RE: SLA - Viper Issues

From: Alex Laymon (
Date: Sun Oct 13 2002 - 23:19:12 EEST

Dear Jeevan and RP List,

Having followed this RP list for several years, this is my first time ever
posting out of respect for the "anti-advertisement" desires of the list.
However, since it seems you have not heard too many response to your
inquiry, I felt compelled to respond from the laser community.

I have been involved with UV lasers and stereolithography for 16 years now,
supplying the first LiCONiX HeCd lasers to Chuck Hull at 3D Systems. Then
personally installing the first lasers on SLA-1 and SLA-250 systems. Now our
company, DPSS Lasers Inc., manufactures a UV solid state laser for a wide
variety of applications, including retrofitting current laser systems on the
SLA-250, SLA-500 and SLA-5000 systems to our solid state lasers. Over the
years, UV laser technology has moved from the older gas lasers (HeCd and
Argon Ion) to the newer solid state UV lasers. 3D Systems has also followed
this technology trend. The SLA-1, SLA-190, SLA-250, and SLA-500 systems all
used gas lasers, while the newer SLA-350, SLA-5000, and SLA-7000 all utilize
a solid state laser. Up to the introduction of the SLA-7000, 3D Systems
purchased either the gas lasers or the solid state lasers from laser
manufacturing companies. With the introduction of the Viper, 3D Systems is
now manufacturing their own solid state laser systems.

Regardless of which company manufactures a UV laser (gas or solid state),
many of the issues and problems are similar. As with the recent "lively"
discussion on the RP list about different prices from different service
bureaus, you must understand what a price includes, and what a certain price
does not include.

As to your specific questions.

1) Laser optics replacement by 3D for $50,000? - It would be important to
understand what this includes. By "Laser Optics Replacement" does this refer
to an entire new laser system (laser head and power supply), all routing
optics and the scanners? Does this include a new 7500 hour warranty?
Installation, etc.? All laser manufacturers must have a plan for dealing
with service needs of their customers. When a laser "fails" or has low
power, we cannot always tell immediately over the telephone what
component(s) have failed. So the easiest and quickest way to handle the
problem is to replace the entire laser. Depending on the particular laser
manufacturers' pricing or service contracts for a full replacement, this
might be an expensive approach. However, it will usually result in the
customer's SLA system being back to operational the fastest. There are less
expensive ways to try to bring the laser power back to specification. The
first is to service the system. This might include cleaning, alignment, and
electronic adjustments. If this fixes the problem, then the cost is probably
very small and the lost time was not too great. The second approach would be
to start to replace individual components. Each component will have a cost
to it, and it must be shipped and installed. This can create several days of
delay in the repair. In addition, maybe it was thought that replacing an
optic, crystal, diode, etc. would fix the problem, but after the part was
installed, did not fix the problem. Now another part has to be ordered,
shipped, received and installed.

I have seen postings to this list many times, in which a SLA user had
several visits from a service person over a period of several weeks without
the problem being ultimately fixed. By replacing the entire laser, the
customer has the highest degree of confidence that they will be up and
running the fastest. Only individual customers can determine the
cost/benefit to their operations with a decision to order a complete
replacement, try to fix the problem by replacing one component at a time, or
attempt to service the system.

2) Laser Age Question - Yes, it is true that as a laser runs, it will slowly
deteriorate. The reasons for the deterioration vary from manufacturer to
manufacturer, and from laser type to laser type. It is not only important
for customers to be fully aware of the manufacturers' warranty periods and
hour limitations, but also how a given manufacturer will fix a problem, if
one occurs, and at what power level will they guarantee to restore the power
level to. Speed of your SLA system does depend on the laser power. Scan
speeds are directly proportional to laser power. However, the time to build
a part also depends on spot size, build style, resin, recoating parameters
and various other factors. If all of these other factors are assumed to be
constant, and only the laser power was changed, then if you have a 50% drop
in power, you will now scan at 50% of the speed.

3) Resin Contamination Questions? - I am not an expert in this field, but
from talking with our customers, I would say this is not a particular
concern. I am sure that the resin manufacturers can each individually
respond to this.

If you have any other questions about the types of lasers used on all SLA
systems, replacement solid state lasers for SLA-250, SLA-500, or SLA-5000
systems, or general questions on lasers for other applications, then I would
be happy to discuss this with you, or anyone else on the RP list.

Best Regards,
Alex Laymon
President, DPSS Lasers Inc.
Phone-408-298-7755, fax-408-298-7722
Email -

-----Original Message-----
From: []On
Behalf Of Patwa jeevan
Sent: Tuesday, October 15, 2002 11:02 PM
Subject: SLA - Viper Issues

Dear List,

I am very much surprised that none from 3D Systems
experts made any clarification on the issues. Also
very few users of SLA / Viper made thier
comments.Hence I am posting this query again and
expect that people will respond to this.

Issues are following:

1. Laser Optics replacement: 3D systems gives the
warranty of 7500 hrs for their laser optics.After that
the whole laer optics need to be changed which costs
around $50,000.This is pretty costly affair to change
whole laser optics.Recently 3D systems claim that
there is no need to change the whole laser optics, but
it can be repaired in parts.IS THIS TRUE?

2. Laser Age: As laser gets old the speed gets
reduced.That means the speed of laser is inversaly
proportonal to the life of laser.As its get older,
speed reduces.IS THIS TRUE and what is this factor of
proportionality.By what percetage it gets reduced?

3. Resin Contamination: After 30-40 runs the whole wat
of resin needs to be replaced due to contamination.It
cause a great loss of material.IS THIS TRUE?

Any comment on this would be greatly appreciated,


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