EP5000 Crack detection, but no crack...

[Marcusthegladiator CDT]

So 3 times in the last couple months we put in 6 or 8 veneers in a 200 gram ring. And the EP5K throws a crack detection error at us just seconds after it actually begins to press. And of course nothing is pressed and nothing is cracked. The program didn't even begin to press.
Anyone else ever have this issue?
Thanks.

 

[rkm rdt]

With all those grills you're making,it assumes there must be crack around somewhere.

 

[Ron.Ferland]

So 3 times in the last couple months we put in 6 or 8 veneers in a 200 gram ring. And the EP5K throws a crack detection error at us just seconds after it actually begins to press. And of course nothing is pressed and nothing is cracked. The program didn't even begin to press.
Anyone else ever have this issue?
Thanks.

What kind of plunger do you use?

 

[Kaypan]

When removing the investment ring from the silicone form and the top/bottom, it is essential to remove the excess investment material that escapes through the top cap. This investment creates a small button on top of the investment ring, which is the side that is down in the press furnace. If this is not removed, the ring balances on top of this button. When force is given during the press cycle, this button can cause the investment ring to slightly tilt and fool the furnace to thinking it is a crack. Could be the problem...

 

[sidesh0wb0b]

When removing the investment ring from the silicone form and the top/bottom, it is essential to remove the excess investment material that escapes through the top cap. This investment creates a small button on top of the investment ring, which is the side that is down in the press furnace. If this is not removed, the ring balances on top of this button. When force is given during the press cycle, this button can cause the investment ring to slightly tilt and fool the furnace to thinking it is a crack. Could be the problem...

i doubt it because on a 200g ring the center where that "button" of investment would be usually isnt in contact with the seating plate.
and because im guessing Marcus knows to scrape the ring.

 

[AL1]

call tom at ivoclar you may need a new pressing head.

 

[Marcusthegladiator CDT]

Yea I am wondering about the drive press. No buttons here for a pro. I fill it just enough that I dont even have a button. The center of the ring has a small void where there is usually a button. And I use The Perfect Ring so I have Zero flash to clean up. Just pop it out of the ring and straight into the oven. No fuss with a button or flash. And we don't press more than a ring or two a day. So I always wait out a 20 minute bench set and throw the rings into a cold oven and wait 1.5 hrs to get to 842, then wait another hour. And I am using Shofu's Cerevety, measuring with a whipix aquaspenceII and mixing with the matching whipmix mixer. Very nice damn machines... And using cold Alox plungers that I clean the hell out of. Still not sure whats going wrong. Thats why I am worried about the press drive. For now I'll start pressing in the Dekema...

I programed the EP5K to audible and turn blue when the press began during the press cycle. It turns blue, beeps the music, and instantly tells me it detected a crack and aborts the program. Damn plunger never moved.

I've sent this EP5K to ivoclar for repair 3 times this year and the last time I told them to tune it up like a mechanic would a car. Just tune up everything, new gaskets, sensors, fuses, whatever it takes to keep her running well for a couple more years. Its cursed.

One thing I just realized I have changed is I haven't been removing any glaze layer from the ring, but I don't think that could cause this problem...

 

[PDC]

I also use the EP5000, but never had those issues. I do use disposable plungers though. So you're saying that the pressing distance readout is 0 mm... as if it never moved. The only thought I had was maybe your plungers have lost some of their circumference due to cleaning. If the plunger doesn't have a snug fit, it could cause the glass to run up the sides of the plunger. That could cause the sensor not to recognize any backflow pressure making it think there is a crack. Just a thought.

 

[Marcusthegladiator CDT]

I also use the EP5000, but never had those issues. I do use disposable plungers though. So you're saying that the pressing distance readout is 0 mm... as if it never moved. The only thought I had was maybe your plungers have lost some of their circumference due to cleaning. If the plunger doesn't have a snug fit, it could cause the glass to run up the sides of the plunger. That could cause the sensor not to recognize any backflow pressure making it think there is a crack. Just a thought.

I kept my eye on the plunger through the wire mesh on the back. The plunger never moved and instantly gave me the crack detection.

 

[PDC]

Interesting. I have never tried the Perfect Ring. Have you been using it with this furnace for a while? Maybe go back to the old Ivoclar ring and do a test run to see if you have any problems with that.

 

[AL1]

Press head has pretty much all the electronics in it and they do fail.
Mine was the opposite, wouldnt stop pressing in my ep 600 although a new press head
didnt solve the problem, I was told that 99% of the time it is, mine was the exception.
Just bought a new ep 3010, instead of trying to fix an 11 year old press furnace.

 

[Marcusthegladiator CDT]

Interesting. I have never tried the Perfect Ring. Have you been using it with this furnace for a while? Maybe go back to the old Ivoclar ring and do a test run to see if you have any problems with that.

for about 2 years

 

[Tayebdental]

I think this is due to a slight movement of the ring being pressed giving the senser an indication that a crack being detected.
Before I press I make sure I test the cold ring on the platform (included )to eliminate any movement beforehand.

 

[Marcusthegladiator CDT]

I think this is due to a slight movement of the ring being pressed giving the senser an indication that a crack being detected.
Before I press I make sure I test the cold ring on the platform (included )to eliminate any movement beforehand.

I am a button free kinda guy. She's as flat as a pancake. Or a crepe if you like crepes.

 

[sidesh0wb0b]

I am a button free kinda guy. She's as flat as a pancake. Or a crepe if you like crepes.

how well do those stay clean or clea up after use? the ivoclar ones are crap for cleaning the base and cap.

 

[Marcusthegladiator CDT]

how well do those stay clean or clea up after use? the ivoclar ones are crap for cleaning the base and cap.

The emax rings from ivoclar Leave flash on the top and bottom. And the Super ring doesn't.
I also like how its tapered toward the top. Instead of scraping that last of the 100 grams from the bowl to fill your 100 gram ring, these are probably 95 gram rings so you always have enough.
And cleanup is a breeze. Its all silicone, no hard plastic to chip away at. Just squeeze like you would a green mixing bowl.

 

[Gru]

Just a thought: on the ep600 the alox press plunger would sometimes get a little ceramic on the sides and hang up ever so slightly. I know, no crack detection on it, and I can't figure out how to make the plunger activate on the ep5k with the head open, but if it had some "vaporized" ceramic on it, it might act that way. Maybe take the press plunger out of the head and clean it? Fortunately I haven't had to take my 5k apart yet, so can only assume there's a set screw behind the screen on top to do this.

 

[AL1]

Checked plunger when I put in new press head, I always clean alox after each press,
As I said before went to my friends lab used his ep 600 did everything as usual, pressed fine.
Using my alox, sprue base and ring, microstar investment.
And yes a set screw.

 

[Gru]

Has anyone figured out a work around to disable the CDS on the ep5000? I have lost more work due to false "crack detection" over the last 7 years than it has saved by 1000%. I hate it so much I would probably consider other presses without it if I were buying again. At least let me turn it off! hh!

 

[charles007]

I think its a problem with the ovens crack detection ?? maybe I'm wrong !

No long have my ep5000 but I did have the crack detection to pop up maybe 5 times in 6 years. Oven
continued to press and I was lucky I was able to salvage all the crowns. My crowns were sprued to close to
the outside wall and emax hit the wall. Just like cutting off a wall of gold flash,,,,, lol
Always used Ivoclars Alox plungers.