Desktop 1000 mm x 600 mm Gantry Router

[CharlieRam]

Hi Charlie, thanks for the feedback. When designing the machine I considered various issues with possible flex in the various axis. Like you the ability of the gantry to move due to cutting forces concerned me. Although I have not done any complex calcs working through the axis, my logic is......
Z axis - 4 Hiwin carriages on 15 mm rail will easily support 5Kg of the spindle, carriages and plate
X Azis - 4 Hiwin carriages on 15 mm rail, I am using closed sided aluminium extrusion plus the rail, as long as I don't compress the axis when setting up there will be virtually no flex, it needs to support 12kg (see picture of extrusion)
Y axis - again 4 carriages on 15 mm rail, in compression this shouldn't be a problem, the only issue is the sideways cutting forces as you pointed out. I am using 8 mm bolts to attach the gantry plates and they will be embedded in 2 mm pockets as will the carriages and ballnuts. This leaves about 150 mm by 750 mm 'box' shape that has the potential to deflect. I am using 10 mm cast tooling plate. My gut feeling is this will not flex since the cutting forces for a 1 kw spindle will be comparatively light



If there is too much flex I have a couple of get out of jail options
1) add a cross beam, I would prefer not to do this as I am planning to use the space under the machine to house the electronics
2) Add another rail on each side with more carriages, again more complexity, weight and cost





40 mm x 40 mm KJN aluminium extrusion

I am starting to cut soon so I will have to fix the design

Thanks

Ian

It's not so much the deflection as it is the lack of rigidity which will lead to chatter, premature tool wear and tool breakage ect, probably ok for woods but I would imagine you'll struggle cutting aluminium.

Charlie

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