A logical conclusion

Using the same steps discussed in the last entry, I have taken a vector drawing of a Celtic Cross (created by “CarveOne” on the Vectric Forum), and produced a 3d rendering of the design.

This is the first time I have really tried using multiple paths on the same object.

The first pass was a roughing pass – used to remove as much of the unwanted timber as possible with a strong router bit, and higher feed rates to perform the task quickly.

DSC05816For this I used the 46294 3D carving bit from Toolstoday.com  It has a Zirconium Nitride (ZrN) ceramic coating, so this bit is also appropriate for routing in aluminium, brass, copper, cast iron and titanium alloy.  It makes very short work of the camphor laurel!

DSC05818There wasn’t a lot of material that needed to be removed, but it is still a worthwhile step to minimise any unnecessary load on the finishing step (and router bit).

DSC05820The final design was then carved using the 46282 3D carving bit.  This has a 1/16″ diameter tip, so can really get into the details.  Even so, there is a bit that is even finer, if even more detail is required (with a 1/32″ round nose tip).

I was using these at around 80mm/sec.

Once the design was cut, I swapped over to a solid carbide 1/8″ upcut bit to first cut around where the gaps were meant to be inside the design, and then to cut around the outside, down to about 12mm deep.

DSC05822For a sense of scale, the cross is about 300mm high, and 200mm wide.  Straight off the router bits, there is no need for sanding where the carving bits have been.  There is a bit of feathering on the outside of the cut out, but that is both a function of the timber, and insufficient router bit speed.

I deliberately didn’t cut all the way through the timber, so there was no need for tabs to hold the cut pieces in place.

To release the cross from the surrounding material, I turned the whole thing over, then ran a basic flattening profile on the back, taking off 2mm at a time with a surfacing cutter – using the RC2248 replaceable tip cutter.

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Once this cut down to the required depth, the cross was released.

Each project presents different challenges, so I get to know more and more about how to use the CNC router effectively, and how to incorporate it as another workshop tool.

I had a look back at some tests I did on the CNC Shark using 3D carving bits – the finish I am achieving here is chalk and cheese compared to my early experiments.  I don’t know if I can attribute it all to the platform, but having such a solid, heavy duty CNC router certainly is not harming the finish that I can now produce!

 

Grinling Gibbons

From a link provided by Australian Wood Review, I have been watching a couple of video series on historic wood carvers.  The work is unbelievable.  The first, here, is on Grinling Gibbons, who came to London following the Great Fire as a wood carver.  The body of works he produced is astounding, and well worth watching.

Groovin’ on the Dancefloor

A CNC machine may be capable of placing a router in precisely the right place, and follow an exact path, but still a router is just a motor.

The real tool is the router bit – it does the real work.  If you were hand carving an intricate pattern, you’d want your tools to be razor sharp, and have the variety of profiles that you need. Just because a router is a powered version of a chisel, it doesn’t stop the need to have sharp bits and correct profiles.

This is where the Amana Tool In-Groove Engraving bits from Toolstoday.com come into their own.

Normally, if you want a really fine tipped engraving router bit, you either have to go with tool-steel, or a particularly expensive solid carbide bit.  The In-Groove bits have a real point of difference (pun intended).  They have replaceable carbide tips.  And not only that, but a variety of profiles that fit the same router bit body.

Toolstoday.com In-Groove

Toolstoday.com In-Groove

You choose either the 1/2″ or 1/4″ shank, and either just get the components you require, or get the 8 piece set which gives a good sample to start with, that you can then grow as required.  If a tip becomes blunt or is broken, it is a low-cost replacement and not the entire router bit being written off.

There are also a surprising variety of each profile, with different tip widths, allowing you to precisely choose a profile to match the job you are doing.

Profiles

Profiles

There is another real benefit to the In-Groove system that is not immediately apparent.  You can change profile (effectively the same as changing router bits) without removing the bit from the router, or even having to disturb the current location of the CNC machine.

So you can set up a job with multiple paths, and like really expensive CNC machines that can change tools partway through a job, start with one profile to define edges, switch to a second for bulk clearing, then finish with a third profile that refines the design.  All by undoing a single hex bolt on the router bit itself.

Changing tips

Changing tips

As a bit of a test (and only in pine), I quickly threw together a design to test the different profiles out.  It really was simple changing tips on the fly, and matching design to bit.

Different profiles

Different profiles

As much as a V groove bit is the most commonly one used, I really liked the result of the cove tip

Cove Tip

Cove Tip

I also gave a more complicated design a try, with a bit of a Celtic knot, a photo of a saw blade turned into a path, and some text on a curve.

_DSC2485

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This was done with a 30 degree V groove tip mounted.  Forgot to mention, I normally choose 1/2″ shank router bits, but knowing the CNC shark router is 1/4″, that is the way I went here.  The bits don’t get heavily loaded up – it is not bulk material removal after all.

The In-Groove router bits do sound like they are not running true (you develop quite an ear for that sort of thing after a while), but I didn’t see any particular problem at the router bit tip, so I suspect it is more because of some asymmetry caused by the tip retaining plate rather than the bit not running true.  For any bit mounted in the CNC, I made sure they were fully inserted into the collet.  No matter what the size, the router is single speed, and kicking along at 33000RPM.

Finally, I ran the same design onto the laminated board that I did the Mayan calendar and Japanese dragon, to see how well it came out.  I could have refined it further by choosing different bits (and depth of cut) for different portions of the design, but took the simplest option – letting it run from start to finish.

Stu's Shed design

Stu’s Shed design

This isn’t some new design for a Stu’s Shed logo, although I don’t mind the saw blade and text layout, but I’d want to replace the Celtic design with something more applicable.  Perhaps the outline of a Festool Domino, or something!

If you are so inclined, see what you can come up with (Illustrator format preferred!)

So that is the Amana Tool In-Groove CNC Router Bits, from Toolstoday.com.  If you have a CNC router, these are definitely worth some attention.

Continuing the family tradition

Year 2 😉

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Using the Dremel to carve the pumpkin.  If I had the mini carver from Arbortech, who knows what I could do.  Not that it cannot be achieved manually, but the Dremel in this case made it much easier!

Tis the season to be scary

I have never tried this before, but thought we’d try the Halloween pumpkin carving thing.

Bit wonky perhaps, but for something not tried before, and done freehand, it’ll be be good to have for the trick-or-treaters tomorrow night 🙂

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The things you do when you have kids!

And only one cut that drew claret- the ol’ “don’t cut towards yourself”. So if the pumpkin comes to life tonight, you’ll know why (aka Stephen King‘s “Mangler“)

Aotearoa Pounamu

It is sometimes hard to find the perfect souvenir, especially from a place that was once also home.  I was looking for something particularly meaningful, a bit of a statement of my past. I already have a bone fishhook – a very traditional symbol representing the hook used by Maui when he hooked and pulled Aotearoa from the sea.  Hei Matua (the fishing hook) represents strength & determination, and safe passage over water.

Polynesian Sailing Canoe at Auckland Museum

I wanted to add to this something carved from Greenstone (also known as Jade). With such a flood of cheap Chinese knockoffs, and non-New Zealand Jade being sold as if it was genuine, I tried hard to identify something locally crafted, from genuine New Zealand stone. As a woodworker, there was an extra layer of meaning in the piece I chose – a traditional adze-head form. Greenstone is Pounamu in the native tongue (an official language in New Zealand).

It is said that each piece absorbs the mana (the spirit) of the individual, and the stone forever yearns for its source- Aotearoa, and a promise that those whole leave the shores will one day return. (Added importance therefore of getting New Zealand stone, and not some Chinese knockoff.  To be fair, Canada is also a source of quality Jade, and a lot of that is also sold in New Zealand.  Look for “New Zealand Nephrite Jade”.  If it just says “Nephrite Jade” it is likely British Colombian.  If it doesn’t have that, it is likely to be Chinese. You have to ask if it is not clear.  Not that Chinese jade is necessarily of lesser quality, but I have a problem with the concept that I am trying to buy something authentic- hand crafted/carved Aotearoa Pounamu (New Zealand Greenstone), and don’t want some cheap crap machine manufactured, potentially inferior quality jade that may or may not be chemically treated so it looks better than it is.)

Greenstone is a traditional material chosen primarily for its ornamental properties. It was used as a practical material although was often reserved for obsidian- a volcanic glass. Very hard, and being glass, can be chipped to form an extremely sharp working edge.

Adze Heads at Auckland Museum

I must admit to being very disappointed (but I suppose I shouldn’t have been surprised) when I discovered that there was so much foreign jade imported, and shaped offshore into traditional designs.  Why there isn’t a ban on the importation of it is rather confusing. Is the pursuit of the almighty dollar more important than heritage? One major reseller of jade in Rotorua looked as if almost 3/4 of their stock was foreign materials and/or foreign shaped & carved.

Something to be aware of, if shopping for a memento, and wanted something traditional. Not everything green is (NZ) stone.

Aotearoa Pounamu

Other than the bone fish hook (Hei Matua) that I already had, the Adze head piece was the one that I added this time.  Known as Toki, it was originally a carving tool that became ceremonial, inherited Taonga (treasure), which symbolises strength and courage.

The final piece was one my wife got, which incorporates the Koru, which is the unfurling fern frond and depicts new beginnings and growth.  Both jade pieces were carved by a young Rotorua carver Scott Parker.

Silver Fern Frond

Carving Kava

I’ve been working with some images taken in Fiji by one of the Lecturers in the Arts Faculty – Dr Matt Tomlinson. During our discussions, my interest in all things woodworking came out, and he’s sent me some photos of some traditional woodworking related to an area he has been researching – traditions and the culture surrounding Kava  – both its consumption – use in different traditional roles, and its preparation.

Reading the Wikipedia about Kava, and I wonder if it can be bottled and sold – sounds like a very interesting substance.

However, it is the production of the Kava preparation bowl that is the real topic here.  These photos were taken in May 09 on the island of Kabara, which is in the Lau chain of eastern Fiji. It’s the traditional homeland of carvers of kava bowls made from Vesi wood (Intsia Bijuga), but the island has been badly deforested, and is rapidly running out of Vesi.

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