Giant 20' x 3' x 2' router build

[charlieuk]

ok so for the long x axis to get the fast speeds zapp have recommended the nema 34 8nm motor SY85STH118-6004B Nema 34 High Torque hybrid stepper motor

but said that the EM806 drivers would not be powerful enough so it would have to be the 2m2280n driver which looses the functions we have been discussing unfortunately. 2M2280N Digital microstepping driver

from a users point of view is it worth reducing the speed requirement just to run the other drivers?

while i want to build the machine to a good quality i just need to be careful the costs down spiral out of control.

[JAZZCNC]

ok so for the long x axis to get the fast speeds zapp have recommended the nema 34 8nm motor SY85STH118-6004B Nema 34 High Torque hybrid stepper motor

but said that the EM806 drivers would not be powerful enough so it would have to be the 2m2280n driver which looses the functions we have been discussing unfortunately. 2M2280N Digital microstepping driver

from a users point of view is it worth reducing the speed requirement just to run the other drivers?

while i want to build the machine to a good quality i just need to be careful the costs down spiral out of control.

If your going to run Nema34 motors then these are the drives you want. Kinco are good drives and while you won't have the abilty to tune out resonance they are still very good drives with advanced alogrithms for dealing with resonance and motor tuning so the chance of resonance being a problem is very very low. Also they provide a Fault output so you can use this to E-stop the system if you have stall just like the EM806.
I wouldn't lower the spec to save money and these drives are 100% what you need with 8nm Nema34 if you want resonable speed from the motors. Also being 240Vac you won't need a power supply with these drives so you have to factor this into the mix. Obviously if your not using on all axis you'll need a PSU for the other axis.

Don't be tempted to try running smaller Nema23 motors with gearbox and heavy gantry running at high feeds because while the smaller motors may provide the speed and enough torque to move the gantry they will struggle to provide the torque needed to handle the slowing down and inertia of the gantry from higher feeds. The affect would be positional loss from steps being lost due to pushing affect.

Understand your point about keeping handle on the costs but The truth is that you can have high feeds but they do come at a cost. While 3.2 or 4Nm Nema23 motors run at 75V on the EM806 connected to correct gearboxs would work fine you would have to accept the fact they would be limited to what feeds/acceleration they can provide and the balance between working within an acceeptable motor tuning range and one that will cause miss steps etc will be a lot finer.
The High power Kinco drives and Nema 34 motors are the correct choice to deal with all the friction and inertia your going to encounter using R&P with gearboxs and heavy gantry and in the long run they will save you money by not needing replacing if you found the smaller setup just couldn't cut the mustard.

Unfortunatly if you want the best possible machine your just going to have to lube up Bite down hard and take it like a Man.!! .