[KTP]

This is rev #3 of my starts on building a small benchtop mill. I am 99.9% sure I will be going with this design as we are moving and lose the Shizuoka cnc bedmill I have in the garage. This mill will mount on the workbench in the garage pod of the custom RV we have been building the past few years (a main reason I have not been active on cnc zone).

Quite a few years back I did some posts on Adept robot slides and my thoughts on how to make them into a milling machine. I ran some rigidity tests and found they had above 60,000 pounds/inch rigidity for the H series (which I am using for the X and Z). I am using the M series for the Y, which moves up and down on the Z axis but has the least amount of moments. The H series are constructed inside with dual NSK linear square rails with four carriages and a ground ballscrew with a 10mm pitch. All of the slides are driven by 4 pole 300 watt brushless Tamagawa servomotor. These require sinusoidal drive or they run very rough.

The machine will likely rapid at above 1200IPM and has travels of 50cm in X, 35cm in Y, and 30cm in Z (roughly 20" x, 14" Y, and 12" Z). I milled a mounting plate for a Taig ER16 spindle which I am driving via toothed gear belt by a 400 watt brushless servomotor with a max speed of around 10,000 RPM. I made the plate semi generic so other spindle options can be tested.

I plan on driving the axis motors with EN-204 or EN-208 sinusoidal drives as I have a ton of them on hand. I am going to start with a Kflop and just use step direction (the drives take that as well as analog +/-10V). I may move to a Kflop + Kanalog after I proof the mill design with some test cuts.

I mounted the Z axis to a base plate of 1.5" thick MIC6 aluminum plate and this plate also holds the X axis. The vertical supports of the Z axis are 1" plate with a 1" thick gusset. Some quick checks with a dial indicator in the Taig spindle and referencing the X axis table surface (also 1" thick MIC6 plate) show no measurable deflection at the mid point of Y travel with 10 pounds of force on the end of the Y axis. This is quite encouraging although until a test cut can be performed I really have no solid proof that this design will make acceptable (light) cuts in aluminum.

It is probably going to be a few days of wiring before I have it up and running, but the mechanicals are done. Here are a few pics and also I tossed in a pic of our homebuilt RV which will eventually be the home of this mill when we are on the road.

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[dharmic]

Interesting. One of the things that pushed me into the CNC arena was looking for something to replace mill, lathe, drill press and grinder that take up half my workshop at the moment with something that would fit in the workstation of a liveaboard yacht.

You've gotten one heck of a lot closer than I have so far!

[KTP]

Oh that is eventually stage two for us also! Moving from the house to the RV is stage one and then moving from RV to bluewater sailing on a 40 footer. I want to use this mill or some variation in the yacht (or at least have the ability to easily take it apart and stow it in locker on the yacht and use it when onshore). Each section is under 60 pounds and it can be assembled in about 10 minutes (alignment pins on all the plates).

This is the space in the garage pod on our RV. We built the steel bench welded into the frame of the pod so it can support a massive amount of weight. Obviously move the motorcycles when using the garage as a workshop!