help with new design please.

[oneturboneeded]

I'm starting to accumulate parts for my build and i am having trouble deciding on size of steppers, and gantry design.

i have a persky 2.2 hp spindle and vfd, so far and that's it. i want to use Aren's guides and R&P. will nema 34 be way to much will nema 23 be enough?? if i go with a 800 oz nema 34 a gecko 540 would not work correct? what will? and of coarse i want it to go as fast as possible.

The base will be 8020. I'm deciding on gantry design of just 8020 and cold rolled steel on the top and bottom of a 4x8 or 4x10 8020 section, for the carriages to ride on and to strengthen the beam. Or do all that but put another piece of 1/8 steel on the face of the 8020 and weld it to the cold rolled rails making an i beam? to much?? i think i'm over thinking it but i've had 2 years.
i want to do lot of mdf and a fare share of alum., plastic, and foam. the table will be 5 ftX10ft.

thanks guys,
shawn

[Swiss]

I guess the important questions to ask are:

1. What accuracy do you require
2. What speed and acceleration do you require
3. what is the mass of the spindle etc

Knowing the mass of the spindle, and the acceleration you want, you can work out the load due to acceleration, and therefore estimate how much the gantry will flex during acceleration.

Knowing the mass of the gantry, and the power of the motors, you will be able to work out if the gantry is too heavy to achieve that acceleration.

If the motors can easily handle the extra mass, then why not? A stiffer machine is always better.

If they can't, then decide if it's stiff enough without it. You can always build the gantry first, and measure the movement of the tool with a gauge while you press on it.

Hugo

[oneturboneeded]

maybe I can just make a steel gantry? i need it to be accurate enough to produce lithophanes.