Hi All,
Our Jewelry program is getting a laser, http://www.ganoksin.com/gnkurl/o
and I want to make sure that students can’t damage it or break it as
we won’t get another one in this funding climate.
What can people do to it that we should watch out for? What ways are
there to injure it? What accidents are possible?
I want to develop a test that people have to take before being
permitted to use it. What questions and should be on that
test?
thank you!
Charles
If used without due caution a laser can do severe and permanent eye
damage, as well as cause serious burns. Before operatring a laser
every person doing so needs to understand these risks, and how to
avoid them. Safety comes first. Each and every student using the
laser needs to know the safety rules, and understand that this
machine is no toy, and can inflict nasty injuries on the operator,
if they do not use some simple common sense precautions.
As for damaging the laser, I know that the only damage one of the
two Crafford Laser Star machines I have used, ever fuffered was from
lack of a good routine maintenance schedule. Follow the prescribed
monthly, simi-annual and annual maintenance schedules, and do not
ever allow an untrained person to dismantle or adjust the laser in
any way, and it should give you years of good service.
As a college student who broke all the rules, himself, and was
surrounded by those who did so as a rule, you may have your hands
full, and may wish to ensure that your laser is only available under
supervision.
Charles,
this is one of the distinct differences between buying from a catalog
company and buying from a company dedicated to manufacturing the
finest equipment and for providing the best rated formal training
program. In these classes a LaserStar owner obtains a solid
understanding of the laser welder and we teach you the techniques
for success. Many institutions adopt key points of our program. If
you have not already bought, take a look and the more powerful iWeld
Series from LaserStar Tech. Made in the USA!
Best Regards,
Andre Friedmann
LaserStar Technologies Corporation
What can people do to it that we should watch out for? What ways are there to injure it? What accidents are possible?
Not much can be done on the outside of the laser to damage it. If
you have a rolling chair in front of it, people will tend to grab the
eyepieces to pull themselves closer to the machine. This will cause
the eyepieces to move and the laser will not be aligned with the
crosshairs. Yes, this even happens here with trained people.
Performing the maintenance on the machine should keep it working for
a long time. Doing the maintenance usually means you need to get
inside the machine and that is when damage can happen. I would have
only two or three people allowed to open the machine to do
maintenance. Put a “Maintenance Schedule” either on the welder or on
the wall next to it that includes what the manufacturer recommends
doing and add a weekly “Wipe and clean” for the chamber where the
welding happens. This weekly cleaning gets rid of dust, but more
importantly, people leave things in there and forget where they put
it. And make sure someone signs and dates when they did any
maintenance.
As for a test they should take, I would just make sure they know what
each setting does:
Voltage - They higher the voltage, they hotter the beam. High
voltage makes holes, in rings and fingers.
Milliseconds - The higher the MS the longer the beams hits. High MS
melts more metal but makes the piece hotter faster.
Hertz (not the rental company) - The higher the Hz the faster it
shoots. High Hz makes control difficult for new users.
Beam diameter - The higher this is the larger the beam is when it
hits. High beam diameter may cause the beam to hit stones close to
the weld area.
John (J-Laser) Vandergriff II
Stuller, Inc.
What can people do to it that we should watch out for? What ways are there to injure it? What accidents are possible?
Accidents are mostly minor (but sometimes briefly painful) burns.
People learn to avoid this quickly. Other accidents are usually to
the work, via incorrect settings not giving you what you want, or
damaging something.
One possibility that may occur with some machines, especially I
think, some of the older models, so this may not be so much an issue
any more, is that using very high voltage power settings puts a bit
more stress on the flashlamp. Doing this a lot can tend to shorten
the apparent life of the flashlamp. The flashlamps don’t last
forever, and their life is in part determined by the total amount of
energy pumped through them over time, and the thermal shock they
endure from this. Especially as the lamps get older and nearer their
end of service life, using very high power can get them to fail a bit
earlier than they might otherwise have done.
But in truth, this is probably a minor issue, and may not be the
case any more with current generation machines, which tend to have
better power supplies and more highly controlled pulse shapes, which
will minimize those shocks to the flashlamp.
Not much can be done on the outside of the laser to damage it. If you have a rolling chair in front of it, people will tend to grab the eyepieces to pull themselves closer to the machine. This will cause the eyepieces to move and the laser will not be aligned with the crosshairs. Yes, this even happens here with trained people.
And, in use, if people rest their eyes on the microscope cups with
any weight, it tends to move the eyepieces apart, as well as changing
the eyepiece diopter adjustment of the eyepiece. This does no harm to
the microscope, of course, but if users learn to not do that, they
will have fewer problems with welds not quite doing what they expect
(changing the eyepiece diopter adjustment changes the beam diameter
since you’re then welding at a different focal point.)
As for a test they should take, I would just make sure they know what each setting does: Voltage - They higher the voltage, they hotter the beam. High voltage makes holes, in rings and fingers. Milliseconds - The higher the MS the longer the beams hits. High MS melts more metal but makes the piece hotter faster.
it also changes, some, the geometry of the melt pool, with higher MS
making the weld deeper and wider as the heat spreads out.
Hertz (not the rental company) - The higher the Hz the faster it shoots. High Hz makes control difficult for new users.
But it can be very useful sometimes when doing things like working
over a surface plagued with porosity, or for texturing an area.
Besides, running the thing like a machine gun is kind of fun… 
Beam diameter - The higher this is the larger the beam is when it hits. High beam diameter may cause the beam to hit stones close to the weld area.
Yes, but mostly it spreads whatever power settings you’re using over
a wider area, in effect giving you a larger weld but with lower
effective power (like lowering the voltage settings) With some
welders, wider beams can give somewhat smoother welds.
You can also play with how the beam hits the metal. Usually one
places the weld pretty much at a right angle to the beam, which gives
you essentially a round weld spot. If, on the other hand, you tilt
the surface, sometimes strongly, then not only does more of the beam
reflect off with less being absorbed, but the beam contact area
becomes a long oval instead of a round spot. In this use, the area
covered by the beam is increased, just as with using a wider beam
diameter, except you’re doing it without actually altering the beam
diameter setting. The long oval weld shape also will have a different
degree of surface distortion, ie the resulting texture will be
different. If you’re trying to smooth a surface, for example, normal
weld spots (round) can give you a somewhat dimpled or pebbled
texture. Making them long ovals, and overlapping them, also of
course is a bit dimpled, but differently, and the texture does not
seem to be as deep, so surfaces end up looking slightly smoother.
Again, useful not so much for actual welding/joining, but for working
porosity out of a surface, or for using the laser for an intentional
surface finish.
Peter Rowe