Making A Third Hand Jig

This is a great lesson in why it is often easier and cheaper to buy something than make it. You can get a 3rd Hand Jig for under $7.00 which functions reasonably well and even has a magnifying glass. But as with many things that is too easy a route to take.


Some 3/8” steel chucked in the lathe.


Groove cut.


A Shaplane radius tool is used to turn a ball end. Setup takes a while but once done it’s easy to get relatively uniform results.


The finish is pretty good.


One down…


I needed 6 but I cut seven, just in case. Notice there’s a bit of variation in the turned down shanks. As you can see by the precision CAD drawing I’m not that worried about tolerances. The goal was to make a functional third hand tool as rapidly as possible.


Dressing the stem a bit.


Drilling a hold for a push fit on the shank of an alligator clip.


The alligator clip ends are a bit springy so they will stay put in the hole. Later I may make a better tweezer to replace them.


Setting up the vise so a hole is drilled on center. The ruler trick works well.


Drilling…


Three pieces with 1/4” holes.


Drilling for a #8 tapped hole.


Three pieces done.


Drilled and reamed a 5/8” piece of steel rod for the shank of one of the ball pieces.


Drilled for a #8 screw.


Another part done.


Drilling three pairs of steel plates. Two holes for the balls and one for the #8 screw (one piece clearance, the other tapped.)


Tapping.


Almost done, sort of.


Matched pairs screwed together.


Ends radiused for clearance and aesthetics.


Drilling some brass rod for a press fit on the heads of the #8 SHCS.


Knurling.


Cutoff.


Knurled heads pressed on the screws. Note that I sanded and polished the parts.


All together. It mounts in one of my Panavise bases. Once tension was set on the screws it holds well in position and adjusts relatively easily. Whole thing took about 4 hours not including the time spent cleaning up the shop afterwards…

Links I’ve Found Useful Lately

Just a dump of links I’ve found useful or interesting lately.

• How to install Android-x86 in Virtualbox
  Totally pointless but fun.(?)
• French Pneumatic Mortars in WWI
• Connecting to NXT on Windows 7 64 bit
  This was really helpful when I installed my old Lego Mindstorms NXT software on the new PC.
• The Braun Lectron
  Stylish electronic learning tool.
• DC Motor Control Using an H-Bridge
  I am hoping to play with it this weekend, have the ICs.
• Control a DC motor with Arduino and L293D chip
  Another helpful page on the subject.
• Programming an ATtiny with Arduino
  Via Make:, this is also on the plate for a weekend project. I just received the ATtiny45 and ATtiny85 ICs from Mouser yesterday. My clever plan is to combine it with the H-Bridge and make a PWM case fan control. Failure expected.
• Beaver Bar Camp 8
  I’m probably going to climb out of my shell and check it out.
• Vintage Computing and Gaming Blog