Best Router Bit for a Dado

[Joel Wesseling]

I'm doing many 1/2" Dado cuts 10mm deep.
I use a down spiral by Whiteside. It works fine and keeps the top edge clean but
with the dewalt router I need many passes to get to 10mm.. Likely 2mm per pass without chatter..

I'm curious if another style of bit will give more depth per cut or is it router power?

Thanks, Joel

[Bruce Wrenn]

When I build cubbies for local "Y", I use a Her-Saf screw on reverse helix cutter. My dadoes are only about 1/8" deep.

[Bill Huber]

Could you make 2 passes with a 3/8 bit? When I do 3/4 dados I us a 1/2 in bit and make 2 passes, with my Bosch 1617 router with no problems.
How are the bearnings in your router and which router do you have.

[pat warner]

"I'm curious if another style of bit will give more depth per cut or is it router power?"
I doubt it.
Your cutter is dead or your router is underpowered or 1/2 dead. 1.5Hp should get you to 10mm in 2 passes.

[Andrew Joiner]

With 1/2" bits I route 3/8" deep dadoes with one pass in hardwood ply. Unless your routing very dense stock, I'd say change bits.

[Hunter A Keller]

You might find a more expensive bit, but the Whiteside's I've used are pretty good bits, and yours should be solid carbide. So unless it's really dull... Some more information on what you're cutting into might be more helpful. I prefer to use a dado blade myself. For small repetitive cuts or for shelves I use it on my RAS if the TS is impracticle.

[Phil Thien]

Is there any chance you're running the router at too low a speed (RPM)?

[Joel Wesseling]

Thanks.

Router speed is full. Its 2 1/4 hp dewalt

I've done some with 2 passes on width and yes that's better. The thing is I'm repeating these cuts many times and
have a fence with panel in a fixture so want to stay with one fence position...

The stock is Baltic Birch with Phenolic Glue.

What is a better bit than Whiteside?

I should try upspiral to clear chips as long as edge is ok..


Thanks, Joel

The Herf-Saf looks interesting

[Tom Walz]

Whiteside bits are very, very good. I would call them and ask them. Chris Miller is the head of sales. (800)225-3982

Your best bet is to take it to where you bought it and ask them to check it.

If you bought it from us, please call us. We would like a little more information then we will replace your bit with a new one at our expense. Two reasons for this. 1. Our 100% satisfaction guarantee covers you even if you just bought the wrong bit. 2. Carbide Processors and Whiteside Machine are both slighly nuts about quality and customer satisfaction. If there is anything at all wrong with that bit we really want to know.

This is really supposed to go through where you bought it but, if you run into any trouble, call us.

Tom Walz
Carbide Processors
800 346-8274

[Hunter A Keller]

Sounds like Tom just stepped up to the plate for you. I didn't read close enough and interpret downspiral. You do want an upspiral for a non-through dado. The chatter you wrote about may very well be caused by the bit (as designed) forcing the chips into the bottom of your dado. Unless I'm mixing up my spirals. If the bit is in good condition, and not dull, I'd just get a new upspiral and try that. You'll eventually need both anyway. Of course I collect bits like a hound collects ticks... When I said above that you may find a more expensive bit, what I meant by that is that you may be able to pay more for one, but not neccessarily receive a better one.
Edit: The plywood you're cutting shouldn't be a problem at all, and I don't think chipout would be a problem with an upspiral either. Only one way to find out...

[pat warner]

"The stock is Baltic Birch with Phenolic Glue."

Most plies are intolerant of upspirals.
If you have a lot of cutting then a straight solid carbide tool is a better choice.
Note: As a rule, a wear line will show up on brazed carbide tools inside of 250'. At a 20'/min feed rate that is = 15 minutes of constant cutting, a 1/2 dead tool in 15 min! Solid carbide is much harder than brazed carbide on steel, thus it will stay sharper longer.
Let the cutter dwell without cutting and the wear rate accelerates. Good cutting is technique sensitive, less sensitive to cutters and routers.

[Alan Schwabacher]

"Solid carbide is much harder than brazed carbide on steel, thus it will stay sharper longer.

Thank you Pat, that's a useful piece of info I have not encountered before.

[Jerrimy Snook]

The 30° helix on the Whiteside RD5100 Solid Carbide spiral may cause chatter especially with a hand held router on a dado. The bit is moving the chips into the dado and the flutes are trying to climb out of the dado.

A better solid carbide option would be a RD5100S which is a slow helix (maybe 10°). It retails $8-9 more than the RD5100 but is designed for dado cuts.

A more economical solution, that was designed for dados, is the Whiteside 13-500. The 13-500 is a screw on "reverse helix" bit that is designed with good chip clearance and a slow down spiral. These bits are easily replaced without removing the shank from the router which allows quick, consistent bit changes without readjusting the depth.

Jerrimy

[Jeff Duncan]

Unless your doing something particularly special like say a stopped dado, you'll go much quicker and cleaner with a dado blade in the table saw. A router would not be my first, or even second choice for that type of work.

If you have better luck with the 3/8" bit then you can use that without moving the fence. Setup the fence for outside line of the groove and make all your cuts. Then add a 1/8" spacer to the fence and make the rest of the cost. If you have to go back for one or two that were missed simply remove the spacer....the fence never needs to move.

always more than one way to skin the cat
good luck,
JeffD

[Joel Wesseling]

There's lot's of good information here and I thank everyone..

I'll have to look at it closer and try some other bits..
The 3 flute spiral looks good.
Upspiral or straight is only slightly possible as I'm not crazy about the frayed edge..
No problem owning many bits as I alway find a use at some point..

I plan to do many of these cuts as I could be building these regularly..

As you can see from the picture there's 3 places on the side panel that get dadoed so kind of stuborn
about keeping one set up for each position..

I enjoy all feedback and will take the time to aim for the right tool

Joel