Digital Wood Joinery Lesson No.1

Wood joinery is a priced craft.

Traditionally, any carpenter will feel insulted if you say he nail up his work...

 Deep inside, I too feel humiliated without implementing some sort of wood joints in my personal projects.

The RED & Blue are simple butt joints... I don't feel proud when I use them....

The Magenta & Cyan are tong & groove some call it tenon & mortise... this is the least I'll have in my personal projects.

Another modern woodworker's must have is PVA glue, commonly called wood glue or white glue. It is a water based glue that will not break before the wood fiber tears... great for indoor use.

A properly glued  joint will take all the abuse you can throw at it before the wood itself give way...

SAY NO TO NAILS!

CNC-ed Stools

Kenneth & Gabriel threaten to boycott me if they don't get a chair to seat on their next visit to my shop... :(

Buying chair for my shop use just isn't me... Too lazy to hand build some chairs... Procrastination sets in when it is a non-paying design job....

There must be plenty of free chair plans available in the net... so started strolling mindlessly across the WWW....

One will find when one seeks.
A nice stool design in the project page of 100kgarages. I like what I saw here and downloaded the free cad files immediately.

Unfortunately, I can't cut it as it was designed for 3/4 in thick Plywood but I only has 18mm thk MDF. Some customisation is require... but hey, having a free download already save me from loosing gallons of brain juice... can't complain over that...

Without further a do, open up the CAD file, changed the slot & finger joint size to suit the 18mm thk MDF I have, It is always a goof practice to double check the actual thickness for both plywood & MDF before working with it as they can very as much as 3mm... A good a verneer caliper reads 17.4mm averageof 5 readings...
To prevent any possible infringment of trademark of the Makers & the Shopbot, I  removeg their logo from the stool panels just in case & pop in some simple graphic pattern? The added bonus is reduction in weight :)

Then pop the modified CAD file into my CAM program, do some careful tool bit selection, tool feed rate, put in some tabs & G-code is ready for my Mighty Blue Beast.
Load up the MDF sheet, calibrate the positions, turn on the dust collector & I'm off for an extended coffee break.
The stool parts are completed & ready for assembly when I return...
As usual, everything snap-on perfectly.... ;)

This should make Kenneth & Gabriel happy on their next visit ;)...

EMC2 Revisit

Had a go at the Mach3 trial version earlier, it is nice package packed with load of goodies but it does has a 500 lines limit, until I pay up US175 for the full version... It was a lot of money to me so I revamp my system to EMC2 the open source program that is free to own & most importantly free to tweak.

Presently, EMC2_2.4.3 release is available & it can run in the latest Ubuntu 10.04 LTS released which can handle dual-core mobo. BUT since my mobo is single core ATOM board & I'm to anxious to get my machine in full operation mode as soon as possible, I stick to the Live Disc which contains EMC2_2.3.4 + Ubuntu 8.04LTS. I'll go for 10.04 & EMC2_2.4.xx when they comes in live disc...

It is great to have EMC2 back in business, the motors sounded happier, smoother & refine.
From the jam packed Mach3 screen, the bare & simplistic EMC2 AXIS screen suddenly feels empty... AND I missed the Auto Z Touch-off feature... Without further a do, I dig into information on Auto Z Touch-off feature in the wide sea of WWW.

Nothing is new under the sun... apparently; Many EMC2 users had their own concoction & I found good information on one of the step-by-step how-to here...
http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?ClassicLadderExamples#Single_button_probe_touchoffand  here is how this thingy came about.
http://www.cnczone.com/forums/showthread.php?t=62423

They involve pyPVC which is a screen editor to tweak the custom virtual panel & Classicladder which is a ladder program. on top of that one has to be well verse with the MDI_COMMANDS in the Axis HAL & some Python language....

Took over a week to have a creak at the programes without much success... hence, to save time & loosing hair, I put on my copycat hat & shamelessly copied every step to the teeth & after some debugging & troubleshooting, ITS ALIIIIVVVE!!!

While I was at it, I squeeze in the jogging button for convenient operation.

Next will be a HID (Human Interface Device) using a common wireless game pad.... Don't wait up, I'll never know when I'll get there...

Children Study Desk & Chair Set

Carving, Engraving & Profile Cutting is fun & the product are pleasant to the eye. BUT mostly useless... Very much like having sex...
This doesn't satisfy my natural crave to build something useful...
I've seen many furniture we made with CNC router... but can this really be done without any further human inteference?
It is unevitable that I set out to build a set of functional furniture... eventually... & that "eventually" came sooner then I could anticipated...
The choice of the month is a Children Desk & Chair set. Why Children furniture you may ask... They are no less difficult then any other furniture & they are smaller (that means less material to buy...) period...
Took some serious effort into research of suitable joineries... After over 2 weeks of toying with various design combination in my head... I conjure enough energy to keep myself nailed infront of the computer monitor for 2 full days to come up with the 1st version...

After a not-so-satisfied prototype & some alteration on the original version. This is my final results. A chair that is ergonimically correct, light-weight & assembled (easily) without glue straight out of the machine. AND (most importantly) they look right to my eye too...

"Flat-packe" profile cut

Now... How should I paint this thing...

MACH3 endeavour

My Ubuntu OS based PC controller for my MechMate died...
After days of hair-pulling troubleshooting hours, the culprit was found to be the fried Thumb Drive I used as the main storage media... Now, that was a surprise... how often you hear of fried USB thumb drives...
The opportunity of an alternative motion control software arises.
From what I learnt, EMC2 & MACH3 are the two dominant controller software used in the CNC hobbyist community. Both has strong & huge community based support forums & free to download user developed plug-ins.
I took on EMC2 in the first place because it is a free software, not just it doesn't cost real money to own, it is also free from constrain when use.
Thanks to a donated Dell P4 machine with a licensed Window 2000, 1.6Ghz, 512Mb Ram, 20GB. & most importantly a LPT port.
I seize the opportunity & downloaded the Mac3 Trial version for the job.
This trial version is as much as the paid version (USD 175..) the only limitations are that it can take up to 500 command lines... & they limit the pulse rate to 25kHz. Still it is enough for trial cut with simple design but insufficient for complex engraving & carving works.
Setting up is a breeze with my prior experience with EMC2 under my belt.
I immediately rig up the much talked about Auto-Zero programme and scavenged a piece of blank PCB from my junk pile as the touch plate, soldered a thick gauge wire to it & connected to the free I/O ports on the breakout board. Down loaded the plug-in & again, everything worked seamlessly. It was a breeze, even monkeys can do it!
I the tried my luck with the Joystick HID setup, but unfortunately, the plug-in don't work in Win2K... #@!$@#~$!
There are lots of handy feature cramped into this package, it can generate G-code for table surfacing, Pocketing, Spiral cutting, Thread cutting... etc etc etc.. Many handy controls were on the screen & the screen is programmable... Learning curve isn't that steep too.
The down side is that the screen is really cramped with many feature that are not required...
My verdict?
If this is the first time for you with this PC based Motion Controlling Thingy... stick to MACH3...Everything you need for a beginner are there! Even those that you don't need... Its a no-brain-er... It even comes with a CAM programme call LazyCam...
BUT if you want more freedom over the program functionality, go for the EMC2 where the screen is Spartan & the user need to custom their own any additional features such as Auto Zero, Auto-Homing... etc which are also available for free download...

For now, (USD175 is still a lot of money for me...) I will spend more play time with this Mach3 Trial  program & when I decided to switch back to EMC2, I'll teach my EMC2 all the neat tricks in Mach3...

Another Health Hazard Management - Dust Collector

Anyone whom ever worked with wood working power tools can tell you how fast & convinient they make, BUT no one ever mentioned the mess it left with the amount of wood dust, saw dust they generate...
Wood dust get into everywhere! That includes every possible crackes, gap, opening in the building... Those which manage to get air bourn will stay air bourne for hours!!!
Not forgetting the demage they can do to our lungs, nostril & any other opening in your body...

I'm a lazy sob, I hate to do cleaning chore... & I don't want to die of lung cancer...
Naturally, I'm reluctant to use my CNC Router....Cleaning the mess is hell!!!

To keep my sanity & healthy lungs, I installed a full fledge 2-Stage Dust Collecting System... which really is nothing more then a glorified industrial grade vacuum cleaner...

I bought this Twin-Bag Single-Stage Dust Collector, I did planned to build this from scratch but again... As I'm a lazy sob especially when the financial benifit did not churn out more the 70% savin...

The white thingy is the fabric filter bag which stop fine dust from entering the shop ambient.

This is the centrifugal fan which acts as the "sucker"

Since the fan impellar & filter bag do worth some money, it will be best to have a buffer to remove most of the saw dust & foreign object from getting to them. The ideal solution (for me) will be a dust cyclone, which is not difficult & expensive to construct but I came accrose this Thien Separator in the internet which is even easier & cheaper to construct.

This is the Thien Separator which were constructed from a 200L barrael which I robbed from a friend & some fitting & CNC cut plywood. This will drop off 80~90%  of the saw dust & any heavy foreign object from contact with the fan impeller and fill up the filter bag.

This how they look inside.

Another view of the separator internal organs

This is the fully assembled dust shoe,

 it will confirn the saw dust within the effective vacuum suction region. Also capture larger wood chips from flying all over the place. the brush is a door seal brush & the rest of the wooden structure were cut by my CNC router. Everything just snapped on seamlessly.

The original hole around the cutting bit is round but was accidently demaged during test... but it still work beautifully as it is now... (too lazy to make another...)

suction hose attachement.

More pre-assembled pixs.

Then the flexible host.

And the assembled 2-Stage Dust collection system.

Now.... I am fresh out of excuse to delay cleaning up the workshop....

Upgrade Cooling water System for Water Cool Spindle

My spindle cooling water pump gave up on me!
No, I didn't fry my spindle along with it :)
I was so glad I had the reservoir made out of transparent plastic container! Saw that the water flow was reduced to a trickle when I started up the pump 2 weeks ago...

After some leg work, found a nice submersible pump. It was a love at 1st sight! black aluminium body, stainless steel impeller & shaft, 415V/3 phase, 1/10 horse power (75 watt) , capable of 2m head but didn't indicate the flow rate... & the best part was its has a RM250 price-tag! well within my RM300 budget! I love it so much that I couldn't care less about the flow rate...
I only need 350 ml/min which I recon a lovely pump of this specs will surely achieve.

Another pleasant surprise to find the shop next door carry some heavy-duty PE tanks! So I just got hold of a 16 liter tank, I choose it as it look about right size to keep the pump stable...

More leg work to find some extra 6mm tubing, connector, reducer, 4 core wires, an on-off switch, some screws, washers, pp tubing tape...
Took a nice Sunday morning in cooling rain to tie everything up nicely...

Open up all the necessary opening for mounting the pump, fit the reducer at the outlet,use up some 20m of 6mm pneumatic tubing to go along the cable chain,  I like the pneumatic tubing as it has stiff tube wall, it is light weight & the glossy finishing eye-catching... & some fittings to go along...

Tie up the electic cable, switch, got the motor direction correct & ready for a test.

The pump fills up a 1 liter paint can in 2 minutes 45 seconds, so a healthy 363 ml/min. consider the amount of work it has to get through some 30m long tiny 6mm tubing... an improvement over my old aquarium which was 300 ml/min at its best...

Ran the motor with the spindle running for over an hour & everything is cool & nice! This industrial grade outfit will serve me trouble-free for a long time...

Total damage? RM276... yeah... don't believe everything written on the price tag.... LOL

I would conclude this upgrade a complete success!

What next?
I can' really see the water level despite the translucent tank wall, will buy some of car radiator coolant to give a distinct color to it & give better corrosion protection to my pricy spindle. If it still doesn't work, I'll die the coolant with ink :)