# Going deep with a router.



## richgreer (Dec 25, 2009)

I need to go deep with a router bit. The question is my mind is how shallow can one go in the collet without taking any inappropriate risk.

My intuition says that I need to go at least 1" into the collet. I've never heard any "official" rule about this.

It is probably germane to say that I will be making multiple passes and only lowering the bit about 1/4" with each pass to minimize the stress on the bit.

Any thoughts?


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## donbee (Feb 7, 2009)

Rich,
In my experience, the cost of a long shank bit is well worth the price.
ddwwb


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## KnickKnack (Aug 20, 2008)

Interesting question - I've wondered this myself whenever I've needed to not push all the shank in, which is usually.
For what it may be worth, Trend, my supplier of bits, has this to say...

Always insert as much of the Shank as possible into the collet, and at least three quarters of the shank length as a minimum, to decrease the chances of deflection of cutter when under load.

Ummm, I often don't get them much in.


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## renners (Apr 9, 2010)

Rich, maybe you should think about a collet extension. It's one of those things "that you think you'll never use but now can't live without".
Especially useful on a router table.


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## HerbC (Jul 28, 2010)

You could invest in a collet extension…

Herb


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## Bobsboxes (Feb 8, 2011)

Rich, I have had a bit come out from not being deep enough in collet. It came up under my featherboad and scared me, Iwas lucky I had the feather board on or It may have got me. I got on computer that night and ordered some longer bits, and of those i have used all but one. I saw a picture in a mag. awhill back of a fellow with a ding in his forehead from a loose bit. So be careful. I have seen the bit extenders, they scare me also, if bit grabs as it has to most of us.


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## richgreer (Dec 25, 2009)

Don's point is well taken. My problem is that I am working on a project that I must complete by Friday, which means I need a router bit today and I already own the longest bit available locally.

I cannot afford to wait even a day for a longer bit to be sent to me.

Did I tell you how much I hate deadlines?


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## S4S (Jan 22, 2011)

I would suggest not cutting more than 1/8 inch depth per pass if you are using a 1 1/2 horse power router or less horsepower than 1 1/2 h.p. . The less increased depth per pass equals less tear-out and burning and maybe worse .


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## renners (Apr 9, 2010)

What is it exactly you are routing so deep? If you tell us what it is we should be able help you…


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## jmos (Nov 30, 2011)

The collet of my PC has jaws that are about 1-1/4", I can push the bit further than that to bottom it out, but the end would be past the jaws. As the collet grips by wedging the leading edge of the collet onto the shaft, thus pinching the collet around the bit, I would be hesitant to insert the bit less than 1-1/4". You could probably run it out slightly (say an 1/8") but too far and tightening the collet would tend to close the gap in the collet fully before actually tightening down on the shaft. It may seem hand tight, but under load it could slip, or worse, come out.

As Renners asked, what's the application, maybe someone can come up with a work around?


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## Loren (May 30, 2008)

What happens if the collet releases is the bit falls out and doesn't
do much damage. I have had it happen a few times. In the
milliseconds as the bit comes out the end of the cutter may
wobble and mess up the work.

In terms of breaking your router or wrecking the bit, the
danger isn't too great. I would look at the collet and make
a mark on your bit shank and leave the bit 100% inserted
in the collet proper. What happens if the bit is pulled
farther out, I believe, is the collet can get distorted.


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## richgreer (Dec 25, 2009)

In response to "What is it exactly you are routing so deep?"

I'm routing mortises for a critical joint on some chairs. The mortise pal jig takes some depth away and I feel I need to get at least an inch of depth in the mortise. My horizontal travel is only about an inch. To avoid too much horizontal stress on the collet, I am doing more up and down motion that wide ways morion and only going sideways to clean up.


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## DrDirt (Feb 26, 2008)

I use a 3/8 HSS mill.
I had to get an adaptor for my 1/2 inch router from Lee Valley - but it has the length.
Stay away from a 4 flute mill as those cannot plunge cut.

I got this set-up when Michael Fortune gave a weekend seminar at the Tulsa Woodworking guild meeting 2 years ago. He shared the plans for his mortising set up (also in FWW 197) 








Best prices are at wholesale tool
www.wttool.com - hss bits are ~5 bucks.


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## renners (Apr 9, 2010)

If you are using a plunging motion to nibble the waste out instead of pushing the router, I think you are ok leaving just 1/2" in the collet, you could even clean up with a chisel. Is the router used on the jig with the pheonolic base on? Could you gain a couple of mm by taking the router base off? (Plunge router I'm thinking off). 
Can you use your mortise jig to get as much depth as possible, take router off and then go deeper using the fence for alignment/take more out with mortiser? What width mortise are we talking here and are you using a 1/4" router?
How many mortises, if it's only 1 chair could you do it by hand? What about shallower mortises but pinning/fox wedging the tenon.


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## Loren (May 30, 2008)

If you have mortise chisels, I'd recommend establishing the
geometry with your router jig and then having at it with chisels.

Even if you don't have mortise chisels, the sides of a shallow
plunged mortise can act as a guide for drilling with forstner
or brad point bits. Then clean out with regular bench 
chisels. Goes pretty quick.


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## TheDane (May 15, 2008)

Rich-Without a collet extension, I wouldn't do this with a router. I would either go to the drill press and waste out as much as I could then finish with a chisel, or find a buddy with a hollow chisel mortiser.

-Gerry


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## PurpLev (May 30, 2008)

I would just use chisels… I know it's not electric or anything, but it can go pretty deep and chances of something going wrong are almost non existent.

think about it- you state that you are on a deadline with this project - is it really worth the extra trouble of messing up your work piece, or your collet at the last minute and not meeting that deadline just cause you wanted to get off that extra 1/4" of depth in that hole?


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## Gene01 (Jan 5, 2009)

Rich, I'd miss your posts. So, don't do it!


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## North40 (Oct 17, 2007)

Rich, I took a look at your shop, and it looks like you have a mortising machine. That won't work for this particular mortise?


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## richgreer (Dec 25, 2009)

Thank you for all your comments and concerns. For the record, I decided to cut my mortises 1/4" shallower than originally planned. That enables me to set the router bit 1.25" into the collet.

To add a little more strength to the joint, I am putting 2 dowels through the tenon from the side. The ends of these dowels are visible. They are "styling details".

I'm reasonably confident that the joint will be strong enough. I have cut 20 of the required 24 mortises with no problem. Now I am off to the store to buy more dowels. I'm using 5/16" dowels.

Someone asked about using my mortising machine. It is not working correctly and I think it would create more problems than it would solve. Its hold-down feature does not hold anything down.

Behind the scenes - it is virtually an absolute that I have to get this job done today. I am NEVER committing to a deadline again other than to say "I will get it done when I get it done".

Woodworking is suppose to bring me happiness. I'm not enjoying today.

I didn't say this earlier, but this whole problem is due to a bit breaking last evening. Why it broke is another whole discussion.


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## renners (Apr 9, 2010)

Just a note re: the hold down on your mortiser.

The hold down/fence on my own sits on a shelf, because it is frankly, pants.

Instead I G cramp on a 2×2" batten at the back and use that as a fence, then cramp the work piece to the batten for the first cut, release the cramp and move the piece over for the next bite, and keep it held down by hand. It works surprisingly well.

Is your client that inflexible they can't allow for 'circumstances beyond your control?'


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## NBeener (Sep 16, 2009)

Most of the time that I use my hollow-chisel mortiser, I use it with the cross-slide/X-Y vise that I bought.

Smoother … easier.

The hold downs do seem like more trouble than they're worth….


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## DIYaholic (Jan 28, 2011)

richgreer,
I hope your day ended on a positive note! It really does suck to have gremlins getting involved when there are deadlines involved. Isn't that when they ALWAYS show up???

Neil,
*cross-slide/X-Y vise* BRILLIANT! I have heard bad, very bad things about the "Clamping/hold down" ability of the table on the Jet Mortiser. I have one I have not used yet, but just playing with it , I believe every word. I think I may be purchasing a cross-slide/X-Y vise very shortly!


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## TheDane (May 15, 2008)

The X-Y vise looks like a stroke of genius! The 'holddown' is the Achilles heel of the Jet JBM-5.

I retrofitted mine with an auxilliary table and fence that was available from Rockler a few years ago … that gives me some clamping space that you don't have with the stock table and fence.

-Gerry


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## richgreer (Dec 25, 2009)

Well, the day ended well and I am on schedule for complete this project on by Friday. A little more sanding this morning and then I will do final assembly and stain by noon. I always let the stain dry for at least 24 hours. I'll still have enough time for 5 coats of poly tomorrow afternoon and Friday morning.

Some real good may have come out of this situation. I had never thought of a cross slide vise for my mortising machine. Of those who have them, is there any particular brand that works better than others and/or do you have additional advise to offer?


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## mtenterprises (Jan 10, 2011)

I know this is a "bit" late but here is some info any ways, End mills can de purchased in long lengths, 1/8" with a length of 3"length up to 1/2" with a length of 6" collet sizes on the smaller sizes should be 1/4", 5/16", 3/8". Since flute lentht is anywhere from 1" to 1 1/2" the shank could be cut down to whatever you need. find these at www.jtsmach.com.
MIKE


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## jbertelson (Sep 26, 2009)

Hmmm, me of few tools, has an X-Y vise, and I've had it for 15 to 20 years. Can't remember why I bought it, but it does come out for use with the drill press from time to time…..........

Mine is not the greatest piece of gear…....put a little money into it rather than go cheap.


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## NBeener (Sep 16, 2009)

Couple links I just found, on the subject:

LINK

LINK

LINK

LINK

When I bought mine, from HF, it was with full awareness of all the reviews … that indicated you should disassemble the thing, to a moderate degree, clean everything well, lap the ways, lube it, and reassemble it.

All of which took me less than an hour. The before/after … was staggering. It went from rickety and sloppy to smooth and precise.

If memory serves, a "good" cross-table vise is pretty expensive.

SHOULD you buy a better one ? Why not ??? ;-)

Could the HF version get you buy, if you're willing to invest a little time and effort ?? IME … yup


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## richgreer (Dec 25, 2009)

This is great Neil - Thanks.


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## renners (Apr 9, 2010)

Hats off to Neil, the cross vice really is a good idea for the benchtop mortiser. For cabinet doors and small legs it would work just fine on my machine, then demount it for getting big stock under the chisel.


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## richgreer (Dec 25, 2009)

I've spent a little time looking at X-Y (or cross) vices today. It seems like all of them have adjustment cranks on 3 sides and it looks like one of those cranks would interfere with the post on the mortising machine.

I read about modifying a Grizzly vice - but that vice appears to be no longer available. Does anyone know anything about a vice that does not interfere with the post and/or a vice that is easily modified?


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## TheDane (May 15, 2008)

Rich-Check out http://www.grizzly.com/products/Cross-Sliding-Vise/G1064 ... I think the LJ posting Neil provided the link to had two numbers transposed.

-Gerry


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