Okay, after some distraction looking at one of the most beautiful builds here for a very small steel frame design, I got a little daunted by the work needed on such a steel frame. Think it was Andy cnc (yellow and black paint job) I need to be realistic to my needs

I will only ever need to pocket out say 50mm thick Ali, or brass, woodwork and some intricate designs for electronic enclosures, microphone designs .Not in a high production capacity either, so finish more important than speed. I have spec'ed out the components for what I think will result in a build envelope of 290 x220 x 60 in z, which im hoping will be more than capable for my immediate requirements (and will have inherent value)


I want to check that i'm not going over board for such a small design that only needs modest soft metal cutting. To use 50x25 Ali box section (any recommendations on uk supply?) and essentially have similar design, guides to the red design in this post, only smaller footprint. Also the omio cncs seem quite capable although still larger than I need

http://www.mycncuk.com/threads/13547...hlight=omiocnc

My current thinking
500mm rails, 450mm 1605 DFU ballscrew kit, 4 HGH carriages - 2 each side next to each other (for main gantry slide, side mounted). The gantry will therefore have 450mm-about 160mm= 290mm travel, leadscrew will have about 305 of travel, ie travel limited by the main rails

300mm rails, 365mm 1605 DFU ballscrew kit, 2 HGH carriages (running on top and bottom face of gantry).Spindle head will be approx 80mm wide so travel here is say 220mm, the 365 leadscrew also giving about 220mm of travel

Not too sure about Z yet but possibly
200mm rails, 200mm 1605 DFU ballscrew kit, 2 HGH carriages for the Z. 200mm leadscrew gives about 55mm of working travel

800w 4 bearing air cooled spindle/ vfd, ER11 collet

3 closed loop 3Nm steppers https://www.aliexpress.com/item/3245...533b761fP4ER5j

48v 360w SMPS or ideally a 400va transformer (what capacitance is recommended? Can get pricy for caps at this voltage).

planetcnc ethernet controller/ software

3 off 3:1 gears and belts plus lots of other

Main bed- I was thinking 8mm Ali plate? , the machine can skim itself and drill a mount hole matrix.


Am I right with the ballscrew lengths above ? , I am under the impression that a 365mm (for example) assembly is its total length (i.e 300mm of thread, plus 11 at one end and about 50mm other for the motor mount?). And using a double ball nut which is 80mm means a 365mm assembly essentially gives me 220mm of workable travel? Is that correct ?

Also wonder if I need double ball nuts for all axis? They limit travel a lot

My main questions are do these sound reasonable components for my requirement and is the design linked above appropriate for such a small size machine? Looks neat but maybe there are better choices.

When building these type of designs how difficult is it to get all the guides true? I assume there is near to zero play in these carriages which makes me a little concerned about fabricating the rest of the machine

Apologies for lots of questions here, the amount of info on this site is a little daunting just now

Cheers!