I’m planning a 2’x4’ build. The build documentation says the X dimension should be the smaller one, but having a wider X would fit my space much better. I plan to put it in a space that would be boxed in on 3 sides. I guess that’s a 4’x2’?
I assume this would give me the same rigidity and performance as the 4x8 reference build. Is that a valid assumption, all other things being equal?
Will the rigidity and Z accuracy of a 2’ gantry be a lot better than a 4’? I would like to be able to cut aluminum with this machine, and I want to validate my assumption that a 2’ gantry will give me noticeably better performance than a 4’ gantry.
If it matters I’m currently planning to use 0.065 wall seamless stainless steel because that appears to have the highest hardness of reasonably available materials. Open to better information of course.
This is a common question before folks start a build.
Here’s a thread where it was addressed:
Most think you’re sacrificing a little potential performance but that it should work. I’ve considered it because it would let me have the flexibility to temporarily set up a full sheet and transfer the gantry for special projects. However, it’s definitely not the easiest path to a working machine because of the inability to cut its own struts in a single operation.
I have always had the wider X (because I wanted to have the option to make the CNC longer), though not recommended I’ve never had problems with it, even for tiny inlays. It really depends on what you expect as well though. The better idea is to make Y the more narrow side.
Thanks for the information. I missed that thread in my search, not sure how.
Regarding cutting struts in one operation, that is unfortunate. I think the one time hassle of cutting them (or convincing someone with a bigger cnc to cut them) would be out weighed by the long term convenience of easier access and fitting the space better. I wonder how much longer I would need to make Y to cut them on a diagonal. A 48x30 gives a 56.6” diagonal and the struts are 54.6. I don’t know if the rectangle would fit though.
I read that other thread but it doesn’t have and quantitative differences between a 4’ and 2’ gantry and barely any qualitative commentary.
I see a long thread from 2019/2020 testing different tubes.
Has anyone gone through the trouble of building a 48” X gantry and a 24” X gantry with the same materials (prints, struts, tubes) and compared the properties? I think the math would say the 48” would have 8x the deflection, right? Or does EI/L^3 not apply to this?
the issue I have seen is cutting the strut plates. Your X will never be wide enough to cut its own strut plates. There are workaround fixes. Buy them from @Jonathjon at Northwoods is the easiest. Second would probably be doing the flipping trip that @Tokoloshe mentioned. And third which I dont even know if I have seen worked or not is to cut out half struts with a scarf joint of sorts. But I cant confirm that works.
As others have mentioned the actual length of the X being full sheet capable is 54.5-57" so you’ll be fine cutting 4’. I’m actually looking at setting up a second Y rail on a second bench for working with a much shorter y and doing the same 2x4 overall, but with the ability to put it back on my big table to cut full MDF sheets at 49x97
I made mine with a longer X, I think before I cut the spoilboard to the final size I had about 1365mm in the X direction, and I think 885mm in the Y(I’d have to double check on the Y though, but it was close to that) and I just had enough to position the brace diagonally.
