Which longer, X or Y?

Post Reply
calica
Posts: 107
Joined: Wed Apr 11, 2012 8:13 am

Which longer, X or Y?

Post by calica » Fri Oct 04, 2013 6:38 am

Hi,

Now that I have the updated end and motor plates in hand, I'm going to increase my working area. The shortest dimension is going to be 23.5". The longest is TBD. I have 2 4' sections of MakerSlide and 1m misumi 20x20 extrusions. I will do dual X mod. I also have alum spacers.

Which (X or Y) should be kept smaller for rigidity? My ideal would be shorter Y and max X. My gut feeling that is most rigid as well. At least wrt extrusion deflection due to weight. Am I missing anything? I mainly mill PCBs, plastics and aluminum. Very little wood.

WillAdams
Posts: 8533
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
Contact:

Re: Which longer, X or Y?

Post by WillAdams » Fri Oct 04, 2013 6:51 am

Most people (all but one?) have gone w/ the longer Y-axis.

On the http://www.shapeoko.com/wiki/index.php/Scaling_Up page, we do mention:

http://www.shapeoko.com/forum/viewtopic ... 10&p=10392 by mjohns --- notable for extending the X-axis much more than the Y and using the new end plate design, resulting in a much more open / accessible machine.

Unfortunately, mjohn hasn't been back on the forums since 17 July, and hasn't posted since 23 April.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

calica
Posts: 107
Joined: Wed Apr 11, 2012 8:13 am

Re: Which longer, X or Y?

Post by calica » Fri Oct 04, 2013 7:15 am

Yeah, I've mostly seen the longer Y configuration. Just wondering if there is a reason for it, or just personal preference.

Looking at mjohns thread, he JB-Welded the extrusions together. How about talking that further and putting epoxy granite in the extrusion? Wouldn't do too much for rigidity but would dampen vibrations.

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
Contact:

Re: Which longer, X or Y?

Post by cvoinescu » Fri Oct 04, 2013 8:54 am

I can confirm that, given a choice, almost all people buy eShapeOkos that are either square, or with the Y a little longer than the X. There was one wide machine (longer X than Y), and only a few long and narrow machines (Y significantly longer than X).

The X is more rigid if it's shorter. The Y can be attached to the table mid-span to increase its rigidity, and it's much less of a problem anyway. If the gantry is shorter, thus lighter, Y will accelerate faster. Incidentally, weight is why I would not fill the extrusion with epoxy -- I think the cost, both in $ and in kilograms, outweighs the benefit.

Assuming a dual-X, dual-Y machine with open end plates, it's also marginally cheaper to have the X shorter than the Y. To add to Y size, you need to lengthen 2 x MakerSlide and 2 x belt. To add to X size, you need to lengthen 2 x MakerSlide, 1 x belt, and 2 x extrusion connecting the end plates, which costs more. (However, if your machine has more frame elements than the bare minimum, the math changes.)

On the plus side, the wide machine (X > Y) is more open than the long one, as in easier to access. If bench space is limited and the long side of the bench is against a wall, it may be a better choice. With open space at either end, it also allows cutting larger sheets (with indexing), the limiting dimension being the width.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

Post Reply