Rabbeting kit,1/4" or 1/2" shank

[newood2]

Which router rabbeting bit shank size is more flexible or better to buy, 1/4" or 1/2".
I'm looking to purchase a kit but I'm not sure which one.. Say if you want to cut a 5/8" deep rabbet(or groove, dado) in the center of edge of a 1" thick board, I see where a 1/4" shank would be required. How else could I do this? I do prefer the 1/2" shank, but would I be limiting the use of the bit?
Hope I make sense here.
Howie

[gwyneth]

Get the 1/2" shank.

I hope someone who's better at explaining rabbet math than I am will chime in with the equations, but it shouldn't be a problem.

[Ken Massingale]

Howie,
I'm not clear on what you want to do. A rabbet is American for the English term Rebate, which is like an 'L' profile on the edge of stock.
They don't do dado's or grooves, these are done with a dado blade or straight bits.
All that aside, I prefer 1/2" shanks, but also ue 1/4" shanks when working with thin stock.
HTH

[eezlock]

rabbeting kit?

I'm not sure what you mean by a rabbeting kit?...... If you are wanting to cut a groove down the center of a 1" thick board, 5/8" deep...it can be done with a router making multiple passes. Actually, that cut your wanting to
make sounds like a dado instead of a rabbet. A cut that depth in that thick of stock would be easier to make and safer if done with a stacked dado blade
on the tablesaw. eezlock

[LCHIEN]

I read rabetting kit to mean a rabetting bit with a number of interchageable bearing sizes to do rabbets of assorted sizes by changing the bearing. Like this (photo courtesy of MLCS):



I always get 1/2" shanks except for very small diameter bits (like less than or equal 1/4"). Because 1/2 shanks are four times stronger and stiffer, they won't flex or vibrate giving smoother cuts and if really pushed they surely won't bend as some 1/4" shanks have been known to do.

Rabetting kit bits are usually like 1-3/8" diameter so a 1/2" shank is in order.

[gwyneth]

I believe Howie wants to run the router along the edge of a flat board and have d on Loring's diagram equal to the 5/8".

With that kind of rabbet kit, Howie, the shank size is not related to the dimensions of the groove/rabbet but I'll be the first to agree that rabbet math and the way it's presented in bit product descriptions can be highly confusing.

[gsmittle]

Rabbit Math...

One boy rabbit + one girl rabbit = 3645792 baby rabbits.

What? Oh, sorry--wrong rabbit....

[LinuxRandal]

I have a 1/4" rabbet, and I believe a 1/2" rabbet. but without the extra bearings. I thought I would use it more, but I use a straight/dado bit more for both rabbets and dado's (dado's or dadoes?). If you don't have the size you need (bearing), don't forget that approach!

[LCHIEN]

the math isn't that hard.

Basically the shank has nothing to do with the dimensions of the rabbet. Buy big for strength as I suggested.

The rabbet dimensions are H and D as the picture suggests, with the router vertical in a table.

H is set by the weight of the bit top surface above the table.

D is set by the bearing diameter and the bit diameter. D is 1/2 the difference between the bit dia. and the bearing diameter.

on this page there are several kits:
http://www.mlcswoodworking.com/shops...ng_kits_anchor
The only kit that will do 5/8" rabbets is the kit #8666 with a 2" diameter bit and you will need a 3/4" bearing.

The "Standard depth" and Additional Depth" values listed for the kit are with the bit diameter and the set of bearings. The bit diameters range from 1" to 2" and all but one have 1/2" shanks.

5/8" is a large rabbet. Be careful.

[newood2]

I believe Howie wants to run the router along the edge of a flat board and have d on Loring's diagram equal to the 5/8".

Yes you're right. It was hard to explain so I hope this sketch help.



Loring kinda clear up the math a little for me.
I think I've got a rabbet, or rabbit in the hat.

Thanks all y'all.

Howie

[Mark Smith]

You could use a rabbeting bit to create that profile but you'd just have to be lucky to find one with the right size cutter height for your use.

What I think you are actually looking for is a slot cutting bit. These are available in a wide range of cutter thicknesses.

Here's MLCS's listings: http://mlcswoodworking.com/shopsite_...le_slot_anchor

[gwyneth]

the math isn't that hard.

...

The only kit that will do 5/8" rabbets is the kit #8666 with a 2" diameter bit and you will need a 3/4" bearing.

...

5/8" is a large rabbet. Be careful.

Loring, what I meant wasn't so much the math but deciphering the non-standard use of "width" and "depth" in product descriptions. Not all of them are as clear or as diagrammed as MLCS's.

Howie, IMO, using a 2" diameter bit in a handheld router is risking the material and your body parts unless you've been routing for many years. If then. Remember, the outer edges of a 2" diameter bit can actually approach the speed of sound!

Much simpler and safer to get a 5/8" straight bit and use the router table. Or make a bridle mortise/tenon jig and use the TS.

[newood2]

Howie, IMO, using a 2" diameter bit in a handheld router is risking the material and your body parts unless you've been routing for many years. If then. Remember, the outer edges of a 2" diameter bit can actually approach the speed of sound!

I was thinking of using a router table and a split fence. Lay board flat with the edge up against the fence. Cut 1/8" depth each pass by adjusting the fence. For the last cut I would remove the fence and use the bearing guide.

Howie