New CNC Mill on the horizon

[Jonathan]

Forgot to mention, those are all rails/blocks with 4 rows of balls which is what you want since their load rating is equal in all directions and the moment load is greater. Two rows is still fine if they're quite big and clearly still far superior to supported round rails.

Probably Stolen goods. . Lol

I better keep them locked up else they will be!

[JAZZCNC]

Forgot to mention, those are all rails/blocks with 4 rows of balls which is what you want since their load rating is equal in all directions and the moment load is greater. Two rows is still fine if they're quite big and clearly still far superior to supported round rails.

I very rarely see 2 row bearings for sale.! Where do you see them.?

I better keep them locked up else they will be!

Better still get them working and earning there keep.!!

[Jonathan]

Agree with jazz about the X-screw - RM2005 wont help. The problem is the pitch is half what you get with RM1610, so you have to spin the screw twice as fast to get a given feedrate. Going from 16mm diameter to 20mm doesn't make the critical speed twice as much (only 25% more) so you actually end up worse.

RM1610, critical speed - 1460rpm => 1460*10=14.6m/min
RM2005, critical speed - 1825rpm => 1825*5=9.1m/min

The feedrate with either screw is plenty, but since 20mm is more expensive and in addition to the above a 20mm screw requires significantly more torque than 16mm, so you only gain stiffness/lifetime which on a router like is completely negligible since the 16mm screw is strong enough and will last for many years.