets seem good - haven’t had any issues and have a torque wrench for that one so consistent
I’ll bring my 2-sided tape… that shit is powerful enough to hold anything down. That plus clamps will help answer the hold-down question at least.
The fact that the job runs fine on the small is interesting. Of course, it could be the calibration of the little guy that’s off in the way we expect! If everything fails I can bring back some of the same stock and try to run the gcode on mine here w/ that tool… see what’s what.
But yeah… maybe Just verifying some of the calibration setings. Notably the surface speed since that with the RPM and number of flutes should be enough to figure out the chipload, right? or something… I’ll check the formulas tonight. What time u getting in?
Little guy is good (after you and I re-calibrated it) - you tell it to cut a 8mm hole and it does it - all good - the big one comes out at 6.5mm… 
like 9:30-10 - add yourself here:
https://discourse.southlondonmakerspace.org/t/23-59-big-cnc-tuning/21885
Cheers!
The cut settings run like a dream on the little guy 
Just missing feed rate in your formula as chip load is feed per tooth.
ok! So we KNOW we have a calibration problem. Coolio
Seems like it!
More progress!
Big CNC spindle tools mounted:
Spoil board mounting holes and countersinks cut by the CNC!
Next steps are the big long job of cutting all the rest of the mounting holes…
Thanks to
@Kyle
@Amit_Kohli
@Julia
On these improvements!
This is amazing! Gutted I couldn’t be there. Have you scheduled already your next session?
Nice one. So it clears the board in all directions now? Do we know how long the holes job will take? That might be a 2-shifter? Cause it’s all the holes x2 right?
Not to be a jerk or anything, but the next step… the billion holes, they don’t have to be FLAWLESS, right? I mean as long as the two boards get them holes in the same place we good? Is there logic in drawing a grid with a pencil, taking a powerdrill w/ the correct size bit/hole_saw and going to town? I know we have a CNC to do this, but… in fact this might even be more accurate cause when we flip the boards, we’re going to have to line them up using some reference on the bed, right? So it might be off by a few mm anyway… at least the grid way is fast and ensures the holes on the spoilboard and base match (even if not perfectly aligned with the bed) .
Or?
Yes! We moved the Y Axis relative to the bed and now can reach the whole board and have it lined up!
One set of holes was 3hrs or so - so x2 = 6hrs…
You make a great point! They are just for the hold downs, so really we could attach the boards together and just use the pattern to mark out the board down to 2 or 4mm (1-2 passes) and then use a hand drill to go the rest of the way!
@kyle - thoughts!?
I remember seeing a drill stand somewhere in the space. That’ll save you a bunch of time and will give you perfectly straight holes to the table. You’ll also not need to make a plunge cut on the router, perhaps just go in with a small bit to get a centre and then go the rest of the way with the drill.
Yea a drill stand would be perfect - we can use the CNC to make a shallow hole and finish with the drill stand… is it kicking around the woodshop?
Thanks!
I think I may have seen it in the snug, but I could be wrong. You’ll have to have a look around 
Indeed you could mark w/ the CNC, 2mm would be enough, just big enough to see, right?
Still, I think a big ruler + square would be faster than all that jogtime, even if it’s just one pass! But the result would look prettier yourway.
Nice suggestion on the drill stand Ryan!
Big enough to locate the drill also… one pass will be fast, and we need this to be easily repeatable, so better to have the CNC do as much as possible…
Hey @Jonathan - any luck with CNC hold downs? Thanks!!
Another big CNC project by @Julia
Marking out fabric!
Just dots so the fabric doesn’t pull, worked really well!
