wax milling parameters

sidesh0wb0b

sidesh0wb0b

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so awhile back i posted a similar thread about milling parameters in 3shape for wax copings and full contour....took me ages to get to a passable result for most cases. but not a super result. well, here i am again...chasing my tail with not enough time to solve the riddle of high quality fit and margin integrity with the milling parameters in exocad.

most recent version of exo, roland 51d (2mm, 1mm, .6mm, .3mm milling tools)......anyone have any helpful tips? so far the reseller has tried to help but the results were less than satisfactory. basically ended up with the same thing ive been getting.
 
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erykd1

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Same setup here, except older version of exo. I'm guessing these are for pressed crowns? These are my workflow steps and I usually have good luck with it:
  1. Manually set insertion pathway to be as vertical as possible (Sometimes my exo skips this step, not sure why)
  2. Set margins in exo to horizontal .15mm, Angled 0mm. Cement gap of .02 is usually fine.
  3. I'm milling TD Dental Gray wax using my used zirconia burs. TD Dental diamond coated 2/1mm and Carbide .6/.3mm on Roland 51D
We like to mill and press, then thin down the margin after pressing. Hope it helps!
 
sidesh0wb0b

sidesh0wb0b

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Same setup here, except older version of exo. I'm guessing these are for pressed crowns? These are my workflow steps and I usually have good luck with it:
  1. Manually set insertion pathway to be as vertical as possible (Sometimes my exo skips this step, not sure why)
  2. Set margins in exo to horizontal .15mm, Angled 0mm. Cement gap of .02 is usually fine.
  3. I'm milling TD Dental Gray wax using my used zirconia burs. TD Dental diamond coated 2/1mm and Carbide .6/.3mm on Roland 51D
We like to mill and press, then thin down the margin after pressing. Hope it helps!
thats pretty similar to what settings im currently using. angles slightly different, but that doesnt effect internal fit. maybe im unreasonably picky? just isnt a good fit yet.
im using my carbides for milling, and yes most are for pressing but some are copings for PFM :eek: ...yes they still exist lol
 
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@sidesh0wb0b

What the issues? Open margins? Too tight/loose?

Are you correcting your margins as a last step? Thats always a must with every restoration type.
 
sidesh0wb0b

sidesh0wb0b

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@sidesh0wb0b

What the issues? Open margins? Too tight/loose?

Are you correcting your margins as a last step? Thats always a must with every restoration type.
margins usually sealed, but fit is loose
 
Car 54

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I don't know how it translates but with 3Shape for emax I'm at .010 for spacer and extra spacer.

I think as user name implied, I only connect to margin after my crown main parameters are completed.
 
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I don't know how it translates but with 3Shape for emax I'm at .010 for spacer and extra spacer.

I think as user name implied, I only connect to margin after my crown main parameters are completed.
Not what I was saying...
I always jump to expert and make tiny margin corrections as a last step. Even if you dial it in earlier in wizard, it will have some small areas that need to be moved.

Its also not a great idea to use old Zr burs. They get worn and dont mill as accurate as new burs.

Parameters Im at for wax:
gap .025
additional axial .07
additional radial .05

horizontal crown margin .1
angled crown margin .1
angle 68

Pour an extra die. Mill and cement it. Cut it in half and see where your issues are.
 
sidesh0wb0b

sidesh0wb0b

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Not what I was saying...
I always jump to expert and make tiny margin corrections as a last step. Even if you dial it in earlier in wizard, it will have some small areas that need to be moved.

Its also not a great idea to use old Zr burs. They get worn and dont mill as accurate as new burs.

Parameters Im at for wax:
gap .025
additional axial .07
additional radial .05

horizontal crown margin .1
angled crown margin .1
angle 68

Pour an extra die. Mill and cement it. Cut it in half and see where your issues are.
been tweaking all sorts of settings, havent tried cutting out the zirc tools though. i will say it hasnt mattered if i used carbide tools or diamond tools that i use on zirc. results havent changed based on those. ive gotten "closer" to ideal results but i am not where i want to be. i like the idea of cementing it to a die. thanks for that!
 
Car 54

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Not what I was saying...
I always jump to expert and make tiny margin corrections as a last step. Even if you dial it in earlier in wizard, it will have some small areas that need to be moved.

Its also not a great idea to use old Zr burs. They get worn and dont mill as accurate as new burs.

Parameters Im at for wax:
gap .025
additional axial .07
additional radial .05

horizontal crown margin .1
angled crown margin .1
angle 68

Pour an extra die. Mill and cement it. Cut it in half and see where your issues are.

I'm glad I wasn't tracking with what you were laying down, user name, as you followed up
with a heck of an informative post :)
 
brayks

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I'm not a Roland guy but I would:
Start with new tooling
Tighten all fixture and part mounting points.
Verify acceptable backlash in all axes including rotary
Clean and/or change collet
Check spindle run-out
Check tool run-out
If not seating properly, Check prep radii of curvature. Smallest radius in any area must be larger than the smallest cutting tool radius used. FreeCAD had good tools for this and as it's name implies, it's free.
 
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I agree with Brayks, this has little to do with your exocad settings and a lot to do with the mill performance. In a perfect world you should be able to set a 30 micron spacer and no spacing within .7 or margin and get reasonably good fits. Your machine idiosyncrasies will effect this. I have also found that the tooling design will have a lot of effect on the fit of things I mill. I switched from Amann Girrbach 1mm burs to Sierra Dental because the AG design allows for a deflection of the bur while milling while the SD has less.
 
esamuelr

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If you have millbox adjust the internal cavity for in Cam and see how the results are. Also use ctrl p in exocad to check the spacing ngf you have set on your system. May just need to tweak a few settings. Another setting in exocad to check is tool diameter. Figure out what your smallest cavity side milling tool is and increase decrease the preset tool diameter by .01 increments.

Just food for thought.
 
sidesh0wb0b

sidesh0wb0b

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I'm not a Roland guy but I would:
Start with new tooling
Tighten all fixture and part mounting points.
Verify acceptable backlash in all axes including rotary
Clean and/or change collet
Check spindle run-out
Check tool run-out
If not seating properly, Check prep radii of curvature. Smallest radius in any area must be larger than the smallest cutting tool radius used. FreeCAD had good tools for this and as it's name implies, it's free.
i would agree with all of that if the issues i am having were across the board. acetal, pmma, and zirc all mill and fit properly. its just wax that i struggle with.
 
sidesh0wb0b

sidesh0wb0b

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I agree with Brayks, this has little to do with your exocad settings and a lot to do with the mill performance. In a perfect world you should be able to set a 30 micron spacer and no spacing within .7 or margin and get reasonably good fits. Your machine idiosyncrasies will effect this. I have also found that the tooling design will have a lot of effect on the fit of things I mill. I switched from Amann Girrbach 1mm burs to Sierra Dental because the AG design allows for a deflection of the bur while milling while the SD has less.
again, see above post.
 
sidesh0wb0b

sidesh0wb0b

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If you have millbox adjust the internal cavity for in Cam and see how the results are. Also use ctrl p in exocad to check the spacing ngf you have set on your system. May just need to tweak a few settings. Another setting in exocad to check is tool diameter. Figure out what your smallest cavity side milling tool is and increase decrease the preset tool diameter by .01 increments.

Just food for thought.
not using millbox. using sum3d. been toying with anticipated tool diameter(as well as spacer settings). its been helping but not getting me to the results i would like to have.
will try ctrl+p and see what exocad shows. thanks
 
JMN

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i would agree with all of that if the issues i am having were across the board. acetal, pmma, and zirc all mill and fit properly. its just wax that i struggle with.
Have you investigated your material specific settings? I might have missed it if you said so already as I'm still on the first coffee.

I'd also think about the fact that wax is much softer than any other material we mill and that a mildly bent burr from runout issues will be 'shaved back' a bit more on other things. This is conjecture at a near academic and irrelevant level.
 
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Have you investigated your material specific settings? I might have missed it if you said so already as I'm still on the first coffee.

I'd also think about the fact that wax is much softer than any other material we mill and that a mildly bent burr from runout issues will be 'shaved back' a bit more on other things. This is conjecture at a near academic and irrelevant level.
I would also grab a micrometer and verify the tools are the claimed and expected dimensions.
 
sidesh0wb0b

sidesh0wb0b

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Have you investigated your material specific settings? I might have missed it if you said so already as I'm still on the first coffee.

I'd also think about the fact that wax is much softer than any other material we mill and that a mildly bent burr from runout issues will be 'shaved back' a bit more on other things. This is conjecture at a near academic and irrelevant level.
yes, thats what i have been adjusting. wax specific parameters.
i agree with you on the softness. im clearly not a tooling strategy guru, hence posting these issues openly. swapped out for new tools to try that, no dice there either.
 
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