Dust Circles

It is a little known fact that although crop circles have all but been proven as hoaxes by the scientific community, dust circles also exist. Unlike the crop circles in wheat and other agricultural produce, dust circles are created, not in the dust as the name implies, but in solid wood, which in turn creates a lot of dust. (Perhaps better called dust-creation circles).

Some still suspect the hand of man is involved in these creations, but overwhelmingly, the dust circles have been subsequently used in furniture making and period details, disguising their true origins.  They then go by another name, one you may be more familiar with: rosettes, as they also are representative of flowers and this second term is the French diminutive of rose.

In modern times, companies have provided woodworkers with the tools to make their own rosettes that they can use to add period details to their creations, and it is one of these tools that we are looking at today.

Today being the operative word, as this rosette cutter comes from Toolstoday.com

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Unlike many other rosette cutters I have seen in the past, the one from Toolstoday.com has some unique features that are particularly interesting.

For one, the cutter has replaceable/exchangeable carbide edged knives.  Rather than spending money on the shaft and body of the cutter each time, you can buy the much more affordable cutters of different profiles and insert the style you want for a particular job.

Being carbide edged, these are sharp with an enduring edge. There are 15 different rosette profiles to choose from, as well as blank knives that you can have made to a specific custom design.

The cutter may look like a router bit, but it is far from it (and would be incredibly dangerous if mounted in a high speed router).  The shaft has flats on it, which is an excellent feature as these allow the teeth of a drill chuck to grip it firmly and prevent slippage.

They are designed to be used in a drill press, lathe, mill or similar, running around 800 RPM or so.  However, as I found as well, the drill press has to be heavy duty.  My floor pedestal drill may be ok for basic drilling operations, but it was not up to the task of a rosette cutting operation.  Too much runout in the shaft, too much slack in the components, and the rosette cutter had a tendency to whirl offcentre, and the subsequent vibration was not able to be resisted by clamps, table or drill head, and the chuck kept falling out.

However, I may not have the best drill press (yet – as in that one will get sold once I have a replacement lined up at some stage (hopefully the Teknatool DVR drill press won’t take forever to come to market)), but my lathe is well up for the challenge.

With the chuck (and MT2) secured in the tailstock (with the rosette cutter), and the workpiece held in the lathe chuck, the workpiece was spun up to 1000 RPM, and the non-rotating tailstock wound in.  The net result is the same effect, and the whole system a lot more stable than my drill press.

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In this case I was looking more for a test, so grabbed a scrap of timber that the jaws could grip easily.  It was prone to tearout, so the rosette wasn’t as pristine as is possible, but still it confirmed the proof-of-concept.

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(For those playing at home, that happens to be the Titan chuck with Powerjaws – that puppy wasn’t going ANYWHERE!)

Back to the rosette cutter, and just to reiterate those points – tungsten carbide blade edges, interchangeable knives, and solid body – it is a serious rosette cutter.  I was thinking that it would make for an interesting wheel cutter if the particular knives were made, and being interchangeable, you could have a much wide range of sizes, and wheel types without the cost of a full wheel cutter each time.

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You can get this particular rosette cutter here, knives here, and start making your own dust circles!

The Hydra and the Router

The hydra is a mythical beast, with multiple heads, and when one is lost, another grows in its place.  I’ve never imagined I’d speak of the creature, the hydra, and router bits in the same sentence, but there you go.

In the past, router bits are a solid unit, with the sharp edge (tungsten carbide commonly these days) brazed to the body of the router bit.  The science behind the brazing can be quite profound, allowing the brittle tungsten carbide survive significant abuse.  These router bits can be resharpened, but you need to get them done professionally to achieve the best result.  Tungsten carbide on cheap bits is dull, often even painted to disguise the (lack of) quality.  I have also been told in the past that tungsten carbide is tungsten carbide, so cheap bits are the equal of the “overpriced other ones”  Bullsh*t! Sorry, but I have been told that on more than one occasion, and I really wish those who don’t know (or don’t care) wouldn’t continue to spout such crap.  It is like saying all diamonds are the same, and we know that is not true either.

Oh – bit of an aside – you may well ask, if carbide is so wonderful, why are there not diamond router bits?  Might surprise you, but there are!  There is diamond embedded in steel router bits, used to rout glass – such as putting a chamfer on glass.  Even more recently, in the Amana Tool catalogue, there are polycrystalline diamond router bits, with an edge that lasts up to 200 times longer than tungsten carbide.  Not sure why, but for CNC machines only.  The Amana Tool catalogue is scary – sooooo many awesome router bits.  Drool.

Ok, so we have established that some router bits (the most common) are all machined and brazed together.  The cost of replacing the edge requires the replacement of the entire bit.

The next approach has been detachable carbide, held onto the bit with one or two (hex) bolts.  Larger pieces of carbide is often used, thicker, and they can also use harder (and more brittle) pieces due to the thicker section, giving longer edge life.  If something goes wrong, and the carbide breaks (or dulls from use), it is a very cheap replacement.

A few of my bits have replaceable tips, such as my surfacing bits.  The two that have replaceable tips can be rotated to present 4 edges in total, providing significant life expectancy, and the tips are cheap even when they all do wear out.

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Now the point of all this is there is another option. Replace the head!  Its the hydra model for router bits!

It is a fascinating model, and there are some distinct advantages.  I’d never heard of them before, but the guys at Toolstoday.com recommended them, and they haven’t steered me wrong yet 🙂

The tungsten carbide is brazed to the head, so the body of the head does not need to be as ‘chunky’ to support a threaded section to hold the tips on.  The head can be machined so each tip is accurate, and the whole assembly becomes rather cost effective when you start running through the consumables.  Not sure how much it matters, but exchanging the consumables is faster than replaceable carbides, as you don’t have to do each tip individually. They are called the EZ-Change Replacement Head router bits, and you can change the head while it is still attached, and set up in the router.  This is particularly useful if running large jobs and you don’t want to have to recalibrate the setup because you’ve had to change router bits to get a sharp edge again.

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There are two types here – whether you require the bearing to be below or above the cutters.  The spare packs come with 3 replacement heads.  The cost won’t kill a budget either – $US18 for the router bit (including a head), and a 3 pack of heads is $27 – less than $10/head.

What will they think of next?!

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