idea for z axis improvement

[ve3sjk]

I had tried to describe an idea earlier here are some pictures

I took the top plate of the tool holder, reversed it and placed it at the top of the axis, added a nut then the bearing then a nut then the gear.

the lm8uu are only to line things up, the smooth rods should butt into place instead, like they do on the x axis carriage so the top plate would be smooth above the rods, Won't need anything to the right of the black line

Side views, can make a raised platform section with an open slot from the back to all the stepper and gear to slip in

at the bottom its a matter of removing the gear, and moving that bearing somehow to the space below the black arrow, or it could go right through to the bottom of the x axis carriage

i think this creates a good solid frame that you could then put a z carriage in with backlash nuts like the other axis..
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[ve3sjk]

I am finished the basic build now, i have modified it slightly by using 2 more y-smooth rod holders at the back and cutting out the holders that are part of the side frames, it was pretty easy to do. I have centered the tool point at the center of the y-axis distance. Haven't put a work bed on it yet, This give me 13.5 inches of total length on the y-axis and 12 inches on the x-axis. i would say it took me approximately 25 hours to print everything and about 4 hours to lay it all out too this point. Next thing i think is to extend the y threaded rod, i didn't have a piece long enough but my thought is to bring it flush with the front y smooth rod holders.

[D-Byte]

Hi @ve3sjk i think this is what you want als a top for the z-axis. Its a fixed top in the x-carriage the nut need to be removed and there need to come a place for a radial bearing. And a new z-carriage need to be designed.

[ve3sjk]

pretty close i would have the bearings on the outside, excuse my handwriting maybe this might help you visualize it. this would be a side view from the left side, the upper bearing would have a nut on the inside to prevent it from slipping down, so it would be nut, bearing, nut

the a new z carriage would look something like this, with just a mounting plate facing the front of the machine you could incorporate backlash if you wanted not sure its needed on Z. i know i have seen backlash nuts before there as well

[D-Byte]

You are right, there is still a lot to do :-) . I think i will try work on the files around Christmas when i have a little more time. But i like the idea that the threaded rod stay in place and not move up or down.
If you have more wishes or ideas a bout the z-axis just put them here in this issue.

[ve3sjk]

thank your for working on it, i am good with the idea but bad with open scad, lol. but i am learning fast. On my machine i have offset the x axis to -180 since i have 330mm smooth rods, Its a bit more plastic and it going to need some work, i am printing this part right now, One thing i am having trouble with is where in the code is that Y-smooth rod holder that is attached to the x-frame being built. I built the machine with two extra y-smooth rod holders in the back cutting off the ones that where there, but i like the structure of this frame, i had to offset the bottom back mounting hole in the back of it, as the smooth rod holder just rendered on top of it. This puts the spindle tool tip dead center of the y axis. Still working out how to calculate the new workbed size to max out the working area.

[ve3sjk]

one other thing i have modified is i took the end stop assembly out of the standard parts file and made it standalone, added the parameters for it to the configuration files. I going to use highly VS-15 roller switches instead, this way i can modify the file for different kinds of switches. I am thinking and option in the config file to choose which one you want. Still want to get all 4 endstops on the machine, i think one can be added to the front Y frame for sure then its a matter of getting on on the right X frame.

[ve3sjk]

i noticed you created a v2.1 branch in your repo. Is that for the new version release. I am wondering how i keep my repo up to date with your changes. I forked from yours.

[D-Byte]

Yes the v2.1 branch is for the new release. Carlosgs released v2 last weekend. I think you need to create a new branch in your repo and than pull my branch in it that way you have my new branch and than you can update that again.

[joco-nz]

I like the ideas on the revised Z-Axis part. It looks to have similar concepts per the portalcyclone project? Is there value in looking at how that project does this part? From what I can see it seems to be pretty sturdy.

@ve3sjk re the the overall adjustments you are making. I was wondering what length you were using on your X and Y smooth rods? Are you experiencing any "sag" over the longer lengths or did you use 10mm or 12mm diameter rods to counter that possible issue?

[D-Byte]

Hi @joco-nz thanks for pointing out the portalcyclone. That z-carriage looks very sturdy and i think something like that will make a perfect fit for this project. I will look at it when i have some more time because it need to be configurable for rod diameter and length and bolt size and other parameters.

[joco-nz]

@D-Byte Agreed - you won't be able to just take it as it is as I think only the STL is published. So you are still going to have to code things up. However having a target shape instead of a blank sheet of paper always helps.

[ve3sjk]

@joco-nz I am using 330mm M8 rods, i don't see any sag that would cause an issue but if it becomes on i will switch to a bigger smooth rod. As a quick test i placed a temp work bed on the system centered on the y-axis. I put two old ide hard drive on it weighing 2.2 lbs. I can't measure any deflection with a micrometer with that on it.

[ve3sjk]

is the captive nut for the z axis that is held in the space on the x carriage supposed to be glued in, from what i can see if it isn't then as soon as the tool pushes down on the circuit board, the z axis threaded rod just lifts out of place at that point making downward pressure unobtainable. Maybe i missed something on assembly

[ve3sjk]

solid frame idea