Slab Flattening Router Bit - Which one?

[Ron Kanter]

Planning to build a slab flattening jig. Might get the Lee Valley kit or build a jig from scratch similar to the one suggested by Infinity Tools.
I'm wondering what router bit folks have used successfully. Infinity has their Mega Dado & Planer Bit that looks like it would be an excellent choice, but I am concerned that it might be too much for my Triton 2 1/4 HP router unless I took very shallow passes.
Would love to hear from anyone who has put together a successful slab flattening setup.

[Ron Selzer]

watching, have the Lee Valley kit, have not assembled it yet

[Roger Bull]

I use the Infinity Mega Dado & Planer bit and love it. Yes it might slow down a little on your router but the width of the bit means fewer passes. You almost always want to be taking shallow passes anyway when flattening.
I originally started using this bit with a Triton 3-1/4 and it had more than enough power. I have since gotten rid of the Triton and gone back to my Milwaukee routers plus one Makita RP2301FC plunge router which I really like.

[Andrew Gibson]

Hi Ron, I have used the Triton 2.25 with the Mega Dado quite a bit and have no issue recommending the combo. Regardless of the router itself I always recommend a 50% (1") wide pass at a maximum of 1/8" depth with the Mega Dado. I will go up to 3/16" on the first pass or two if there is a good amount of irregularity but then drop back to 1/8" once a start cutting a majority of the slab surface. Here is a pick of my coffee table flattened with the 2.25 combo. The wood is red eucalyptus which is at least as hard as hard maple and typically more abrasive. There are some great choices for sleds out there these days, I tend toward the homemade side simply because I have run into slabs of all different shapes and sizes and don't personally work with slabs regularly, maybe once every year or two.
435959

[Neil Gaskin]

I use Magnate Bits, Link below.

If I'm doing a small slab with light passes I use a Bosch 2 1/4 HP router and I think it's a 1.5" bit. For larger slabs or bigger bites I use a Porter Cable 3 1/4 and have used up to a 3" bit.

I bought a small flattening jig from Woodhaven I use predominately on smaller pieces. I've also made a wooden frame jig for larger slabs. I prefer the manufactured because the aluminum frame is likely going to stay straighter than wood. I've toyed with just buying new extruded aluminum for rails to make the Woodhaven jig more versatile but have never pulled the trigger.

I looked at the Woodpecker jig at a woodworking show in January and it looked pretty well thought out and engineered.


https://www.magnate.net/ProductDetails.asp?ProductCode=2714

[David Utterback]

watching, have the Lee Valley kit, have not assembled it yet

Same here. Looking forward to ideas.

[Jim Becker]

I use Amana insert cutters for this application...the same tooling I use for conditioning my CNC's spoilboard. They make them small enough that they can work well with a typical router and sled system that many folks use for slab flattening as well as for those of us with modest CNC machines to do the same.

[Ron Kanter]

Jim, is there a reason to chose a Spoilboard flattening bit over a bottom flattening bit?
Which Amana bit do you use?
Thanks

[Jamie Buxton]

I use a 1 1/4" ordinary straight bit. Nothing fancy, nor expensive. Use it until it gets dull, and go get a new one.

[Peter Kelly]

Agreed. I’ve actually gotten better results using a regular $30 Amana 1 1/4" morticing bit than a more expensive insert one.