CAMheads CNC Router Forum By: CAMaster CNC

Go Back   CAMheads CNC Router Forum By: CAMaster CNC > Tips & Techniques > Router Bits

Reply
 
Thread Tools Display Modes
  #11  
Old 02-02-2016, 08:39 PM
Ger21 Ger21 is offline
CAMhead Legend
 
Join Date: Apr 2014
Location: Shelby Township, MI
Posts: 433
Default

Why not just router the hole with a 3/8" upcut spiral?
How precise to you need the holes to be?
And how clean do they need to be.

With larger holes, and drilling in plywood, I've found that routing holes gives a better quality hole.

We have a recurring job that requires 30 - 25mm holes in a sheet of red oak plywood, and we do 40 sheets at a time.

We have a $150,000 Morbidelli with a drill block on it.
When drilling with a 25mm carbide tipped boring bit in plywood, 10-20% of the holes are very ragged. This is due to the poor quality core of the plywood. The same bit will drill perfect holes in veneered MDF all day long, but not in plywood.

So, we route the holes with a compression bit, where we get consistent quality through the entire job.

If we used the spindle for this, we might see better results due to the increased rigidity of the spindle vs the drilling spindles.
__________________
Gerry

JointCAM - CNC Dovetails & Box Joints

Reply With Quote
  #12  
Old 02-03-2016, 08:00 AM
homersmth24 homersmth24 is offline
CAMhead Friend
 
Join Date: Jun 2015
Location: Monmouth Il
Posts: 50
Default

I would never say never but it is quite expensive to drill with a 10000 rpm router. Using Guhring series 5514 (140 degree) to drill in aluminum @ 855 sfm it is possible to drill up to .3281" hole. I use a letter f to drill 5/16-18 tapped holes and a 8mm to drill clearance holes. I hold them in a 8mm collet in my muscle chuck as they both have a 8mm shank. These bits are around $70 ea.

I would not suggest a HSS or a 118 degree drill bit to drill at 10000 rpm.
__________________
Homer F. Smith
HomerS@carnaeder.com

Stinger II SR-44
3.5 HP Milwaukee Router
Performance Pro Package
Nema 34 900 oz Motors
4th Axis Ready
2" Gantry Lift
Graphtec CE6000-120 Vinyl cutter
BossLaser LS3655 150 watt
AutoCAD
VCarve Pro 8.0
Photo VCarve 8.0
CorelDraw 2017

www.carnaeder.com
Reply With Quote
  #13  
Old 02-03-2016, 11:12 AM
de5 de5 is offline
Cobra Owner
 
Join Date: Jan 2011
Location: Honea Path, SC
Posts: 917
Default

Quote:
Originally Posted by Ger21 View Post
Why not just router the hole with a 3/8" upcut spiral?
+1 for what Gerry said. I never consider making holes with anything other than the regular upcut carbide end mills I normally use. Just feed them in at 30ipm and get a clean hole.
__________________
Charlie Hind
Cobra 404 ATC with 12 tool positions & 4th Axis (2012-present)
(2006-2012 - K2 CNC... sold in 2012 to buy the Cobra)
WinCNC
www.hindocarina.com
http://facebook.com/hindocarina
Reply With Quote
  #14  
Old 02-03-2016, 11:55 AM
CosmosK CosmosK is offline
CAMaster Owner
 
Join Date: Jul 2014
Location: Fort Worth
Posts: 821
Default

Quote:
Originally Posted by CAMuser View Post
Is there a better bit to use for drilling using a CNC router?

Are drill bits the correct bit to use when drilling holes in a material? I primarily do work with plastics and wood, and always drill completely through the material.

Some additional questions:
Are there any specific bits I should use (or maybe more importantly should not use) with a router/CNC machine?
Is there a reason not to use a reduced shank drill bit?
Is there a reason to go for carbide over the HSS in a drill bit?
When would one choose a 135 degree bit over a 118 degree bit?
What is the reason why one might use an end mill to drill a hole?
What kind of spindle speed should I be using while drilling using a drill bit?

For a specific application of drilling a 5/8" hole into plywood, is any issue using a 118 degree, HSS jobber drill? I want to be sure that there are not special bits that are needed for a router vs. a hand drill
I use metalworking drill bits everyday. They work great in wood and plastic and metal. I used to use a ľĒ jacobís chuck, but now I have a full set of collets, so I can grab any bit 2-16mm. Yes, drill bits are the best choice for drilling holes IF your machine allows. If you had a router and not a spindle, it may be a different story.

These comments are with spindle:

Specific bits: I use HSS drills

Reduced shank: Not much reason not to. The only time I like a longer bit is when the hole is pretty deep. If the bit is near fully submerged, I can feel vibrations in the spindle. I attribute this to the drill bit wandering and effectively creating a runout like effect. With longer bits, I stress the spindle less.

Carbide: they will handle more heat, but Iím not sure youíll see any difference in the cut

135 vs 118: not sure it matters in plastic and wood.

End mill a hole: your XY location will be better especially in wood. Wood grain can EASILY make the drill bit wander. I always use a center drill to start my holes to give the drill bit a better chance of staying on track. Drill bits will remove material faster as thatís what they are designed to be good at (drilling holes).

Spindle speed: It depends on several things. Your spindleís power is a constraint. It will lose power as RPM reduces, so you have to take that into account (wood and plastic less a worry than AL). Also, the SFM of the bit has limitations to prevent burning or melting and for bit lifetime. Then there are rules of thumb for chipload. Example, for a 1/4" hole, you probably want to stay under 6k RPM (to keep SFM under 400), 3/8" it drops to 4k RPM. My 1.7 is not reliable under 2.5k RPM, so you can see you have to be careful. Drilling typically is slow and high torque. CNC router spindles are high RPM and not much torque at low RPMs. If you stay in your window, it works great.
__________________
2014 Stinger II (SR-44)
1.7 kW Spindle w/ speed control, Performance kit, VCarve Pro
www.cosmos-industrial.com
>Pen Marking Tools
Reply With Quote
  #15  
Old 02-03-2016, 01:32 PM
CosmosK CosmosK is offline
CAMaster Owner
 
Join Date: Jul 2014
Location: Fort Worth
Posts: 821
Default

Also should mention, my favorite drills which I've recently discovered are parabolic flute drills. I had to drill out a bunch of AL plate and the parabolic flutes were rockin'.
__________________
2014 Stinger II (SR-44)
1.7 kW Spindle w/ speed control, Performance kit, VCarve Pro
www.cosmos-industrial.com
>Pen Marking Tools
Reply With Quote
  #16  
Old 02-05-2016, 12:44 AM
migrainekustoms migrainekustoms is offline
CAMaster owner
 
Join Date: Dec 2015
Location: Florida
Posts: 29
Default

Quote:
Originally Posted by james mcgrew View Post
I.am in.car.at.jobsite em me and I will.check.later
Just checking up if I am in the owners section?
Reply With Quote
  #17  
Old 02-05-2016, 07:29 AM
james mcgrew's Avatar
james mcgrew james mcgrew is offline
Administrator, (MOD, KOTR)
 
Join Date: Sep 2008
Location: ridgeway sc
Posts: 7,124
Default

check email
__________________
James McGrew
CAMaster ATC 508
The principle of Measure twice cut once has not been replaced by a CNC

www.mcgrewwoodwork.com

https://www.facebook.com/pg/Mcgrew-W...=page_internal

Camera 1 ATC Closeup !
https://video.nest.com/live/esNTrZ
Reply With Quote
  #18  
Old 02-05-2016, 07:29 AM
james mcgrew's Avatar
james mcgrew james mcgrew is offline
Administrator, (MOD, KOTR)
 
Join Date: Sep 2008
Location: ridgeway sc
Posts: 7,124
Default

whoops email me
__________________
James McGrew
CAMaster ATC 508
The principle of Measure twice cut once has not been replaced by a CNC

www.mcgrewwoodwork.com

https://www.facebook.com/pg/Mcgrew-W...=page_internal

Camera 1 ATC Closeup !
https://video.nest.com/live/esNTrZ
Reply With Quote
  #19  
Old 02-05-2016, 07:32 AM
james mcgrew's Avatar
james mcgrew james mcgrew is offline
Administrator, (MOD, KOTR)
 
Join Date: Sep 2008
Location: ridgeway sc
Posts: 7,124
Default

look in faq for the info I need to allow owners section, what camaster do you own? send me invoice copy to mcGrew636 at msn dot com
__________________
James McGrew
CAMaster ATC 508
The principle of Measure twice cut once has not been replaced by a CNC

www.mcgrewwoodwork.com

https://www.facebook.com/pg/Mcgrew-W...=page_internal

Camera 1 ATC Closeup !
https://video.nest.com/live/esNTrZ
Reply With Quote
Reply

Tags
bit, drill, drilling

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 On

Forum Jump


All times are GMT -4. The time now is 03:45 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.