Please review this router gantry idea

**EddyCurrent** · 06-09-2013

This is not a build log, I'm just wanting to know if this design is any good. I've read that the L shaped gantry is good but it tends to put the ballscrew too far back so this is a double L shape made from aluminium box section with the ballscrew mounted centrally. The black & white object is the energy chain, sizes of the box sections are probably not correct yet.

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**GTJim** · 06-09-2013

I no expert but all the strength seems to be in the centre of the gantry, yet your rails are top and bottom the weakest points.
I may be wrong though.
Jim

**EddyCurrent** · 06-09-2013

Yes I see what you mean, there will be end plates so I'm expecting these to resist any twisting, there will also be blocks mounted on the end plates behind the ballscrew to support the horizontal box sections.

**JAZZCNC** · 06-09-2013

Don't let the ball-screw being slightly further back put you off the L design.!!. . . In reality it makes very little difference it works fine and makes for a very good stiff gantry. It also very neat and keeps screw out of arms way and makes cable management easy.

Your design would be too tall making for a weaker design.

**EddyCurrent** · 07-09-2013

Jazz, thanks for that, I'd read you mentioned this before and obviously Matt's machine works well.
So before I set off down the L design how about this one ? pipe + 2 bits of channel

I'm also thinking that any hollow material could be filled with builders expanding foam to act as damping as it's very lightweight.

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**Jonathan** · 07-09-2013

Your tube design would be hard to fabricate, particularly when it comes to getting the rail mounting surfaces parallel. However it would be exceptionally strong as a tube is the strongest shape in torsion.

To make it easier to make you could put the rails on the front flat surfaces, as they could be machined or leveled with epoxy. If you did this you'd want to use profile rails to reduce the overhang.

**JAZZCNC** · 07-09-2013

Originally Posted by EddyCurrent

Jazz, thanks for that, I'd read you mentioned this before and obviously Matt's machine works well.
So before I set off down the L design how about this one ? pipe + 2 bits of channel

Yes it would work and tube is very stiff. But large tube is expensive and will resonate quite a bit.!! How about something like this.? It will probably be cheaper and stiffer with 2 x 100mm tubes