this happens with normal wear on the collet. In contrast to another
answer on Orchid, this IS user servicable and adjustable. Some
parts of the Techno are not so servicable, but you’re not “there”
yet. The collet is made to be adjusted, to a point. Once you’ve
reached the point where it won’t tighten any more (won’t adjust
tighter), then you’ve worn out the collet, and it must be replaced.
This may be a problem is you’ve got the original Techno, made in
Sweden, since that company is no more. At least two copies are now
being made, one swiss, one american. I don’t know if the collets for
these will fit the original, however. You’d have to ask the dealers.
But before you do that, lets try and get your Techno back together.
Trying to figure out how it worked and maybe remove the
collet for cleaning, I have gotten myself in a mess and don't know
how to clean it up. I unscrewed the quick release and inside the
bolt there was a piece just sitting in there. Now I can not get
the release back on and have still not solved the problem with my
collet. Does anyone know how I might fix this myself or who I
should send it too?
As others have said, you can send it in for service. But so far,
this sounds simple enough. Try following this:
The quick release is a cam that revolves in that screw on housing,
with the handle screwed to it’s outer squared end. The inner side
has a tab, kind of like the end of a slotted screwdriver tip in
shape. That tip is supposed to slip between two bearing surfaces, a
gap you can see looking in the hole. You’ll note that it’s closed
tight, as the two sides of the bearing are spring loaded. And they
may not quite align under th hole, once the cam is removed. You need
to force a small point (such as the tip of the screwdriver that came
with the handpiece between those bearing surfaces until you can push
that cam tip back between them, then holding it there, screw the
housing back in place. this may take a couple tries, as to really do
it easily, you’d need another hand and differently shaped fingers,
but heck. it CAN be done. Sometimes you can get lucky just by using
the screw driver tip to pull the gap so it centers in the opening,
then just use the housing to screw down, forcing the cam in place. If
it doesn’t go easily, just try again. the trick sometimes is keeping
the slot fitting tip of the cam going crosswise as you assemble it,
rather than letting it turn. anyway, just look at it again, and
you’ll see how it goes. Swear at it a bit, and you can reassemble
it. Now, before screwing the handle back on, put a drop or two of
light machine oil into the screw hole in the cam. As you may have
noticed, it goes all the way through, and is how you lubricate the
cam/release mechanism. The two bearing surfaces that ride on that
cam are the outer, non rotating parts of ball bearings, so there is
not a great deal of wear on them or the cam part, and this is why you
can use the lever on the handpiece even when the bit is turning,
since the bearing surfaces don’t rotate.
Now, to actually adjust the grip on the collet, you first need to
clean inside the collet. The collet screws into the main shaft
(internal) of the handpiece, and the farther in it screws, the
tighter the collet is, as the tapered section of the collet pulls
into the tapered opening in the end of the shaft. Adjustments amount
to screwing the collet in or out to adjust the grip range. The
adjustment is held in place by a set screw, inside the collet, that
locks the collet in position so it won’t screw in or out of the
shaft. (the collet is a tube, threaded on the inside. that screw
fits down into those internal threads, tightening on the end of the
shaft, jamming the collet in place. Now the trick is that in use, the
threads that set screw ride in get gunked up, and the slotted end of
the set screw gets even more filled with gunk, wax, filings, and
whatever else gets in there. So you won’t be able to adjust that
set screw till you clean the cross slot on the end of the screw. it’s
down at the bottom of the collet opening. If found the best way for
me, at least, to do this is by taking a can of WD-40 with the
extension plastic tube, and holding the handpiece collet facing down,
over a towel, put the extension tube into the collet and blast a bit,
then let it sit, and repeat. Then use a fine point of some sort to
dig down and stir up whatever you can feel at the bottom of the
collet opening, and repeat again, until you can slip that little
yellow screwdriver that came with the handpiece down in there and
feel it slip into the slot on the end of that screw (this is what
that screwdriver is for)
Now unscrew and remove the silver housing from the back of the
handpiece, exposing the sleeve into which the end of your flexible
shaft fits. NOT the larger diameter lower housing of the handpiece
itself. Just that back sleeve. Now, with the quick release Open
(loose), the collet extends slightly from the handpiece, and you can
gently grip one jaw of the collet with a pair of slim nose pliers.
Only one jaw, so you don’t crush the collet. Held like this so the
collet itself cannot rotate, loosen the screw. It backs out
counterclockwise. Loosen it about a half turn. Now, grab that
rear sleeve that the flex shaft fits into with a round nose plier
(one nose inside the sleeve) so the shaft of the handpiece cannot
rotate. Gently screw the collet itself clockwise perhaps a half turn
or so, which will tighten it into the handpiece slightly. Again grip
the collet itself by one jaw, and retighten that internal screw (it
shouldn’t move much, since you’ve moved the collet in by about the
same amount you unscrewed that screw. Once it’s tightened down
snugly, you only need put the rear housing back on, and check the
fit of your burs in the handpiece. If it fits, you’re done. If not,
you can repeat this procedure as needed, either tightening the collet
some more, or backing it off a bit if it’s now too tight.
It’s important to note two things.
One is that this cannot go on forever. As noted, collets DO wear
out. the inside surfaces of the jaws wear down, opening the collet,
and the outer taper of the collet (and perhaps it’s mating taper on
the shaft) also wear. You reach a point when tighting the collet
pulls it deeper into the shaft without tighteing the grip any
further. The collet is then worn out
The second thing to note is that all quick release handpieces have
some limits to their grip range. Some more than others. And though
we buy burs and attachments listed as having 3/32 shanks, the truth
is that they seem to vary by a surprising amount. I think
manufacturers all assume we’re all using the old jacobs chuck #30
handpieces, which don’t care much about a half millimeter difference
here or there, but the quick release handpieces very much do care.
Some burs, such as the Busch and similar dental type burs are
consistant and accurate. Others, such as plated mandrels for rubber
wheels, the snap on mandrels for moores disks, and even many high
speed setting burs, can vary a LOT in their manufacturing tolerances
as regards actual shaft diameter. Before assuming your handpiece is
shot or worn, check it against known diameter burs like the busch
burs. if these grip well and tightly, it may be that what you’re
trying to grip has simply worn smaller, or wasn’t up to full spec
diameter in the first place… I bought some Spearhead brand high
speed ball burs once that were enough oversize that none of my
several types of quick release handpieces would accept it at all.
Usable only in a #30 handpiece. Rather annoying. And I’ve some of
those various aformentioned types of mandrels, often plated brass or
cheap plated steel, that are enough undersize that only a brand new
collet still has the grip range to hold them, and even then, they’re
not that secure. Also rather annoying. But the fault of the bit or
bur, not the handpiece.
It was purchased through a jeweler friend of mine through
Gesswein. Should I send it back to them? I sent an email to them
and they never responded. The company that I work for does not do
too much buisiness with them but have offered to send it to
Gesswein for me, but I am concerned that I might not get it back.
Any help will be greatly appreciated.
If you Do need to send back your handpiece, you should expect to pay
for the service, as from the sound of this, it’s kinda normal for
several types of quick release handpieces to do this, and need
periodic adjustment. The Techno is actually easier than some to
adjust, once you figure out how. Once you know how to do it, it’s a
ten minute job at most. But if you find you just can’t get it
together again, then perhaps the most time efficient is to send it
in for repair. As i said, the main problem might be availability of
new parts, if they are needed. I’m not sure if the collets for the
swiss version now sold fits the old handpiece.
Gesswein has a fine reputation, and offers good service. But better
through the phone, in my experience, than via email. They are not
alone in this, by the way. Several of my favorite suppliers kind fall
down when it comes to good email support, and I’m not talking about
minor companies.
You might try contacting Elaine Corwin at Gesswein. An orchid
reader/member since way back, she’s also the technical/product V.P.,
I think, there, and if their service staff hasn’t helped, she can
certainly help move things along.
Also, depending on who you normally deal with, other companies may
also offer service. You don’t have to go to Gesswein. Frei and
Borel, for example, has long offered good service on handpieces of
many sorts, and there are a couple actual tool repair services, such
as Lone Star (who just today posted in response to someone’s
ultrasonic problem) and others, who do nothing else but repair our
tools and toys. Check the Orchid archives if you need to find these
folks…
Hope this helps.
Peter Rowe