I haven’t yet cut any wood or MDF so I thought why not just jump into aluminum and cut some XZ plates? It can’t be that bad, right?
Oh, by the way, this is also the first time I’m using the Kobalt.
Well… (warning: loud)
Ultimately the workpiece shifted on me, which is what made me stop the job, but it was making what seemed to be “unhappy” noises. The M5 holes are not large enough for an M5 bolt to fit. The M3 holes are large enough for a M3 screw, but that’s not saying much since the endmill is 1/8".
The bit I was using was a random old bit that I found on my workbench. After this unsuccessful result, I decided to take a look under the microscope:
Also the workpiece was hotter than I expected, so I think a combination of spindle too fast, feed too slow, and most of all a dull endmill is the reason for the outcome. A sharp endmill may have been able to succeed with sub-optimal parameters in other areas but this endmill is toast.
Here’s what a new one from V1E straight from the box looks like:
You really need to make sure that you are getting good chip clearing when working with aluminum, otherwise the re-cutting of the chips will end up welding the aluminum to your end mill (which I’m pretty sure has happened to your used endmill, based on the photo).
Air/IPA Mist system and Trochoidal make aluminum cutting much easier IMO…
In my projects I insert a pause in g-code at the end of cutting the screw holes, put some wood screws through those holes to secure it to the spoil board, then hit Resume. No chance of the work piece shifting…
Seems to be another Z endstop issue. I might have to change the XZ plates. They work for the omron, but I might have to edit them to get the rollers to fit.
Very nice! 1/4" or 5mm Alu? If 1/4", were you tempted to recess M3 bolt heads extra ~1mm so they reach deeper into the rail blocks? Noticed V1E linear rail blocks bottom out 5mm so M3 x 12mm are too long (ignoring alternative options to use washers, or packer/shim between plate and rail block).
This is 1/4". I hadn’t considered a counterbore for the M3 screws. I think it should be okay.
As for the XMin belt slot, I will try it this way. In my head it doesn’t look that bad to thread the belt through the hole instead of inserting after the Z stub is attached.
The idea for the nub is this, which I haven’t been able to shake:
The nub can be small and still provide a reliable spot to trigger, while still allowing it to move beyond the endstop. Maybe I can compare repeatability on the shallow face and on the nub. I’m not sure yet.
Because I am building the RC in completely stock form (aside from off-sized tubing) I will go with standard XZ plates, but Im with you there. Seems to me that a layer of MDF sawdust might have a several mm effect on homing the Z axis, but I’ll give ot a.shot in stock form.
I thought I had some 1/16" 1/8" shank endmills, but I broke the one in the V1 variety pack. I bought one with a 1/4" shank though, I just need to change the collet, and I need a new spray bottle for IPA before I cut the aluminium.
Kind of tempted to just cut the XZ with a 1/8" endmill, maybe leave the belt slot for later.
That is sort of the reason for the redesign. The LR3 has a platform dust can settle on and literally throw it off. The LR4 as two 80 degree surfaces that nothing should be able to settle on.
Dust can stick even on vertical surfaces so the angle is not 100%, but I can see how a steep angle will get dramatically less. And I could see how the rubbing action would tend to clear dust so it can’t bias the measurement over the long term.
In terms of LR3 to LR4 triggers it is night and day. Obviously none are perfect, I did actually want them on the back to make them even better but not horizontal shelf seems like the right move.
