Skip to main content

Bar Clamp

Clamped Up
I needed a little clamp, but we were in Covid19 lock down.  So I made one.  No transistors, no batteries, no thermionic valves, no flashing neon bulbs!

There are many complicated ways to make a bar clamp, but I prefer the simple way.  A picture is worth a thousand words:


Mini Bar Clamp

It can't be simpler:
  • One 6 mm dowel rod
  • One 6 x 80 mm bolt
  • One 1" nail
  • Ten popsicle sticks
  • Glue
Yup - ten popsicle sticks glued together, made a small piece of plywood, that I could cut up for the clamp jaws.  You can use the exact same method to make a big bar clamp.  You don't need a super long lead screw, just a long bolt and a whole lot of little holes to adjust the other end of the clamp.  Scale it up as required for size and strength.

How do I keep the movable jaw in place?  Some funny putty (Press Stick) in a hole.  It churns around in there and keeps the block from falling off the end of the bolt - a little piece of rubber will also do.  The best way would be to file a ring in the end of the bolt, cut a washer in two and glue that into the block, but that is a lot of hassle - another day - do, do that on a big clamp.

Is it really worth making a bar clamp?  Of course not!  One can buy a perfect clamp for a few Dollars, but what is the fun in that and what else can you do with a bag of craft store pop sticks?


Have fun!

Herman

Comments

Popular posts from this blog

Parasitic Quadrifilar Helical Antenna

This article was reprinted in OSCAR News, March 2018:  http://www.amsat-uk.org If you want to receive Satellite Weather Pictures , then you need a decent antenna, otherwise you will receive more noise than picture. For polar orbit satellites, one needs an antenna with a mushroom shaped radiation pattern .  It needs to have strong gain towards the horizon where the satellites are distant, less gain upwards where they are close and as little as possible downwards, which would be wasted and a source of noise.  Most satellites are spin stabilized and therefore the antenna also needs circular polarization, otherwise the received signal will flutter as the antennas rotate through nulls. The helical antenna, first proposed by Kraus in 1948, is the natural solution to circular polarized satellite communications.  It is a simple twisted wire - there seems to be nothing to it.  Various papers have been published on helix antennas, so the operation is pretty well ...

To C or not to C, That is the Question

As most would know, the Kernighan and Ritchie C Programming Language is an improved version of B, which is a simplified version of BCPL, which is derived from ALGOL, which is the Ur computer language that started the whole madness, when Adam needed an operating system for his Abacus, to count Eve's apples in the garden of Eden in Iraq.  The result is that C is my favourite, most hated computer language , which I use for everything. At university, I learned FORTRAN with punch cards on a Sperry-Univac, in order to run SPICE, to simulate an operational amplifier.  Computers rapidly lost their glamour after that era! Nobody taught me C.  I bought the book and figured it out myself. Over time, I wrote a couple of assemblers, a linker-locator, various low level debuggers and schedulers and I even fixed a bug in a C compiler - not because I wanted to, but because I had to, to get the job done!   Much of my software work was down in the weeds with DSP and radio modems...

Unlock CRA PDF Forms

Unlock Canada Revenue Agency PDF Forms It appears that there is a relatively new PDF feature to prevent casual copying and saving of a file and that some programs save PDF files with these foolish features active by default.  Many forms from the Canada Revenue Agency are locked in this way, which makes it difficult to do one's taxes, since one can fill the form, but cannot save it.  One can only print the form.  It should be possible to print to a file or export it to a new PDF file, but it is far better to reset the annoying anti-taxpayer flags, since the 'printed' form cannot be edited easily any more and I always manage to make a mistake or three that need to be corrected after review. If there is a Linux (virtual) machine handy, install qpdf and use it to reset the silly flags: $ su - password # dnf update # dnf install qpdf # exit $ qpdf --decrypt lockedfile.pdf unlockedfile.pdf One doesn't need a password to unlock these flags, so the fix is instant. La voila! He...