Well nerdegutta asked for it so I figured I should post something. I purchased one of those cheap CNC 3020 routers on eBay for milling PCBs.

I have yet to mill anything as I am having issues with the X Axis and I think it is a Mackh 3 software related or I have a bad parallel port as I am not seeing any transitions with my scope on the output pins for the x axis but I am seeing it on the y axis

Overall I am very satisfied with the quality of the product. The frame is very solid and sturdy. X, Y and Z motors seem to be adequate for the job. The spindle motor seems a bit whimpy though. All cables are encased in some nice cable protectors.

All axis move on screws with smooth operation.

I modded mine a bit with a spoils board and a nifty dust extractor that I found on line.

Some pics are posted below.

 

Nice
Wait I remember fixing one of those.
There is a thread somewhere with pictures

 

All.that for $500? Seems pretty substantial. I was guessing it would be simple threaded rod instead of (what appears to be) ball screws.

Have you cut anything yet? Looks pretty clean so far.

 

Thank you, @spinnaker, that's what I'm talking about.

What is the minimum size the chuck on the spindle can handle?

 

Be interesting if it has the rigidity to mill aluminum and max tool dia?
Max.

 

All.that for $500? Seems pretty substantial. I was guessing it would be simple threaded rod instead of (what appears to be) ball screws.

Have you cut anything yet? Looks pretty clean so far.

More like ACME screws.

John

 

Thank you, @spinnaker, that's what I'm talking about.

What is the minimum size the chuck on the spindle can handle?

It is a collet. Pretty small, Dremel size and looks like it can't be swaped out. Without getting the whole assembly. The collet cannot be separated from the threaded collar like on a Dremel.

 

Be interesting if it has the rigidity to mill aluminum and max tool dia?
Max.

Some people have done very light aluminum but most don't recommend it without a spindle upgrade.


Is there anything in Mach 3 that would keep my x axis from working? I have my x step configured for pin 2. Pin 3 is my direction pin on my PC's parrallel port. When I press x axis in Mach 3 I see no transitions on pins 2 and 3. They are always low. The y axis pins work fine.

I was about to try an LPT Testing software to see if it is a bad port.

 

I guess you must have fooled Santa.

 

I guess you must have fooled Santa.

Nope I was a REALLY good boy this year.



Got the x axis working now! The next thing to do is to mill a flat surface in my spoils board.

 

The collet cannot be separated from the threaded collar like on a Dremel.

Thats an ER collet. The collet itself should come out. Most of them have a flat on one side of the collet and a corresponding flat in the nut. turn the collet until the flats line up and pull out the collet. Each size of ER ccollet holder has a range of collet sizes that fit, yours is an ER-11.

Just a random page - https://www.maritool.com/Collets-ER-Collets-ER11-Collets/c21_56_60/index.html

While the lead thread looks like an Acme, if it is metric it is called a Trapezoidal thread -
http://www.engineersedge.com/hardware/iso-metric-trapezoidal-threads1.htm

 

Thats an ER collet. The collet itself should come out. Most of them have a flat on one side of the collet and a corresponding flat in the nut. turn the collet until the flats line up and pull out the collet. Each size of ER ccollet holder has a range of collet sizes that fit, yours is an ER-11.

Just a random page - https://www.maritool.com/Collets-ER-Collets-ER11-Collets/c21_56_60/index.html

While the lead thread looks like an Acme, if it is metric it is called a Trapezoidal thread -
http://www.engineersedge.com/hardware/iso-metric-trapezoidal-threads1.htm

I am not seeing anything flat. I saw another article about diamonds that you need to line up. Not seeing that either. I really can't see anything usual other than little indents on every fin of the collet on the outside facing side but I see nothing corresponding in the nut.

 

Some of the less expensive one in the smaller sizes just "snap" in and out. We only used the expensive ones at work. Never saw one that used a nut for each collet though. The flat wouldn't show on a collet that's in the nut. It allows a internal rib in the nut to go in the groove under the nose angle of the collet, to pull it out of the taper when changing tools. Thumb pressure will pop the snap type out.

 

Thumb pressure will pop the snap type out.

You have never seen the size of my thumbs. No way can I get a thumb in there. I did try a pe. Pressing hard. Nothing. Does it need to be lined up somehow first?

I can't see a flat spot in the nut either. Other than on the outside.

 

Try this site - http://www.precisebits.com/tutorials/er_collet_system.asp

 

I did it. Those instructions worked great! It took a little while but I guess it requires practice. and my problem is my fingers are so big it is hard to grab small stuff.



Thanks.

 

Is there anything in Mach 3 that would keep my x axis from working? I have my x step configured for pin 2. Pin 3 is my direction pin on my PC's parrallel port. When I press x axis in Mach 3 I see no transitions on pins 2 and 3. They are always low. The y axis pins work fine.

.

Did you try another pin combo?
Max.

 

See above. Got it to work. Thanks.

 

All.that for $500? Seems pretty substantial. I was guessing it would be simple threaded rod instead of (what appears to be) ball screws.

Have you cut anything yet? Looks pretty clean so far.

They look rather like acme screws to me. At least the vertical one.

 

Be interesting if it has the rigidity to mill aluminum and max tool dia?
Max.

Hi Max, her the spec's
very nice machine for that price.
Maximum Dia mill depends on speed x,y and z plus stability system
My machine 8mm mill alu Z1,5 mm 2 cutter/ 8000 rpm feeding (x/y) 20 mtr per minute need 2KW. weight machine 600Kg Approx.
max mill dia for 2kw machine is about 12mm. accuracy 0.01
The other one deckel fp42nc 100mm mill z=20mm 15KW and a machine weight of 3500 kg approx. accuracy 0.001 with enhancement.

The 3020 is build to engrave and work with small mills <=3mm bigger ones will destroy this beautiful machine.
I think that cnc 3020 does alu milling @ 2-3mm maximum diameter @ low feeding(x,y) and Z 0.3 at the time.
spec's
X, Y, Z Guide: Rolling ball screw

• X, Y, Z Work Area: 230 x 320 x 55 (mm)

• Drive type : Stepper motor

• Spindle : 800W high speed (air cooling)

• Max Speed : 4000 mm/ min

• Resolution : ¨Q 0.0 5 mm

• Repeatability : ¨Q 0.0 5 mm

• Interface : Ncstudio / Mach 3; DSP handle (read USB memory directly) optional

• Command code : HPGL, G-code

• Spindle tools: §æ 3.175, §æ 6

• Power : AC110V, AC220V ¡À 10% / 50~60Hz

• Machine dimension(mm) : 550*650*550

• Packing dimension (mm): 700*700*680

• Net weight: 38kg(including controller box)

• Warranty : 12 Months (6 months for Spindle)