Hi there.

I have had a request to machine a 100mm pitch 30mm lead screw and 600 mm long 2 half nut, Both need to be made from plastic as used to move bio fuel tanks. They have not specified the type of plastic and asked if i could do some digging into it and thought id ask the cleaver guys here. As a guess im thinking UHMWPE. These are intended to be turned by manual wheel hense the large pitch.

I dont have the weight information of the tanks yet but my concerns are twist in the screw by large amounts of friction - could a delrin nut and uhmw screw have less friction or are there any other plastic's that may be better? The actuation required does not require precise movement so backlash is not of concern, Does anyone know how tolerant such a nut and screw might be to adding lots of slop and the effect on friction.

Any advise would be most appreciated. Cheers

Jon