Friday, February 29, 2008

The pendant is finally done... yahooooo

Finally complete the pendant as it was originally planned. All toooo happy with the outcome. The front label was printed on regular paper using a color laser printer. It was later laminated (top side only) using a lamination machine. The LED holes were punched using the cheap single hole paper puncher... just perfect for the LED holes... The button holes were cut using a circle cutter... the cutter had a minimum hole size of 10mm... slightly bigger than the button but, in the end, it gave a better look to the unit... 3M adhesive spray hold everything flat and permanent... the sides and bottom are covered with black velvet (left over from previous project)... it gave a matte finish and provide good feel when you're holding the pendant...

It is during this kind of moment, I pat myself for being tools collector... I have very strong tendency to buy tools even though I might use it once a year! The hole puncher, the circle cutter and the laminating machine make the whole process very enjoyable...

%^$#%%^$%:-(*:-(*... just realized that the X-Axis LED is wrongly labeled as Z-Axis... arrggghhh... dang....
I'm just gonna leave it as it is... I designed the unit, I know where X-axis led is anyway....

Thursday, February 28, 2008

New casing for the pendant

Here's what got done last night... I milled the bottom half from a solid plastic piece (not sure what type of plastic it is) and then milled the top cover plate. Having a CNC mill make the whole process effortless... Decided not to engrave the legend for the buttons as this is a test unit anyway... will probably paste a full size label later on once I decided what the buttons should do...
Should have use a taller switches, it will give enough 'headroom' to enclose the PIC inside the casing... Nonetheless, it is a beauty in disguise, having the 'open' cover for the PIC will allow me to take it out for reprogramming if I need to fine tune the pendant as the two halves of the casing is permanently glued...
My current thinking on the label and buttons functional mapping...Link to CNCZone thread on this pendant is here... Some more details and discussion there...

Wednesday, February 27, 2008

Update on Pendant Build...

27th February Update:
Finished coding the controller and fine tuning last night. Wired it up to the parallel port and it worked well. The indicators are in sync with Mach3 settings (for selected axis and MPG modes). Now, I don't have to look at the screen to know which axis is selected (X, Y, Z) or what MPG mode I'm using (X1, X10, X100, continuous)... a real time saver...

Will be working on the casing tonight...

Tuesday, February 26, 2008

Mach3 Pendant... Work in Progress

Just a quick update on the progress of the new pendant for Mach3 that I am working on. The PCB has been completed and populated as shown on the right. The empty socket is meant to hold the PIC microcontroller to manage the quadrature signals to the parallel port. This pendant requires a total of 13 input/output so a second parallel port will be totally used up.

I am currently coding the microcontroller codes and it should be completed before this week ends. After full functional test, I'll decide on suitable casing for the unit... probably another acrylic based enclosure...

4 buttons are reserved for Axis+, Axis-, AxisSelect and JogMode... The rest of the other buttons can be mapped to other functions in Mach3...

Friday, February 22, 2008

New Casing for Webcam & New Clamp

After initial trial with the webcam for visual workpiece positioning and referencing, I decided to make more robust casing for the webcam. Made out of aluminum with a steel 6mm shaft, the casing is very rigid and robust. Unfortunately, as a result of perfect workmanship, the shortfall of the webcam became evident... It turns out that the sensor on the camera is not perfectly centered along the lense. After assembly, there is a fixed offset of 1mm on x-axis and 0.5mm on y-axis... I could just enter the offset in Mach3 but being the lazy person I am, I wanted the camera to center exactly on target... After tilting the front cover slightly, the camera is now tracking as it is supposed to...

I also make additional clamp for the Sherline. Fabricated by a machine shop, the clamp is made from steel thus it is very rigid (compared to the Sherline clamp which is aluminum). All too happy here both with the functionality and quality of workmanship.
The webcam and clamp side-by-side with the Sherline clamp shown for reference. What a beautiful picture... (for those who know how to appreciate it...)

Wednesday, February 20, 2008

Amateur Radio Foxhunting Revisited...

After a long silence about this topic, some brave souls would like to restart this activity. I'm glad to be of help... below are some of the links I've gathered before relating to foxhunting... Photos courtesy and credit to the originating sites...

International Amateur Radio Union Region 3 Site detailing various rules and guidelines for Foxhunt competition...

PIC-Based PLC for Machine Monitoring...

After months of working of hobby that spend money, I needed a way to get involved in hobby that generate money... After short discussion with 9W2DTR, I quickly design and built the following circuit in hope it will generate some money for my hobby spending... It's basically a simple analog voltage monitoring device... It compare 2 different analog inputs against 2 different setpoints and triggers the output accordingly... The LCD, button and a simple potentiometer is there to allow for setpoint setting and input monitoring. It's already functional, just waiting for delivery of the suitable chip for the controller from RS Electronics... While the PIC16F716 has a lot of features, it is lacking EEPROM data storage... needed for setpoint storage... Overall board size is 4.0" x 4.5"...

Thursday, February 14, 2008

Webcam on Sherline and Mach3

I received the webcam I ordered yesterday afternoon.

After removal of a few screws and a quick cut with a cutter, the NEW webcam was butchered to what remains as shown in photo below...

The same webcam on the Sherline for size comparison...

Mounted on the chuck... The shank of the webcam pillar is 5mm...

A close up photo of the webcam mounted on the high speed spindle... After a quick alignment, a drop of superglue fixes the plastic ball to the webcam casing...

A screen capture showing the video using Mach3 video overlay... I didn't do a screen capture of the CenterCam image which was better and had more options...

Overall, I'm very happy with the webcam... picture quality is very good, exposure adjustment is perfect even in minimal lighting condition... Possibly want to make better housing for the webcam to ensure perfect alignment everytime it is used... or abuse...

Monday, February 11, 2008

In the pipeline...

I've been busy thinking what to do next... As those who knows me, I enjoy designing and making things but not necessarily use them... I just enjoy learning...

Here's what to expect in the next few weeks...

  • I just came across this site on using webcam for workpiece referencing and planning to use it for my Sherline. After looking at ways and means to stick home switches to Sherline, I figure this is an easier alternative. Found webcam below at the local auction site and it seems a perfect fit... Ordered mine and I will update later on results...
  • I also got hold of a bunch of new PIC16F716 from Farnel recently. Buying them in bulk (25pcs) result in per unit price of slightly above RM4... cheaper than Pasar Road PIC16F84! So from now on, most of my PIC-based project will be based on this chip... The chip has 2k, 4 8bit ADC, 4 CCP/PWM, 2 8bit timers and 1 16 bit timer. The first project will be a Mach3 pendant (yes... another one... no encoder required... no driver required... just a lot of switches...)

Monday, February 4, 2008

DIY MPG for Mach3 (Part 2.. cont)

Just more photos...

The wiring harness from a different angle...

The flip side of the DB25 wiring and solderings...
Side view of the completed pendant... clear acrylic was roughen using scouring pad to give it a smoked appearance... colors of wires are still visible to facilitate configuration in Mach3... :-)
The pendant next to the Sherline is gonna control... the mess is from cutting the acrylic for the housing... ;-) The buttons are currently configured as follows (for Mach3):
1. Axis Select Toggle (X, Y, Z)
2. MPG Mode (Velocity, Step Velocity, Single Step, Multiple Steps)
3. Step Size (1.0, 0.1, 0.01, etc)
4. Yet to be configured... not used now...

Several people asked me for the wiring diagram so I put it here for reference. In my case, I used 2nd parallel port for the connections to the PC. Mach3 allows pin2 to pin9 of the 2nd parallel port to be configured as input. Individual wiring may need to be revised based on your setup. On the wiring diagram, the encoder is 'viewed from top', same orientation as originally mounted on the mouse PCB... the original center wheel would be to the right... The red wires are +5V coming from the USB and the purple wires are ground connections...


BTW, there is a post in CNCZone on this build... link is here

DIY MPG for Mach3 (Part 2)

This is how the encoder was mounted. I wanted a single handed pendant so the wheel is located at the top of the pendant so that I could turn it with my thumb. Made from acrylic, works fine but it doesn't freewheel well... May be I'll make an aluminum wheel later... The original wheel from the encoder was 'captured' between the acrylic so that the axial forces are not passed to the fragile encoder... The buttons are normal push-on switches... to be hardwired to the parallel port with pull up resitors for OEM triggers in Mach 3... Photo showing the individual wiring to the encoder and the buttons... Wires taken from regular network cable... 8-core, non-shielded... The daisy chain is for the ground...
Tested as sealed... the pendant is 30mm x 30mm x 120mm... comfortably designed to fit into my palm... :-)
The wiring harness at the DB25... the red and black wires are power taken from USB port... no external power supply required... also avoid ground loop, over voltage, etc... once enclosed inside the DB25 shell, the unit is very robust...

The completed unit... tested it with Mach3... all okay to go... One happy camper.... :-)