If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #1062
Joined: Tue Oct 16 2007, 02:01AM
Location:
Posts: 1529
hey, for a CNC project i am working on (still in planning stages, in the process of CAD), I was wondering what kind of methods there are to hold the mill bit, up to 1/4". Does anyone know of any suppliers for 1/4" keyed or keyless chucks? If you have someother attachment method, that would work great too.
BTW, I am not buying now, but will in the future, so if you have one, post it up, i may buy depending on price.
Registered Member #397
Joined: Wed Apr 19 2006, 12:56AM
Location: Western Washington
Posts: 125
Hello,
I would NOT suggest using a chuck to hold end mills. Drill chucks tend to have strange three-lobed deflection and the jaws on a chuck have a hard enough time clamping on drills when drilling. They aren't very precise and they're not rigid at all. Adding a side-load will cause it to slip for sure and lose your z-axis tool offset, plus chip your end mill from the chatter and ruin your part. The contact area on a drill chuck is nonexistent. It's three small contact patches, and usually at the tip of the fingers.
Also, drill chucks will ruin drill bits if they slip at all (and they do!). End mills require even more clamping force so a chuck won't cut it. Collets won't ruin your tooling if it slips by chance. It'll only gall the surface a wee bit. Collets also have superior clamping force compared to three jaw jacob's chuck because of the huge contact area. These should be able to handle milling with a 1/4" end mill for sure, even 2-flute end mills. If you're going to hog stuff, it's best to get a dedicated 1/4" toolholder with a setscrew and grind flats on your tooling for the setscrew. These won't slip unless you crash the tool into your part, and you've got much bigger problems at that point.
If you want good, affordable accuracy, go with an ER collet system. There are enough overseas manufacturers now that you can buy the holder or shank and a set of collets for a reasonable price and they'll be plenty good enough for hobbyist use. The collets have the least amount of runout and they're self-centering and precision ground. Usually TIR is within .0005" even on India/China made sets.
Since I don't know what sort of tooling interface system you'll use (DIY, Morse taper, etc), its difficult to give more specific advice.
Registered Member #1062
Joined: Tue Oct 16 2007, 02:01AM
Location:
Posts: 1529
A collet is like the system used on a dremel, and similar to a xacto knife, right? I will probably be using round shank, and maybe grind a partial hex.
A collet was my first choice, but it seemed that a chuck would hold better, guess I was wrong. Here is the motor I am using: If you download the second PDF on that page, 550PM, it is the motor that has 14.4v nominal. It offers nearly 20k RPM at no load (confirmed yesterday with a oscilloscope, 1 ms between contacts, 3 contacts). The motor was taken from a cordless drill. The main use was going to be PCB milling/drilling, but I wan't to be able to use it for other stuff if the need arises.
Registered Member #397
Joined: Wed Apr 19 2006, 12:56AM
Location: Western Washington
Posts: 125
The dremel and xacto collets use the same clamping idea as the standardized ER collets. They indeed grip much better. CNC machines don't use chucks for toolholding. The exception is if you're manually drilling on a Bridgeport. Some people still use chucks for drills on a Bridgeport because it's quick and cheap.
Collets for machine work are centerless ground and the assemblies are balanced for high RPM use. A drill chuck isn't going to be balanced at 20,000RPM. You also have much less toolholder clearance using a bulky drill chuck. Properly sized collet systems for the tool are smallish and give you more shoulder clearance.
Something like this ER11 set can be incorporated relatively easily since its a raw shank (as opposed to being attached to a CAT or Morse taper) :
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
chuck
