Tuesday, June 4, 2019

Tools to Make Tools

I've been wanting a tubing bender.  So, I downloaded plans from the chopper builders handbook website (a JD2 clone), ordered some stock, and started making it.  In the middle, I realized I needed to bend some flat stock on a hard angle for the handle.  So, my tool quest turned into a second tool quest.  This tool, my "brake attachment" for the harbor freight shop press, is made from :

  • 1" angle iron about 16" long (4 pieces)
  • A flat bar stock that will fit two pieces of angle iron wide
  • A flat bar stock to hold the upper piece of angle iron
  • 7/8" tool steel dowels about 5" long (two of them) for guide pins

First, I cut the edges on two of the pieces of angle iron so they could be welded site by side to the bottom plate.  I then welded the second piece of angle iron to the other two inverted.  This gave me an inverted 90-degree channel offset by 45 - exactly what I needed.

I then drilled and tapped at 3/4-16 the two ends of the bottom plate, turned down the two dowels to 3/4", and then threaded them to 3/4-16" to fit the bottom plate.  This was my first foray into power tapping.  Can you do it on a harbor freight mini mill?  Yes, but you want the tapping head.  Collets are a bad idea - you'll ruin your collets when it galls from spinning.  This got it started, and I was able to hand finish the tapping.

I punched two matching holes into the top plate to loosely fit the two dowels.

Lastly, I need to weld the last piece of angle to the top bar with everything in place so that it all lines up perfectly.