Tuning the KaVo for high-preformance

[DMC]

Tuning the KaVo for high-performance

I have been milling the same few teeth over and over and over since Monday.

Dialing in the feed and step and rpm and about 100 other parameters for Titanium. We have a "PFM" and an "Anatomy" strategy so far.

The finished product is 10x better looking then the OEM KaVo.

For starters, the internal finishing of the KaVo CAM Strategy looks to me to be about 125-200uM step inside. YIKES! I can see the rings from a foot away!

My strategy has tight 40uM rings (actually a continuous spiral) at minimum and .03mm at the area closest to the margin. It looks almost like mirror finish close-up.

We do a dual zig-zag pass on occlusal for anything with anatomy at -45 and 45 degree angles with a tight 50um step with smallest bur at a 1800mm/min. feed. (Waaaay faster than the KaVo strategy) and that is 32000RPM. The occlusal is ready for polishing with minimum labor.

The KaVo has a Spindle limit of 80,000rpm and a max feed of 3000

We can program many many different feeds for a single operation.

ex.
- Z-feed (only going down to next Z-depth)
- X-Y feed for normal cutting
- Maximum material removal feed (when tool is against walls or the tooth...not in the middle area)
- tight corner feed (user definable)
- edge feed (user definable
- no material removal feed (rapid-trans. feed)
etc.

I have a most excellent product in a faster time. Kinda happy!

Little over 20 minutes for the Full Anatomy Strategy.
Just under 18 min. for the coping version.

I stand by the mill with a flashlight and watch everything.

I am happy with the internal side, and have just been milling the same occlusal over and over today. We eliminate the instructions for the stuff we already have sorted. No need to see that again. I cut those tools out of the strategy to finish working out the top only.

I run around the building to show everyone what is good and bad, and what to change to fix it. We change only one parameter at a time if we can help it. Sometime you just know you need major adjustments and change many things, but we try to be scientific about it. I am trying to find a surface finish that is like..."WOW"! for a milled metal surface to polish....in a decent time. It takes 50uM, or less, step unfortunatly to make that happen. I think we will have to go down to 40 or 35uM on the occlusal Zig-Zag to get super-funky awesome surface finish.

I defined a tool incorrectly. It was a conical shaped tool, and I was one degree off in the taper of the tool. The shank of the tool slightly rubbed on material. (Minor collision). It made a subtle difference in audible noise, and I could see the Gold coating wearing off the tool above the cutting flutes. I stopped that cycle and re-measured the tool and programmed that new shape into the CAM.

Same type of mistake with the reach of another tool. We have been over hundreds and hundreds of changes all week. I'm almost done.

It takes about Twenty-Fourty milling hours to dial in a new material and tools at minimum. IMO. Than you will be tweeking it forever!

 

[Mark Jackson]

Cool Scott. All that tooling stuff is a hassle, but at least metal is kind of forgiving in terms of chipping etc. Post some photos when you get time. Thanks for the update.

 

[DMC]

Hassle??

This is the most fun I've had all year!


You know I have lost BIG $$ on playing with Zirconia.

Please don't remind me!

I LOVE playing with metal1!!!@#$

The CAM for the dental sector�-�DATRON AG

[YOUTUBE]s0QiISSuZC4[/YOUTUBE]

 

[DMC]

The Video shows how you can define EXACT tool shape and avoid collision, and mill some undercuts even with only a 3axis mill.

Very "smart" CAM. Very automatic if set-up correctly.

Awesome simulations of your exact mill and fixture and spindle assembly and tools! This is not shown in the vid. (User programs CAD shapes once, or ask me)

Great simulation to test strategy before the tool hits the metal.
We have saved many a tool by looking at simulation first!

 

[DMC]

 

[DMC]

So far I have the sprues down to .3mm!

I still can't "press-out" the element with my thumb or even a piece of steel tubing.

I will go smaller until I can flex the Titanium, or end up with a broken sprue.

You can define the starting diameter and ending diameter, and all angles on the auto sprue generation. The distance from the margin and many other parameters are definable as well for auto-placement. Or, you can turn-off the auto-placement and just manually place the sprues. In Sum3D, if you have teeth near each other and try to sprue inbetween....the software detects what you are trying to do, and links the two teeth together automatically. Very very smart software.

I have my sprues at an unusual -20 degree angle on the horizontal plane, and not just flat on the same plane.
It provides a little traingulation to the sprues to better hold unit in the up-down (Z-axis),as well as X-Y axis. The sprues are angled up and away from the margin. Easier to cut as well. This is also to tame the vibrations in the material and the tool...I sometimes hear tool chatter. I sense a slight disturbance the "the Force" when I hear it. I think I am dampening the up/down vibrations of tooth with such thin sprues by adding the angle. Make sense?? It does to me. I don't know why others are not doing this in their software??


I can't believe you can cut Titanium this fast! This is faster Roughing feed than our soft Zirconia. The tools are still holding up. I'm kinda shocked at the final speeds of this weeks tests. Can it be faster??

It's NewCastle time on the East Coast folks!!

Good Night!

Scott

 

[DMC]

KaVo bench is questionable for a milling table.

It's all squares that flex like crazy. It want's to "fold-over".

Needs triangulation, or just a complete replacement.

The design is kinda sucky, from an engineering standpoint.

I tried to tighten all the little Aluminum braces, but...

Otherwise....excellent bench.

(It's for sale.)

I am going to strap the mill to the floor and the wall! No joke!
Drilling holes in the bench, and running straps criss-crossed to steel anchors in the concrete floor. Might have to move the pumping system somewhere else?

The mill is a SOILD 1000lb rock, but it is moving on the flimsy table and I've only hit 60% feed limit during cutting! We need more cowbell!



Scotty

 

[DMC]

Ah. Can't leave work.

Too much fun.

The sprues can be thinner than .3mm for Ti.

My strategy is soooo almost done! I need to try one more time.

Thanks again to Luigi @ CIMSystem for teaching me! I feel like a new person with new skills. It's not always about money.


Oh, John W., I'm kinda bummed out that milling Ti does not produce sparks like it does when we use handpiece. Really a big let-down. I was so looking forward to something like that.

Maybe we will add flame-thrower on the roof to make up for that?

 

[Clear Precision Dental]

This is so cool, and I can hear the excitement in your "voice." I've admired your ability to think outside the box and take things to another level. This is fun for me, and I ONLY get to think about it.

I, too, am looking forward to some photos of your creations.

Great job, Scott!

 

[DMC]

It is fun!

If anyone is interested, I'd be happy to support you for a trial or purchase of SUM3D and DentalShaper and Rhino. You can then do almost anything with any material and any scanner and any mill. Really adaptable for future materials and machines! Always evolving.


I would travel and spend a few days to help get going.
I have Three people and myself that are ready to answer questions from 7:00AM est - 9:00PM est. I have an employee, Brad, who went to college for CAD design, including Rhino. He is very good at problem solving with many things. He runs SUM3D for Ten hours a day.

Send me a PM if you are interested. I promise it is all that and more! I have seen it with my own two eyes all year now. Been clicking on every button and playing and breaking and messing up and then fixing it. Glad to share! I can save you time by showing you what NOT to do! LOL

That is the real info you need.

CIMSystems is open to customer request. All things are possible, if there is enough $$ involved. Some things just don't make sense. Stick with mainstream machines and you'll be good to go. If you have funky, obscure machine that nobody else has, then expect a slightly higher fee to adapt that technology to "open" format.

Scott

 

[Labwa]

Im with you. having worked with that milling strategie of kavo's, I personaly found it was buggy and had faults and im excited you hear you can mill and smaller steps. why didnt kavo do that. getting rid of the lines in the titanium used to be the worst part of the job for me.

Scott on a different note (and not knowing much about the inner workings of the cam) when you need to mill a tight undercut, will the cam recognise that itself and select that from its list of strategies? as im typing this im thinking to myself what a stupid question. Anyway would you go through each strategie before you milled to be able to leave it over night without wondering if you're gonna come back in the morning with a slightly inaccurate mill.

Im excited to see these photos mate.
keep it up.

 

[DMC]

I have only seen just One example of the KaVo CAM (OpenMind). That was all I wanted to see. It was pretty poor. Margin was sharp, and I never bothered to back fill with wax/resin to mill the flip side. I had seen enough to know I never wanted to use that system.


This setup is very accurate.

I have full control over EVERYTHING! All aspects of tooth placement and angles of undercut milling etc etc.

We can run only Two tools at once. Then human needs to change tools, then resume.

The number of teeth is pretty much unlimited. You could have a big plate of Ti and mill 200 teeth if you want?

 

[DMC]

Right now, I have 1.5"x2.5" rectangle pieces of Ti.

9mm
12.5mm
15mm
all the up to 25mm

I also have 98mm round pieces, but nesting such a large group is annoying to me. I like to do Ten and Ten, or Twelve and Twelve at a time. Something like that. Easier to keep track of who's is whos?

I can put any thickness on the Left side in Position "A"
and I Import any thickness into Position "B" in SUM3D.
So we can have Two thickness in one milling session.
We developed this system to meet our specific stock of material and our modified KaVo fixture. that I hacked up earlier this week. It all just happened. No plan really. LOL
You can make up any system you want. As a matter a fact...I am doing just that.
I have a local shop making me some steel fixtures as we speak.

I also will make a real trunion style fixture. Do you know what that is? Just like a DMG 20. Then, we can mount big chunks of things to do weird projects and get to all sides...Not a "window" fixture. Not a flat plate going across.


See how the trunion goes down, then across, then back up?

We'd mount something verticle, and maybe add a 6th axis on the trunion?

 

[Alistar]

This sounds super cool.

Keep rockin Scott!

 

[DMC]

For Metal, unlike Zirconia....we changed machine Roughing style from bi-directional to climb-mill.

We reduced the spindle RPM and INCREASED the feeds.

We added a Z approach angle of 6 degrees. Like when a Duck lands in water.

This softens the "hit" to the tool at First Contact.

We reduced the X/Y Step during Roughing from 50% of tool Diameter to 30%, and later up to 35% for metal. Reduced the Z-depth steps by a little bit.

We have safe, and low feeds at full material removal, then back up to light-speed.

So far, so good!

 

[DMC]

......when you need to mill a tight undercut, will the cam recognise that itself and select that from its list of strategies? as im typing this im thinking to myself what a stupid question. Anyway would you go through each strategie before you milled to be able to leave it over night without wondering if you're gonna come back in the morning with a slightly inaccurate mill.

Im excited to see these photos mate.
keep it up.

I bought the 5-axis module from CIM Systems. The video above is for only 3+1 Axis milling, and it shows the possibility of milling undercuts, even with only 3 axis. (Cheaper software and cheaper machines)

Of course the Kavo can run simultanious 5 axis, and so that's what I use.
We have more options to get ideal tool angle. It is automatic in the CAM software. You define the total amount of undercut you are willing to accept, or not in the internal of crown, and limits of tool angles, on and on..

 

[paulg100]

I contacted CIM about milling with their software and the Original CERCON brain, but they said it couldnt be done.

Maybe there is a way.

Seems a shame to let a perfectly good mill go to waste.

 

[DMC]

Yeah, don't know about that unit.

Does it run on a PLC computer? Not a simple USB cable to regular computer, but rather a couple hundred wires in multiple cables going to a fancy-schmancy Board or multiple circuit boards next to PLC computer inside or beside the mill?

Is it a real mill I mean? If not, then sorry. It is not worth the effort probably. Same for the Cerec. It's more like a toy and not an Industrial CNC machine. Totally different world. Different language. Complete different make-up of machine control systems.

My KaVo runs on a German IBH Automation type PLC computer.
Lava mills are Beckhoff Automation, or PowerAutomation PLCs.

These are Industrial type computers and hardware to control the axis motors and spindle and other accessories very fast! You can't do this with a regular PC and a USB cable. Impossible.

Datron, DMG, iCore, Haas, etc are all in the same catagory. They require superfast feedback from each axis endoder and axis motor. That takes up multiple wires for each axis. Then, you need full spindle control and feedback. A FAST computer dedicated to looking ahead in the G-code programming blocks to adapt that to the mill, by slowing feeds or ?? within the machine's limits. It is a lot of data to be pushing through a USB, so a different computer I/O set-up is needed. Just the
computer and I/O Interface of a Lava mill or KaVo is actually larger in physical size to a Cercon or a Cerec mill in it's whole being. LOL
That does not include anything but the computer and control system.

That I/O Interface usually takes up a lot of physical space, and fancy machine componants. To have that, usually comes a big cast frame and a $100k price tag minimum.

That set-up is usually in a sealed Industrial cabnit with a Chiller system that may also be used for the spindle. The KaVo is under the cabnit, and is exposed, but kinda encased in a big a5s Aluminum "suitcase" under tha PLC computer. Not sealed from environment.

(I'm an idiot trying to explain this...LOL)


The Cerec and Cercon I believe are not these types of machines.
The Roland is also not a real CNC mill IMO.

 

[DMC]

This is the KaVo milling strategy for Ti in First Two pics.






This is a rare sight. I will post pics of my mistakes. Some were my son's fault. I let it mill and saved as example of what NOT to do.















Ya gotta watch those decimal points boy!

 

[DMC]

There are hundreds of things you could point out as crap in these photos.

That is why ?I posted them. For discussion.

For ex. Do you see the tool collision in the second from bottom pic?

Look at the side walls of the raw stock. I fixed it for the next go around on the tooth beside it. See the difference? I avoided collision and got a better angle the next time. See the dpeth was deeper as well? Each time we learned something, or Two.

[YOUTUBE]NAKZFeX_Sd8[/YOUTUBE]