Bystronic 4020 Dirt and SPOT @ back of Lens.

[KonQueR]

Hey guys.

I getting black spot and little dirt on the back of my lens. I went through 5 lens in the last 5weeks and I have asked LMC ( Australia Bystronic Rep). But it seem this guys has no clue whats goin on. They ask me to check all the seals, change the distance piercing and put more gas pressure when piercing. I have try all that But nothing seem to work.
Any suggestion to fixed this is greatly appreciated.

Thanks in advance guys. Cheers

 

[HenryRollins]

What are you running for beam purge? Shop air or Nitrogen? If you are running shop air, check the ultra pack filters, inspect the bellows for holes and check your mirrors. If something is on the beam entry side of the lens then you may have some spots on your mirrors as well.

 

[HenryRollins]

Konquer, I may have spoken a little too fast, you said the back side and when I hear that, people are referring to the side the beam enters the lens. If this is the case, then check from my last posting. If it is happening on the beam exit side of the lens, please check you stand by gas pressure. Is this a MMC machine or a Byvision machine?

 

[KonQueR]

Hi Henry, We are using ByVision with this Byspeed. The default Gas pressure standby on most of the parametre is about 1-1.2Bar

 

[HenryRollins]

The parameters should be around 2.2-2.4 bar for standby gas pressure. More than likely the pierce to standby causing a vacuum and sucking deposits onto the lens. The low stand by gas pressure was intended for machines using CPP or RPP, in theory it is a good idea but in application not so much.

 

[KonQueR]

Thanks for that advice Henry
I will change the gas pressure standby to 2bar and run a few jobs and see how it goes.
I'll keep you inform.

Thanks mate.

 

[KonQueR]

Hey Henry, 24hrs of Cutting 10-20mm Mild Steel and a couple of thick S/S and NO SPOT or mark on lens.

Thanks mate