Here we go again . . . MK4

[Chaz]

Hi Chaz,

Thank you. I can't tell you how relieved I am to have finally 'finished' the machine (they are never truly finished are they?) and I can spend some time with the family again. I hope it gives some ideas and inspiration to others.

Yes, the spindle is a 1.5 kW Chinese spindle and I knew it would be the next limiting factor. I have other designs in CAD for various spindle options but they will have to wait for now. It works, and I can certainly make a few hobby parts with it.

It was running at around 12,000 rpm in the film (full speed is 24,000 rpm), with a 6 mm 2 flute 45 deg cutter for aluminium, with the approximate WOC and DOC shown on screen. Feed rate varied - the heavy cuts were around 700 mm/min and the finish cuts were around 1400 mm/min. I finished the tram and final build yesterday morning, and I basically had about 20 minutes yesterday afternoon to get some cutting footage before my 'time was up' so basically went for it. Although I didn't have much time to experiment I soon found the limits. I actually broke the tips off both flutes by being so aggressive.

Much to think about and reflect on over Christmas, but first a break !

Ok, that makes sense. Go 24K, anything less has even less torque. I'd fit the largest spindle that you can in there, clearly limiting the machine. Congrats once again.

[routercnc]

OK I’ll try some other speeds / feeds next time

[Nickhofen]

I enjoy so much the build and the detailed video you upload.
Thank you so much about all the effort and the documentary!
Great machine!

[routercnc]

Thank you. There should be more videos in future but time for a break !

[Fancy]

Congratulations on a phenomenal build. What ever i write i feel i won't do you or your build justice. Love the videos and would love to see more of your projects.

[routercnc]

Congratulations on a phenomenal build. What ever i write i feel i won't do you or your build justice. Love the videos and would love to see more of your projects.

Thank you ! Feels good to have finished it - or at least get it working (already thought of a few tweaks here and there).

Something I asked about along time ago on this forum and received plenty of help on (thank you!) was getting the 24V prox signal into the 5V breakout board. In ep22 you saw the circuit that was recommended to me but I have found it a bit unreliable and actually crashed into the sensor on one occasion. So I did a bit of searching and tried a diode in the black wire from the sensor (bar pointing to sensor I think?). This works very well without any issues and gives either a solid 5V or 1V when switched. The diode I had to hand was a generic 1Nxxx type which is meant for relays (?) and such but have since bought a proper switching diode (not fitted yet) which I guess is much faster or at least more suitable. When I’m back at the PC I’ll post a diagram for the electrical guys to comment on.

[paulus.v]

..and finally making chips after a 3 year journey! Congratulations!

I would be grateful if you could measure the stiffness in the x and y directions.

What breakout board/ controller are you using? Does it have optocouplers on the inputs? I had the same problem feeding 24v signal to 5v bob. In my case the signal was fed to the optocoupler through a current limiting resistor with a value calculated for 5v input. I just had to replace the resistor with one calculated for 24v.