CNC 3020 USB

Finally, after so much time spent in thinking, I’ve bought a Chinese CNC. I’ve choosed the model “3020T USB” from CNCEST manufacturer because it have a USB port; other cnc’s need a pc with parallel port and I have no pc with it! I’ve just a MacBook PRO with Windoze7 running on Parallels…it must work!  I’ve bought it from ebay seller “top5zoom” that shipped it from Germany via DHL for free.

The machine arrived into two big boxes. The packaging was made very well with 5cm soft plastic foam that protect and stabilize the machine into the box. The total weight of the two parcels was 35kg!!!

The machine is very noisy during operation. I’ve enclosed it in thick foam boards to reduce it.

The first thing to do after unboxing was assemble it. Just screw in 4 power supply connectors. Simple and easy. The second was check the ball screws,all 3 axes are moved on ball screw, and greas it with heavy aeronautical grease “Anderol” from US Army surplus. Probably standard grease will do the job but I’ve preferred my military grease.

Power on!

At first I’ve found that the VFD controllor had a corrupted configuration. Following the first part of this post that I’ve found on a forum, thanks to user “gmungas”, I could have it running well.

This is the VFD controller.

The post:

"I finally figured out the VFD and Mach3 software settings for my 1.5 kW, 110Vac, 400Hz Spindle with the PRT-E1500W VFD in order to run the spindle either in manual mode or with PWM control through the PC. Here's the procedure I used. (Note I didn't change the 220V setting to 110V in the VFD since there isn't a mechanism for generating higher voltage than the VFD supply and it doesn't appear to be necessary, but this should be vetted by another party (CHIMERA1960?) prior to long duration running).
 1) Reset the VFD to factory settings
 a) Set D001 to 1 (may be able to skip this step)
 b) Set D176 to 1 and press Func (this resets VFD to factory settings)
 2) Reset the VFD to 400Hz max operating frequency rather than the 50Hz default:
 a) Set D002 to 400 (need to set this before D000)
 b) Set D000 to 400
 c) Set D003 to 400
 d) Set D009 to 400 
 e) Set D021 to 400 
 f) Set D093 to 400
 3) Set VFD to receive input frequency setting for spindle throttle control from the AVI terminal:
 a) Set D031 to 1
 4) OPTIONAL but I would recommend for additional debug/safety reasons: Set VFD to allow manual spindle "stop" from terminal even when running from PC
 5) OPTIONAL: Set AVI terminal to readout spindle rpm instead of VFD frequency:
 a) Set D039 to 1
 6) To run the spindle manually with variable speed directly from the AVI terminal:
 a) Set D032 to 0
 b) Make sure switch next to AVI terminal is set to "Manually"
 b) Use AVI "Pot Dial" to set spindle rpm
 c) Use AVI "Run" to start spindle
 d) Use AVI "Stop" to stop spindle or turn down Pot Dial to 0
 7) To run the spindle from the PC (note the PWM signal from Mach3 adjusts the setting of the AVI terminal as if it were the VFD Pot. The PWM signal is NOT going directly to the spindle motor):
 a) Make sure you have the right Port/Pin settings in Mach3 (see example settings below)
 b) Set D032 to 1
 c) Make sure switch next to PRT is set to "PC"
 d) Very important: On Mach3 User Panel, make sure you select and input the max spindle speed (i.e. 24000).
 e) Select the actual spindle speed by adjusting up/down arrows or dragging the column up/down for relative speed setting changes.
 f) Use "Spindle CW F5" button or "F5" to toggle turning the spindle on/of
 Mach3 software settings that work for my spindle and wiring configuration (if you have an issue with the X,Y,Z position controller settings let me know, but I think most don't have this issue):
 A) Ports/Pins
 1) Port Setup and Axis Selection
 i) Port #1 Enabled
 ii) Kernel Speed Set to 35000 Hz (this worked for my 2.9 GHz desktop controller, but you may need to use the lower 25000 Hz setting for slower machines)
 2) Motor Outputs
 i) Spindle Enabled = Active
 ii) Spindle Step Pin# = 1
 iii) Spindle Dir Pin# = 0
 iv) Dir LowActive = Active
 v) Step Low Active = Active
 vi) Spindle Step Port = 1
 vii) Dir Port = 0
 3) Input Signals
 i) EStop Enabled = Active
 ii) EStop Port = 1
 iii) EStop Pin Number = 10
 iv) EStop Active Low = Active
 v) EStop Emulated = Inactive
 4) Output Signals
 i) Enable1 Enabled = Active
 ii) Enable1 Port# = 1
 iii) Enable1 Pin Number = 14
 iv) Enable1 Active Low = Active or Inactive
 iv) Output#1 Enabled = Active
 v) Output#1 Port# = 1
 vi) Output#1 Pin Number = 17 (this should NOT be the Motor Output Step Pin (e.g. Pin #1 in my configuration) as may be indicated in some of the user manuals)
 vii) Output#1 Active Low = Inactive (important to make sure Spindle is On when Mach3 Toggle Switch is on. May need to change this setting if switch appears to be operating backwards)
 5) Spindle Setup
 i) Select "Use Spindle Motor Output"
 ii) Select "PWM Control"
 iii) Input "PWMBase Freq." (I used 421)
 iv) Input "Minimum PWM" ( I used 0%)
 B) Pulley Selection
 i) Pulley Number 4
 ii) Min Speed = 0
 iii) Max Speed = 24000
 iv) Ratio = 1
 Good luck! Hope this helps!"

The machine comes with some accessories:

  • 4th axis with it’s accessories
  • USB cable – power chord
  • fixing screws – clamps
  • some wrenches
  • 4 flute mills
This is the 4th axis with it’s wrench

The 4th axis after an hevy greasing works well. It’s not precisely machined but it works.

Mill bits

The spindle is water cooled, included into the package there is a water pum. I’ve made this super-simple water cooling system. It’s work without any problem but is ugly!

Water cooling

I’ve tested this CNC with Mach3 software. The setup is very simple. Just download USB 4 axis 3020 and unzip it into your Mach3 main folder, typically “C:\Mach3”. Pay attention there is a licence file in it supplied by the CNC’s seller, probably is fake/illegal/cracked/cloned but is working. Buy a licence of Mach3 if you like it. The VFD uses “RnRmotion.dll plugin”. Select it if Mach3 ask you during startup wich plugin must be used for motion control. With the supplied package you obtain a correct motor/step contiguration so there is no need to change it.

More testing/video soon… stay tuned!

Hamamatsu R6095 photomultiplier tube

I’ve bought this R6095 PMT tube from iRad ebay seller. It cost me about 40$ plus shipping. iRad sells it as just tube or with socket and voltage divider kit. I’ve bought the complete kit.  A link to his auction: iRad

R6095 PMT from iRad
Minimum Wavelength 300 nm
Outside Diameter 28 mm
Peak Wavelength 420 nm
Maximum Wavelength 650 nm
Viewing Direction Head on
Rise Time 4 ns
Photocathode Material Bialkali
Window Material Borosilicate
Anode Current 0.1 mA
Typical Photocathode Luminous Sensitivity [µA/lm] 95
Photocathode Peak Radiant Sensitivity [A/W] 0.088
Gain 2.1 x 106
Max. Supply Voltage Between Anode and Cathode 1500 VDC
Max. Supply Voltage Between Anode and Last Dynode 250 VDC
Operating Temperature -80 to +50 °C

This tube could be used to make a nice scintillation probe coupling it with a 30mm diameter NaI(TI) crystal and feeding 800-900V. Yes… just 900 and you can expect a gain of 10^6. Within the box there is the datasheet of the tube plus an instruction sheet to wire the voltage divider network to the socket.

Tube plus socket and instructions

SI-19BG(M) си19бг-м mini Geiger tube

I’ve bought this cute mini Geiger tube from eBay. It’s cheap… in the order of 10-15€. The interesting thing about this tube is it’s size: 20mm lenght per 9mm diameter that makes it a good choice to make a portable dosimeter.

SI-19BG-M geiger tube

It’s sensibility is not hight but is better than SI-3BG. Another cool thing is it’s glass window. People around internet say that is a mica window for alpha particles but, I’ve testd it in contact with a piece of pechblende that, is a strong alpha+beta emitter sample and I’ve seen that it’s count rate is so small… like it ounts just beta+gamma.

SI-19BG window

Tech info:

  • Sensitivity: 1000-1500 Pulses/s/R/h
  • Plateau inclination: 0.25%/V
  • Working voltage: 360-440V
  • Maximum registering range: 900 Roentgen/hour
  • Lenght: 20mm
  • Diameter: 9.3mm
  • Weight: 4 grams

I’ve found on eBay a photo from a seller that sold it with it’s original connector… looks more an enclosure/socket than a connector.

SI-19BG connector

MST17 MCT17 Mica window Geiger tube

Searching for an alpha-sensible Geiger tube to buy, you’ll find for sure some Si8B and SBT11 pancale style tubes. This are great tubes but… if you found this MST17? It’s not a military surplus pancake tube, is from the professional series “M”. You must know that russian tubes that name starts with “M” are made for professional and scientific use. Usualy are made in glass and are fragile, they need higher voltage to operate but…. they are true scientific tools not cheap surplus!

MST17 Geiger tube

This is the MST17 tube, a professional tube used by russian in professional scientific equipment. Is cheaper than other mica windowed tubes because il hard to use. It need 1600V in order to operate. It was used to measure milk nuclear contamination after Cernobyl disaster in contamined ukrainian zones.

MST17 Front cap

The tube have a metal cap to protect the mica window and to filter out most od Alpha particles, i say “most” and not all because it have a small hole in the center. The mica window is not so thin so I think this tube is more suitable to beta and gamma use.

MST17 Mica window

I’ve found some other infos about this tube:

Tech. spec.:

  • Radiation determine: 
    1. Alpha *
    2. Beta (>0.16Mev)
    3. Gamma

*- the distance between source and mica window must be 25 mm or less (for alpha radiation only).

  • Voltage of start of counting: < 1600V
  • Operating voltage (recommended): 1620 – 1740V
  • Length of flat part of counting curve (plateau):  150 V
  • Slope of the counting curve:   < 0.05%
  • Own background:   < 0.41 counts/s
  • Maximum radiation: 10,000 counts/min
  • Load resistance: 7-10 MOhm
  • Allowable stray input capacitance: < 10 pF
  • Working temperature range: -30…+50 C
  • Anode material: Platinum
  • Mica window thickness: < 5 mg/cm2
  • Weight: ~20g
  • Dimensions: counter length 100mm, diameter 40mm
  • Mica window diameter: 20 mm.
DP100 milk dosimeter

The DP100 russian scientific instrument use the MST17, enclosed into a lead chamber to reduce background radiation, to mesure milk contamination.

CHERNOBYL ACCIDENT” there is a physical modelling and mathematical analysis of this device.

Random “Walker”

This program simulate the random motion of an object, the “walker”, that is governated by the trow of a dice. Face one? Go une pixel up. Face two? Go une pixel left, exc. I’ve implemented it first in Processing language following “The nature of code” book’s introduction. I sugest you to buy your copy if you find interesting the simulation of nature (fractals, randomness, physics simulation, exc…). Finaly I’ve made a traduction of the code for mbed compiler. Now it runs on STM32F469-Disco board because of his very nice LCD display.

This is the mbed source code: main

All the needed include files to compile it in mbed are avaiable from mbed. Just select the proper board and create an LCD demo project. Then, copy the dependencies from the demo project files to your project and copy the content of the “main” link in your project’s main.cpp. More info in my video.

If you use Keil uVision 5 compiler here the project, complete: Walker_uvision5_disco_f469ni

Here how it works in Processing.

In this video you can see the program at work and his explanation.

LYSO crystal scintillators

Hi! Some time ago I’ve bought some 4x4x22mm LYSO Crystals to make a scintillation probe or just to test they.

From the manufacture:

LYSO crystal is an ideal generation scintillator crystal. LYSO (Cerium-doped Lutetium Yttrium Orthosilicate). LYSO crystal has the advantages of high light output and density, quick decay time, excellent energy resolution and low cost. These properties make LYSO an ideal candidate for a range of ray detection applications in nuclear physics and nuclear medicine, which require higher, improved timing resolution and superior energy resolution. “

The seller on ebay is the well know: “The Rad Lab”. For 12$ I’ve received 2 crystals. They are for sure intended to use into a proton emission tomography machine “PET”. More docs from Saint Gobain:

LYSO datasheet  NextGen LYSO


The Rad Lab LYSO Crystals

Some more info about this type of crystal:


Crystals in their package

I think this crystals are from a PET machine who was scrapped… but hey, they works great! Take a look at how they react when are exposed to some UV light.

LYSO crystals under UV light

MadExp PMT adapter

“What the hell are you talking about?”. How to power a photomultiplier tube for gamma prectrometry? How to power and aquire signal of a scintillation probe? You I need some high voltage and signal conditioning circuit! Inspired by the Theremino PMT project, I’ve decided to build my own customized version of their circuit.

My project goal is to make an all-in-one photomultiplier tube power supply and audio ADC powered by a single USB cable. The high voltage generator is regulable in the range 700-1500V with a simple trimmer.

Corrent status of the project:

  • Schematic ready
  • PCB routing ready
  • First batch of PCB’s arrived from chinese manufacturer
  • Testing the HV/signal conditioning blocks

To enlarge the schematic right click on the image and select “Show Image” or download it and zoom with your image viewer.

This is the PCB board top layer

UPDATE!!! 23 November 2017 First run with PMT Hamamatsu R9420 and NaI(TI) crystal (Antrachen-russian surplus)

First test connecting the adapter to my pc soundcard. The program is Theremino MCA, is not calibrated… I need to set each control of the MCA at the right position so I need some time for setting up it.

Testing a camera lens containing thorium
Testing a natural Pichblende sample from a mine situated in northen Italy.

NE5534 RIAA amplifier

Some time ago I’ve received a Technics SL-1910 turntable from a friend. At that time mine problem was that this turntable doesn’t have integrated RIAA network and my vacuum tube stereo doesn’t have too. I needed an external RIAA active network to equalize the audio from the turntable and rise it’s volume to the 1,5Vpp needed to drive the stereo amplifier. I’ve designed a simple active RIAA network powered by a low noise op-amp NE5534 or OP27 or other pin-to-pin compatible op-amp’s. I’ve made some PCB’s for it too. I sell the PCB at 5€/each plus shipping. Contact me for more info or buy.

The PCB populated
RIAA schematic.

The simulated circuit result and the result from the real circuit measure fits very well.

Frequency response simulation
Real frequency response, please note that actually the dB loss is a dB gain. +35dB at 20Hz and 0dB at 20Khz aprox.

All resistors are 1/4W

  • All capacitors must be high-quality poliestere but I’ve used standard ceramic type without any issue
  • IC’s are mounted on DIP-8 package
  • I/O are made soldering directly coax cable from RCA sockets to the pcb
  • The circuit is powered by 2x 9V battery to minimize noise from power supply. I use a connection like this to power the circuit. Just add a double trow switch to connect/disconnect the +9V and -9V supplies.
Battery connection diagram
  • The output cap must be a 2.2uF polyestere non polarized from WIMA or high-quality equivalent.
  • The PCB that I’ve realized is 100x50mm in size, 1.6mm FR4 thick, double layer professionaly made. There are 4 mounting hole at corners. The PCB is noise free without any enclosure thanks to my  design but I sugest you to enclose it into an alluminium enclosure like this one, cheap, from
  • For I/O use only quality gold plated RCA connectors mounted on the alluminium front/real panels


Riaa_1 click here to read the BOM (bill of materials)