Re: Advice on Mammoth CNC Router Build - Steel Framed - 2440mm x 1220mm cutting area!
It would be too simple wouldn't it!
Re: Advice on Mammoth CNC Router Build - Steel Framed - 2440mm x 1220mm cutting area!
Quote:
Originally Posted by
Wejjmeister
Ok question whilst Im back to the drawing board.... Can I run profiled rails upside down, as in, on the base of my gantry box section? If not I will have to build the Y axis completely differently to the way I intended and therefore the Z too.
.
A picture from Jonathan's build which shows exactly what i mean. I assume you know it by heart till now :toot:, going with that design. I wouldn't be over inventive, especially knowing that his machine works wonderfully.
http://www.mycncuk.com/attachment.ph...1&d=1377723791
Quote:
Originally Posted by
Wejjmeister
Also I have seen the difference between the 2.2kw and 3kw spindles and am aware of the differences, also the diameters are different 80mm vs 100mm I recall? I will use the 3kw at some point, but as with everything, budget has to come in somewhere
Then just alter the design so you can fit it in the future.
2 Attachment(s)
Re: Advice on Mammoth CNC Router Build - Steel Framed - 2440mm x 1220mm cutting area!
Before I go any further...How am I doing so far? Is this along the right lines?
Also, mad question, but could I get the top, bottom and sides cut from 15mm Steel plate rather than Aluminium and use the epoxy method again? It would cost a LOT less than 20mm 6082!!?? The Gantry ends would still be 25mm Aluminium...
Re: Advice on Mammoth CNC Router Build - Steel Framed - 2440mm x 1220mm cutting area!
Hi Weijjmeister,
The double beam 'MechMate' style gantry is a difficult design especially if you want to exceed the performance of a well made standard gantry. Hats off for trying it.
The design in post 83 is very limited by the rail being mounted to a flat plate which is mostly cut away. Also, the overall gantry is effectively 2 'C' shapes. As each 'C' shape is joined to the other only at the ends then you've lost a lot of stiffness.
One of the other tricky areas is the bit you haven't drawn yet which is the Z axis and the options for joining it to the Y axis including fitting the Z ballscrew etc. The design will quite literally hinge on what you do there which is making it difficult for everyone to critique the whole thing.
If you study Jonathan's design you will see that the gantry creates 2 box sections (to resist the twisting forces that your 'C' shapes will not) which are joined by a single top and bottom panel. You will also see that the top and bottom panels, plus the sides which take the rail are about 20mm (?) thick, whereas the outer panels are more like 10mm. This is an economical use of material where it is needed.
I think that you would be better off starting from your earlier post (#70?), but mounting the rails onto the inner faces of the box section, but with a thick plate between the rail and box section. Or you could put the thick plate inside the box section so long as it spanned most of the height of the section. This is because with this layout the rails are being twisted off the frame (rather than pushed in or out on a conventional gantry), and the relatively thin wall of the box section may not be good enough.
1 Attachment(s)
Re: Advice on Mammoth CNC Router Build - Steel Framed - 2440mm x 1220mm cutting area!
Thanks for the above, I really appreciate the time taken to reply and include so much detail. I am working on the gantry again so hope to ppst a new revised design taking everything on board.
This is what arrived today!! Exciting!!
3 Attachment(s)
Re: Advice on Mammoth CNC Router Build - Steel Framed - 2440mm x 1220mm cutting area!
Revision 5 of the Y axis with the beginnings of the Z axis too for your opinions on guys if possible. The Z axis is not finished, the upright plate will be mirrored to the other end and boxed in with the profiled rails mounted to it, the ballscrew will run internally on the same face.
Attachment 12694Attachment 12695Attachment 12696
Re: Advice on Mammoth CNC Router Build - Steel Framed - 2440mm x 1220mm cutting area!
Did this ever get finished? Looks like exactly the kind of machine I want to build.