Which bits... a deep rabbit hole... - Router Forums
 6Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 16 (permalink) Old 03-09-2018, 07:41 PM Thread Starter
Registered User
 
Join Date: Nov 2017
Country: United States
First Name: Ashley
Posts: 67
 
Default Which bits... a deep rabbit hole...

Question... Help me make a good choice on a flush trim bit. I'm not just interested in which bit - I'm interested in why it's a good choice.

I'll share my thinking below so you can confirm, correct, or guide me elsewhere. But first I'll share a little context...
  • I'm a routing newbie, reasonably experienced elsewhere in a shop, about to buy my first bits for use in a Bosch 1617, which will be handheld until I build a table (currently at least four projects down the queue).
  • I'm asking about flush trim bits - just to make the question concrete - but my immediate purchase list also includes others. I'll include specific immediate routing needs at the end of this post in case it's relevant.

How I'm choosing a flush trim bit...
The questions seem to be - what brand, what diameter, what cutting length, number of flutes, what shank size, and straight vs. spiral-up/down/combination...

What brand... is addressed in many other threads on this forum. Here's what I've gleaned from them...
  • Eagle American, Whiteside, Infinity, Sommerfield, CMT, Freud, Amana all seem to be top favored brands with a very slight bias toward those earlier in that list.
  • MLCS seems to be the most recommended brand of the lower tier. Some here favor MLCS for less used bits and others wouldn't use them without full body shrapnel protection.
  • Sommerfield has the edge for matched sets (like tongue and groove) because no height adjustment is required after changing to the second bit. Freud matched sets have fans here but I don't know whether they share that specific advantage. Neither is relevant to my current choices since my immediate purchase needs are not sets.

What diameter...
  • It seems that larger diameter bits are better, as long as the router has the power to swing it... which doesn't appear to be an issue for a Bosch 1617 with a flush trim or any of the other bits I'm considering.
  • Exception: if flush trimming inside corners, a smaller diameter bit may flush trim a tight corner that a larger diameter bit cannot. However, this is not an issue for my current project or for the next four projects in my queue.

What cutting length... I've seen little or no discussion of this question, though it also seems this is an application specific issue. For a flush trim bit there's a minimum required cutting length for whatever material I'm using. Beyond that, I'd pay slightly more for longer cutting length to make it useful in a future project with thicker material. I see no disadvantage to longer cutting length beyond price, as long as the work is supported in a way that doesn't make the extra cutter protruding below the workpiece a major hazard. My current use is flush trimming 1/2" baltic birch, but I'd buy a 1" cutting length over a 1/2" for future versatility.

How many flutes... I understand that more flutes are generally better, yielding a smoother cut and allowing higher feed rates.

Shank size... I'm considering only 1/2" shank for a stronger bit. I might make exceptions and use a 1/4" shank if I needed to flush trim tight inside radius corners (I don't right now) or for cost reasons if I was buying a solid carbide spiral bit (addressed below).

Straight vs Spiral... and spiral up/down/combination...
  • On first look, solid carbide spiral bits seem to have significant advantages if I ignore cost. A second look shows a price difference enough to make me take notice, especially if I stay with a 1/2" shank. Even if my budget allows me to pay $70-100 for what would be $20 in a straight bit, it doesn't mean that I want to.
  • My current projects are shop projects not cabinets. Materials are mostly baltic birch and dimensional lumber. I think straight bits have been successfully used with such materials for decades, so I don't think spiral is needed.
  • If I buy spiral, I'll buy up-cut so the router wants to stay firmly on the work.

So, which flush trim bit? I'm considering the following options from this Eagle America page. Once I narrow to a specific bit, I'll compare that precise bit against other brand choices - at least Whiteside and Freud for their many recommendations on this forum.
  1. #117-0412, 2 flutes, 1/4" diameter, 1" cutting length, 2-7/16" total length, 1/4" shank, single bottom bearing, $28.95
  2. #117-0615, 2 flutes, 3/8" diameter, 1" cutting length, 3-1/8" total length, 1/2" shank, single bottom bearing, $17.95
  3. #117-0825, 2 flutes, 1/2" diameter, 1" cutting length, 3-1/4" total length, 1/2" shank, single bottom bearing, $17.95. (That's also available with downshear for $21.95, but I'm uncertain whether that makes the handheld router less stable as it would with a spiral downcut bit.)
  4. #117-0835, 3 flutes, 1/2" diameter, 1" cutting length, 3-1/4" total length, 1/2" shank, single bottom bearing, $21.95 here
  5. #117-0865, 3 flutes, 1/2" diameter, 1-1/2" cutting length, 3-5/8" total length, 1/2" shank, single bottom bearing, $25.95 (also available with 2 flutes for $19.95, #117-0855; both also available in 2" cutting lengths for about $5 more)
  6. #117-1215, 2 flutes, 3/4" diameter, 1" cutting length, 3" total length, 1/2" shank, single bottom bearing, downshear, $32.95 (yes, still uncertain about downshear; straight version is cheaper; longer cutting lengths available)
  7. #117-1215B, 2 flutes, 3/4" diameter, 1" cutting length, 3" total length, 1/2" shank, top & bottom bearings, downshear, $46.95
  8. #117-1305B, 3 flutes, 3/4" diameter, 2" cutting length, 4" total length, 1/2" shank, top & bottom bearings, $53.95.

If money was no object, I might buy the last one - 3 flutes advantage, 2" cutting length probably exceeds anything I'l ever flush trim, and the versatility of top & bottom bearings. The only anticipated need it can't meet is tight inside radius corners which would suggest the first one - but that's not a need today.

If I ordered this moment, I'd buy #4 - or similar in another brand. It's likely I'll actually buy Freud or Whiteside because I can get Freud locally at a big box store and I can get either fast via Amazon prime. That bit choice is paying a few bucks extra for three flutes (vs #3), and getting 1" cutting length which works fine today. That's missing the opportunity for a longer cutting length for future needs, missing the benefit of top & bottom bearings... and that's ignoring the smoother cut of downshear options because I'm lacking expertise on whether it makes the router squirly.

All input is welcome.

Broader picture promised at top... besides a flush trim bit, here's what I'm buying ASAP for specific uses in current projects...
  • 1/4" straight bit, both for routing 1/4" through slots, and possibly also for routing dados using an exact width dado jig. I may consider a solid carbide spiral up-cut bit for this with a 1/4" shank, or I may stay with a basic straight bit.
  • 3/4" straight bit, for routing 3/4" - 1-1/2" dados using an exact width dado jig.
  • 1/8" roundover bit, for softening edges. My ROS works, but I'll use this bit enough that I'm willing to pay for it. If I was going to consider MLCS anywhere, I might consider it here and get this set for $30 vs paying the same for the single Freud bit needed now..
  • (Optional)I'm considering a rabbet set. I can build what I need without it as the above straight bits are perfectly capable of cutting rabbets with the RA1154 edge guide... though the convenience is tempting.

-Ashley
AshleyJ is offline  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 03-09-2018, 07:58 PM
Forum Contributor
 
Stick486's Avatar
 
Join Date: Jan 2013
Country: United States
First Name: Stick
Posts: 25,153
 
Default

Quote:
Which bits... a deep rabbit hole...
dirt or sand.. auger..
rock .. diamond core bit...

This would have been the week that I'd have finished chewing thru the restraints...
If only new layers hadn't been added....

Stick....
Forget the primal scream, just ROAR!!!
"SNORK Mountain Congressional Library and Taxidermy”
Stick486 is online now  
post #3 of 16 (permalink) Old 03-09-2018, 08:58 PM
Forum Contributor
 
Stick486's Avatar
 
Join Date: Jan 2013
Country: United States
First Name: Stick
Posts: 25,153
 
Default

Quote:
Originally Posted by AshleyJ View Post
Question...

1... Help me make a good choice on a flush trim bit. I'm not just interested in which bit - I'm interested in why it's a good choice.

How I'm choosing a flush trim bit...
The questions seem to be - what brand, what diameter, what cutting length, number of flutes, what shank size, and straight vs. spiral-up/down/combination...

2... Eagle American, Whiteside, Infinity, Sommerfield, CMT, Freud, Amana all seem to be top favored brands with a very slight bias toward those earlier in that list.
3... MLCS seems to be the most recommended brand of the lower tier. Some here favor MLCS for less used bits and others wouldn't use them without full body shrapnel protection.
4... It seems that larger diameter bits are better, as long as the router has the power to swing it...
5... Exception: if flush trimming inside corners, a smaller diameter bit may flush trim a tight corner that a larger diameter bit cannot.
6.. What cutting length...
7... How many flutes... I understand that more flutes are generally better, yielding a smoother cut and allowing higher feed rates.
8... Shank size... I'm considering only 1/2" shank for a stronger bit. I might make exceptions and use a 1/4" shank if I needed to flush trim tight inside radius corners
9... Straight vs Spiral... and spiral up/down/combination...
10. On first look, solid carbide spiral bits seem to have significant advantages if I ignore cost. A second look shows a price difference enough to make me take notice, especially if I stay with a 1/2" shank. Even if my budget allows me to pay $70-100 for what would be $20 in a straight bit, it doesn't mean that I want to.
11. My current projects are shop projects not cabinets. Materials are mostly Baltic birch and dimensional lumber. I think straight bits have been successfully used with such materials for decades, so I don't think spiral is needed.
12. If I buy spiral, I'll buy up-cut so the router wants to stay firmly on the work.
13. So, which flush trim bit? I'm considering the following options from this Eagle America 14. I'm uncertain whether that makes the handheld router less stable as it would with a spiral downcut bit.)
14. I'm considering a rabbet set. I can build what I need without it as the above straight bits are perfectly capable of cutting rabbets with the RA1154 edge guide... though the convenience is tempting.
1... I was a commercial operation... My choice ended up being Freud because they were the best value.. cost of bit vs LF of material cut... they made for a decent return to the bottom line..
2... as long as the bits are USA, Italian, Swiss, Austrian, German or Israel made you'll do fine..
some these mfrs import bits from the far east and put their name on them... Amana/China are some really sad bits... expensive junk too...
3... the shrapnel issue was me.. got hit w/ a flute in the left ear... now that was expensive.. their balance could be a lot better.. out of balance bits are prone to failure, give mediocre cuts at best and are hard on the router's bearings...
4... correct...
5... correct...
6... little more than you need to do the job...
over length bits aren't worth it over all scheme of things since you are only using a section of the bit... what you end up w/ is a partially worn out bit that you can't use in it's entirety..
also.. if you use just the end of the bit against thinner material the bit won't like the lateral forces at all and you are setting yourself up for a dangerous situation if the body of the bit separates from the shank because of the the lateral stresses..... I did what you are thinking... VOE...
7... correct... the more the merrier.. wait till you experience a Freud Quadracut...
8... good bet... bit body strength is a major item here...
9... this is where I migrated to.. very nice economical trade off... quality cuts too... the bit shears the wood fibers instead of tearing the..
Freud Tools - Search Results for helix
10. up-cut bits tend to pull into the work and generally leave a fuzzy top edge.. down-cut bits tend to push away and leave clean top edges... up/down bits are are the fix for the pull/push thing and top fuzzy edges..
11. correct.. make sure they can plunge cut...
12. not an issue.. unless you try to hog w/ it...
13. at those prices those are imported bits... I've learned a long time ago the are not worth the money...
FWIW... I tend not to think strictly w/ my wallet.. but go for value. less danger, less down time, better CS, better production and etc...
14. good choice.. better accuracy and control...
one thing you'll learn is to cut away as much material w/ your table, band or jig saw before you rout and save the drops.. valuable pieces of material... 1,001 uses for them...

15.. what do you do... type 200 plus WPM???

NOTE:

discoveries of on/of Asian bits...
  1. out of balance..
  2. 2 piece bits..
  3. poor brazing..
  4. shanks out of tolerance..
  5. bits out of tolerance..
  6. dull
  7. short usage life..
  8. soft carbide..
  9. poor CS.. (you bought it.. you own it.. now go away..)
  10. tapered straight bits..
  11. bent...
  12. do not handle heat well...
jj777746 likes this.

This would have been the week that I'd have finished chewing thru the restraints...
If only new layers hadn't been added....

Stick....
Forget the primal scream, just ROAR!!!
"SNORK Mountain Congressional Library and Taxidermy”

Last edited by Stick486; 03-09-2018 at 09:38 PM.
Stick486 is online now  
Sponsored Links
Advertisement
 
post #4 of 16 (permalink) Old 03-09-2018, 09:06 PM
Registered User
 
JOAT's Avatar
 
Join Date: Apr 2010
Country: United States
First Name: Theo
Posts: 6,121
 
Default

I'd say a good part of it depends on what you want the bit for. With me, for what I do 99.9% of the time, I use a flush trim bit, 1/4" shank, 1" cut, no HSS (unless that is all that is available, until I can get better), used in my router table. The brand I use is, whatever is available at the local hardware, or Lowes, when my last bit dies. I don't use 1/2" shank bits because none of my routers are 1/2". Works for me.

"It ain't what you're told, it's what you know." - Granny Weatherwax
Gather the villagers, pitchforks, torches; we march at dusk!
Some days, the supply of available curse words is insufficient to meet my demands.
.....Call me a craftsman, artisan, or artistic, and I will accept that. Call me an artist and you will likely get a quite rude comment in return. I am not a @#$%ing artist.
JOAT is offline  
post #5 of 16 (permalink) Old 03-09-2018, 09:08 PM Thread Starter
Registered User
 
Join Date: Nov 2017
Country: United States
First Name: Ashley
Posts: 67
 
Default

@stick , re 15: I've been thinking about this far too long. Over processing.


Sent from my iPad using Tapatalk

-Ashley
AshleyJ is offline  
post #6 of 16 (permalink) Old 03-09-2018, 09:15 PM
Forum Contributor
 
Stick486's Avatar
 
Join Date: Jan 2013
Country: United States
First Name: Stick
Posts: 25,153
 
Default

Quote:
Originally Posted by AshleyJ View Post
@stick , re 15: I've been thinking about this far too long. Over processing.


Sent from my iPad using Tapatalk
take the humor and run w/ it...
you did that typing on your phone...
YOWZER!!!
sure beats my 5~WPM...
I edited my original response...

This would have been the week that I'd have finished chewing thru the restraints...
If only new layers hadn't been added....

Stick....
Forget the primal scream, just ROAR!!!
"SNORK Mountain Congressional Library and Taxidermy”

Last edited by Stick486; 03-09-2018 at 11:08 PM.
Stick486 is online now  
post #7 of 16 (permalink) Old 03-09-2018, 09:20 PM
Forum Contributor
 
Herb Stoops's Avatar
 
Join Date: Nov 2014
Country: United States
First Name: Herb
Posts: 7,399
 
Default

I use both 1/4" shank and 1/2" shank bits. All of my routers now have 1/2" collets, so I use them more than the small shank. Also the selection of 1/2" shank bits is greater for different profiles than the 1/4" shank.

A lot of my favorite profiles are only made for 1/2" shank.
Herb
Herb Stoops is offline  
post #8 of 16 (permalink) Old 03-09-2018, 09:43 PM
Registered User
 
hawkeye10's Avatar
 
Join Date: Jul 2015
Country: United States
First Name: Don
Posts: 2,603
 
Default

Hey Ashly, I now buy Whiteside bits because of their quality but I am sure Freud bits are just as good or better. I also try to buy all 1/2" shank bits for safety reasons. I do have a trim router that I do have to have 1/4" shank bits for. For a flush trim bits I like the solid carbide ones. They sure make a smooth cut. I would buy Freud bits if I could find a good place to buy them without having to pay sales tax. Ours is 9 3/4% where I live.

Here is where I buy WS bits. No tax and no shipping.


https://www.hartvilletool.com/category/router-bits

Don in Murfreesboro,Tn.

Measure once cut twice and it's still to short.
hawkeye10 is offline  
post #9 of 16 (permalink) Old 03-09-2018, 09:56 PM
Forum Contributor
 
Stick486's Avatar
 
Join Date: Jan 2013
Country: United States
First Name: Stick
Posts: 25,153
 
Default

Quote:
Originally Posted by hawkeye10 View Post
Hey Ashly, I now buy Whiteside bits because of their quality but I am sure Freud bits are just as good or better.
no issues w/ WS bits...
better than Freud out of the box...
good items..
but.......
the Freuds are way better in the mileage category...
I think this because WS have a fuzz softer carbide than Freud...
softer carbide can be made sharper than harder carbide w/o extra process...
hawkeye10 likes this.

This would have been the week that I'd have finished chewing thru the restraints...
If only new layers hadn't been added....

Stick....
Forget the primal scream, just ROAR!!!
"SNORK Mountain Congressional Library and Taxidermy”

Last edited by Stick486; 03-09-2018 at 09:58 PM.
Stick486 is online now  
post #10 of 16 (permalink) Old 03-09-2018, 10:04 PM
Forum Contributor
 
Herb Stoops's Avatar
 
Join Date: Nov 2014
Country: United States
First Name: Herb
Posts: 7,399
 
Default

Quote:
Originally Posted by Stick486 View Post
no issues w/ WS bits...
better than Freud out of the box...
good items..
but.......
the Freuds are way better in the mileage category...
I think this because WS have a fuzz softer carbide than Freud...
softer carbide can be made sharper than harder carbide w/o extra process...
How do you know that fuzzy softer carbide?
Herb
Herb Stoops is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Router Forums 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











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
New member intro DaleFiorillo New Member Introductions 14 11-06-2017 10:19 AM
Getting started martyb New Member Introductions 9 10-07-2017 04:38 PM
Hi jazzzbo New Member Introductions 8 10-01-2017 10:41 PM
Andrew from Cedarville, OH StrawHOC New Member Introductions 11 09-25-2017 11:54 AM
First bit set Mike Router Bits - Types and Usage 46 07-29-2015 09:56 AM

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 On
Refbacks are On

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