best gantry extrusion

[PorcoMaster]

hi guys, i am starting my research on the hardware list on my project the Voron Tower, and while looking into misumi, i saw that the prices are not bad for just the gantry, i will spend about 30 dollars, buying from then. 

and while is more expensive than buying from amazon or china, the price is not bad, my question is quite simple, is misumi the best choice ? will the extrusions will be all well cut, and straight ?

i can cut myself, but for 30 dollars it might be worth it, the sizes i am looking right now is for the 350x350mm build with some offset, so the sizes are 385 mm, 470 mm, 575 mm, 575 mm.

[claudermilk]

I would presume it's a good choice since Misumi is what's called out for the self-sourced Voron BOMs. The only reason I didn't go with them on my Trident is because LDO had just come out with their frame kits with the fancy colors.

[PorcoMaster]

On 4/17/2024 at 9:11 AM, claudermilk said:

I would presume it's a good choice since Misumi is what's called out for the self-sourced Voron BOMs. The only reason I didn't go with them on my Trident is because LDO had just come out with their frame kits with the fancy colors.

thank you man, yeah it's the one i am coming too for now it's cheap enough, and it looks good. if i were to make all frame it would get expensive fast but just for gantry is not that much.

[chrisalbertson]

The Misumi stuff is good, but not different from what is sold by others, as long as you get the same profile.     A better question, I think, is if 2020 extrusions are the best materials for making a gantry.    Voron chose it only because it is easy to work with using only hand tools.    If you remove the "only with hand tools" restriction then many other, possibly better materials become options.   Why not square-wall tubbing?  Why Aluminum, maybe you have the funds for Titanium?  And then there are carbon fiber square tubes.    All of these are harder to work with.      But 2020 is not bad because you should care mostly about stiffness and secondly about weight.

The other thing to worry about when choosing materials is thermal expansion.   the aluminum 2020 parts only work well up to about 350x350 size because they expand and BEND when heated because of the linear rails that are attached.   if building a 500x500, you might want a different material.   This is the reason Voron recommends going only up to 350 size. 

Edited Friday at 03:18 PM by chrisalbertson
typo

[PorcoMaster]

58 minutes ago, chrisalbertson said:

The Misumi stuff is good, but not different from what is sold by others, as long as you get the same profile.     A better question, I think, is if 2020 extrusions are the best materials for making a gantry.    Voron chose it only because it is easy to work with using only hand tools.    If you remove the "only with hand tools" restriction then many other, possibly better materials become options.   Why not square-wall tubbing?  Why Aluminum, maybe you have the funds for Titanium?  And then there are carbon fiber square tubes.    All of these are harder to work with.      But 2020 is not bad because you should care mostly about stiffness and secondly about weight.

The other thing to worry about when choosing materials is thermal expansion.   the aluminum 2020 parts only work well up to about 350x350 size because they expand and BEND when heated because of the linear rails that are attached.   if building a 500x500, you might want a different material.   This is the reason Voron recommends going only up to 350 size. 

Thank you man I really appreciate this insight, I really taught about linear expansion, but didn't think it would matter this much, and that makes sense, yesterday i cut all my 4040 that will be used on the voron tower, so I already defined the final printer size, and that will be 355x355x350, so I am sticking on the 350mm³ factor, as mentioned, however I got interested in the titanium router because of weight as I could get some speed later on, even if I need to remake all models that are already adapted to the 2020.

 

Do you have any more advices about the titanium, I would like to look it up.

 

Again I appreciate your response and insight on the linear expansion.

[chrisalbertson]

You can find Titanium backer plates for the gantry at places that sell Voron parts.  Those pretty much fix the bending problem.  The Ti plate applies the same force the linear rail does but in the other direction.

[claudermilk]

I suspect part of the selection of those extrusions was also the "easy to get off the shelf" ethos. The slots for the nuts to make bolting things on wherever you need them also had to have had an influence.