Our CNC Building Blocks are one of the easiest ways to assemble a CNC machine. Follow this forum for information and sharing plans, blue prints and other ways to make your machines using these parts.
By frodeheg
The Reference design has a longer y axis than x axis. Is it very discouraged to use 30" on both x and y axes?
I got some feedback earlier that I shouldn't go above 30" on linear shafts due to various quality issues, but I wasn't sure if it was for both axes.
By frodeheg
I guess one of the limiting factors on the x axis is that all the weight on the z-axis is on the same side of the Block. I wonder if the shafts can be longer if the weight of the z-axis is more evenly distributed. For example if I mount the motor upside down on the back side and transfer the motion to the z-axis with cogwheels. I might lose some precision in the gearing, but I also get some precision back due to linear shafts not being bent, and especially if they are long.
By frodeheg
New idea. I leave the motor where it is and add some support on the front side that the top of the z-axis can slide on. I'll use some sliders and wheels to reduce wear. That will allow me to have a longer x-axis... I need to be careful about not reducing the z-axis though...

I'll post some images of my design plans when I'm finished. It's starting to get quite cool, I'm combining 3 kickstarter projects in one machine :-)
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By AJ Quick
We do not recommend going over 24" x 24" (30" shafts) without some kind of additional support like you are doing. Deflection will be worst on the X axis (gantry axis) as that is where the weight will be the greatest.
By frodeheg
Ah, I will be buying the 30" shafts once my design is complete, since that is the longest you provide. I guess I won't need any additional support then :-)

...well, I'll post my design later, including the blender 3d-model if anyone find it useful. It will be an all aluminium design that has an unlimited build area because it doesn't have a floor, so it can be mounted anywhere on any (flat) surface. (or I can add a detatchable floor if I want)

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