This brings me one step closer to being a true Homo Universalis.

A freshly acquired skill like I talked about in one of my more dramatic postings lately. A skill I had been longing for since I discovered the split insulator in yagi driven elements.

Yes I am talking about using a lathe to manufacture custom parts. I spent ten to twelve hours in my school’s workshop and asked one of my very experienced colleagues to share the basics of his vast knowledge with me. And so he did.

 

It’s not that I have become a true machining expert. By no means, this would take many hours of training. I just wanted to master the basics so that I can make my own simple parts. Yes I admit: I envied SM2WMV who has the tools available and even knows how to use them without himself being a trained metal worker. Or he just poses next to the machinery and has a subcontractor   🙂

We have a few dozen of these machines at school, but I can’t always expect fellow teachers to do stuff for me. I want to be able to do it myself. Just to enhance the fun of building something.

What is the main use for a lathe in amateur radio homebrewing?

  • Adjust (reduce) the diameter of a cylindrical piece so it slides into another tube.
  • Maybe keep it thicker in the middle (centre insulator) for split elements.
  • Make a clean cut through or clean up a badly cut rod (I am terrible with a hacksaw) and provide a nice flat surface.
  • Provide metric thread to join parts together.

I was surprised that using a lathe to machine metal and plastic parts on this very basic level was not primarily a matter of being handy. It was more a matter of using the brain to adjust the machine’s parameters and setting it up in the right way for the job at hand. Once this is done, the machine does most the work for you. And I’m not even talking CNC machining. Of course you have to learn the function of the various controls and parameters and consider their impact on how the machine will behave. And you must keep a close eye at all times and stop the movement of the part and tool before you remove too much or cut too deep.

So here are some parts that I machined that have no real use except for learning.

Part 1:

  • Clean up both ends for flat surface.
  • Drill through center.
  • Provide inner thread M6 with thread tapping tool.
Make surface flat and clean, drill through, cut inside thread for M6.

Make surface flat and clean, drill through, cut inside thread for M6.

Part 2:

  • Clean up both ends for flat surface.
  • Adjust for three different diameters.
  • Prepare one end for outer M6 and use hexagon thread die.
  • Join parts together = success!
Turn down to different diameters, cut M6 outer thread and see if it fits with previous made part. Success!

Turn down to different diameters, cut M6 outer thread and see if it fits with previous made part. Success!

Part 3:

Ertalon wheel with groove to guide stainless steel cable. For use in telescopic and tilt-over installations.

90mm ertalon wheel with groove for 8mm cable and M12 bolt.

90mm ertalon wheel with groove for 8mm cable and M12 bolt.

Part 4:

M22 thread with lathe thread cutter.

Cut M22 thread (bought a nut to try and it fits!) and finish other end of the part in a 'freestyle fantasy' way. If it reminds you of a phallic symbol: you're not the first (Freud!) and it was NOT intended.

Cut M22 thread (bought a nut to try and it fits!) and finish other end of the part in a ‘freestyle fantasy’ way. If it reminds you of a phallic symbol: you’re not the first (Freud!) and it was NOT intended.

This last one was really hard because it involved a lot of parameters and settings. But after the explanation and demonstration I was able to cut the M22 with success. I didn’t have a real nut to test except for the calibrated thread gauge. Of course if the gauge fits, the nut will fit. But it was cool to screw on the nut on my own piece of work.

This was really a crash course and I’m glad I took detailed notes about the parameters and which value is set with what handle or dial. My plan is to sneak my way into the workshop once in a while and repeat these procedures on a piece of scrap metal just to make sure I will be able to perform the tricks when I need to make a part, and maybe even get better?

Now what skill to pick up next? Cupcakes are hot. And how about knitting socks?

4 Responses to Operating a lathe

  • Great Franki! I would say that you are a more experienced lathe operator now than I am. I did some threading I believe when I was around 14 years old at school, but since that I have not done it and would not be able to today without some serious instructions or reading 🙂

    It is a really nice tool to have though when wanting to build especially antennas.

  • Wayback Machine! This story took me back to my days as an engineering student in the late eighties of last century (has it been *that* long already?). Even though I had chosen Electronics/RF as main subjects, us humble ‘candidates’ had to learn all about (+fluid) mechanics. This included torch welding, CNC programming, and of course lathe machining. I can still recall the eerie smell of machining oil…. Thanks for taking me back down memory lane, Franki!
    73 de Glenn ON4WIX / OR4W

    • Aahh yes the smell of machine oil indeed. Let’s admit: it smells better than solder smoke and burning resistors!

      When I was a kid I visited the local technical school’s ‘open house day’ and I always loved the smell of those workshops with those huge machines making a lot of noise. Much more impressive than what I did as a teenager in school: studying medieval literature in Dutch, French and English. Study basic finiancial law. Make up accounting balances for small and medium enterprises… 🙂

      So I’m starting to catch up 20-25 years later 😉

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