Comments on my first attempt at a design (if you would)

[Muzzer]

Yes, the carriage height in Z (top to bottom of the moving body) is very short and quite a bit less than the overhang of the spindle. Also the depth in Y from the spindle to the column is fairly limited. Once you have a vise in there, you will lose some of that, reducing it even further. The Sieg cast columns are standing on spindly pillars - solid blocks would be sensible.

Looks like a plan though - get cracking and show us how you get on! You are bound to evolve the design as you go so the sooner you start the better.

[JAZZCNC]

Everything the others mention plus a few more.
#1
Widen the Y-axis rail spacing, you have plenty of space so use it. Also, this will allow easier access to the bearings bolts, the way you show it now looks like you the X-axis bearings will block access to the Y-axis bearing bolts.?

#2
The triangle plates at the rear I would move to the outer edges and fasten to the side of the columns, this will give a wider footprint, I'd also think about adding some lateral bracing to add sideways support. Like muzzer mentioned the column risers look a bit flimsy so maybe beef these up.

#3
It's been said but worth mentioning again because it's a Biggy. The Z-axis plate needs to be double the height and the spindle housing needs to be wider.
Also, the spindle motor plate needs supporting or the vibrations will kill the spindle bearings and vibrate on the machine general.

Good luck.

[lukekjackson]

JAZZCNC, thanks

Widen the Y-axis rail spacing, you have plenty of space so use it. Also, this will allow easier access to the bearings bolts, the way you show it now looks like you the X-axis bearings will block access to the Y-axis bearing bolts.? - One iteration actually has these wider, not sure why i closed them up but i will move them back out,. Nice easy win there

This brings me to one thing I've been struggling with, the X axis has a lot of overhang. Using 25mm HIWINS with the block spaced 36mm apart does anyone know what the max overhang should be? Obviously the longer i make the table to more travel but there has to be a point where you lose rigidity



#2
The triangle plates at the rear I would move to the outer edges and fasten to the side of the columns, this will give a wider footprint, I'd also think about adding some lateral bracing to add sideways support. - Again another easy win. the ridiculous reason they are there is that the column came with holes tapped for the Z rack so i used these. it will actually be far easiest fixing them to the sides as i don't have to drill through the depth off the gusset plate,. Should definitely have been doing it your way in the beginning

Like muzzer mentioned the column risers look a bit flimsy so maybe beef these up. - Still surprised but you all seem to agree. this may be one to do when i have the mill working so i can skim the sop of some stock to flatten it out. Either that or i could fit letteral section in between the risers to strengthen the riser design

#3
It's been said but worth mentioning again because it's a Biggy. The Z-axis plate needs to be double the height and the spindle housing needs to be wider.
Also, the spindle motor plate needs supporting or the vibrations will kill the spindle bearings and vibrate on the machine general. - Ill pick these up on the next revision and repost a snapshot of it

Good luck.- Cheers, Ill need it

[lukekjackson]

Muzzer

Cheers for you comments. The one about the pillars surprises me i thought 25 x 100 solid steel bar would be over the top if anything. My logic was that the columns only contact at those points and are relieved in the middle of the base, so with the 25mm thick flat bar fixing the top of the risers, and the plate at the bottom i thought it would be as strong as having them on straight to the base plate.

carriage height in Z (top to bottom of the moving body) is very short and quite a bit less than the overhang of the spindle. Yes I will increase this to 150 - 200mm from the 100 it is now

Also the depth in Y from the spindle to the column is fairly limited. Once you have a vise in there, you will lose some of that, reducing it even further. - I tried to space it so the axis of spindle was relatively central to the limits of the Y travel, see below. Would it be more useful further out. Lack of experience on my part to know this


Spindle axis to table edge - 23.5mm


Spindle axis to table edge - 10.42mm