Fixing jammed chinese scale and some tips
rashid111
my mini mill's DRO and also added longitudal digital readout
to my mini lathe.
I use SHumatech's DRO - most excellent DYI design. Highly
recommended (google it for more info). Bottom line - for under
$200 you will have a complete 3-axis DRO with set of features to
rival commercial one retailing for x20 times the amt.
Use remaining gallons of Dykem as nail polish
Anyway, had my Z axis caliper stuck/jammed so solid I could not
move the assembly with the hand crank. But not to worry - peel that
handy conversion table off the caliper's back, remove 4 philips head
screws
and open the assembly. Don't do anything stupid with the part that
contains the PCS, buttons etc. Remove brassy strip (the gib) and
now the carrier part comes off the scale. I had a chip somehow lodge
into the slide. Marred the way a bit too. Few strokes of 2000GSP with
some WD40 sprayed on it, some cleaning and I was back in business in
about 2 minutes.
A handy tip for those who read this post: the 4-6" digital calipers
from HF ($16) and Ebay ($10) are so cheap that I use them now, quite
extensively, to scribe "foolproofing" lines on assorted work I do.
Just set the caliper to whatever reading, lock it, scribe the part
using one of it's edge as guiding rail. Like I said be4, I use DRO
instead of traditional Dykem/scriber layout, but having some lines on
the work, in more complex scenarios, helps to avoid errors.
These calipers have the jaws made out of pretty decent hard steel so
they will last you quite a bit, even with the scribing abuse.
I find these digital calipers to be completely trustworthy (but then
again I don't work for NASA). I do recommend rechecking the zero,
before taking more critical measurements. I wish they had a key-lock
feature (enabled by pushing/holding one of the buttons for say 5 secs),
as it is very easy to accidentally push one of the buttons. MM/inch is
harmless, "zero" is less so.
If you go down the conversion route I took - converting calipers to
scales, you can easily cut the jaws off with Dremmel and cutoff wheels.
This thing will cut through the hard metal like it were butter.
Be careful - as the metal will get EXTREMELY hot. Don't pickup the
pieces as they fall off, with you fingers. Wear eye protection.
Forget about drilling the jaws with drill bits. May be diamond
tipped Dremmel bit will get the job done. I instead opted to build
mounting blocks that lock the remaining pieces of the jaws in place
with a simple strip of metal.
Allrighty then - if you managed to read THIS far, here's another tip.
You can use that digital caliper as imperial-metric converter. Slide to
get the desired reading in desired system, optionally lock the slide,
push the Inch/mm button and viola, you have that converted value.
Example of where it could be useful: you need to drill a 6mm hole but
all you have is imperial drills.
More tips:
buy rolls of shop towels in auto parts store. They have them in carton
boxes - must be a few hundreds of towels, in a roll, in that box. Nice
feel to them too, pretty thick and durable. The porous material picks
up the chips/swarf with ease.
For shop vac - get remote control unit from HD. Tie the controlling
remote to something big and colorful (similar to what they do
with bathroom keys @ gas stations, yet do it for dift reason). Now you
can turn that vac on/off
with ease, from anywhere in the shop. I like that vac as far away from
my work table as possible - to reduce the noise and amt of dust that
vac's exhaust kicks up in the air. Being colorful (I attached some
bright electrician tape to it) will help you to locate it with ease,
should you misplace it.
Ralph Henrichs
You can drill the jaws with a carbide end mill.
Pilgrim
> Used recent HF sale on their 12" calipers to add Z to
> my mini mill's DRO and also added longitudal digital readout
> to my mini lathe.
>
Any idea where can I get plugs to fit the caliper port, or is it a matter of
soldering to the internal board.
Any help would be appreciated.
Cheers.
Peter Northway
rashid111
Use soldering iron with a thinner tip. I used smallish diagonal cutters
to cut off the plastic around the edges of the connector.
Make sure not to overheat as PCB traces will lift off the PCB.