Thread: 2.5" flush-trim bit?

Is it possible for you to use a top mounted template and a flush bit with the bearring at the top of the shaft, cut down to its full depth, then flip the job over and use a flush bit with a bottom bearring riding on the previously routed surface?

Mick

Carbitool's catalogue show their longest bearing ended flush trim bits as having cutting edges of 50.8mm or 2" in length and their longest inverted flush trim bit is 38mm or 1 1/2" in length.

You may find it difficult getting anything longer.

HTH,

Mark.

If you absolutely must have one then contact Carbitool, they will most likely make you one.

They'd most likely tell you to buy a spindle moulder!
You wont get a router bit over 2" in lenght thats a 1/2 in dia!
Jmick described a good way of doing it safely.

Originally Posted by Harry72

They'd most likely tell you to buy a spindle moulder!
You wont get a router bit over 2" in lenght thats a 1/2 in dia!.

Do you mean 2" of the actual cutting blades, or total overall length?

Yes carbide lenght.

That's some thick timber. What are you trying to do?

Tex

Do what Mick says. All you have to do is obtain the CMT 2" L/19mm dia with 1/2" shank super flush trim bit. Get the 19mm bearing to fit the 1/2" shank and you then have a 2" bit with bearings at both ends. If your timber is too thick for 2" cut length, then just flip timber and template and set bit height. In this case you will have to only have one bearing fitted at any one time to achieve the desired result. This is also very useful for template routing difficult wood grain. Just do the flip to change direction using the top and bottom bearings to obtain desired result.
This CMT bit I mention also has a 6 degree negative shear angle and provides the best possible surface due to the timber being sliced and not chopped.
Regards
Les

Thanks for all the replies, and especially for
the suggestion about flipping over and using
the first routed surface to guide the bearing.
That trick had never occurred to me.

For those who asked what I'm attempting...
the job I'm doing is the same one I asked
about here several weeks ago. I.e: putting
a large roundover (~40mm radius) on the
ends of 220 42x42 ballusters. Template Tom and
others gave me lots of helpful advice at the
time. But I've been away, and have just now
returned to the task.

I also asked a question a few weeks ago about
"whipping" when I noticed striations (uneven
cutting) along the timber. My current question
about long bits with bearings was in a (probably
lame) attempt to stop this happening. But I
now suspect my real problem is that I wasn't
clamping the piece close enough to the end,
thus allowing it to vibrate slightly like a tuning fork.
When I changed the design of my
template to allow clamping closer to the end,
the problem is vastly reduced - to the point
where a light sanding afterwards is enough.

Thanks again everyone.