Steel frame cnc router design/build

[CraftyGeek]

Y-axis rear plate...partly to help keep crap out of the leadscrew etc Thought it would add some extra sideways/diagonal rigidity...can easily drop it.

Z motor - probably didn't think it through quite correctly...with that arrangement, the y axis front plate is considerable shorter than it would need to be to have the leadscrew & motor attached.
The rail lengths are pretty much spot on compared to the screw length - maybe i've got the Z axis linear bearings spaced further apart than needed? (170mm outer face to outer face along the axis). I'll look at swapping the leadscrew & motor to the Y front plate.

Base frame - do you mean raise the lower shelf/surface, or reduce the overall height?
I don't really want to lose much overall height if possible as it will be at a good height for me to work with it at...rather than being low down on the floor like my last mdf machine which was a major pain in the back.
I don't necessarily need all that adjustment - I could raise the lower surface & add more cross bracing to the outer frame?

[JAZZCNC]

Z motor - probably didn't think it through quite correctly...with that arrangement, the y axis front plate is considerable shorter than it would need to be to have the leadscrew & motor attached.
The rail lengths are pretty much spot on compared to the screw length - maybe i've got the Z axis linear bearings spaced further apart than needed? (170mm outer face to outer face along the axis). I'll look at swapping the leadscrew & motor to the Y front plate.

With 350mm Thread length and only 400mm rails then you have loads of excess thread. You only need enough thread for required travel + ballnut length +10mm or so spare.
RM1605 nuts are approx 50mm in length so for 180mm travel then 250mm thread length is plenty.!

Base frame - do you mean raise the lower shelf/surface, or reduce the overall height?

Yes raise it and widen bracing to match. You don't want to rely on bed frame to form main frame strength, obviously it will add strength but better is main frame is strong enough without.!

[CraftyGeek]

Yep - sorry, I had another look at the Z-axis screw....I did shorten it earlier - but it looks like I lost that set of changes & didn't think/notice when I was copying the sizes down above.

Have started revising the layout - its fitting together nicer with the z-axis sorted the right way round :-p

I'll do some more tweaking tomorrow - should have a fully revised version then

[CraftyGeek]

I've been fiddling with it again

Beefed up the diagonal cross bracing on the main frame - all diagonal cross braces are now welded at one end & bolted at the other.
Also rasied the lower surface/shelf - removed the very bottom height adjustment position so it could come up a little further.

I've done a fair amount of tweaking to the gantry & z-axis.
The knock on effect of extending the y-axis front plate to mount the Z motor meant that the z-axis wasn't giving me an optimal range of movement. I had to shorten the height of the gantry (between y rail mounting surfaces) from 200mm to 175mm in order to sort it out - everything is now peachy with a good range of movement & 2mm+ clearances all round.
Making these tweaks along with removing the rear panel looks to have saved a decent amount of weight from the gantry as a whole

Am I safe to start peppering the parts with holes & adding pinions etc ?

Edit: Just spotted that the Z rails could now be longer than needed as well...or the bearings might need moving lower.

[CraftyGeek]

Here's the tweaked Z-axis...ball nut lowered to allow more clearance at the top of the axis & Z rails are now 350mm instead of 400mm.