Volvo 3 blade folding propeller

[Slowtack]

Wear at the blade root (where they slot into the hub) has now led to wear in the gearing with the result that the prop does not open smoothly sometimes sticking. I am interested to hear from anybody who has treated this problem. I have had the boat 10 years, not sure of the actual age of the propeller.

 

[Sailfree]

I think its replacement time.

Is it a volvo prop or radice prop branded volvo?

Had volvo folding prop on first charter boat and never lasted more than 500 hrs. Volvo replaced it once then asked me to accept cash refund and buy another prop. 1yr on charter boat is up to 10yrs private use but still not good enough IMHO.

 

[Quandary]

If it has been thrashing about for a long time perhaps it is done. Mine has a lot more hours than Sailfree refers to without discernable wear, looked just nicely run in at the last lift out.
I used to get two blade folders serviced in an engineering workshop run by a guy who was a steam traction engine enthusiast, I also had one done by a hi tech shop that did work for Bombardier, the steam man did a better job. I took them in when the blades started to get close to rattling. Usually the main thing was turning new slightly larger pivot pins and boring the blades and hub to suit so that it would fold smoothly and silently, the gears serve only to bring the blades in together so perhaps a bit of wear there does no great harm.

 

[aluijten]

Guessing your propeller originated from 2004, I would say you still have one of the first gen three-blades before they changed the composition of the metal to have better resistance against corrosion and wear and tear. Mine is from 2002 suffering the same problem.
Either get a new one or move to a different supplier are the two options I'm looking at. Any treatment of the existing propeller is probably more expensive in the long run.

Currently looking at Flexofold as an alternative. Their mechanics seem better up for the job by using damping blocks. I imagine those help taking the peak load off the gears.

 

[Lucky Duck]

Mine showed the same symptoms after 7 years/1000 hours. The teeth/cogs had worn out so the blades weren't opening/closing in a uniform fashion. IIRC a replacement set of blades was in the region of £900.

 

[Slowtack]

Volvo prop I think. Flexofold or Radice for two blade and Kiwi 3 blade seem like the more economical replacements so far. Wondering if changing to two-blade to save on cost will mean much efficiency loss.

 

[rudolph_hart]

If it has been thrashing about for a long time perhaps it is done. Mine has a lot more hours than Sailfree refers to without discernable wear, looked just nicely run in at the last lift out.
I used to get two blade folders serviced in an engineering workshop run by a guy who was a steam traction engine enthusiast, I also had one done by a hi tech shop that did work for Bombardier, the steam man did a better job. I took them in when the blades started to get close to rattling. Usually the main thing was turning new slightly larger pivot pins and boring the blades and hub to suit so that it would fold smoothly and silently, the gears serve only to bring the blades in together so perhaps a bit of wear there does no great harm.

+1.

Did this on my (then) 19-year old Volvo 3-blade folder last year. Local engineering shop. Here's to the next 19 years.

 

[Pavalijo]

If it has been thrashing about for a long time perhaps it is done. Mine has a lot more hours than Sailfree refers to without discernable wear, looked just nicely run in at the last lift out.
I used to get two blade folders serviced in an engineering workshop run by a guy who was a steam traction engine enthusiast, I also had one done by a hi tech shop that did work for Bombardier, the steam man did a better job. I took them in when the blades started to get close to rattling. Usually the main thing was turning new slightly larger pivot pins and boring the blades and hub to suit so that it would fold smoothly and silently, the gears serve only to bring the blades in together so perhaps a bit of wear there does no great harm.

When I purchased Calypso the 2 blade folder had worn pivot pins. I looked at having the blades bored out to fit larger pins and was strongly advised against that (by a reputable propeller engineering firm whose name escapes me) on the basis that it would be virtually impossible to achieve acceptable tolerances to prevent vibration potentially damaging the saildrive. The vendor made an appropriate allowance and I replaced with a Volvo 3 blade folder.

 

[Quandary]

When I purchased Calypso the 2 blade folder had worn pivot pins. I looked at having the blades bored out to fit larger pins and was strongly advised against that (by a reputable propeller engineering firm whose name escapes me) on the basis that it would be virtually impossible to achieve acceptable tolerances to prevent vibration potentially damaging the saildrive. The vendor made an appropriate allowance and I replaced with a Volvo 3 blade folder.

Why??? If it is possible to bore them accurately to begin with why would it not be possible to repeat it, surely this is what is known as precision engineering. I knew the engineer who did a couple of mine and if he had not been confident that he could do it he would have said so, they opened and closed like silk, no detectable vibration and I think the cost was about 10% -!5% of a replacement.
I do, however understand why some one might prefer to sell a new product than apply skills to repairing an old one.
Similarly I had VP 2003 engine beautifully rebuilt inc honing, new bearings etc in an agricultural/construction engineering workshop where the labour cost was less than the parts kit from Keypart, there are a lot of skills around if you are prepared to drop the adjective 'marine'. The engineer, a guy in a greasy boiler suit who mainly worked on diggers and dumpers, could not believe that the VP after market could screw so many yachties without complaint or reaction.

 

[Pavalijo]

Why??? If it is possible to bore them accurately to begin with why would it not be possible to repeat it, surely this is what is known as precision engineering. I knew the engineer who did a couple of mine and if he had not been confident that he could do it he would have said so, they opened and closed like silk, no detectable vibration and I think the cost was about 10% -!5% of a replacement.
I do, however understand why some one might prefer to sell a new product than apply skills to repairing an old one.
Similarly I had VP 2003 engine beautifully rebuilt inc honing, new bearings etc in an agricultural/construction engineering workshop where the labour cost was less than the parts kit from Keypart, there are a lot of skills around if you are prepared to drop the adjective 'marine'. The engineer, a guy in a greasy boiler suit who mainly worked on diggers and dumpers, could not believe that the VP after market could screw so many yachties without complaint or reaction.

I did hesitate to post my comments as I am not an engineer and cannot provide a fully reasoned response. I have just looked back through e-mails from the purchase in Feb 2013 and in one advised the broker that "the 2 companies I spoke to (specialist prop repairs) have both said “don’t do it”! They say it is too difficult to do it precisely enough not to cause further problems"

Perhaps when originally manufactured the parts are held in purpose made jigs and that cannot be recreated in a general purpose workshop. I recall being advised that the vibration may not be discernible. Maybe I was badly advised, but I discussed a new propeller with neither party and they both lost business.

I have kept the old prop as a spare.

 

[Slowtack]

Now you've got me rethinking! There has always been some degree of "loose fit" movement which the saildrive has tolerated so why not try reboring and using slightly larger pins? Another option might be to rebore the blades and sleeve the existing pins using stainless steel tube if I can find a suitable tube diameter and thickness?