Thread: Bit Selection For Dado's? How to...?

I would suggest spiral upcuts for both. You'll get really great clean cuts. I would buy 1/2 in h shanks as well, particularly for the 16m. A router that takes half inch shanks is more flexible anyway. You can buy collets for 1/4" 8mm and 12mm shank bits.

Also measure. Just because the board says '16mm' don't assume it actually is 16mm OR that you can make a perfect straight cut without any wobble in the non-guided side. Corollary - if you hold the router real hard up against a guide to stop wobble, don't assume the guide won't deflect under pressure. Don't ask how I know this...

Also (if you are going to do this regularly) consider making a captive guide (gives two guide edges for the router) and use an undersize bit (ie if cutting 16mm wide, do it with a 10mm bit, with one pass along each side and 4mm of crossover in the middle)

Not sure if this will help you out, but, it may give you another idea. Instead of trying to match bit size to timber sizes this jig allows me to get exact matches. I use straight bits and will certainly get spirals when I finally exhaust the old ones.

https://www.woodworkforums.com/f44/ugly-34437

Originally Posted by LGS

I would suggest spiral upcuts for both. You'll get really great clean cuts. I would buy 1/2 in h shanks as well, particularly for the 16m. A router that takes half inch shanks is more flexible anyway. You can buy collets for 1/4" 8mm and 12mm shank bits.

Thanks. Question "H" Shank?

Like the Linbide SC12.7M8UC ? - Up cut prevents burning in plunge cuts. Requires good vacuum. Suitable for slotting, grooving.

They (Linbide) dont seem to have too many sizes avail - so may need to look elsewear?

On the Linbide site I can see compression routers with upcut and downcut. 12.7M4CC for example - these sound good?

"Fitted with sub-micron grade tungsten, they are designed to be easily sharpened with out using expensive spiral grinders. Compression routers are just the tool for double-sided laminate boards like Formica and Melamine, plastic coated boards, hardwood or veneered plywood where a clean cut is needed on both top and bottom surfaces. The Linbide Compression Router Bit makes clean, chip and splinter-free cuts for truly excellent finish in materials 10mm to 20mm."

Originally Posted by Master Splinter

Also measure. Just because the board says '16mm' don't assume it actually is 16mm OR that you can make a perfect straight cut without any wobble in the non-guided side. Corollary - if you hold the router real hard up against a guide to stop wobble, don't assume the guide won't deflect under pressure. Don't ask how I know this...

Also (if you are going to do this regularly) consider making a captive guide (gives two guide edges for the router) and use an undersize bit (ie if cutting 16mm wide, do it with a 10mm bit, with one pass along each side and 4mm of crossover in the middle)

Hi MS

True - Measure "Stock" First.

"Saftey is always needed when using power tools" - A router at speed which looses its line can be dangerous and destructive so consider a table or Hold Downs wherever and whatever you do. Tons of "Jigs" are easily sort here and other places on the internet.

Re Captive guides. I'm using a Triton Table saw bench with a sliding router frame. So this will fix that issue, however for more "portable" work a Jig is easy to "knock up".

Consider Multi cuts.

Yes - with regular work and saving the tooling it is and idea. What about "Slotting"...?

Thanks

Originally Posted by Bob38S

Not sure if this will help you out, but, it may give you another idea. Instead of trying to match bit size to timber sizes this jig allows me to get exact matches. I use straight bits and will certainly get spirals when I finally exhaust the old ones.

https://www.woodworkforums.com/f44/ugly-34437

Thanks Bob. Great ingenuity. Highly recommend this to others who are either starting out or want some ideas on "Adjustable Jigs".

Originally Posted by RecyclingKiwi

Thanks. Question "H" Shank?

Like the Linbide SC12.7M8UC ? - Up cut prevents burning in plunge cuts. Requires good vacuum. Suitable for slotting, grooving.

They (Linbide) dont seem to have too many sizes avail - so may need to look elsewear?

On the Linbide site I can see compression routers with upcut and downcut. 12.7M4CC for example - these sound good?

"Fitted with sub-micron grade tungsten, they are designed to be easily sharpened with out using expensive spiral grinders. Compression routers are just the tool for double-sided laminate boards like Formica and Melamine, plastic coated boards, hardwood or veneered plywood where a clean cut is needed on both top and bottom surfaces. The Linbide Compression Router Bit makes clean, chip and splinter-free cuts for truly excellent finish in materials 10mm to 20mm."

Sorry, the "h" was a typo, means nothing.
You may want to have a look at the CMT bits which are available at Carbatec And also Carbitool bits. Both are good quality cutters.

Regards,

Rob