Lifter material

[Samjw]

I’ve chosen and designed a 4 bar lifter mechanism.

I’m really torn between using 1cm box section aluminium for the lifter mechanism, or 1cm2 hdpe.

obviously hdpe bends and flexes which wouldn’t be great for the lifting, but would stand up to a little more abuse before deforming than aluminium would.

does anyone have any experience, suggestions or opinions?

[Ocracoke]

It would be all in the construction as how rigid that'd be.

HDPE probably wouldn't work as well here because of how flexible it can be (say the load on the mechanism was off centre for example, that'd warp it I feel). That being said, given the thickness you mention, it might be OK but I can't think off of the top of my head any lifters who use HDPE in the mechanism.

The box section, I think, is going to be lighter overall (since it is hollow) and more rigid, at the expensive of impact absorption as you mention.

Not a 4 bar lifter but Snappy is a good robot to take a look at for this sort of build I think.

[Samjw]

Ive watched the snappy build video, i believe he used 4mm hdpe, with the servo resting against it.

I think it might be a case of making both up, and having a play to see which one seems a more suitable. The 10mm hdpe although it does have some bend and flex, with it being a lifter, I don’t think energy absorption will be much of an issue, and with the BW weight limit only bein 1.5k, perhaps ill cut a piece and do a couple of tests.

I just have a vision of aluminium tearing apart after a minor hit 😂