Can you use a slot cutter router bit on woods less than 1/2 inch thick? Also, is installing a border only possible with thicker woods and does the wood have to be solid? Is it possible to install borders with engineered?

Borders can be installed with engineered or solid hardwood. Slot cutters come in various sizes and the sizing would be roughly 1/3 of the total board thickness. You can get borders prefinished too to match the engineered wood.

A while back I installed a Bruce 3/8" 3-ply engineered with an Oshkosh prefinished border.

Where can different slot cutters (with bearing near shank) be purchased? I just picked up a cutter from onlinefloorstore.com and only saw this one bit for 3/4" thickness:

http://www.onlinefloorstore.com/store/product?id=2240

The problem I had was that this produces a 0.215" wide groove and my spline stock was all 0.252", so I needed to plane down 40' to remove ~0.037" material. Only then did it fit perfectly.

I'd consider going with a 3/16" slot cutter for a 1/2" thick floor assuming you have the capability to mill the spline yourself.

http://www.cmtusa.com/store/index1.ihtm ... erbits.jpg

Michael

But this has a bearing at the bottom and will interfere with the floor when the wood is laid. This bit only works when I can put the flooring, board by board, on my router table.

There are various ways to cut grooves in flooring to receive slip tongues/splines. If I need to groove an end butt before I install a board, I use a shop made router table and a simple 1/4" carbide dado bit that looks like these:


To cut a groove lengthwise, you could use the router bit but it will be slow and noisy. Instead, use a table saw with a dado blade and a feathering jig.

To cut grooves into flooring already laid, using the "Easy Groove" for 3/4" is the easiest:


But it's expensive. To the guy who said the bit's groove was too narrow for his spline and he had to mill the spline down. Well, just adjust the depth of the router to make one more small additional cut/pass to enlarge the groove. Pretty simple and easier than making spline thinner.

As to cutting grooves in thinner material, use the two methods I mentioned above for flooring not yet installed. If it is installed, you will need to locate a router bit with the guide bearing above the cutter like these from Amana.

I get most of my router bits from MLCS. http://www.mlcswoodworking.com/ordersta ... _slot.html

I think I got the 3/16" top bearing bit from Woodcraft.

You should also pick up an assortment of bearings. The bearing diameter determines how deep you cut with top bearing slot cutters. You don't want to rout too deep in engineered wood.

Be sure the set screws are tight... even on new bits. I learned that lesson the hard way.

I checked out the Mlscwoodworking website and found the top bearing bits in the CNC router bit section. What is CNC?

CNC = computer numerical control

So basically CNC = ultra precise?

I don't know.... point me to it

No, the manufacturing processes are the same. The shank sizes may be metric or non-standard diameter or length to fit computer controlled milling (routing) machines.

You can do no better if you buy Amana, Whiteside, Freud bits with standard 1/4" or 1/2" shanks for use in name brand hand held or bench mounted routers.