Bench-top or welded frame

[Doddy]

Hi doddy,

What work area are you aiming for?

Bigger than my StarMill (160x100!). Height isn't a massive issue for me (at least not as yet), but 200mm would be an aim. X/Y = around 600x400 was my goal.

Did you concidder going vertical?
This might solve some of your space problems.
And you could move through doors more easy.

Only the crazy people go vertical! Actually, it's something I had just started to think about - I know Dean here has done this in the past. That might be the next machine.

Will there be a rigid fixed connection between your gantry sides?
How do you prevent gantry going out of square?
Your design does not look like it has a rigid gantry now.

(assuming you mean square across the Y-Axis) Yes, a beam across the top, with gusset plates to hold square (sorry, the design is obviously incomplete - more to get the concept right in my mind before burning hours on Fusion 360).

Is it made out of 3 separate moving parts?
I think it will be very hard to get a rigid end result that way.

Yes, more steel to be added yet. As above, this is just a basic geometry sanity check.

Also the spindle is not in between the linear bearings, this also does not help for rigidity.

Now for me i am no expert. So please have the more experienced guys here point you in the right direction.
I started my cnc design reading at cncroutersource then came here :-) Still on a steep learning curve.

My 2cts worth,
Verstuurd vanaf mijn SM-A320FL met Tapatalk

That's exactly why I posted this. Placing the spindle where I did I'm very conscious that it's putting a large force on the rails. Having said that, better and brighter people than me have suggested that the rails are more than strong enough for anything a small machine like this is likely to throw at them, and Dean's earlier comment re. most mills - yeah - they'll place a similar cantilever load on the rails as well.