Want to replace some brass rollers on a winch we have, the old ones are incredibly worn out on the surface in contact with the steel cable. Would nylon be a suitable material for this? And if so what would be the best type of nylon?
At a guess, I would think the braided cable would be much too harsh for even hard plastic, especially if brass has worn out (I appreciate brass is a fairly "soft" metal). Unless you plan on replacing them regularly?
a bit of a guess... but I'd say they're probably phosphor bronze not brass (they look the same, and I only know because I've made the same mistake myself!)
why are they worn out? - did they jam up?
I'd replace with brass/phosphor bronze... if they wore out the nylon would ware out even faster
My first thought was phospor bronze but the spec sheet for the roller says they are brass. I thought nylon as there are some spare rollers in one of the boxes for another winch but that might take another type of cable..
Yeah basically they live on a boat and people often forget to grease them, they then seize and the cable runs into them. So brass is the best material for job then!
Nylon has a tendency to crack under load and can crack readily with impact. So it's mechanical uses are a little limited sometimes.
Nearly all machining brasses are hard by the way. It's 'generally' only sheet that varies with half hard etc. I'm a slight confused by the soft comments. The common stuff you guys will most likely come across is most likely CZ121 and this does machine very easily and maybe this makes you think its not hard. It's actually classified as hard and is a hard material in engineering terms. It's this hardness that makes it chip, materials that chip naturally machine more readily than more ductile materials. Often there is a confusion when more then one material property is present and also machining property. Hardness does not always means a material is like a piece of hss or carbide.
Nylon or Oilon is what I would use, horrible to turn on the lathe because it comes off in tough streamers but it should stand up reasonably well.
Delrin/Acetal is another option but it won't last quite as long as Nylon but it is lovely to machine.
If using Nylon it will swell with sea water so you will have to allow clearance for that unless you are fitting bearings as I do in the creel boats rollers I make.
Delrin/Acetal has very low water absorption so doesn't swell much but it does wear out quicker than nylon and is also more expensive, it is what I use for underwater applications such as rudder tube and pintle bushes..