[Delta] Mag-arms vs vacuum suction?

[o_lampe]

Hi gents,
I wanted to discuss my idea about using vacuum instead of magnets for Delta effectors.
Background: I've worked out an idea for a simple tool changer, but that requires removing the rods from the balls on the effector side.
A vacuum pump would be easy to control. And the rods would be lighter, too. Replace steel balls with Delrin balls to make it even lighter.
The carbon rods are already hollow. A little grease on the ballstud will seal it good enough to limit leaking.

Has anyone seen something similar?

[cosmowave]

@o_lampe I'm not sure if that will work properly in any conditions...
And a vacuum pump normally is very noisy.

But when you need a 24V vacuum pump, i have some of them. They make -0.8bar vacuum with a diaphragm pump.

[dc42]

Haydn claims more than 1kg holding force for his magnetic joints. Atmospheric pressure is a about 1kgf per square cm. Therefore, even with a perfect vacuum, you would need the ball cup area to be at least 1cm^2 to get the same holding force. With 0.8 bar vacuum you would need 1.25 cm^2. So it looks doable to me if you use larger cups and balls.

[o_lampe]

@dc42
Cool, I already have larger Delrin balls from an earlier experiment where I put two rods on one ball.
How much safety margin is in the mag-arm holding force? I never had an accident, even with a direct drive extruder at 4000mm/s/s acceleration.