Shaft diameter and Ropecutters

[MASH]

Is it critical that a ropecutter is sized to suit metric or imperial shafts?

ie will a - for instance - 25mm cutter fit the equivalent imperial shaft without problem?

 

[philip_stevens]

The equivalent imperial size is 1 inch or 25.4mm. That 0.4mm makes a difference. I cannot fit a 1 inch shaft anode onto my 25mm shaft, as it will not close onto the shaft tight enough to not rattle loose. The same is for rope cutters.

In fact, I have fortunately got my rope cutter at a good price from another forumite who bought a 25mm cutter whereas his shaft is 1 inch. He has had to buy another rope cutter for a 1 inch shaft.

So yes, size does matter.

 

[earlybird]

It is neccessary to have the correct size. On my "Spurs", for instance, the rotating blade clamps tightly around the 1" shaft. It would not grip a 25mm shaft. ( I suppose a shim 0.2mm thick could be put round the shaft if you really wanted to try ). Conversley, a 25mm unit would not fit on the shaft unless its inner diameter could be machined out, but this would probably be a tricky job.

 

[TigaWave]

On cutters that clamp to the shaft this will be important, but ours are sized to the outside diameter of the bearing carrier, either a stern tube or P bracket. So in answer to your question it depends which cutter you are looking at.
S16 is for bearing carriers less than 90.00mm S25 for carriers greater than 90.00 although there is some over lap in that an S16 an be used on larger sizes, say to 105.00mm with smaller hp engines, say less than 200hp