Converting Mini Mill to CNC

[Former Member]

Although you can't see it in the photo, the casting of the head frame didn't allow me to put anything above the pulley. Mine is running 60 pulses per rev IIRC plus the index of course. I've been able to do power tapping with that. The other day I ran it 6 RPM to ream some 3D printed PLA and not melt it while reaming.

Lot slower than mine will go. Bottom end at 20hz is about 67rpm (not tested yet, just calculated), my cover will have to be removed and a new safety shield manufactured, atleast for the front, the rest makes it easier to change pulleys when needed. ACORN recomends a rotory encoder for tapping. Alternatively a tapping mill and a run a helical program instead, and tapping head for smaller stuff (the latter which I already have).

Shows that there is more than one solution to a problem.

 

[jcdammeyer]

ACORN recomends a rotory encoder for tapping. Alternatively a tapping mill and a run a helical program instead, and tapping head for smaller stuff (the latter which I already have).

Shows that there is more than one solution to a problem.

Mine is a rotary encoder with A,B and Index. Just physically large and out in the open. But otherwise it produces the same quadrature output done with your little one. However, I'll also own up to a big mistake on mine. Look closely and you can see the slots are wider than the teeth. That's because when I finally milled the slots I installed a 4mm end mill when the drawing and G-Code was designed for a 3mm. An Oh CRAP! moment.

 

[Former Member]

Here is the updated pickup, currently within 10 rpm at 1900, at this point, move on, got to cut the cover.

Mount Servos.

 

[jcdammeyer]

Here is the updated pickup, currently within 10 rpm at 1900, at this point, move on, got to cut the cover.

Mount Servos.

Interesting approach to providing spring tension to the pressure roller. Nicely done. Do you just loosen the nut and then retighten or leave it slightly loose?

 

[Former Member]

Interesting approach to providing spring tension to the pressure roller. Nicely done. Do you just loosen the nut and then retighten or leave it slightly loose?

The spring is actually not needed, just enough tension to make contact and tighten down.

 

[Former Member]

It's alive, doing an upgrade will you need the mill is difficult. VFD is hookup complete with speed control, all three axis home and flood cooling is working. Now just have to set up first programs.

For those that don't know I'm using and ACORN CNC, CNC4PC adapter board for Clearpath SDSK servo's and a LENZE SMV VFD. For the most part, the control is fairly simple to set up, the most difficult was the VFD interface because of how LENZE does things indirect safety circuit that ACORN does not see, so two relays needed added to act as the interface so that you could power off the VFD, that way no changes needed to ACORN's system.

 

[Former Member]

The mill is a CT054 the older version of CX603. The biggest issue with this mill is tramming the head, so I will be adding a ball joint assemble to control the rotation as it is trammed.

 

[NGrimberg]

There are plenty of options present in the market, and choosing the right one takes time. As a professional CNC machining expert, I suggest you go with the TAIG 2019 CNC Micro Mill. It is one of the best small CNC mills available in the market and is cheap on the pocket. It’s a smaller machine making it easier to come to grips with the high accuracy and precision seen in costly models. It is good if you are a beginner and will serve the purpose. You can get the TAIG 2019 CNC Micro Mill on eBay.

 

[Former Member]

Looking at some spec's while the steppers may be able to do it, the lead screws won't, which is why I didn't purchase the 6400 encoded servos only the 800 count ones (at and accuracy of 0.000125 if everything is perfect on my machine...ha ha ha). While steppers are nice my the SDSK servos are rated at 200+ inch/onces @100% to 100+ inches per minute with a 50lb load on the the bed well beyond what steppers can do. The second reason I went to SDSK is they don't lose step in the event you over load them as they continue to count.