Zirconia crowns come out .2~.3mm higher on occlusion

[idrg]

Currently I’m using 3shape D1000 with Roland D51 milling.
And somehow all the zirconia crowns gets thicker on the occlusion (.2-.3mm higher)..
Has anyone experienced that problem?

 

[JMN]

Z axis needs recalibrating?

Slipping burr from the chuck/collet?

Correct shrinkage factor entered correctly when changing discs is certain if it always happens with every disc/shade/thickness, so that is out.

 

[Affinity]

Calibrate the z axis..

 

[Contraluz]

Currently I’m using 3shape D1000 with Roland D51 milling.
And somehow all the zirconia crowns gets thicker on the occlusion (.2-.3mm higher)..
Has anyone experienced that problem?

Besides what has been suggested, above, check if the scanned models are occluding. I usually 'squeeze' the models, virtually, 0.15 mm to get them occluding. You can also calibrate that in you 'occlusion adjusting tools'.

I have found that occlusion is one of the issues where scans can be easily off. Especially with bigger and heavier models a shift can occur while scanning. To eliminate that issue on bigger, multi unit cases, I put lab putty between the models, so they stay stable.

With the newer scanners, that can take a whole articulator, this is problem is resolved.

 

[idrg]

I always calibrate the milling machine everyday.
Is there another way to calibrate just Z axis?

Z axis needs recalibrating?

Slipping burr from the chuck/collet?

Correct shrinkage factor entered correctly when changing discs is certain if it always happens with every disc/shade/thickness, so that is out.

 

[idrg]

Besides what has been suggested, above, check if the scanned models are occluding. I usually 'squeeze' the models, virtually, 0.15 mm to get them occluding. You can also calibrate that in you 'occlusion adjusting tools'.

I have found that occlusion is one of the issues where scans can be easily off. Especially with bigger and heavier models a shift can occur while scanning. To eliminate that issue on bigger, multi unit cases, I put lab putty between the models, so they stay stable.

With the newer scanners, that can take a whole articulator, this is problem is resolved.

It just happened since last week.
Same guy always scan with same ways.

 

[JMN]

It just happened since last week.
Same guy always scan with same ways.

Look at what is different between when it did and did not work right.

Software updates?
New burrs? Might have gotten a just slightly shorter burr 'on sale'? New burr supplier?
Did anyone else scan ever, at all, even once? Did you check the scan mounting plate to see that it is secure and proper?

 

[Contraluz]

It just happened since last week.
Same guy always scan with same ways.

On my Wieland Mini, I have to change the touch plate every so often, since it gets 'worn out'. I have seen discrepancies keeping up, due to it. Not sure if your Roland has something similar, but you might want to check it out.

We have a bunch of knowledgable CAM people here on the board. When it comes to mills or CAD/CAM in general, I am more the user type of guy...

 

[JMN]

[...] When it comes to mills or CAD/CAM in general, I am more the user type of guy...

must....supress.....jokes....so...many....must.....arrrgh

 

[Contraluz]

must....supress.....jokes....so...many....must.....arrrgh

Feel free...