# Burnt End Mill



## Seldonman (Jul 30, 2013)

Here's an easy question. While attempting to learn how to make mortises using my plunge router I burnt the end mill bit. It was my fault as it started smoking and I just pressed on until I reach the end of the cut. Is the bit worthless now or can I somehow salvage it?

Thanks,

Jim M.


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## Stick486 (Jan 4, 2013)

Seldonman said:


> Here's an easy question. While attempting to learn how to make mortises using my plunge router I burnt the end mill bit. It was my fault as it started smoking and I just pressed on until I reach the end of the cut. Is the bit worthless now or can I somehow salvage it?
> 
> Thanks,
> 
> Jim M.


Toast...
sounds like you were trying to cut/remove too much material in one pass... 
what style of end mill are you using???


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## Seldonman (Jul 30, 2013)

Stick486 said:


> Toast...
> sounds like you were trying to cut/remove too much material in one pass...
> what style of end mill are you using???


Ok, here is a picture of two types of end mill bits that I have. As you can see the burnt one is on the right. I know I want to use a bit that pulls the material up and out or in another words, an up spiral but I do not know if either of these is the correct end mill for mortising. 

Any ideas?

Jim


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## Stick486 (Jan 4, 2013)

Seldonman said:


> Ok, here is a picture of two types of end mill bits that I have. As you can see the burnt one is on the right. I know I want to use a bit that pulls the material up and out or in another words, an up spiral but I do not know if either of these is the correct end mill for mortising.
> 
> Any ideas?
> 
> Jim


I use end mills all the time...
and do you think I could find a specific link to what I use...
spirals are fine for mortises...
it appears that cutters are on the end of the mill and they lack cutting capabilities on the spiral...
look at this one and you'll see what mean...

Freud Tools | 1/2" (Dia.) Up Spiral Bit

are those tool steel or solid carbide???
where were they made???
what speed are you turning???
how much material are you trying to cut in one pass...

have a study..

Freud Tools


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## Seldonman (Jul 30, 2013)

Here is what I know. The bit is marked HS so I assume High Speed Steel. Do not know brand as they were given to me as a gift. The router is a Bosch 1611 EVS set to highest speed setting of "5". Routing White Oak and using depth setting set about 1/4 inch per step. I plunger down and then forward but may be moving to quickly. I did not remove waste material between cuts but will do so in the future.


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## Stick486 (Jan 4, 2013)

Seldonman said:


> Here is what I know. The bit is marked HS so I assume High Speed Steel. Do not know brand as they were given to me as a gift. The router is a Bosch 1611 EVS set to highest speed setting of "5". Routing White Oak and using depth setting set about 1/4 inch per step. I plunger down and then forward but may be moving to quickly. I did not remove waste material between cuts but will do so in the future.


agreed.. Steel.. 
25,000 RPM is a little quick for steel.. dial back to 3 or 4 and slow the feed rate... 
use carbide on Oak... steel is pretty much defeated before you even start..
look to that Freud link for some product...
CMT is good if you can source them...
Whiteside is a very good bang for the buck...
Whiteside Machine Company
people swear by them but bits from china are not worth the money at any price IMO...

What I use the most of in a production shop... they come from Travers...
SuperCEED® Solid Carbide Hi-Feed X-MAX® Force Coated Multiple Flute Roughing End Mills | Travers Tool

good man to talk to...
Clayton Lewis
P:800-234-9985 x 2595
F: 800-838-8308


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## Seldonman (Jul 30, 2013)

Thanks Stick for the good information. I will follow it and let you know what happens. I did think that the faster you cut the cleaner it would be but looks like I am mistaken. Is there a rule of thumb for router speed? I know if I am using a big bit I want to go slow but that is all I know at this time.

Jim


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## Stick486 (Jan 4, 2013)

Jim...
Mill ends work better if you multi-pass for width...
say you are mortising for 3/4". use a 1/2" mill...
1/2' mortise use a 5/16 mill...
you get the idea
you can collet that 1617 of yours for 1/4, 5/16, 3/8 and 1/2 inch mills... 
start out turning the mill on slow speed and work your way up... you'll sense what works...

another thing...
there are tons of mortising guides/jig posted in this forum...
use the search function and look for "mortising jig"...
or maybe somebuddy here has the best links already ready to go...


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## Quillman (Aug 16, 2010)

"bit that pulls the material up and out or in another words, an up spiral but I do not know if either of these is the correct end mill for mortising. 

Any ideas?
Jim
****************************************
Cutters are bottom cutters but sick and old. If these cutters will not allow a 1/16/pass without burning they are shot. 1/4 pass, even with your big router, is too much waste/pass.
Router bits are better at cutting wood than mill cutters. Switch whilst you're ahead.


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## Seldonman (Jul 30, 2013)

*Tage Frid Jig*

I found this jig in the Highland woodworker site and it was supposedly used by Tage Frid when he needed to rout a mortise. I am surprised that you said that end mills are not the optimal bit for routing mortise. Are you saying that a straight bit is better?


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## Seldonman (Jul 30, 2013)

*Temperature in Shop last week*

This is no joke, this was the temperature in my shop last week and it will stay that way until October! Yes, I am in a desert call Phoenix, AZ.


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## boogalee (Nov 24, 2010)

Seldonman said:


> This is no joke, this was the temperature in my shop last week and it will stay that way until October! Yes, I am in a desert call Phoenix, AZ.


It is no wonder that your end mill burned up. :blink:

Al


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## Quillman (Aug 16, 2010)

"Are you saying that a straight bit is better?"
***********************
Not necessarily, (end mills best for morticing). (woodworking cutters) Spirals are efficient, designed for wood, ding the top corners of the mortice; they're expensive.
In fact, their efficiency is such they're always over driven and make moritces >their diameter.

They are very limited in length and diameter compared to carbide brazed onto HSS.
Given vacuum chip collection, straight bits, tho technique sensitive too, are your best buy for morticing. 

Not more efficent but >acceptable. All cutters are compromises. Just what your criteria are for best morticing, determines the best cutter for you. Is it speed, efficiency, cutter selection, 1/2-life span, safety, waste/cut, cleanliness of mortice wall, floor, or corners, deflection resistance, $/mortice. Lots of nuance to consider.


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## RainMan 2.0 (May 6, 2014)

Seldonman said:


> This is no joke, this was the temperature in my shop last week and it will stay that way until October! Yes, I am in a desert call Phoenix, AZ.


Jim we were in the 90's last week and I wish I had a thermometer as I'm positive is was over a hundred ten in my garage . I had 3 failed attempts during the week in the evenings trying to router some project . Just couldn't think straight or see as the sweat was pouring into my eyes . The dust mask wasn't really helping either . 
Sorry if I'm taking this thread off subject but I feel your pain 

I have no idea how you guys deal with it


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## neville9999 (Jul 22, 2010)

Jim that is just the wrong cutter, it looks about 1/2 inch on the photo so any double flute carbide 1/2 inch cutter would be a better choice than the end mill would be, up-cut spiral cutter would also work great but I always say that a normal double flute carbide cutter is fine and will work very well in most workshop situations and in fact I user normal carbide cutters for most of my work, you also need to cut at the cutters pace so if you push it too hard then the cutter will get hot and that is not good, with experience you will hear when the cutter is being pushed too hard, end mill, not the best cutter for a mortice. N


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## rwl7532 (Sep 8, 2011)

Seldonman said:


> This is no joke, this was the temperature in my shop last week and it will stay that way until October! Yes, I am in a desert call Phoenix, AZ.


Temp, barometer and humidity all in one. Laid out horizontally to boot. I want one!


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## timbertailor (Oct 4, 2009)

Seldonman said:


> This is no joke, this was the temperature in my shop last week and it will stay that way until October! Yes, I am in a desert call Phoenix, AZ.


That's about what I am running in the garage but I am closer to 65% humidity.:help:
Houston, TX.

I was looking at the photo he posted and the bit looks like the tips are worn away. No salvaging that.
I use a Freud 1/2" up spiral bit for routing blind holes. Clean holes, stay sharp longer, and are reasonably priced compared to boutique bits.

Here is a basic chart for bit speeds but you should follow the mfg's recommendations for your bits.


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