Aluminium Universal joints for 6DoF Platform

I developed some universal joints last year based on the Chinese style platforms I'd seen. These are 6061 grade aluminium, with dual thrust bearings and they attached to each end of my large linear actuators.

I have since developed some others, so these are now for sale, preferably to someone in Australia.

I have 12 bearing sets
Material: 6061 Aluminium
Bearings: 12 pairs of dual angular contact bearings (20 x 42 x 12mm)
Bearings: for actuator top end 20mm x 26mm x 30mm needle roller bearings
Pins: steel 20mm x 65 mm shoulder bolts
I can supply exact tech specs if required.
Screw in actuator top x 6
Teflon spacer washers x 24
You will need to provide a "fork" for the bottom end of your actuators.

My total investment in these was about $950USD or about $1380AUD

For the geometry of my Stewart platform (very upright legs), they had slightly too much slop/tolerance for me, so I developed a whole new yoke & trunnion style of U-joint to replace them.

Happy to answer questions and/or take best offers for these.

I am searching for replacement of my heim joints for rotary design.

Could you give more feedback ?

Do they have any singularitys (positions where they can “lock”) ?

If the actuator can reach 100% vertical there is a small chance they can lock. If it’s a standard Stuart platform they won’t lock up.

My custom universal joints are excellent but expensive to make. They are 7075 Aluminium yokes with cross trunnions.

Still, you may be interested.

I am veeery interested but I have no idea yet how I could incorporate the concept of “rotary U” inside my crank levers.

Implementing it only for the upper platform doesn’t make much sense.

If somebody has done it already I would be grateful to see the sketches.

Reading your email again I see you have heim joints. I would have thought they were the best for a rotary based design. My uni joints would not be so good.

Of all people I would have expected you to have a linear actuator system. LOL.

CKAS platforms uses “rotary U” in their cranked design.

The main two questions for me are to know if they can perform better than high bank heim joints and if yes, how to integrate those in the crank lever.

The only way I see is to ask them directly.

Would you agree to share the manufacturer contact ?

Thanks

I am effectively the manufacturer. I designed them and had them made under contract. I really don’t think they would be that effective for you.

How much more angle do you need out of your heim joints?

I can imagine something similar working where the central rotating part of that join was a fork shape. And inside the fork was a rotating part that accepts the thread of your joiner rods.

What is exactly the kind of bearings are you using here ?

Upper and lower attachment is rotating or only one of it ?

This is the style I use. There are many sizes to fit your application.

https://www.aliexpress.com/i/32931627047.html

Oh, small misunderstanding... I was not talking about the U part... the other bearing ... the 360 one:

There are two bearings. I’ll send you a pic later when I get to the office.

I think we should design a custom one for you.

Yes, we could think about a heim joint replacement for rotary design.

How to integrate them with a moving lever arm. (Bottom connection)

Maybe @sagrada737 could also be interested.