« Reply #3 on: Mar 05, 2021, 10:57 am »
 
Hi Pat, Make a cardboard template, make a plug using plywood & extruded Styrofoam. Glass & smooth it. Wax it well, 5 times at least. I have found that Turtle Wax car polish,,wax,, works much better than the official stuff. Paint on 3 coats of PVC release liquid. Apply a decent layer (ers), of CSM & give a couple days drying time. Pop it off, clean it up. Wax it, etc. as above lay up a few layers of CSM etc., etc. & there it is. A new part & a mold for future use. Very satisfying. I haven't made PVC pipe unit yet but prob. will.

« Reply #2 on: Mar 05, 2021, 10:24 am »
 
Alignment would be my guess - keeping an eye on engine rpm (visual and aural) is a good indicator of wet belt slip - it's usually pretty obvious.  A small amount of slip (or "creep" ) is normal and the belts will get warm during use (the 2-4% transmission loss is heat).  Rain-wet belts will usually dry rapidly at idle due to excess heat (i.e within a few seconds at idle they will stop slipping).  Correct belt tension is also crucial - and also not allowing the belts to slip and overheat excessively - if they do, the tension members will stretch and they become "elastic" and useless.   

Haven't got any pics of belt guards but it's pretty simple.  The vertical belt runs can be protected using lengths of cut half-round PVC pipe (38 or 42mm) or, if more than two belts, a section of flat rectangular kitchen extractor ducting with one short side cut off to make a deep "U" section.  A simple guard for the top pulley can be fabricated from the rudder plastic sheet combined with some PVC pipe (it all glues together solidly).  Best to minimise any prop intake restrictions or turbulence-creating stuff when making guards.

« Reply #1 on: Mar 04, 2021, 1:17 pm »
 
Hello All.
Last Summer I had a belt jump from the prop drive (sev surveyor 2 engine) which damaged rudders but luckily nothing else and I was very close to shore so got back on one belt. Looks like there were two issues one the alignment of the pulleys and secondly that the belts were wet as it had been raining. Someone spotted that the belts were giving off steam but didn't get to me in time to stop me. Sorted the alignment issue and I want to put in some sort of belt protection. Has anybody got pics or designs.


Thanks


Pat