CNC 3020T

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CNC 3020T

Postby Andrej » 09 Mar 2012, 21:02

I got one of those cheap Chinese CNC machines, model 3020T.
Connecting it to controller was easy. Adapter with DB25 (female) has correct pinout and I just plugged it in.
I set StepsPerUnit setting to 800 and it was ready to use.
Spindle seems little week. For my tests it will be alright but something more powerful would be better.
Now I need to mount limit switches and sensors.
3020T.jpg
3020T.jpg (30.77 KiB) Viewed 19455 times
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Re: CNC 3020T

Postby Kristof » 09 Mar 2012, 21:06

I was thinking about getting that one but it sounds too weak to use it in aluminum
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Re: CNC 3020T

Postby Andrej » 09 Mar 2012, 21:27

Spindle is too week. Mechanicaly machine is not so week and might occasionally cut some aluminium.
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Re: CNC 3020T

Postby Kristof » 09 Mar 2012, 21:47

I have seen a guy who make the spindle himself and was able to cut 3/8" thk aluminum on that machine
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Re: CNC 3020T

Postby Jorn Deruyck » 11 Mar 2012, 10:18

I have the bigger version of this machine

the CNC6040

First thing i did was replace the controller (Parallel port) to the Mk2 controller of Andrej.
The stepper drives that come with this machine aren't verry good as well, i already had one of which the 5V supply failed.

They fitted a linear regulator that down converted the 24V directly into 5V. Those regulators are not designed to dissipate such voltage drops. So i replaced the regulator with a switching regulator. I'm planning on redesigning the whole control electronics into one integrated solution that contains 4 stepper drivers capable of handling 5A and the Mk2's PIC Controller.

There where some other small issues.
The cable chains where not big enough to fit all cables / hoses (i have a water cooled spindle) so i had to replace those as well
1 hose fitting of the spindle was broken when it arrived, and they seem like bad quality, to brittle!
There are also 2 plates of steel to cover the X axis ball bearing spindle, those where rusty. They should have at least painted those.

I use the machine to mill Aluminium on a regular basis, and it does a nice job.
One thing i noticed tho, is that you should not generate helical paths for holes. Helical paths use all 3 axis at the same time, and the power supply (10A) is not capable of generating enough current, so you miss some steps! which is off course devastating for the accuracy!

Another thing i noticed, is that when you move the Z axis down to Drill/Mill into the material, the entire X/Z axis assembly rotates around the x axis a bit. I feel that it is lacking rigidity on that side.

All things said and done, its still a decent machine for the price that you pay!
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Re: CNC 3020T

Postby NickE » 05 May 2012, 17:25

I bought also one 2 weeks ago. At 1st sight it looks like really good quality but now I'm really disappointed. I did not use it 5-6 days and now it is hard to move Y axis. I tried to turn the stepper by hand, its hard.

It is made of plastic: http://dl.dropbox.com/u/67125876/x/cnc2.jpg
Horrible. :cry:
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Re: CNC 3020T

Postby Andrej » 05 May 2012, 19:19

Plastic nut might be better than brass one. If it is plastic then this does not mean it is bad.
Did you solve problem and how?
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Re: CNC 3020T

Postby NickE » 05 May 2012, 19:38

I disassembled it, yes, its plastic and now I'm sure the problem is with this part.
http://dl.dropbox.com/u/67125876/x/cnc3.jpg

No, I did not solved yet. Any idea? 1st I will try lubrication with oil. Hope that will help.
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Re: CNC 3020T

Postby Andrej » 05 May 2012, 20:00

I used plastic nuts in my first router that I build.
http://www.igus.com/wpck/default.aspx?pagename=drylin_trapezgewindemutter
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Re: CNC 3020T

Postby m_thread » 06 May 2012, 06:51

I also have a CNC6040 and I think it is ok quality wise if you replace everything but the bare mechanics.

As of now I have replaced all cabling for the steppers and the spindle. Replaced the water hoses for the spindle cooling. Replaced the chinese 'controller-box' with a Mk2/4 card and stepper drivers from Andrej.
I have mounted limit switches and tool length switches (x2, fixed and moveable). All cables are of very good quality (Lapp-Ölflex) and are shielded.
I am thinking of changing the cable chains to some with a larger capacity since the cables does not quite fit.

I am using one of Andrejs output-cards to control the VFD controlling the spindle and spindle cooling pump. The spindle rotation direction and rpm can now be controlled by code. My cooling pump is controlled by using the 'third' output relay on the output-card as a slave to the relay used to control spindle on/off.

Everything is put in a new 19" chassis with XLR connectors for all cables. I have integrated the china VFD in this chassis and it works great.

Some day I will try to find the time to put up som pictures if any of you are interested.

If I were to get a new mill today I would not buy a CNC6040. It becomes very expensive in the end before you get what you want.
If you got the electrical and mechanical skill and some spare time I would recommend a scratch build.

/Fredrik
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Re: CNC 3020T

Postby NickE » 06 May 2012, 15:40

Ok, now it works fine. I cleaned and lubricated it. The trapezoid screw was a little bit oxidized. I did not expected this after 2 weeks and a very few use.
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Re: CNC 3020T

Postby NickE » 22 May 2012, 15:10

I have the 3020T model and I use the chinese "Mini-CNC Controller". I'm unsure what are the correct setting in Mach3 at Motor Tuning.

The chinese user manual wrote:
Steps per: 400
Velocity: 2000
Acceleration: 200
G's: 0.0203952
Step pulse: 10
Dir pulse: 3

I think these settings are incorrect. When I enter G0 X100 then it moves 50mm. I changed motor tuning values to make it good, but I think I overrided some limits.
It would be nice if an experienced user could write me the correct settings.
Thanks in advance.
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Re: CNC 3020T

Postby skillalot » 23 May 2012, 06:44

Change steps per unit from 400 to 200!

After you did that, and you see that your machine works correct, go to your C:\program files\ folder, and delete the whole MACH3 folder, and order a cnc-usb MK2 controller at www.planet-cnc.com :mrgreen:
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Re: CNC 3020T

Postby ramiro721 » 06 Jul 2012, 02:59

I just got one of this cnc machines. I installed Mach3 and followed every step. I can not get the damn thing to work at all. Any idea what could it be? I'm trying to running on windows vista could this be the problem? I'm not sure if my pc is recognizing the controller. Any good step by step instructions out there to double check I did everything right?
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Re: CNC 3020T

Postby skillalot » 08 Jul 2012, 15:10

mach3 will not work with planet-cnc.

If you have a planet cnc-usb controller card then download the software from www.planet-cnc.com.

If you only have mach3, GOOD LUCK :lol:
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Re: CNC 3020T

Postby mj9999 » 25 Sep 2012, 15:16

Can anyone here tell me which replacement stepper motor I can get for this machine? One already went out.
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Re: CNC 3020T

Postby kgravlin » 18 Jan 2013, 22:46

Purchased a CNC3020. Don't really mind it's cheap as it gives me a working base for moving forward. I can design or create new hardware/firmware for anything with time but wondering how anyone was doing anything with this machine as both CDs install almost completely non-english versions of everything it seems to come with. There is almost no english on even buttons in the install that have more than question marks on them. Is there a simple set of software I can begin with just to get the equipment going? Thank you anyone!
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