M6 Heim Joint (tie rod end)

I wanted some tie-rod ends (heim joints) for a skateboard that would steer by turning the wheels independently. This is the result.

First up: DON'T DO THIS. PLA softens at moderate temperatures, creeps over time and there are a million other reasons why this part is likely to fail. If used in any critical application, it's certainly worth spending the few dollars to buy one.

That said, this is designed in such a way that it should be pretty robust. If printed in nylon it should be pretty reasonable.

The design is print in place, and ideally after printing the two parts will be bonded. Then you can put a bolt through the ball and free it up with a hammer. In this way a nearly completely slop-free joint is possible.

Printed at 0.3mm they are a little rough, but only take 30 minutes to print and are smooth enough for my application. Smeer a little lithium grease or vasaline on the ball to make it smoother.

Print with enough perimeters that the critical parts are solid pastic (shown in one of the pictures)

Video of strength test: https://www.youtube.com/watch?v=S0lcIF6u9uE

Video of a steering system made with these joints https://youtu.be/dybegZRETbY

The files include the freecad source file, so if you need another size you can twiddle it in the "Parameters" spreadsheet. I wanted to make it parametric enough so you just picked the bolt sizes, but didn't quite get there - so you have to twiddle quite a few parameters.

Category: Automotive