Printed model inaccuracy

subrisi

subrisi

Active Member
Full Member
Messages
454
Reaction score
7
I am having fit issues with printed models. We are used to re-wax all the margins of our milled wax crowns, but now since we are doing printed models from a carestream scanner, we get crowns back with open margins. I assume that by waxing the margins to the printed die, we are creating "hold up's" and the crown does not seat. I can't get myself over it to leave the margins untouched and ignore toe wide open space. How do you deal with that and what might be wrong with the system?
Angelika
 
PDC

PDC

Well-Known Member
Full Member
Messages
997
Reaction score
232
Are you printing them or outsourcing?
 
JMN

JMN

Christian Member
Full Member
Messages
12,205
Reaction score
1,884
I am having fit issues with printed models. We are used to re-wax all the margins of our milled wax crowns, but now since we are doing printed models from a carestream scanner, we get crowns back with open margins. I assume that by waxing the margins to the printed die, we are creating "hold up's" and the crown does not seat. I can't get myself over it to leave the margins untouched and ignore toe wide open space. How do you deal with that and what might be wrong with the system?
Angelika
Just a thought, have you tried designing and delivering completely model-less?
The model creation process adds another family of variables of which you have no control and many times no knowledge(unless you are *really* close with your model supplier). It may be that the scanned data is accurate enough to produce a properly sealing crown, but the model fabrication is not.
 
CoolHandLuke

CoolHandLuke

Idiot
Full Member
Messages
10,078
Solutions
1
Reaction score
1,411
Just a thought, have you tried designing and delivering completely model-less?
The model creation process adds another family of variables of which you have no control and many times no knowledge(unless you are *really* close with your model supplier). It may be that the scanned data is accurate enough to produce a properly sealing crown, but the model fabrication is not.
this is the more likely scenario.
 
CoolHandLuke

CoolHandLuke

Idiot
Full Member
Messages
10,078
Solutions
1
Reaction score
1,411
what do you think i do when it comes to remote troubleshooting like this?

this helmet aint just to hold my giant ego you know.
 
JMN

JMN

Christian Member
Full Member
Messages
12,205
Reaction score
1,884
what do you think i do when it comes to remote troubleshooting like this?

this helmet aint just to hold my giant ego you know.
Nah, there's lots of straps and padding in there too in case someone pulls the emergency brake when you've gone to plaid.
Plus, you've gotten experience with a lot more of these toys than I have.
 
CoolHandLuke

CoolHandLuke

Idiot
Full Member
Messages
10,078
Solutions
1
Reaction score
1,411
i mean alternatively its very easy to say 'yeah your die spacer was applied incorrectly' or 'whoever is milling your wax doesn't seem to have a great grasp of how digital design and milling should mesh together'

this seems too easy though. and i like to give the benefit of the doubt whenever possible, until it irreducibly points in this general direction.
 
JMN

JMN

Christian Member
Full Member
Messages
12,205
Reaction score
1,884
i mean alternatively its very easy to say 'yeah your die spacer was applied incorrectly' or 'whoever is milling your wax doesn't seem to have a great grasp of how digital design and milling should mesh together'

this seems too easy though. and i like to give the benefit of the doubt whenever possible, until it irreducibly points in this general direction.
Yep, break the problem causing process into smaller and smaller halves until you've found the half with error producing outcome.
I think a good tech is more interested in how to fix the problem, not the blame. Unless the problem is between the workpiece and chair and refuses to follow instructions, that you frequently can't fix.

There is a Japanese process called something like "the 6 questions". By the time you've answered the six questions that led to an error, you will have created a documented process to prevent any step towards it's replication and will have discovered and eliminated other issues not only in that process but parallel and feeder processes.
 
rkm rdt

rkm rdt

Well-Known Member
Full Member
Messages
21,409
Reaction score
3,288
Yep, break the problem causing process into smaller and smaller halves until you've found the half with error producing outcome.
I think a good tech is more interested in how to fix the problem, not the blame. Unless the problem is between the workpiece and chair and refuses to follow instructions, that you frequently can't fix.

There is a Japanese process called something like "the 6 questions". By the time you've answered the six questions that led to an error, you will have created a documented process to prevent any step towards it's replication and will have discovered and eliminated other issues not only in that process but parallel and feeder processes.
Where's the beef?
 
T

Torquadon

Active Member
Full Member
Messages
107
Reaction score
16
I believe first question to ask is why are you rewaxing all margins on wax milled crowns? There is something wrong here, sure it sometimes happens, but it definitely should not be a rule. When you working with IO scans your scan is way more detailed than a model you print, so by assuming you are going to change margins you loosing accuracy.
 
KentPWalton

KentPWalton

Well-Known Member
Full Member
Messages
1,789
Reaction score
265
Geez, there are so many variables here! Material settings, design settings, material, material post processing, etc. :rolleyes:
 

Similar threads

M
Replies
1
Views
613
doug
T
Replies
20
Views
1K
Laura Feng
L
LabRat23
Replies
7
Views
320
TheLabGuy
TheLabGuy
Top Bottom