Thursday, May 1, 2014

DIY Eye Terminal Proof of Concept

The project I'm currently working on requires me to use eye terminals, and I'm unsure if what I'm able to buy will suit my needs.  So as a contingency plan I thought I'd see if I could make some.  I started by inspecting some terminals I already had.  The construction of the terminal looks pretty simple, a tube of metal is stamped shut and a hole is most likely punched through the end.

Eye Terminal
Eye Terminal
Eye Terminal
Eye Terminal Wire Entry

To replicate this I thought I'd do a quick proof of concept test to find out what issues I might be overlooking.  To start with, I took a piece of 6 mm copper pipe and cut off a piece about 40 mm long, half of this was then closed by clamping the pipe in a vice.  A piece of wire was inserted into the other end of the pipe to prevent deformation.

Copper Pipe
Copper Pipe Flattened

Copper Pipe
Copper Pipe Flattened

Copper Pipe
Copper Pipe Flattened

A hole was then drilled into the end and it was sanded to a round shape.

DIY Eye Terminal
Drilled and Sanded Terminal

DIY Eye Terminal
Eye Terminal Wire Entry
From this quick test it's easy to see where the problems are.  First of all the wall thickness of the pipe I used is too big.  It doesn't allow larger cables to be put into the tubing.  The other problem is that the professionally manufactured tabs are stamped.  This spreads the metal out to form a wider tab.  I just don't have the equipment to do this.

The conclusion I came to is that this solution won't work in my application, but would be better suited to a project with larger cables.  If a half inch pipe were used the tab would be wider and also allow larger cables to be used.  I should be able to buy what I need, but it would have been nice to have a back up plan.

2 comments:

  1. I have made these in pinch and work fine, better to punch the hole then drill, they tend to catch on the drill bit.

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    Replies
    1. Thanks for the tip. Yeah, a punch would be better.

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