I can't say anything about Hurco but I can say if you are going to be trying to hold any type of tight tolerances, look past a HAAS. Where I use to work we had a 2007 VF3YT and 2009 VF2YT. Both great machines. I left to start my own shop and got a 2016 VF3. First thing I noticed is that after it got warmed up I would loose my G54 Y position by up to .0015. let it cool down and it would drift back closer to it's original G54 setting. Run another program and loose the Y again. I'm not talking about super long, multi hour programs either. It can be a high spindle 30 minute run and I loose the Y. Go to lunch and come back and the Y is back to it's original G54 again. I'm finding myself constantly resetting my G54 when doing multi tool finish programs.
My old boss, 2007 and 2009 machines, is a life long HAAS guy and went and bought a VM3 even after I told him about my issues. Sure enough, he immediately sees the same issues. He said he will never buy another HAAS.
Another guy we work with goes and buys a 2020 VF2SS and immediately sees the same issues. He will only use this machine for roughing from this point forward.
We are all injection mold builders. High tolerance fits and extended, high spindle run times. None of us can afford having a G54 Y setting move around like we are seeing.
We have all talked to HAAS, local and Corp California, and get the same response, "it's not that bad, we've seen worse." It all has to do with the column heating and cooling. If there is something with the axis controls there is nothing they can diagnose without blindly throwing parts at it at our expense.
As far as I can see, HAAS are great machines if you live in the +/- .005 world but when blend lines between cutters have to be non-existent or you need to move your part to an EDM and see the burn doesn't blend, they suck.
I don't think this a "load of crap" - A turd it is not.
I'm guessing here the power output of HAAS spindles in this case has increased (almost) substantially between 2007 and 2020.
So the right angled casting / bracket that attaches the spindle to the column seems to be heating up.
So being a complex do-dad thermal expansion will cause it to expand (get "bigger") in X... in Y and in Z.
The thermal expansion is symmetric in +ve X and -ve x (in the ZY plane) for the spindle head assembly, The Z expansion (spindle growth) is compensated by the control by moving the head up and away (when needed by tenths) and then back again when cooler, but the
Y expansion is asymmetric towards the operator as it heats up. Also the bed at the column is not growing by the same amount in Y to match the heat build up of the spindle head assembly.
I believe the HAAS machines Dooooo have at least one or two temperature sensors in column and or head and hence have a fiddle / algorithm that pre-emptively backs the Z away ; HAAS claim they never violate the geometry of the part and hence one might need to sneak down onto a surface with an artful finish cut / spring pass. BUT that's mainly good for Z.
That does not help thermal expansion of the spindle head casting in Y due to greater spindle power output. (especially for an inline direct coupled spindle motor.).
Some models of HAAS will have thru-spindle coolant and that is one strategy (especially for Aluminum) and happens to keep the spindle and work zone at pretty much the same temperature.
If you are doing mold work on tool steels then presumably you are cutting DRY and don't have the benefit of the HAAS spindle cooling hack.
I believe the venerable
@Gcoder_05and
@Qwan (sp) once mentioned something about 3rd party spindle chillers for HAAS i.e. he has experience of hacking those together in number.
As to the smaller DM machines I assume they are thermally more stable as the spindle is not AMPED up so much ? Or does the whole machine get "Hot" in a smaller "Box" more evenly and the Y dimension of the spindle head bracket is much shorter than a VF3 ?
I get the differences in casting thickness variously through the machine.
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** Just as a parallel "Observation" DMG MORI when they went from DMU 50 2nd gen to DMU 50 3rd gen had to make all kinds of changes and additional systems for a faster beefier machine- i.e. spindle chiller, very extensive cooling systems on ball screws, and bearings and other just to even out "WHOLE" machine thermal "Balancing" (as much as they could) + the greater mass of the machine means much greater inertia for large moving castings = more power electrically (servos etc) to throw the machine around ---> more friction and heat and on and on. - + scales as standard (rotary and linear).
~ There is something to be said for a slightly underpowered under "Amped" machine that can be very precise and reasonably stable especially when "babied" a little bit. Balls to the wall production and mold work not withstanding.