Wet, dry, why?

[JMN]

Having done closed singlesource CAD and outsource, I never knew what needed wet or dry milling. I understand wet is to keep temps low, but:

What gets wet milled,
what gets dry milled,
and why can't you wet mill everything.

These are mysteries to me, and I bet many others who are still figuring out this brave new world.

 

[CoolHandLuke]

you can wet mill everything. its just that the damage caused by liquid zirconia dust slurry can be devastating very fast. so it is frequently dry milled.

mills that have no coolant function also come cheaper. so theres that.

 

[Sevan P]

Having done closed singlesource CAD and outsource, I never knew what needed wet or dry milling. I understand wet is to keep temps low, but:

What gets wet milled,
what gets dry milled,
and why can't you wet mill everything.

These are mysteries to me, and I bet many others who are still figuring out this brave new world.

Wet
All Glass Ceramics (Emax blue Block)
Titanium Abutment Blanks
Titanium Disk for bars
CrCo for non precious copings and frames

Dry
Wax
Zirconia
PMMA
Composites
Models

WHY?
Cause wet milling is messy and coolants may contain oils. No need to wet mill wax or PMMA. Sirona wet mills Zirconia but then you have to let it dry before coloring it and they cut small block. Imagine you wet mill a 98mm Zr disk and only cut two units, then entire disk is wet for no reason. So things that don't need to get wet shouldn't. Wax, PMMA and Zriconia all have limits on how fast they can be cut and trust me they are pretty fast and do not require to be cooled. You wet mill to keep the tool from over heating mainly. You can dry mill CrCo but feed rates and RMP must be slow and it will take forever. Wet milling means faster cut time on Ti, CrCo and Glass ceramics.

It is very easy if you think about it, just to over think it and everything is easy to understand.

 

[CoolHandLuke]

wet milling zr on versamill is ridiculously quiet its spooky. its like watching the tv on mute.

 

[JMN]

Thanks guys!

I had figured glass and metal would need it, and wax or pmma would be near counterproductive due to it's static clingyness.

I was thinking you'd need some type of cooling loop for zirc as it likes to microfracture when it gets warm. Is this mitigated and eliminated by toolspeed and path planning?

 

[zero_zero]

You could install a vortex tube for cool air if you have enough air output and means to dampen the associated noise. Tried that on my DWX50...it worked well enough to get condensation on the puck holder after a short time...was thinking to build a sound proof box for it because it's loud...

 

[JMN]

You could install a vortex tube for cool air if you have enough air output and means to dampen the associated noise. Tried that on my DWX50...it worked well enough to get condensation on the puck holder after a short time...was thinking to build a sound proof box for it because it's loud...

Any guess what kind of cfm you were pushing? I'd take a guess of psi and orifice size if you wouldn't mind.
Do mills usually have temp probes to compensate for thermal creep issues like this would cause or did ypu wait for it to "get up to speed" then calibrate?
Know I'm asking a lot of questions. Thanks.

 

[zero_zero]

Any guess what kind of cfm you were pushing? I'd take a guess of psi and orifice size if you wouldn't mind.
Do mills usually have temp probes to compensate for thermal creep issues like this would cause or did ypu wait for it to "get up to speed" then calibrate?
Know I'm asking a lot of questions. Thanks.

I don't have means to measure cfm on a given line, got a big compressor with 1/2 inch piping around the lab and I forked off of that (plenty of air supply and an 80 gal tank),with a small bleed valve before the mill's pressure regulator so I could keep the proper ratio for the most cooling...
Industrial mills do have temp probes and cooling throughout their structure...AFAIK the low end dental mills don't...
I was merely trying to maximize feed rates by over cooling the tool tip for cutting wax and plastics, the thermal expansion for that given temp differential in that localized volume is magnitues smaller than the mills repeat accuracy, so compenstion wouldn't be necessary nor possible with the given firmware the mill has...

 

[JMN]

I don't have means to measure cfm on a given line, got a big compressor with 1/2 inch piping around the lab and I forked off of that (plenty of air supply and an 80 gal tank),with a small bleed valve before the mill's pressure regulator so I could keep the proper ratio for the most cooling...
Industrial mills do have temp probes and cooling throughout their structure...AFAIK the low end dental mills don't...
I was merely trying to maximize feed rates by over cooling the tool tip for cutting wax and plastics, the thermal expansion for that given temp differential in that localized volume is magnitues smaller than the mills repeat accuracy, so compenstion wouldn't be necessary nor possible with the given firmware the mill has...

So cm or less was the area of effect, I gotcha now. I was thinking a decimeter area. Thanks for clearing that up!

 

[mmbh]

wet milling zr on versamill is ridiculously quiet its spooky. its like watching the tv on mute.

I'm considering getting the versamill 5xs. Sounds like you have one or have seen it in action. What did you think besides it being really quiet?

 

[JMN]

You could install a vortex tube for cool air if you have enough air output and means to dampen the associated noise. Tried that on my DWX50...it worked well enough to get condensation on the puck holder after a short time...was thinking to build a sound proof box for it because it's loud...

Might still be able to dig up one of the Dot-Matrix printer cages. They were fantastic at noise reduction. Maybe try weirdstuff.com or pacificgeeks.com if you don't have friends in office equipment spots.

 

[CoolHandLuke]

I'm considering getting the versamill 5xs. Sounds like you have one or have seen it in action. What did you think besides it being really quiet?

my personal thoughts - the machine is well worth its price. construction is fantastic, table is also well built and heavy. it cuts titanium very nicely, i expect it cuts cocr just as nicely but i havent run that yet. everyone on earth can do wax and pmma those arent challenging enough to make a statement either way.

one thing i keep fiddling with is emax - but clearly other versamill users have it working well enough for them so i am wondering what my hangup is.

i just got a plastic die kit though so i am going to pour some synthetic dies and do some designs and have them sent to steve and his team to see if this is an issue we can solve or if this means we can't do emax on all the cases we want to do emax on. i expect however, its just something i'm hung up on.

steve (brayks) and his team have been great to work with, highly informative and dependable. they arent just some company selling machines and spouting sales pitch BS. they all know this thing inside and out backwards and forwards.

 

[MJFDDS]

CoolHanLuke, we have a Versamill as well.

I agree that Steve, Chris, Ben and Tony have been great with support.

What has been your experience with emax on your machine?



Thanks.

 

[CoolHandLuke]

my milled emaxes don't seem to fit right, like material has been left. they bind. so far i've compensated by adding an enormous die spacer, but i can't add too much or i cut into the room for the minimum amount of material for the crown. Chris added a few microns overmill to my strategies and that helped a bit but wasnt the cure we needed. i am convinced it is an issue i face and probably not many others, as i haven't heard of anyone else having this problem.

 

[mmbh]

my personal thoughts - the machine is well worth its price. construction is fantastic, table is also well built and heavy. it cuts titanium very nicely, i expect it cuts cocr just as nicely but i havent run that yet. everyone on earth can do wax and pmma those arent challenging enough to make a statement either way.

one thing i keep fiddling with is emax - but clearly other versamill users have it working well enough for them so i am wondering what my hangup is.

i just got a plastic die kit though so i am going to pour some synthetic dies and do some designs and have them sent to steve and his team to see if this is an issue we can solve or if this means we can't do emax on all the cases we want to do emax on. i expect however, its just something i'm hung up on.

steve (brayks) and his team have been great to work with, highly informative and dependable. they arent just some company selling machines and spouting sales pitch BS. they all know this thing inside and out backwards and forwards.

Thanks for the info, you've been very helpful. The three mills I had it narrowed down to were roland, vhf(jensen),versamill 5xs(which I'm leaning towards now.) I used to mill everything wet, and dealing with all that dust doesn't sound appealing.

 

[CoolHandLuke]

those are all good choices, but only the versamill gives you enough flexibility to adapt to adding capability to your mill to do new materials as they are developed. while emax works (for nearly all of us) Chris has samples of Obsidian and suprinity by now.

get a copy of delcam exchange and youll be able to do CDT files from cerec i hear (i dont know first hand).

 

[mmbh]

those are all good choices, but only the versamill gives you enough flexibility to adapt to adding capability to your mill to do new materials as they are developed. while emax works (for nearly all of us) Chris has samples of Obsidian and suprinity by now.

get a copy of delcam exchange and youll be able to do CDT files from cerec i hear (i dont know first hand).

I have STL conversion capabilities with inlab SW15, but I'll have Exocad in a few months as well anyways. But I'll check into the delcam exchange anyway, thanks.

 

[Ramon Flores]

At Amann Girrbach, with our Motion 2 we mill
Wet
Glass Ceramics (Emax, Vitablocks, etc.)
Composites
PMMA
Wax (For Dentures)

Dry
Wax (C&B)
Zirconia
Model Material
Peek
CoCr (sintron)
PMMA

We know that milling PMMA dry is an option but the bur wear is higher and the time to mill is longer, so we recommend milling wet. Same for composites, we have the option for milling dry, but I think it is preferable to mill them wet as they milling time can be reduced and tool life can be extended.

 

[mmbh]

my milled emaxes don't seem to fit right, like material has been left. they bind. so far i've compensated by adding an enormous die spacer, but i can't add too much or i cut into the room for the minimum amount of material for the crown. Chris added a few microns overmill to my strategies and that helped a bit but wasnt the cure we needed. i am convinced it is an issue i face and probably not many others, as i haven't heard of anyone else having this problem.

Did you get your milled e.max dialed in yet?

 

[CoolHandLuke]

honestly no. too busy to debug that right now.