Anyone here finding they need more Z travel thana what the Foreman has? For me, with my rotary, I’m right at the edge of what’s possible. Then, with the ATC, the tool rack interferes with the dust boot unless I drop the tool rack, requiring more Z travel… or switching to a boot that moves out of the way.
If I add more Z travel, that solves both problems.
Would anyone else be interested in a Z travel upgrade?
This might help:
It’s not a clearance problem. It’s a travel problem, so those won’t help.
Hey Adam,
more travel is only possible by replacing the Z assembly, e.g. like mentioned here or here or here. I intend to do this sooner or later (Tom is faster)
I know. I’m thinking of doing this too, but by only replacing the side rails, shafts and ball screw. My hope is to keep the offset to the center of the spindle the same.
Those help me with my clearance problem. It raised everything about 3" so I have no issues clearing my rotary, even sitting flush on the waste board on a QCW frame.
I raised my Y rails to provide options for my ATC setup, and my new Z axis design does not add much more travel ( for my particular use cases it was not a goal).
I mainly wanted to experiment with a design that I felt was more rigid for use with my heavier and taller ATC spindle - it incorporates two spaced 80 mm mounts. I also plan to use it in a new machine I plan to build in the future, one where the overall rigidity matches that of the new Z assembly. I am looking forward to repeating my deflection testing to see if my design improves the cumulative rigidity of my Woodworker X50.
One strength of Onefinity’s design, and certainly appropriate for the intended router use, is that the offset to the centre of the spindle (measured from the X axis gantry block) is only 90 mm. My design increases this to ~110 mm.
Part of my problem may be that I mounted tool setter low. With the ATC, I have to either mount the tool racks so low that I causes me this problem where I have to plunge super low, or get the dust boot out of the way.
I mill mostly aluminum, and am quite happy using a chip ‘shield’ vs a vacuum dust shoe. I was able to design two models that automatically retracted the shield during tool changes - one even changed Z height in since with the endmill. I believe my new Z assembly design will give me more options for a vacuum dust show, but the challenge of clearing pull studs etc during tool changes will still need a bit of creative thought:nerd_face:
Yours looks very interesting, both models.
Thank you. I enjoy the design and mechanical/engineering side of problem solving as much as I enjoy making things - keeps my brain busy 
I am just finishing the machining of the top plate of the assembly, and should have it together in the next day or two. Attaching it to the X gantry will take longer as I am also making top and bottom plates to hold and secure the - very heavy- new Z axis. I am really curious to see how much the Y rails deflect with the increased mass. It may mean I can’t use this new design on my current Woodworker.
What do you consider acceptable deflection?
The easy answer is as little as possible 
I get antsy when my parts are off by many hundredths of a mm, which I know given the linear motion components used by Onefinity is unrealistic. Still, I enjoy the challenge of getting much better than +/- 0.127 mm standard machining tolerances. Right or wrong, it is how I like to work and it makes me happy
In my past posts sharing my deflection testing I have always said that I am not naïve about what a machine like this is/could/should be capable of. However, I enjoy chasing zeroes after decimal places, and try my best to get the most accurate and repeatable machining results I can, particularly with aluminum. Working within the machine’s limitations just means I need to be smart about toolpaths and machining parameters, as well as end mill selection and effective work holding.
I recently measured 80 micron Y rail deflection when my X axis gantry moved from home position to halfway through the Y travel. If my new z assembly causes a lot of deflection I will not use it, or move my work holding used for critical parts close to the front nearer the Y axis blocks.
The deflection testing I shared a while ago in the forum was based on a maximum applied force of 50N. Some of the machining calculators I have show that the tool deflection under typical cutting forces for the endmills/toolpaths I use is well within the acceptable range. So to your original question - deflection is acceptable if I can manage its impact on the quality of my machined parts
Hey Adam,
when this question is raised, I always have to think of the deflection test shown here. If the deflection shown here is smaller than the diameter of a red blood cell, you can sleep soundly after building such a machine - goal achieved (however, this machine is very different from the Onefinity machine).
But he is measuring at the spindle mount, so this does not take into account the spindle bearing and tool holder play, and the bit deflection. Total deflection, measured at the end of the bit, can be much greater, and also depends on the force with which you drive the bit through the material and which way. I think I would want to measure the deflection at the end of the bit, but that is difficult.
I would want to measure the deflection under realistic load conditions (while the machine is milling something). In the end, you want to achieve a certain dimensional accuracy of your workpieces, and that’s what counts (and what you can easily measure with a caliper on the finished workpiece)
Do you have a picture of your dust boot?
This is actually my dust boot installed on my machine: Big Suck Dust Boot – Ugly Dog Woodshop
I really like long dust shoe brushes, they are available in 70 and 100 mm length.
I was wondering If those could help with the clearance between the dust shoe and the ATC in your case?
I designed and printed my own dust shoe. Not very elegant but functional.
The Big Suck is my own design also. I find that 2" and longer brushes don’t work well as they get sucked into the bit and can flip upward to block the air flow. 1.5" - 1.75" seems like the longest I can get away with.
This is an example of a company in the hobby CNC router market - with a new machine coming out - that publishes their own deflection data (something they and myself would like to see more of). The video is interesting, with the deflection discussion at about the 17 minute mark in the following video…
Comparing their data to mine, it looks to be 2-3X more rigid (cumulative deflection at the endmill).
