Stick with Ali profile or venture into plate?

[ecat]

Minimum order £100, easy :) I just looked at the cost of the Y cross beam, say 40x200x700, sobering at about £70. Still, in this CNC game everything appears to work out at about £50 to £100 per part :confused:

Time to do the pros and cons calcs..

Cost:
Plate: 700x200x20, something like Steve's, £50
Profile: as above £70.

Weight:
Plate: 7.6kg
Profile: 4.8kg

N.B.
While not total mince, my inability to read all the instructions on botlanta web page resulted in deflection calcs that do not compare like for like, see post 15 for corrections.

Deflection due to 200N vertical force:
Plate: 0.02mm (http://www.botlanta.org/converters/d...c/bending.html, got to love imperial measurements, hope my conversions were correct)
Profile: less than 0.00mm for 40x160 (Bosh profile deflection calc)

Deflection due to 70N horizontal force:
Plate: 0.82mm
Profile: 0.01mm, again for Bosch 40x160

Disclaimer: the above values are from my calcs and sources I've found, they may be total pants!

In this case I think profile wins. k, back to the calcs...