Matching 16mm dia Bullnose and Flute???

**jon46089** · 5th October 2005, 01:14 AM

I have been trying to get a matching bullnose and flute bit for some time now. These are available at many places but only in 1/4 inch bead-flute diameter, e.g. item 7715 at
http://www.mcjing.com.au/routerbits/index.htm or
http://www.northwoodtools.com.au/category203_1.htm
and Carb-i-tool has the same matching bits as well
These bits are used to make canoes and kayaks, offering the advantage of being able to rotate successive pieces along the joined edges to produce complex shapes. But I want to use thicker timber, and need a diameter in range of 16 to 19 mm instead of 6 mm.

The bullnose is easy. I have tried using a matching round nose bit, e.g. item 8746 at
http://www.mcjing.com.au/routerbits/index.htm
The problem with round nose bits is that the cuts must be made along the edges, and long cut lengths are required, and the round nose ends up burning the wood, no matter how slow the feed, because control is difficult and there is alot of material to remove and the centre of the bit just isn't rotating fast enough. The McJing bit got blunt after about 40 metres of fluting, each taking about 6-8 passes to get to the required depth. On the other hand, the "canoe-type" internal cutter will be traveling at higher speed and will be better suited for the job.

So I sent email with the first pic to Carb-I-Tool for a quote and they responded after a few days at a cost of $280 with a two to three week wait.

Then I started looking in US and really thought I found it at
http://www.bladesllc.com/arouter4B.html#BL1261
I ended up paying US$84 with shipping for what I thought would be a matching bullnose bit and internal radius bit. The second image showed what arrived today and is a closeup of the two bits. Even though in email I stressed the importance of matching the diameters, and they were both listed as 3/8 inch radius, it is clear they don't match. The bits are made by Roman Carbide and the package says Made in Taiwan!!!! Bu*mer!

So this is becoming a frustrating and costly experience. I am convinced the internal radius bit is the way to go, because of the speed of the cutting edge at the radius, but it will need to be close to the full half diameter cut and a close match with the bullnose. I want 5/8 inch (16mm) to 3/4 inch (19 mm) cut diameter. Anyone know where I can get the internal radius bit??? May be the Carb-I-Tool custom bit???

**Mustang362** · 14th April 2007, 05:55 AM

You could always get a custom bit made. I've gotten a few from WolfCarbide.com. They have great prices(for a custom bit), and they have a lightening quick lead time. I prefer the custom bits because they are easier to use, and you only have to make one pass.

Just thought i'd pass it along

**carbatecwa** · 14th April 2007, 10:57 AM

Jon, have you looked at the CMT Bull Nose bits and the Round nose bits. There are bull nose cutters withe a bead diam of 12.7, 19mm and 25.4mm.
Round nose bits to do the flute of 12.7mm, 19mm and 25.4.
you Carbatec store in Springvale should have them in stock or we here in Perth can supply.
Hope this helps
regards
Garry

**MrFixIt** · 14th April 2007, 12:26 PM

Originally Posted by jon46089

and the round nose ends up burning the wood, no matter how slow the feed,

The SLOWER you go the MORE the wood BURNS. You need to move the router faster to prevent the wood burning. This may of course require multiple passes or a POWERFUL router.

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