[Zvonkorp]

Sorry for the double post, the other thread was in a section that hardly sees any kind of activity relative to this one, and this question is really more appropriate for this section anyway so if mods could delete the other thread I'd be grateful

So.....

Here's where I am so far


25mm SSR THK rails/trucks for the Y axis (back/forth) - 640mm
15mm NSK rails/trucks for the X axis (left right, gantry, carrying the z) 880mm
20mm NSK rails/trucks for the Z axis 300mm


Dual ballscrews moving the gantry Back & forth, another one sliding the z axis assembly left & right and another moving two rails via fixed bearings for the z axis up/down'




Here's where I'm stuck. I originally was going to use a 50x100mm beam from misumi with surface machining for the 15mm nsk rails to attach to - but ended up coming into a much larger extrusion from 8020 for a good deal that i'm debating using instead, a 40series 8016/ 80mmx160mm cross section. This one hasnt been machined flat,and I don't have the option of doing so. It appears to be reasonably straight judging by how it sits on top of the 50x100 misumi,but i'm not sure if this single profile would be just too obnoxiously large or heavy for this gantry. Myconcern with the misumi 50x100 is also the profile spacing -even at their extremes, if mounted on the very top and bottom of the 50x100 extrusion, center to center distance between the rails is still around 90mm or so. Feels like that's just too short.


I'll be moving the gantry with nema23 motors & a g540 - i have no doubt in my mind the motors will drive either of these gantries just fine,but I feel like I could do better with the 80x160mm extrusion over the 50x100, even without surfacing it completely flat.




Attached are pictures of my machine as it stands - the beams in question will be attached in between the gantry uprights, which are composed of 2"x4" 10 series extrusion mounted upright to a half inch thick plate of aluminum that i used my hobby router to cut & drill holes into. I threaded studs into the THK trucks and through the half inch aluminum plate to fasten it to the trucks, and from underneath counterbored holes to allow shcs to secure the 2040 extrusion upright to the plate while staying flush and not interfering or contacting any of the trucks below.


See attached images.




Which profile would you guys recommend using - my goal is to just ultimately mill aluminum - hope that's not too unrealistic here.[/QUOTE]

[xrdcarbon]

do what you want do