# Breaking Router Bits at the Shaft



## Chizl (Jul 20, 2009)

I've only started learning to do dovetails and it's a real hit or miss for me. I own a Hitachi KM12VC and twice now while using a dovetailing bit on popular, I've broke the bit about 1/8" inside the end of the collet. Leaving about 3/4" of the shaft in the collet. This last one was bad enough the collet is a goner. I can't put another bit in it. I'm putting some pressure when tighting the bit so I don't think it's too loose. The back side of the head for the bit is just the dovetail collar so it's not rubbing. I'm at a loss. What can cause this?


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## jschaben (Jun 21, 2009)

Chizl said:


> I've only started learning to do dovetails and it's a real hit or miss for me. I own a Hitachi KM12VC and twice now while using a dovetailing bit on popular, I've broke the bit about 1/8" inside the end of the collet. Leaving about 3/4" of the shaft in the collet. This last one was bad enough the collet is a goner. I can't put another bit in it. I'm putting some pressure when tighting the bit so I don't think it's too loose. The back side of the head for the bit is just the dovetail collar so it's not rubbing. I'm at a loss. What can cause this?


Welcome to the Forum.

I'm a little new to routing but I have the same router. Been warned repeatedly by several sources not to insert the bit to deeply to where the collett tightens up on the bit collar. I always pull mine up just a little to where some of the shank shows. 
This is just a guess, I'm sure someone more experienced will be along soon.


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## dutchman 46 (May 23, 2007)

Hello and welcome. I have seen problems when the shaft is 1/4 in. and the steel is HHS, and not Carbide. tell me if those things are correct, I would use carbide, and check your speed, Also, don't use a lot of pressure on the bit. I did break bits when i used the 1/4 in. bits.


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## BigJimAK (Mar 13, 2009)

Welcome, Chizl...

One way to "protect" yourself from fully inserting the bit is to install a small rubber O-ring into the bottom of the collet. Then insert the bit loosely but up against the ring. I cannot take credit for that advice. A wise old Routologist told me that.


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## levon (Sep 14, 2008)

im no pro, but i dont think the bit depth is causing the problem. something else seems to be going on.

i think Howard is closer to an explanation.


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## Chizl (Jul 20, 2009)

I don't think its the depth either since I'm doing dovetails and that requires me to have a collar, which in turn makes the bit stand out at least 1/2 away from the collet.

I'm not sure what type of bit, I'm just bying them at Home Depot, which seem to be the only one's they have.. But I'll make sure I get a Carbide next time.


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## Chizl (Jul 20, 2009)

Chizl said:


> which in turn makes the bit stand out at least 1/2 away from the collet.


Makes the head of the bit stand out at least 1/2 away from the collet. I'm sure everyone knew what I meant, I just wanted to clarify.


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## bobj3 (Jan 17, 2006)

hi Chizl

The dovetail bit is one that you should buy the very best you can get,,

It's works very hard and is always trapped in the pocket from the word go the norm..heat is the killer on dovetails bits.. I can't tell you how many I have but it's many...and I have cooked my share of them...

A good 1/2" dovetail bit will run you about 30 to 40.oo each..I'm not saying the higher the price the better the bit but it just works out that way..  a good rule is the more carb,on the bit the longer it will last...and do a better job the norm...




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Chizl said:


> I don't think its the depth either since I'm doing dovetails and that requires me to have a collar, which in turn makes the bit stand out at least 1/2 away from the collet.
> 
> I'm not sure what type of bit, I'm just bying them at Home Depot, which seem to be the only one's they have.. But I'll make sure I get a Carbide next time.


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## Twill57 (Jun 8, 2009)

I have only broken one DT bit, a Craftsman HSS. I was cutting a sliding DT and feeding too fast. Now I will use a straight bit to make an initial cut so the DT bit does not have to work so hard. Helps to have a second router to speed this up.


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## SE18 (Apr 6, 2009)

BigJimAK said:


> Welcome, Chizl...
> 
> One way to "protect" yourself from fully inserting the bit is to install a small rubber O-ring into the bottom of the collet. Then insert the bit loosely but up against the ring. I cannot take credit for that advice. A wise old Routologist told me that.


Ok, not to hijack the thread but after this was mentioned, I have to ask the question. "Is it really necessary to NOT install the bit to the bottom of the collet?" What happens if you do install it all the way down?

I didn't see anything about his in my operator manual. If you are not supposed to install the bit all the way down, then why wouldn't the manufacturer supply a rubber washer or other device?


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## levon (Sep 14, 2008)

hi David

i think there may be one manufacturer that doesnt recommend this. but every router ive got the manual says push the bit in all the way and then pull back out, varying from 1/8 to 1/4" i use a rubber sink washer behind my bit. the addition of a rubber spacer eliminates the need for measuring each time.


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## Twill57 (Jun 8, 2009)

SE18 said:


> "Is it really necessary to NOT install the bit to the bottom of the collet?" What happens if you do install it all the way down?


There are several reasons, and I am sure others will add to the list. 
Some bits have shorter shanks and are slightly smaller at the cutting end. If the bit is put in all the way the collet will not tighten correctly. 

As the collet is tightened it will move the bit down slightly, as the bit bottoms out, the collet can not be fully tightened.

And last on my list, if the bit get stuck in the collet, you can not lightly tap it downward to get it loose.

I seem to remember reading about not bottoming the bit in one of my owner's manuals, just can not remember which one.


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## Chizl (Jul 20, 2009)

SE18 said:


> Ok, not to hijack the thread but after this was mentioned, I have to ask the question. "Is it really necessary to NOT install the bit to the bottom of the collet?" What happens if you do install it all the way down?
> 
> I didn't see anything about his in my operator manual. If you are not supposed to install the bit all the way down, then why wouldn't the manufacturer supply a rubber washer or other device?


Any deeper in the collet and it starts eating into my dovetail collar and the dovetail jig.



bobj3 said:


> A good 1/2" dovetail bit will run you about 30 to 40.oo each..I'm not saying the higher the price the better the bit but it just works out that way..  a good rule is the more carb,on the bit the longer it will last...and do a better job the norm...


I would love to use 1/2 bits, but my Jig is the one I can only make half blind dove tails. I tried doing it by hand and that was a disaster. Until the time I can, I have to work with this Jig.


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## Chizl (Jul 20, 2009)

I've been looking at a new Jig..

wwwDOTrocklerDOTcom/product.cfm?page=17367

Sorry for the above DOT, but this forum will not let me paste links yet.


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## bobj3 (Jan 17, 2006)

Hi Chiz

The jig that rockler is selling is the same one that many have,,from HF/Grizzly and many others that you can get for about 50.00 bucks.

ON SALE! - Complete Dovetail Jig, with FREE Dust Collector! - Rockler Woodworking Tools

The 1/2" is the diam.of the cutter ,most use a 1/4" shank bit,but it's best to use a LONG 1/4" shank dovetail bit on this jig..

Gives you just little bit more room inside router housing and in the brass guide..

With just a little bit of rework they work very well,see below 

============



Chizl said:


> I've been looking at a new Jig..
> 
> wwwDOTrocklerDOTcom/product.cfm?page=17367
> 
> Sorry for the above DOT, but this forum will not let me paste links yet.


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## Chizl (Jul 20, 2009)

bobj3 said:


> hi Chizl
> 
> The dovetail bit is one that you should buy the very best you can get,,


So what is considered to be the best?


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## bobj3 (Jan 17, 2006)

Hi Chizl

This just my 2 cents,,But I have had good luck with the brands below..they both have a life time warr. but they will wear how like most router bits...

I do like the MLCS with free shipping 

Katana reverse glue joint, drawer lock, lock mitre, Jointmaker Set
CMT Dovetail Router Bits
Freud Dovetail Router Bits


Freud Router Bits

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Chizl said:


> So what is considered to be the best?


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## Chizl (Jul 20, 2009)

bobj3 said:


> Hi Chiz
> 
> The jig that rockler is selling is the same one that many have,,from HF/Grizzly and many others that you can get for about 50.00 bucks.


The dovetail jig your using looks a lot like mine.. Which you can find here with my pics of my 3 car garage, which I refer to as My Shop in my signature below since I'm still not able to post links yet..

Also thanks for the links to the bits. I'll look through them. I found a website that sold the collet to my router. Seems my router is being phased out and the collet is no longer sold. So I bought a few extras just in case this happens again. 

I have 3 routers, but one is a plunge router with no base and the other is under my routing table, which also has no base. Leaving me just the Hitachi for dovetailing. Maybe I need to look into investing into a new router since it's becoming hard to buy parts for.


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## Chizl (Jul 20, 2009)

bobj3 said:


> Hi Chizl
> 
> This just my 2 cents,,But I have had good luck with the brands below..they both have a life time warr. but they will wear how like most router bits...
> 
> ...


Anyone ever use: wwwDOTwoodcraftDOTcom/family.aspx?FamilyID=1413

The CEO of my company does some woodworking and he says these are the best he's ever used.


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## Twill57 (Jun 8, 2009)

I have used some of the Woodcraft bits. They are OK. I prefer to use Whiteside of Freud bits, and lately I have just been buying the Whiteside bits. I will try some discount bits (bought a few $5.00 Woodcraft bits and a few of the Holbren plywood bits on close out) but for dovetail I stay with the known quality bits.


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## chizdad (Dec 7, 2010)

*Jointech problems??*

I have tried repeatedly to contact someone at Jointech. They referred me to [email protected]. I've corresponded with a person from there at least 6 times in the last six weeks or so. He seems sincere but it appears the company is in chaos. I get the feeling that no one knows what it going on as far as the 'ordering' and 'sending shipments' and 'availability of products'. What they :help:'DO' know is how to accept the money from Paypal. I sent them via Paypal for over $100 for my order and haven't received my full order.
Does anyone know if they are still in business or just unorganized.? I have registered a dispute with Paypal with no effect so far. It makes you not trust purchasing anything over the web through paypal or any other method.!

frustrated workworker


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## walowan (Jan 21, 2011)

SE18 said:


> Ok, not to hijack the thread but after this was mentioned, I have to ask the question. "Is it really necessary to NOT install the bit to the bottom of the collet?" What happens if you do install it all the way down?
> 
> I didn't see anything about his in my operator manual. If you are not supposed to install the bit all the way down, then why wouldn't the manufacturer supply a rubber washer or other device?


When you tighten the bit in the collet it needs to be able move down as the collet nut tightens, if the bit is already at the bottom of travel it has no where to move and can prevent proper tightening of the bit or can become jammed in the collet.


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## BigJimAK (Mar 13, 2009)

I picked up some 1/2" rubber grommets and inserted a couple in my 1/2" PC 7518 to follow Marc Sommerfeld's raised panel method Sommerfeld's Tools For Wood where they're used with matched bit sets and have just left them in place. With them there I drop the bit into the collet and let it bottom out on the grommet, which can compress easily as the collet tightens.

For any who have a deep collet (like mine) where a grommet isn't thick enough, I just added another grommet (or was it two more?) until it gave me the correct bit insertion.

It's a quick and easy, one-time action that only costs a few pennies and the issue goes away. The bit's always inserted properly too.

Check one, use many!


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## bobj3 (Jan 17, 2006)

Router Forums - View Single Post - From Marc Sommerfeld's Site - Why not to bottom out your router bit

see PDF file
=========


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## Cherryville Chuck (Sep 28, 2010)

SE18 said:


> Ok, not to hijack the thread but after this was mentioned, I have to ask the question. "Is it really necessary to NOT install the bit to the bottom of the collet?" What happens if you do install it all the way down?
> 
> I didn't see anything about his in my operator manual. If you are not supposed to install the bit all the way down, then why wouldn't the manufacturer supply a rubber washer or other device?


A book I have on machining metal says not to do it with drill bits. The reason is that the bit gets hot during use and the metal stretches which can loosen the bit in the chuck. Same would apply to a router bit/collet. Movement in the chuck/collet would also cause wear.


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