Easy add quick connect collets or changers to an existing CNC

[Brian Lamb]

Well, the CNC Depot spindles are 23.5lbs according to their website and that is what is used on the Stepcraft Q series machines like mine. I talked to them (Stepcraft) and they said probably 35 lbs without doing anything to counter the weight of the spindle. A couple of small air cylinders on either side with a regulated air supply would be an easy way to counter balance the spindle, but I was trying to keep things simple.

Do you have a link to the eBay seller for yours, I quickly looked on eBay and didn't come across anything.

[Wes Grass]

One other little annoying detail about shrink fit. The cutter has to be solid carbide for the expansion differential to work. And the tolerances of diameter are tiny. The smaller the shank, the smaller the tolerance. Little chance a steel shank brazed carbide 'router bit' will go in and be held properly. And if it does, you probably won't ever get it out without boring the remnants to foil and peeling it out with a scribe.

Air cylinders? What's wrong with a chunk of cast iron suspended by chain and sprockets like my Fadal? ;-)

[David Buchhauser]

One other little annoying detail about shrink fit. The cutter has to be solid carbide for the expansion differential to work. And the tolerances of diameter are tiny. The smaller the shank, the smaller the tolerance. Little chance a steel shank brazed carbide 'router bit' will go in and be held properly. And if it does, you probably won't ever get it out without boring the remnants to foil and peeling it out with a scribe.

Air cylinders? What's wrong with a chunk of cast iron suspended by chain and sprockets like my Fadal? ;-)

Wes - I am assuming that your Fadal is a cnc mill similar to my Matsuura. On my Matsuura, the spindle only moves up and down (Z direction) and there is no X-Y motion. Mine does have a very large counter weight with two chains to counterbalance the weight of the spindle. The table moves in the x and y directions under program control such that the part being machined passes under the rotating cutting tool in the spindle.

By contrast, the cnc router table in question has a fixed table and the spindle moves back and forth along the gantry (x direction). Also - the gantry moves back and forth along the Y axis. These can often times be very rapid moves, and adding an additional 25 to 30 lbs hanging off the back of the z bracket could most certainly be problematic. An air cylinder is much lighter weight and can mimic the function of the counterweight while not becoming a hindrance to efficient spindle xy motion.

David

[David Buchhauser]

Well, the CNC Depot spindles are 23.5lbs according to their website and that is what is used on the Stepcraft Q series machines like mine. I talked to them (Stepcraft) and they said probably 35 lbs without doing anything to counter the weight of the spindle. A couple of small air cylinders on either side with a regulated air supply would be an easy way to counter balance the spindle, but I was trying to keep things simple.

Do you have a link to the eBay seller for yours, I quickly looked on eBay and didn't come across anything.

Hi Brian,
I ordered from the same Ebay seller as Bobby Milam did around 3 years ago. Here is the thread where I had asked Bobby for detail on his ATC spindle.

https://sawmillcreek.org/showthread....nts&highlight=

I checked my Ebay purchase history and it only goes back 2 years, so I really don't know who the seller is by name or item number. The seller does have some videos on Youtube here:

https://www.youtube.com/user/tivoi/videos

At the time of my purchase, the cost was around $1800 plus shipping. The seller is located in Viet Nam, but I expect the actual spindle is Chinese.

Here is a video of Bobby Milams spindle/atc setup.

https://www.youtube.com/watch?v=R0c5StkFUWc&t=84s

[David Buchhauser]

Brian - I found a copy of the Ebay listing for the ATC I purchased. Bobby Milam bought his from the same seller. I don't know if this seller is still active on Ebay and I couldn't find him using an Ebay search by member. But there must be similar spindles out there. This Ebay seller was really great, because he would test each spindle before shipping and provide a Youtube video showing the exact spindle I was to receive. It still had my name marked on it just as shown in his video.

By the way, I converted this Avid Pro4824 table to use the Centroid Acorn contoller and am still in the process of completing my actual ATC. I have it all built and working, but just need to program the macro using the xyz coordinates of each of my atc rack tool holder positions. Bobby had already done the same thing (except for the sliding tool holder rack) and he talked about it in some of his posts.

Here is the search for his posts to make it easier to find these threads.

https://sawmillcreek.org/search.php?...d=17719030&pp=

Let me know if you decide to go the ATC route with Centroid Acorn and perhaps you will motivate me to finish up mine.

David


ATC spindle kit on Ebay.jpg

[David Buchhauser]

The nice thing about this one is that the seller included the spindle, vfd (pre-programmed), tool holders/collets, tool forks, spindle mount, air regulator, solenoid valve, wiring, etc. Pretty much everything needed. I ended up ordering more tool holders and collets from the same seller. These are very high quality and I was quite impressed that the tool holders were only $20 each and collets $4 each. Nice stuff!
David

[Gary Campbell]

Let me know if you decide to go the ATC route with Centroid Acorn and perhaps you will motivate me to finish up mine.

David, etal.....
In the next couple months I will be working with the Centroid software development team to build/improve the Router ATC program. Actually it doesnt really need improvement in function, just form. We will be bringing the ATC function variables and settings, along with the required macros into the Wizard to make it much easier for the DIY crowd, like yourself to build a working ATC systems on routers be as elegant and full featured as the Mill and lathe versions.

Also, and in the same timespan, CNCDepot should be releasing an Acorn based ATC controller for Teknic ClearPath servos that we have co-developed. This will be an all in one control with the VFD, all pneumatics on board, and a custom screen with all ATC functions on screen buttons.

If you hang on (or procrastinate) a bit, your ATC setup may become much easier.

[Brian Lamb]

David, thanks for the wealth of information, definitely doing some research as a quick tool change would be really advantageous for me.

Gary, could you explain a bit further about this CNC Depot/Acorn/ClearPath situation? What does a clear path servo have to do with the tool changer? Or are we talking a whole complete control system for the axis motors, spindle, Acorn and Toolchanger?

[Gary Campbell]

David, thanks for the wealth of information, definitely doing some research as a quick tool change would be really advantageous for me.

Gary, could you explain a bit further about this CNC Depot/Acorn/ClearPath situation? What does a clear path servo have to do with the tool changer? Or are we talking a whole complete control system for the axis motors, spindle, Acorn and Toolchanger?

Brian...
It's simply a package that CNC Depot is investigating. That's about all I can say about it at this time. The real answer is that no one in the know sets up an ATC without servos, or at least closed loop steppers. I realize that the DIY world disagrees with "those in the know" due to cost reasons.

I have been developing an AcornSIX controller for a while now that implements many more IO features than most sub $100k OEM ATC machines use and exponentially more than the DIY crowd does. I am working on combining a small standalone PLC and some gray logic to handle a dozen or more monitoring inputs from the VFD, spindle and servos into the few that Acorn4 has available. The attempt is to make it both bullet proof and idiot proof. I realize neither are attainable.

[Brian Lamb]

I got it, you are talking a complete system, spindle, servos, Acorn and such. Yes, I understand the need for servos or some sort of closed loop system for tool changes, you need to be able to accurately get back to the tool pots.

Brian...
It's simply a package that CNC Depot is investigating. That's about all I can say about it at this time. The real answer is that no one in the know sets up an ATC without servos, or at least closed loop steppers. I realize that the DIY world disagrees with "those in the know" due to cost reasons.

I have been developing an AcornSIX controller for a while now that implements many more IO features than most sub $100k OEM ATC machines use and exponentially more than the DIY crowd does. I am working on combining a small standalone PLC and some gray logic to handle a dozen or more monitoring inputs from the VFD, spindle and servos into the few that Acorn4 has available. The attempt is to make it both bullet proof and idiot proof. I realize neither are attainable.

[David Buchhauser]

I got it, you are talking a complete system, spindle, servos, Acorn and such. Yes, I understand the need for servos or some sort of closed loop system for tool changes, you need to be able to accurately get back to the tool pots.

Brian,

My personal feeling is the for "diy hobby use" open loop steppers may be perfectly fine - as long as the system doesn't loose steps or stall one of the motors. I feel that my Avid Pro4824 with large size Nema 34 motors and Centroid control will be adequate for my needs. And - yes - I certainly consider my table to be of the "hobby" variety. Avid table and motors, Centroid controller, water cooled ATC spindle, diy tool change rack, and so on. I am actually planning to use this particular machine to machine smaller aluminum parts. I don't particularly need the full ATC tool changer system, but this came about as more of a personal challenge back when Bobby Milam was doing something similar and we were comparing notes and exchanging ideas about our systems.

The machines I use for production work do have fully functional ATC, servos with closed loop feedback, etc. My Matsuura machining center uses BT35 tool holders with a 20 tool magazine, 5HP spindle motor, and runs from 240V 3-phase power. Same for my Nakamura Slant 1 turning center, except only a 12 tool magazine and a different type of tool holder.

I believe that for my Avid table, I will be able to accurately get back to the tool pots using open loop steppers. And actually, the tool forks do have some flexibility and do provide a sort of "buffer" to accommodate minor misalignment of the spindle with the tool holder during tool change.

David

[Jim Becker]

Brian,

My personal feeling is the for "diy hobby use" open loop steppers may be perfectly fine - as long as the system doesn't loose steps or stall one of the motors.

I think that the concern with using base level steppers with an ATC comes down to the fact that an ATC demands "hard precision" to insure that the tools are installed and uninstalled accurately...it could even be a safety issue if you think about it. Will they work? Yes, and if there are no missed steps, etc., no problem. But given the cost of an ATC, the cost for better quality motors probably is worth it, IMHO.

[David Buchhauser]

I think that the concern with using base level steppers with an ATC comes down to the fact that an ATC demands "hard precision" to insure that the tools are installed and uninstalled accurately...

Jim I think this depends on the particular mounting arrangement for the tool forks, and the rigidity (or lack of) of the forks. I don't know about "hard precision" and what that really means. Agreed that in a perfect world active closed loop feedback would be used. My Plasmacam table uses servos with encoders for feedback, but of course no ATC. I take Gary's point, but there is a difference (in my opinion) between diy hobby and pro stuff. In any case, I fully expect my Avid with ATC and tool changer to perform reliably once set up and properly calibrated. Opinions may differ.

David

[Jim Becker]

My feeling is that when you start to get into things like ATC, the difference between "hobby" and "pro" blur substantially. But that's me...

[Gary Campbell]

"Gary - will this be a software update/patch for existing CNC12 users, or a new updated version of CNC12? What is the upgrade cost for existing CNC12 users?
Thanks, David"

David...
As far as I know, this is just a part of the natural evolution of Centroid's product development. "Ongoing improvements to CNC-12's Router Pro version" I do not know if there will be any additional cost. I doubt it.

"I got it, you are talking a complete system, spindle, servos, Acorn and such. Yes, I understand the need for servos or some sort of closed loop system for tool changes, you need to be able to accurately get back to the tool pots." ~Brian
Brian...
Yes, if it comes to fruition, a full Acorn/ClearPath/ATC package for AVID machines will be offered by them. Pre-setup, pre programmed, right down to having appropriate "auto-tune" profiles installed in the motors. I have been building a similar system for ShopBot ATC machines for a while now and am looking forward to possibly gaining some of the AVID customer base.

AVID has become popular with the "move up" crowd. IOW, they are experienced and after some years of use they know what they want in a machine, and are willing to put in the labor to get it. We are working on a new swing plate design that will allow adding planetary gearboxes to the AVID Pro kits to enable reduction ratios more conducive to servo use. The stock ~3-3.2:1 reduction ratios are just too low in my opinion.