Thursday, January 28, 2010

The CNC Electronics & Electrical Department Happening

I have a confession to make....

I finally did it! I killed ALL the board in my control panel!!! There goes the PMDX-122 breakout board & the Atom MOBO!!! :(

It all happend in that thundering night, wind howling... fist size rain drop pouring.... blue flashing thunder... door banging....... Err.... nothing of that sort, ;p

Over the X'mas holidays, I proceed to wire up the control panel. Individually,  the magnetic coil contactor, E-stop circuit worked out the Mobo worked fine, BUT they don't jive with each other, ...

Wire all the components, press the start button, hear that satisfying "thump" made by the magnectic coil contactor, and a few blink of the monitor & everything went black-out.... Dead! Mati! Kong! & I didn't have the pleasure to seeing smoke!!!

With a puntured ego & coffer, I went back to search for another board as the return shipping charges to send the dead BOB back to the maker is plainly irrational.

Undetered by this set back, I (again) dive into the vast ocean of information- the internet & picked up this SINYU 5-Axis Interface Board. from the ebay.

This chunk of populated electronic component PCB features a Manual Jog function by connecting a home made joy pad, the circuit for the joy pad is given in the manual.
It has 2 Relays which I can switch on larger Magnetic coil relays for auxillary equipment.
Charge pump featured
Unique 10-wire ribbon cable terminal for connection to the Stepper Driver. I have a choice to configure the board for 5 stepper driver connection or 4.
4 sets of powered 3-port terminal with 12Vdc VCC ready for home/limit proximity switch connection.
Takes 9Vac as power which is easy to implement.

AND it is $$$ friendly too.

As for the Mobo, a replacement were sorte.

Total damage?
RM836  = USD 245 = EUR175 = GBP151= ZAR1,860 = 11,360 rupee = HKD 1,907........


Read the small print

So..... Please support this blog by clicking on the ads.... every cent counts.....


Sunday, January 24, 2010

Paint Job

After some back breaking working with steel, All the steel (at least what I know is requires) are cut, drilled, taped, ground, de-burred and painted.

This is the hardest part of the whole build as I have to lift serious weight, endure flying sparks, deafening power tools noise, work in dust filled environment, work on my knees, squatting for long hours & drinking 3 litter of water each day for over 2 weeks...

My advise, get a helper....

The dust is intensive, I lost count after I swept up two 50 liter buckets of grind steel dust...

I then decided to paint the steel before welding to avoid the intensive Yoga exercise session if I were to paint the table after the table is completely welded... Can always repair the scratches & welding burnt paint with a tat to extra paint...

Painting is a PITA task, easy to do but takes ages to reach a competent level of finishing...

How much PITA? Before you paint, one has to prepare the steel...
  • Firstly, you have to remove loose scale & rust with grade A60 sand paper or power brush with an angle grinder, 
  • Secondly, you have to rub down the dust & any oil stain from the surface with solvent, I use patrol for this task as they are great solvent that are easily available & they will evaporate without a trace. There are other practices such as wahing the steel with light detergent but I alway prefer how I did it...

  • Then you get to paint...

Now, you can op for spray painting or hand painting... as my body is all sore after the earlier works, I hate to haul all the steel into the open & haul them back to the workshop after they are done... AND its raining season... a bad bad thing for wet or half dried paint...

*ps, It did rain a few time (per day) during the 3 day span of my paint job.

I use 4" paint roller for the job, some how, I can't paint with normal paint brush & roller saves me from the emberresment. AND with rollers, it is easy to control paint thickness & produce a even matted finishing which I like.

My paint selection :- 1 coat of Red Oxide primer & 2 coat of Enemal Alkyd paint (commonly know as Glossy paint).

More painting PITA....

  1. Apply the 1st primer coat after the patrol had evaporated & squeaky clean...
  2. Wait...... 4~6 hours for the primer to cure enough for the top coat... Too short the curing then the primer will be too wet for the top coat, too long the primer will harden too much for the top coat to "bite" on to the primer coat...
  3. Apply the 1st coat, do not brush over the same spot over & over again, this will make the top coat to mix with the primer coat... Nevermind if you can still see the tint colour of the primer coat on this 1st top coat, you can get this corrected with the 2nd coat.
  4. Wait..... read the instruction on the paint can, it says 4 hour for touch dry & 6~8 hour to re coat.... I waited 8 hours & they still feel too tacky for the second coat so I left them over night to cure properly...
  5. The 2nd coat will be a breeze as you had already 2 coat of practice & finish in no time.

This is what I got

 The laser cut profiles.
The table parts including the rails in black

The table bearer channels 1 1/2 x 3" channels

Close up of the main 3" x 8" channel

The table leg & supporting tube trusses

Not forgetting the rails, with 2 coat of smooth black Hammerite paint...

Monday, January 18, 2010


The special feature of this MechMate is that one could choose to make their own precision rail guide which are not short in quality in comparison to off the shelf guide rails. With some simple tools, a lot of patient, enduring loud grinding machine noise, & 2 weeks of back breaking work, I eventually completed the rail guides.

The whole lot

A closer view

View from another angle

This is the first milestone of this build & I hope there rest of the build will be less laborous & demanding.

Saturday, January 9, 2010

My Steel Fabrication Arsenal

After much considerations on verious factors, I'd finally decided on work area of 183cm x 380cm (6'x12.5'). To prevent any further change of mind, I went on to buy the steel & started cutting...

Here is my arsenal,
The heavy artillery.
Commonly named Chop Saw, its a 15" Circular Abrasive Disc Cutter.

Others may use continuous band saw or metal cutting circular chop saw for the job, but for my budget, this will work just fine.

Another alternative may be Oxy-Acethylene cutting torch. but the heat will warp the steel which I can't live with.

Plasma cutter is on my wish-list of all cutting tools... They are just way out of my budget limit... :(

Light Artillery,
4" Angle Grinder.
for touch up job & light deburring.

Steel stock scatted all over the shop floor.
Some 3"x8" C Channels, for the X-axis carriage beam
1 1/2" x 3" C Channel for the Legs & cross bearer.
Dia.50mm Black "C" pipe for table trusses
Dia 25mm Black "C" pipe for trusses
T-bar to be cut & grind into X & Y axis rails.
50mm x 100mm x 3mm thk Rectangle Cross Section for the Gantry Beams.
 and Flat bars as drill guide then salvage as clamping strip for the Gantry.

Steel Cut to size, at least for now...

Drilling job,

Drill & tapped for mounting the X-axis Angle Rail onto the main Channel Beam.

Close up of the finished tapped the holes,

The M8x1.25 Spiral bit I used to tap the holes

This is only part of the work done so far, I would say 80% of all steel cutting, more to come... I believe in the 80/20 theory, initial 80% of the job is done with 20% of effort, and the 20% of the remaining job requires 80% of the effort.

The next order will be tough, cutting & grinding the Angle Rail.... Stay in tune!