Seeking tool holder/changer info. Overview resources requested for quick change or automated tool changers.
Assuming a spindle for routing and cutting sheet stock such as wood, plastics, and light metals, please describe the options available in the marketplace.
?: Tool holders for precision work.
?: Tool holders that are easy and quick to change.
?: Tool holders that can be used as quick change and/or used with automatic tool changers.
Thanks for your help!
Precision: The HSK style of clamping system was mentioned (by a supplier) to be better for precision than the taper type.
(Comments or experiences anyone?)
Quick Change: The HSK-C type was also claimed to be "quick change" manually operated. Since I'm a newbie, does anybody have any ideas, comments, or experiences to share?
Thanks.
DIY-Guy "Attempting to convert a software oriented brain to CNC orientation."
Originally Posted by DIY-Guy
For tools 1/4" or smaller, I use Double angle collets. Seems to work well.
http://www.use-enco.com/CGI/INLMK32?PARTPG=INSRAR2 has a couple to work with.
HSK is the most accurate, rigid & expensive. Collets are secondary to auto-change toolholders. Taper toolholders (cat 30-40-45-50 etc.) are less expensive and adequate under most conditions. All compromises. Kinda like the old adage "speed costs money, how fast you wanna go?".
Dick Z
DZASTR
Are collets part of the toolholders?
Do toolholders hold collets which hold the bits (like a dremel collet holds a drill bit?)
Thanks, I still need help with definitions and diagramming the relationships between parts.
DIY-Guy "'Parts is parts' only holds true for chicken nuggets, machine parts are much more specific!"
Last edited by DIY-Guy; 05-07-2008 at 11:32 PM. Reason: Fixed quote tag.
Speed costs money, ok. I wanna go 2800 ipm or as close as a 5 hp (or less) spindle can get me. Feed rates depend on rpm speed and bit characteristics, but some (collets?) tool gripping devices lose it above a certain speed. Is it overkill to use an HSK system for routing wood with a high speed spindle?
DIY-Guy "Spinning an idea of fast spindles cutting wood."
Here is what I know and I worked in the high speed spindle business for 9 years, in charge of training and assembly.
HSK was developed for high speed spindles, the tool locking mechanism in ID, it uses 7 hardened steel fingers which grip the inside of the tool and centrifigal force is to your advantage. Used mostly and developed for the mold industry, the HSK tooling is more expensive yet is believed to be more accurate than the CAT and BT taper tool holders do to the fact that the tool actually seats on a planer surface vs. the CAT and BT just being held soley by the taper. The other major advantage of the HSK is it has a superior design for through tool cooling as far as transfering coolant from the end of the drawbar and through the tool.
CAT and BT tapered tool holders are just fine but are believed to be limited to about 12,000 RPM due to the clamping design. The longer taper is believed to make the tool more ridgid yet does not seat on a planer surface such as the HSK tooling which makes it less accurate.
Shrink fit tool holders for both CAT and HSK style tool holders are by far more accurate and believed to be re-usable for atleast 1000 heat/shrink cycles. The lack of a collet which adds room for error, and the lack of set screws which tend to push the tool to one side and distort the bore of the tool holder make shrink fit tooling much more suitable for precision tool holding. The disadvantages being cost, you have to invest in the equiptment to heat and cool the tool holder and they are easily destroyed upon impact due to operator or machine error.
Honestly, if your not making $100,000 molds and using high speed machining, most of that info doesn't matter. But you guys asked, and that's a quick overview of what I know.
MC
MC-MotorSports, you mentioned a lack of collet for some shrink-fit HSK tool holders. Are there both types of HSK tool holder available (collet and shrink-fit)?
Supposing a wood or plactic cutting spindle were running 24,000 rpm or faster, would a collet style be sufficient? Or is there a (speed, torque, run out, or accuracy) tradeoff with a point of diminishing returns?
The goal here is to find the right tool holder for a spindle in the 3-5 hp range, 24,000 rpm or faster. Trying to get the highest feed rates possible with the finest finish on the bottom of flat cuts and clean sides on depth cuts with multiple passes. (Those little ridges look so bad in clear acrylic and don't polish or stain well with some woods.)
DIY-Guy "Trying to get up to speed on high speed spindles."
Yes, I have seen shrink fit, collet type and set screw type HSK tool holders.
Are you running a router? HSK tooling is probably overkill for what your wanting to do. They were designed and intended for the mold industry where they use VERY long tools and tool holders for deep cavity work and such. In a case such as that, tool holder run out can become critical. Plus the design is superior for high speeds and through tool cooling which are two more needs for high speed mold finishing. For example, tail light or head light molds. Even saw a mold for a blender that looked like a mirror coming off the machine, saved A LOT of polishing time!
What is your specific application? You don't have to get too specific if you don't want to give your product idea's away, I totally respect that!
MC
MC-MotorSports,
Thank you for asking.
I'm looking at an XYZ gantry setup with up to 2800 ipm free traverse speed on X,Y, and something slower but more precise on the Z axis. Overall work area is 4x8 feet X and Y, with a 12" Z depth of cutting. Some people call these 2.5 D machines. (I'm still a newbie and appreciate being taught the correct terms, so feel free to update my brain!)
Faster spindle motors equal faster feed rates, right? Since feed rate can be increased with faster rpm, I'm looking at spindles from DynoMax with 18,000 or 24,000 rpm (wishing for 60,000 rpm!). DynoMax actually talked with me enough to help me find something in the 3-5 hp range. EckstromCarlson has been marginally helpful to me as a newbie, but I'm still trying to get someone to be patient enough with newbies to stay with the sale.
Since I'm just starting in the CNC world I don't know the parts yet. A textbook "exploded view diagram" of the different ways to attach tools to the rotating shaft of a spindle motor would really help me get the terminology right.
[Begin rant-]
Guhring blew me off when I asked if their tool holders performed the same function as a collet in a Dremel(R)! Analogies are sometimes hard to come by for a self-important corporate minded person who has never had to take a phone call from anyone (like me) who is outside their specialty.
Perhaps I was the guy who will be an OEM after the machine is completed, who knows? Or, perhaps my gantry builder will OEM their tool holders with a spindle in a turn-key package. One never knows when some "weird phone call" will pay off and turn into a new business opportunity.
[End rant]
One thing for sure, every clearly answered question here on CNCZONE.Com turns into sales calls for the companies with the products mentioned here in the discussion forum! Communication, good communications, are valuable for sales growth. Please, tell me what I need so I can go out and spend my money!
DIY-Guy "Trying to spend money for CNC to make more money."
Last edited by DIY-Guy; 05-11-2008 at 01:52 AM. Reason: Spelling
Just to clarify, when I refrer to HSK collet, I'm referring to a precision collet holder type HSK tool. Didn't want to confuse you.
Honestly, if you don't mind spending the money, HSK tooling is the way to go, especially if your hoping to get around 24K and over in the RPM's.
I'm assuming your doing light finishing work such as contouring? Another thing is make sure you buy good balanced tool holders. HSK tooling is getting popular and I'm sure quality varies from one manufacture to another.
If the initial investment doesn't bother you, I don't think you will be disappointed with the HSK style tooling. To the best of my knowledge, it's best suited for lower horsepower high RPM spindles just as the spindle you mentioned.
But be careful, high RPM spindles use delicate bearings and will probably be oil-air lubricated which is critical to have a good clean dry air supply. High speed machining can make you a lot of money when things go good, but mistakes are expensive!
Michael
BTW, Guhring makes VERY quality products! Worth the price...
MC
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