New to Routing, Burnt Bit? - Woodworking Talk - Woodworkers Forum
 6Likes
 
Thread Tools Display Modes
post #1 of 15 Old 11-04-2019, 11:18 PM Thread Starter
Member
 
Join Date: Sep 2019
Location: Pahrump (las Vegas) Nv.
Posts: 40
View wjfeeney@hotmail.com's Photo Album My Photos
New to Routing, Burnt Bit?

Hi All,
I have a Bosch 1617 with plunge base. For my first time using it I am making a Paulk work table 4 X 8. I have multiply plywood that I am using a 3/4" straight bit and have completed about 3/4 all the many holes. I set the speed at 5 for a bunch of the holes then decided to try a lower speed (4) for a whole bunch more. After stopping today I was looking at the bit and it was blackish towards the tip. Is it burnt? How did I burn it if it is? Speed wrong or need to modify pressure pushing down? I keep a steady pressure on it. Thanks

BillF
Sponsored Links
Advertisement
 
post #2 of 15 Old 11-04-2019, 11:58 PM
Wood machinist
 
difalkner's Avatar
 
Join Date: Nov 2011
Location: NW Louisiana
Posts: 3,548
View difalkner's Photo Album My Photos
A burnt bit is usually either the speed too fast or the feed rate too slow. Sometimes it's what's in the wood - resins, sap, glues, etc. and the bit is taking the hit in the form of heat.

David
woodnthings likes this.

David

Curly Wood Shop on Etsy
David Falkner - Woodworking YouTube channel
Our music at church - current videos Airline Baptist BC Facebook Live
Romans 3:23
difalkner is online now  
post #3 of 15 Old 11-05-2019, 01:46 AM
Ancient Termite
 
Join Date: Mar 2018
Location: Huntington Beach, California
Posts: 503
View NoThankyou's Photo Album My Photos
What I read is that you're trying to do holes.

Most straight bits out there don't do holes as they are NOT plunge able. Look at the bit. Are the knives completely across the end of the bit? What I mean here is that the knives or cutters reach from the circumference to the center point.

Rich
In furniture 1/32" is a Grand Canyon
NoThankyou is online now  
Sponsored Links
Advertisement
 
post #4 of 15 Old 11-05-2019, 04:51 AM
Senior Member
 
Join Date: Aug 2017
Posts: 1,982
View Tool Agnostic's Photo Album My Photos
Can you post of photo of the burned bit? It might help to see the type of bit as well as the pattern of the burn marks.
Tool Agnostic is online now  
post #5 of 15 Old 11-06-2019, 02:45 AM Thread Starter
Member
 
Join Date: Sep 2019
Location: Pahrump (las Vegas) Nv.
Posts: 40
View wjfeeney@hotmail.com's Photo Album My Photos
Quote:
Originally Posted by Tool Agnostic View Post
Can you post of photo of the burned bit? It might help to see the type of bit as well as the pattern of the burn marks.

I'll take a pic of it tomorrow and post it. I finished up the tabletop with it, increasing the speed which as it sounded like it bored better.
difalkner likes this.

BillF
post #6 of 15 Old 11-06-2019, 08:23 AM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 25,870
View woodnthings's Photo Album My Photos
Plunge bits VS straight bits...... differences!

You must use a "plunge" type bit for starting holes and then going deeper into the workpiece. An ordinary straight bit does not have cutting flutes on the bottom in the center and will stop almost immediately when "plunged" into the work:
https://www.amazon.com/Amana-Tool-Ca...3042288&sr=8-8



Straight router bits look like these:
https://www.amazon.com/Bestgle-Strai...3042571&sr=8-1


Both have straight carbide on the sides, so at first glance they may look the same. A bit that is gummed up will overheat and burn the wood very easily. There is a "best" combination of feed rate and RPMs for different woods. You just have to experiment to find it.

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is online now  
post #7 of 15 Old 11-06-2019, 12:11 PM
Nine Thumbs
 
Join Date: Dec 2015
Location: The Very Tip of Lake Michigan
Posts: 289
View Shop_Rat's Photo Album My Photos
I can't imagine that he wasn't using a plunge style bit. I made that mistake once, but only for a couple seconds. There was no way a straight cut bit could bore a hole. The smoke quickly flew and I knew I had grabbed the wrong bit. Oops!

That said, in addition to feeds and speeds, I have found that router bits come in myriad qualities. The ones you buy in kits from Harbor Freight or most big box stores are often inferior to quality bits like Freud, Yonico, Whiteside or MLCS. They are often not nearly as sharp nor balanced as well. I quit buying Skill brand sets long ago and have not been sorry or frustrated since.

If you have a good bit, then feeds and speeds (dependent on material type) rule the day.

Another $000,000,000.02 worth of advice,
Mark
Shop_Rat is offline  
post #8 of 15 Old 11-06-2019, 08:45 PM Thread Starter
Member
 
Join Date: Sep 2019
Location: Pahrump (las Vegas) Nv.
Posts: 40
View wjfeeney@hotmail.com's Photo Album My Photos
Quote:
Originally Posted by [email protected] View Post
I'll take a pic of it tomorrow and post it. I finished up the tabletop with it, increasing the speed which as it sounded like it bored better.

Here is the bit. Hope you can tell condition from it
Attached Thumbnails
Click image for larger version

Name:	Pic2 (1).jpg
Views:	13
Size:	55.2 KB
ID:	380355  

Click image for larger version

Name:	Pic2 (2).jpg
Views:	11
Size:	44.6 KB
ID:	380357  


BillF
post #9 of 15 Old 11-06-2019, 08:53 PM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 25,870
View woodnthings's Photo Album My Photos
What brand?

I don't see the cutting edge going all the way across on the bottom. It s very dirty, so clean it off and then take a better photo. I suspect it's not the correct bit, but I could be mistaken. It should look like this one:



The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is online now  
post #10 of 15 Old 11-07-2019, 12:27 AM
Senior Member
 
Join Date: Aug 2012
Location: British Columbia, Canada
Posts: 5,248
View FrankC's Photo Album My Photos
Take a photo of the end of the bit, otherwise it is hard to tell if the cutter gets past the center.

Wise men speak because they have something to say; fools because they have to say something -Plato

FrankC
http://sawdustmaking.com
http://woodworkerglossary.com
FrankC is online now  
post #11 of 15 Old 11-07-2019, 12:56 AM
Ancient Termite
 
Join Date: Mar 2018
Location: Huntington Beach, California
Posts: 503
View NoThankyou's Photo Album My Photos
When looking at the picture, I can say that bit is not designed to plunge or drill. The degree or burning is extreme and the bit probably should be thrown away.

The Amana bit probably would work very nicely for you.

Rich
In furniture 1/32" is a Grand Canyon
NoThankyou is online now  
post #12 of 15 Old 11-07-2019, 03:22 AM Thread Starter
Member
 
Join Date: Sep 2019
Location: Pahrump (las Vegas) Nv.
Posts: 40
View wjfeeney@hotmail.com's Photo Album My Photos
Quote:
Originally Posted by NoThankyou View Post
When looking at the picture, I can say that bit is not designed to plunge or drill. The degree or burning is extreme and the bit probably should be thrown away.

The Amana bit probably would work very nicely for you.

Funny you should mention that, The replacement bit from Amazon arrives tomorrow. I will try to get it cleaned up for a better picture to get educated as I know I have more boring to do for the Paulk miter saw work table after this one is done and I would like to use the right bit.

BillF
post #13 of 15 Old 11-07-2019, 07:44 PM Thread Starter
Member
 
Join Date: Sep 2019
Location: Pahrump (las Vegas) Nv.
Posts: 40
View wjfeeney@hotmail.com's Photo Album My Photos
So here are pictures of the bit after I cleaned it up, and the new replacement. Does the old bit look ruined you think? From looking at the diagram of the cut you can see why being a newbie I thought I could use it to bore the holes as it shows a clean cut sides and bottom. Wrong bit you think?
Attached Thumbnails
Click image for larger version

Name:	IMG_0389.jpg
Views:	9
Size:	81.1 KB
ID:	380377  

Click image for larger version

Name:	IMG_0387.jpg
Views:	9
Size:	85.1 KB
ID:	380379  

Click image for larger version

Name:	IMG_0388.jpg
Views:	10
Size:	77.0 KB
ID:	380381  

Click image for larger version

Name:	IMG_0391.jpg
Views:	11
Size:	68.8 KB
ID:	380383  

Click image for larger version

Name:	IMG_0390.jpg
Views:	10
Size:	70.8 KB
ID:	380385  


BillF
post #14 of 15 Old 11-07-2019, 10:07 PM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 25,870
View woodnthings's Photo Album My Photos
No cutting edge in the center!

That bit will not plunge. It will only cut when moved sideways. The diagram is correct and shows a flat bottom dado. Without a cutting edge all the way across you can't plunge it.

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is online now  
The Following User Says Thank You to woodnthings For This Useful Post:
[email protected] (11-08-2019)
post #15 of 15 Old 11-08-2019, 02:28 AM Thread Starter
Member
 
Join Date: Sep 2019
Location: Pahrump (las Vegas) Nv.
Posts: 40
View wjfeeney@hotmail.com's Photo Album My Photos
Quote:
Originally Posted by woodnthings View Post
That bit will not plunge. It will only cut when moved sideways. The diagram is correct and shows a flat bottom dado. Without a cutting edge all the way across you can't plunge it.

Thank you all for the coaching. It seems like a spiral router bit is what I need for boring the holes. I will probably get this one for the next set of dog holes on the miter saw infeed/out feed table.

https://www.amazon.com/Amana-Tool-HS...ustomerReviews

BillF
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome