On 3/30/24 9:38 AM, Charles Kinzer
wrote:
There are some ways to design
zero backlash.? I don't know what is in a Trav-a-dial.? But
one way is to use a split gear (imaging two thin gear disks)
that are spring loaded in opposite rotation directions so
there is no space between teeth on the mating gear.? Another
is to spring load the entire gear to keep it fully meshed with
another gear.? Another is to simply make the gears precise
enough, so they have little or no backlash.? The only one I
remember personally seeing in anything is the split gear
scheme.
This is not from a
Trav-a-dial, but just a general image of what the split gear
scheme looks like.
In searching around for some
disassembly info, I did find a mention that they used
anti-backlash gears, but not specifically how, such as in this
statement.
"...
I did not want to open the thing up again. The
anti-backlash gears are what is being wound up that the
wire holds in place during assembly. This is very
important to make sure that there is no backlash in the
measurement. .."
Another
post mentioned that older units had anti-backlash gears,
so maybe newer ones don't?? Or do it some other way?
That split gear is a pretty
slick setup , I can think of a few applications where one
could / should have been used .
thanks
animal
I then found a YouTube with a
fellow disassembling one.? At bout 8:00 you can see the spring
loaded gear.? However, it seems to be a single gear spring
loaded in one direction.? I'm not able to figure out in my
mind how that works, maybe somebody else can visualize it.?
However, it is not spring loaded for now reason and must be
the main ant-backlash component.
Charles E. "Chuck" Kinzer
As a former Trav-a-dial user, I don't know how they
did it, but there was no detectable backlash whatsoever.
The needle simply reversed direction with the carriage
with no pause. It was very precise engineering, which is
why they were so expensive new.
Someone suggested a magnetic mount... the Trav-a-dial
required considerable pressure toward the vertical front
way face to have the microscopic random pattern on the
hardened wheel emboss a mating pattern on the way, well
beyond, I suspect, what a manageable size magnet could
hold.
Attachments:
