I was pattern routing a 3/4 inch deep outside circle today until the spiral cutter grabbed the end grain and tore (chunked out) the wood to bits.

Had diligently bandsawed the wood close to the desired circumference so not to have the bit chattering too much. Good theory!! Bad execution!!

 

So I gave up & walked away bitching & dejected for the day.

 

Then in the dark depths of my "mind" I tend to remember that if you encapsule/surround  the bit in wood the bit doesn't tend to grab the endgrain as much. Similar to routing a groove in wood even though usually with a groove you're going across the grain.

 

Soooo-- is my mind correct?

 

I understand that I'll be comparing 2 different bits--the bearing guided pattern bit & the plunge cut bit. But both are spiral carbide cutters and the only real difference(s) I see is the location of the cutter & the amount of material I choose to cut.

 

Trouble with doing a circle 1/2 the circle will be end grain at all times. So climb routing 1/2 the time & normal routing the other 1/2??

There must be a better way.

 

ALL opinions welcome.

Thks

smitty

 

Edited November 18, 20187 yr by smitty10101
add'l wording

When I rout circles with a trammel, I don’t precut the circle.  Instead, I plunge into the cut and use several passes cutting about 1/8 to 3/16” on each pass.   I tried precutting once and got the same results that you got.  I figured using the upward spiral bit was the culprit.

Ron    have you used a shear cutter on a circle?

My "fear" is that those kind of cutters are too agressive for that task. Yes/no??

 

Come to think of it you can't plunge with a shear cutter can you??  DUH!!!

Edited November 18, 20187 yr by smitty10101
add'l wording

I’ve always used a spiral upfeed and never had too much trouble. I did however slip out of the pivot pin.  That was interesting.

try a down shear helix panel bit...

Stick  that was what I was commenting about in that reply

1 hour ago, smitty10101 said:

have you used a shear cutter on a circle?

My "fear" is that those kind of cutters are too agressive for that task. Yes/no??

Are these type of bits "better" for end grain?

smitty 

1 hour ago, smitty10101 said:

 

 

36 minutes ago, smitty10101 said:

Are these type of bits "better" for end grain?

smitty 

they work very well on all grains because they shear and not tear their way through the grain...

wait till use it for edge jointing.. you'll be a happy camper...

I was making a bunch of these crosses for presents and was getting tear out on the bases. The tear out was happing when I got to the end grain of the circle. Stick told me to get a better quality bit (Whiteside or Freud). If you guys haven't figured it out Stick is always right.  

 

Actually I was using a Whiteside pattern spiral up cut bit recently resharpened by Whiteside. Still managed to rip up the end grain!

Will be trying a shear bit as soon as I can get it here.

13 minutes ago, hawkeye10 said:

If you guys haven't figured it out Stick is always right.

that's not what she says...

7 minutes ago, smitty10101 said:

Actually I was using a Whiteside pattern spiral up cut bit recently resharpened by Whiteside.

is it clean???

this might help...

 

TEAR OUT - How to avoid....pdf

woodsmith-184-avoiding-router-table-tearout.pdf

Edited November 19, 20187 yr by Stick486

I was getting occasional tearout (hunks) with some poplar, but solved it by taking very light passes.  In my case, it wasn't end grain, it was with the grain/parallel.  I'd be reluctant to climb cut (friend/wood guru lost a finger on that one).

Like Don mentioned, a circle jig and plunge cuts in steps will give a cleaner cut.

22 hours ago, Stick486 said:

is it clean???

2nd time I've used it since being resharpened.

 

Clean & shining more than my bald head!!

Sharp as a new bit

I MIGHT have taken just a tad too much material

 

Went to get a Dialbo bit today. Just to practice. HD said they had 2 in stock--NADDA--Their inventory systems SUCKS!!!  and they "count" stock at least once a month!!  I hope their accountants can count better than their clerks--or maybe they are just cooking the books.

 

Got two different bits coming in from Amazon

Some woods don't like to be routed others seemed to be happy getting the attention.

spiral and lots of flute's 

This one gives a very smooth cut in any hardwood. Dunno about soft woods. It's an Amana 1/2" 3 spiral up cut.

 

I guess this is were I'm a bit funny with the router bit. I'm a bit old school and haven't really bought into the up and down cut bits yet. Usually I just use a straight bit but at a slow pace only cutting a small amount at a time. Even with other bits... I found it took longer but took less time on any repairs...

 

 

8 minutes ago, BillyJack said:

use a straight bit but at a slow pace

This is probably why so many have issues.  We often tend to rush through an operation rather than go slow.  And yes I am talking about myself at times.