Duro-Form router bits

[Ned]

I happened to notice these in the catalog today, and realized that I'd never seen them and hadn't seen comments on FOG either.

The Duro-Form bits are 8mm-shank bits that use carbide inserts.  The inserts have at least two cutting edges, and are replaceable at low cost.  A big advantage over resharpening is that the inserts maintain a constant bit diameter.

The usual Festool economic equation--costs more to get in the door, cheaper in the long run.

Anyone have experience with these?

Ned

 

[Ned]

Well OK.  It's been more than a week and no responses, but the thread has had 118 views.

I conclude from this that there is interest in the Duro-Forms, but few people are using them (and none who post).

Ned

 

[greg mann]

Ned,

Sorry I forgot to reply. I use the Festool 8mm shank inserted style router bits and like them a lot. I come from a metal machining background where this is mature technology so I have a higher comfort level and probably a greater appreciation for what they can and can't do. They hold an edge very well, index accurately, and run with no vibration. I think they really excel when cutting more abrasive materials. I think Jerry Work has commented favorably about them as well but I don't remember the exact context so I won't try to put words under his fingertips.

 

[Ned]

Does anyone have experience with the Duro-Form cutter and high-grade plywood?  What can you tell me about the quality of the cut?

I've been using spiral bits to cut finger (aka box) joints but would like to move to the economy of using the Duro-Form.

Thanks,
Ned

 

[woodshopdemos]

Ned,
  I have used the Duro-Form and have liked them, but I haven't had enough experience to judge them over their counterparts.
  What I am puzzled over is your use of spiral for fingerjoint (aka box). First, the fingerjoint is different  from the box. The fingerjoint has tapered cutter and the joint is the one commonly used on end to end splices such as we find in wood for moldings. The box joint is with squared  cutters. Now my puzzlement: you are using a spiral bit...so you are running the wood over the bit on a jig. I would not have thought a spiral bit would give you a good, tearout free cut - whether up or down spiral. I would think a straight bit with a shear angle would be better and even then require backer boards. I do have a box joint bit that cuts from the side and has 1/8" cutters. It is just limited to a 2" cut.

 

[Ned]

  What I am puzzled over is your use of spiral for fingerjoint (aka box). First, the fingerjoint is different  from the box. The fingerjoint has tapered cutter and the joint is the one commonly used on end to end splices such as we find in wood for moldings.

Terminology problem.  I know the "finger joint" you're talking about--used wherever they say "solid wood, paint grade". 

What I'm talking about are box joints--right angle, straight-sided fingers meshing together.  Many people, including Jerry Work, call such a joint a "finger joint".

The box joint is with squared  cutters. Now my puzzlement: you are using a spiral bit...so you are running the wood over the bit on a jig. I would not have thought a spiral bit would give you a good, tearout free cut - whether up or down spiral.

I'm using Festool spiral bits with the VS600, a recommended combination.  It may not be the best for plywood, though.

I would think a straight bit with a shear angle would be better and even then require backer boards. ...

Thanks.  Just need a little nudge to make the jump.  The Duro-Form's expensive to buy and cheap to run.

Ned

 

[Zaphod]

  I would not have thought a spiral bit would give you a good, tearout free cut - whether up or down spiral. I would think a straight bit with a shear angle would be better and even then require backer boards.

A spiral bit is essentially a straight bit with a large shear angle.  Use 'em for joinery of all sorts with impeccable cut quality.