long spiral router bits

[Ron Bott]

I'm looking for a spiral upcut router bit, with a 3" cutting length. The largest I have been able to find is a 2". Is this as big as they go for a 1/2" shank?

[Steve knight]

pretty much. going for an endmill will work but the 1/2" shank ones may have a notch in the shaft that would get in the way.

[Ron Bott]

going for an endmill will work...

I'm not sure what "endmill" means?

[Steve knight]

an endill is where the spiral router bits came from. they are used in a milling machine to cut metal
http://en.wikipedia.org/wiki/Endmill
http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1695309&PMT4NO=41965096

[Ron Bott]

an endill is where the spiral router bits came from. they are used in a milling machine to cut metal

Got it. Thanks.

[Steve knight]

looked at the solid carbide and they were about 90.00 checking ebay is a good idea. but most of the 1/2" and larger endmills have a notch in the shaft.

[John Gornall]

Steve:

I'm interested in cutting mortises 3" deep - would an end mill such as the one you linked to work safely in a router?

[Peter Quinn]

Here's another option:

http://www.amanatool.com/bits-fv/46350.html

Also check onsrud web site, they have cutters for all occasions.

[David DeCristoforo]

"...would an end mill such as the one you linked to work safely in a router?"

With bits that long, you need to take multiple passes. Otherwise you are going to get a lot of vibration and/or bit breakage. But as long as you keep that in mind and take it slow, yes, it can be done safely.

[Steve knight]

onsrud will cost an arm and a leg. I like them but I only buy them when I can get a good deal on ebay.
one thing I have done is have a shoulder ground on a bit. say the bit only cuts 1.25" I have a 1/4" long shoulder ground on so I can cut 1.5" deep without rubbing.

[Dave Jackson]

I'm looking for a spiral upcut router bit, with a 3" cutting length. The largest I have been able to find is a 2". Is this as big as they go for a 1/2" shank?

I sometimes make decorative posts at work. This involves pattern routing 4x4, 6x6 and 10x10 treated posts. The place to look for a bit that size is in CNC tooling. I have some spiral bits that are 5 1/2" in length (1/2" shank) and can reach 3"+ in depth. Generally, you won't find bits this size in a router bit catalog, but it will be found in CNC tooling. There are many suppliers and prices can vary quite a bit with this tooling, but Goggling CNC tooling should get you in the right direction. The 5 1/2" long bits are the largest that will fit in my PC 7539 plunger, and don't forget to take it slow. --dave

[pat warner]

Tho certain spirals are indeed much stronger and with more cutting efficiency than ordinary straight bits, I would not be digging such deep holes with one, in your shoes.
Moreover, tho there are some mighty long cutters in Routerdom, the machine, its fixturing and safety, preclude this operator from routing much>2" deep.
If 3" morticing is going to be common for you I'd recommend a power morticing machine of some sort.

[John Gornall]

In looking at the practicalities of deep cuts with a router I find my big Makita router only plunges 2 1/4 inches anyway.

I have done many mortises 2 inches deep and have found it's best to plunge cut both ends and then do a series of plunges along the length of the mortise to remove most of the waste and then finish with a side cut to clean it up. Seems to work better and faster than a series of side cuts going down 1/4 inch at a time.

[Bill Hylton]

I have routed 3" deep mortises with a plunge router and a 1/2" up-spiral bit. Actually, a skoche more than 3". The bit is only part of the challenge. You also need a plunge router with a 3" plunge range.

About 2 1/2 years ago, I reviewed 3+hp routers--most of which are plungers--for Woodworker's Journal. One of the specifics I measured was the plunge range. I found that the DW625 would do 3" IF you removed the handy speed nut from the threaded plunge-stop rod, keeping just the acorn nut to prevent the motor from rising off the plunge rods.

A year or so later, I built a couple of passage doors for my shop, constructing them with router-cut loose tenon joinery. The mortises in the door parts are (mostly) 3" deep. Since I had 40 mortises to rout for each door, I didn't want a multi-step approach, such as roughing them out on the drill press.

Leigh sells a 1/2" up-spiral for use with its FMT that is 4" overall with cutting flutes about 2 7/8" long. Two numbers etched in the shank--180 CL and S024988. That's the bit I used. I had 3/4" to 7/8" of the shank in the DW625 collet.

The mortising block I used is shown in my book Power Tool Joinery. Page 99.

BTW, it's really beneficial to have dust collection on the router.

Good luck to you. It worked for me.

Bill

[Mark Singer]

There is a safety issue as mentioned. The spiral bits by Amana and Osrud for my slot mortiser would work and are carbide.

[John Gornall]

Thank you.