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
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