Vertical Vs Horizontal X axis?

Vertical Vs Horizontal X axis? So I am designing a 3D printer that uses a moving bed as the Y axis. My original post is here: [forums.reprap.org] I am working on changing the frame to a more cube shape and eliminating the need for 4 extra extrusions. Anyway, When I just started designing the printer I had 2 8MM horizontal rods spaced 70MM apart. The problem with that is the weight is not evenly distributed on the leadscrews on either side and the one Z axis linear rod. So I simply put one more rod on the other side of the leadscrew to give the z axis a total of 4 linear rods. Since then, I switched everything over from 8MM rods to 10MM rods. So currently I have a cube frame 400MM tall and 350MM wide with a horizontal X axis fully using 10MM linear rods on every axis. The reason I wen't with a horizontal x axis vs a vertical one, was because I thought it would eliminate any horizontal backlash like it did on my old crappy prusa i3. But after thinking it over for a while I realized if there was any backlash on the x axis, it would allow the carriage to move side to side. On a vertical x axis, the weight of the carriage would pin the rods as far as the backlash can go inside the bearings. Making no printing backlash at all unless you manually wiggled the carriage up and down. With all that out of the way, My question is: Which is better for stability and print quality? Horizontal X axis with 2 rods on either side of each leadscrew? Or Vertical Axis with only one rod on each side because the weight is evenly centered? I don't actually have the printer yet, but i'm designing it in Inventor before printing and buying the parts. Click the post near the top of the page to see the progress so far. https://reprap.org/forum/read.php?1,734352,734352#msg-734352 Thu, 10 Sep 2026 16:03:30 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,734352,737536#msg-737536 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,737536#msg-737536
I use 8mm for x axis, but with 10mm i wouldn't worry too much about flexing. Certainly not when you go bowden like me.]]> Govahnator General Tue, 10 Jan 2017 20:44:23 -0500 https://reprap.org/forum/read.php?1,734352,734637#msg-734637 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734637#msg-734637 the_digital_dentist General Sun, 01 Jan 2017 09:30:04 -0500 https://reprap.org/forum/read.php?1,734352,734631#msg-734631 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734631#msg-734631

Quote
o_lampe
Then I'd go for vertical:
1) two vertical rods less
2) less chance of binding between the vertical rods
3) no need to design new X-corners and carrier parts, it's all there. ( except changes for bigger rods )

I suspect 1 and 2 were the reasoning behind that layout in the Prusa i3 - reduced costs and simpler/more forgiving construction. I must admit though that when I saw zastin's design with the horizontal X rods and the doubled Z smooth rods it did feel very promising to me. Yes, it's more expensive, but a Z module which holds the three components securely at both ends and keeps things parallel is what I would do if I was rebuilding my Prusa-like design. I'd replace the steppers in zastin's drawing with bearing blocks and 40T gears for single motor belt drive, but otherwise it looks 'right' to me. And the horizontal X axis fits very naturally onto that layout and offers the possibility of a carriage with the nozzle projecting between the two rails with relatively small Z projection. It would be as close to an optimal layout as possible I think, at least from a rigidity perspective while using smooth rods as opposed to linear guides.

It's a shame that 8mm supported rods don't seem to be readily available. The vertical X rod layout could be made much more rigid if just one of them was supported and mounted to a piece of aluminum angle.]]> JamesK General Sun, 01 Jan 2017 09:07:19 -0500 https://reprap.org/forum/read.php?1,734352,734589#msg-734589 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734589#msg-734589 1) two vertical rods less
2) less chance of binding between the vertical rods
3) no need to design new X-corners and carrier parts, it's all there. ( except changes for bigger rods )]]> o_lampe General Sun, 01 Jan 2017 06:03:49 -0500 https://reprap.org/forum/read.php?1,734352,734535#msg-734535 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734535#msg-734535 JamesK General Sat, 31 Dec 2016 18:26:49 -0500 https://reprap.org/forum/read.php?1,734352,734532#msg-734532 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734532#msg-734532
Vertical x axis like a prusa i3, or horizontal like a Mendel?]]> zastin17 General Sat, 31 Dec 2016 17:33:26 -0500 https://reprap.org/forum/read.php?1,734352,734516#msg-734516 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734516#msg-734516 etfrench General Sat, 31 Dec 2016 15:32:32 -0500 https://reprap.org/forum/read.php?1,734352,734435#msg-734435 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734435#msg-734435 The cost for good linear bearings and quality 10mm rods equals the cost for mgn12 linear guides. I also ordered 400 steel balls in Germany and replaced them in my rails. (tu)
Sorry DD, I know your opinion about them, but sourcing for used ( and matching ) linear rails is no option for impatient guys like me.]]> o_lampe General Sat, 31 Dec 2016 09:45:58 -0500 https://reprap.org/forum/read.php?1,734352,734389#msg-734389 Re: Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734389#msg-734389 the_digital_dentist General Sat, 31 Dec 2016 07:29:46 -0500 https://reprap.org/forum/read.php?1,734352,734352#msg-734352 Vertical Vs Horizontal X axis? https://reprap.org/forum/read.php?1,734352,734352#msg-734352 forums.reprap.org]

I am working on changing the frame to a more cube shape and eliminating the need for 4 extra extrusions.

Anyway, When I just started designing the printer I had 2 8MM horizontal rods spaced 70MM apart. The problem with that is the weight is not evenly distributed on the leadscrews on either side and the one Z axis linear rod. So I simply put one more rod on the other side of the leadscrew to give the z axis a total of 4 linear rods. Since then, I switched everything over from 8MM rods to 10MM rods. So currently I have a cube frame 400MM tall and 350MM wide with a horizontal X axis fully using 10MM linear rods on every axis. The reason I wen't with a horizontal x axis vs a vertical one, was because I thought it would eliminate any horizontal backlash like it did on my old crappy prusa i3. But after thinking it over for a while I realized if there was any backlash on the x axis, it would allow the carriage to move side to side. On a vertical x axis, the weight of the carriage would pin the rods as far as the backlash can go inside the bearings. Making no printing backlash at all unless you manually wiggled the carriage up and down. With all that out of the way, My question is: Which is better for stability and print quality?

Horizontal X axis with 2 rods on either side of each leadscrew? Or

Vertical Axis with only one rod on each side because the weight is evenly centered?

I don't actually have the printer yet, but i'm designing it in Inventor before printing and buying the parts. Click the post near the top of the page to see the progress so far.]]> zastin17 General Sat, 31 Dec 2016 04:42:40 -0500