Rutland 913

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Ardenfour

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Dismantled the wind charger, as there was a vibration which went through the whole boat. The bearings do require replacing, which is fair enough. But there were two kinds of vibration, depending on whether the charger had a load attached to it - under load a pronounced heavier vibration sets in, which disappears as soon as the charger is disconnected. When I seperated the two stators, I found 'N' and 'S' felt-tipped on the inner surfaces, which I assume refers to the magnets' poles. Thing is, they were not lined up in any way, so, should the two north poles be adjacent, or north and south be adjacent? Would this account for the vibration? Can't see any explanation in the manual.
 
Hi - very interesting post.

I have been trying to reduce vibration for 18 months (new installaion then).

I agree that before the charging point is reached there is a small amount of 'noise' and once the charge point is reached then the noise increases substantially (especially below decks).

There are many possible issues here - induced resonance in the pole/mount, wind shedding setting up vibration, etc. I managed to make some reductions in the 'conducted' noise (below decks was very, very loud) by mounting the pole/stays on isolation pads (neoprene/cork) with tophat rubber inserts on the bolts.

However, I have now noticed that there is a ticking noise if the blades are rotating very slowly which indicates bearing or shaft issues. I would imagine that this may well be setting off some vibraton at higher rotational speeds.

Marlec have been very helpful with various suggestions, and they did point out that ... "The three phase output is also perfectly balanced and when a current begins to flow there will be a change in the rotational characteristics of the hub since AC output creates ripples. The three phases to a great extent irons these out".

I have also tried fitting large shaft anodes to the pole to try and dampen actual pole resonance with some improvement. Also, pipe insulation foam inside the pole did not improve anything.

Do keep me posted on anything you find that improves matters!
 
I too fitted neoprene pads between the pole and deck and the two struts, but vibration persists. Don't know why this vibration is never mentioned in test reports, since it's much more intrusive than the swooshing from the blades. Anyway, I'm now struggling to remove the two shaft bearings - got new ones coming tomorrow but can't get the old ones off. Cant get in with a puller and the windings are encased in a resin, the assembly looks too fragile to use levers. I've tried boiling water to expand the bearings, then tap the shaft out but no joy. Anyone got theirs off?
My next step is to fil the struts with dry sand to see if the resonance reduces.
 
please let us know if the dry sand approach works!

I did ping the YachtingMonthy editorial team as I purchased the Rutland genny based on their test report I suggested that they do a follow up with testing the gennys mounted on a soundbox (or real life aft cabin boat) to measure transmitted or induced noise.

If indeed there is true pole resonance at the structural frequency, then the shaft anode approach should work to some extent.
 
I too have increasing noises coming from my 913. They are, as yet, not a big nuisance but after 7 years of continuous use I guess I can't complain that it may now need a service and require bits replaced and/or adjusted.
I was considering blasting some builders type expanded polystyrene inside the hollow pole or through drilled holes along it to cut out the 'hollow tube' resonance.
With either wire stays or rods holding the pole up onto a solid base, noise is going to be transmitted into the boat so it's a case of dampening out these by means similar to those that have been mentioned in the previous posts.
Perhaps an extremely strong bungy connection for a few inches in part of the wire supports would help as well as a cushion at the base attachements. It seems a case of elliminatng any solid connection with a sprung suspension in all areas is the best one can do.
I havn't made any movement towards an enquiry to Marlec yet but without workshop facilities these days I'm reluctant to take it apart. Therefore does anyone know if they do a complete service and replacement of bits and if so are they expensive?
Despite these problems I reckon it is a great piece of kit and good value for money.
p.s. Shaft Anode ???
 
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Mine has been up my mizzen and spinning for eight years now.
When I installed it I put some rubber pads cut from a car inner tube between the L bracket and the mast. Never had a hint of vibration.
Rutland don't make a mizzen bracket so I adapted a Ampair Pacific 100 Mizzen Bracket, it is very well constructed in aluminium.
 
I mounted the pole deck mount onto pads cut from old fire hose, used same material round pole on bracket further up. Had lots of noise in cabin when charging hard so changed the guy wires from soft to hard mounts & that's cured most of it :)
 
I have a 913 which is 4 years old, mounted on the pushpit, and I am happy to say that I do not get any vibration problems even when sleeping on board in a Force 6, so it would appear that the problems are "mountings related" or maybe I am just lucky. I dont know whether the HRDX controller has any bearing on the result ( no pun intended)
 
DipperToo said:
Provenjohn - interesting reply.

Can you expand on 'hard' and 'soft' mounts? Would we be correct in assuming that you had guy wires which were replaced by stainless tube?

Thanks,
Click to expand...

My pole is mounted at base & also to pushpit, both mounts are made via fire hose material & the metal.

The stays are stainless rigging wire, turnbuckles at top & originally shackles to eyes on deck, I shortened the cables & fiexed the shackles to the eyes by cordage (bit like end of guardrail cables), that helped a lot.
 
I have had a 913 mounted on a Gantry over the stern of the boat since 2007. The pole is welded directly onto the gantry. I have not taken any anti-vibration measures at all and luckily don't suffer from any noise problems. It has never been turned off since it was fitted.

We sleep in the stern cabin which acts like a drum in that it amplifies any noise from above. The only noise we pick up is a faint hum - like a generator when the wind speed gets up towards 20 knots or more. The noise is comparable to the general noise of the wind in the rigging.

In fact, when the wind gets up, any noise is more than drowned out by a nearby Air-X from a nearby boat!

The noise free, vibration free aspect of the 913's performance is one of its major pluses in my eyes and I was very surprised to learn anyone was having problems. My experience would tend to indicate that the problems being experienced are not design faults experienced by all users so hopefully a solution can be found.

While I am singing the praises of the 913 I should also add that the after sales advice and service from Marlec is second to none. They helped me finalise my solar/wind system system design which has worked perfectly since the day I installed it and gave me sound advice one one or two installation queries.
 
Silver-fox - agree about Martlec support - excellent.

I think that those of us having noise transmission problems (there are 3 or 4 at my marina alone) probably have mounting poles where we have been unlucky in the structure developing resonance - whether from any small induced vibration from the generator being close to the natural frequency or otherwise (wind sheer etc). I was considering trying to find a 'tuned mass damper' to fit to the pole but no luck so far. Other suggestions have included cutting the pole and rejoining using a sleeve to change the resonance point and maybe fitting 2 additional stays (the pole is 2.6m with the first stays .7m from the top which just clear the blades)

Marlec are kindly going to have a look at the generator this winter in case the bearings might have picked up anything to cause a rumble, or if there might even have been any damage when shipped to me by the dealer.

I am very encouraged that many responses on this thread show no real issues - thanks for the feedback.
 
Wind Generator Magnets

I am not familiar with the generator however.
I feel sure the poles of the permanent magnet should be alternated so S is adjacent to N.
What is actually happening is that the N pole will have its S pole diametrically opposite. Another magnet can can located 90 degrees away.
This assuming the magnets are fixed around the outside and the 3 phase collector coils rotate on the armature with slip ring brush contacts.
The rotor coil (looking at just 1 phase) then will pass the first N pole and get a rise in output followed by a reversal as it passes the S pole. So if 2 N poles are adjacent you will get only one cycle of AC output per turn wheras an N followed by S in 180 degrees per turn will give 2 cycles per revolution. 2 cycles per revolution will give much smoother load on the rotor so less vibration.
However for all that I can't imagine it was assembled with poles in wrong places but yes just possible.
good luck olewill
 
Further to the issue of magnet design, by moving a small compass around the circumferance of the rotors, I've found each rotor consists of 4 N and 4 S poles, equally spaced. The front and rear rotors sandwich the coils between them when assembled.
3 Locating dowels on the housings allow the two rotors to be fitted in 6 different positions, the poles then can align in several ways. Having marked mine before dismantling, each N pole was aligned with the corresponding S pole of the other rotor. Alternative positions cause the poles to be 'staggered', so I think mine has been assembled correctly. In use, A front 'N' and rear 'S' pass through the stationary coils, and vice versa.
The other positions would mean first a 'S' then a 'N' would alternately pass through the coils.
I haven't received replacement bearings yet, so I don't know if they will cure the vibe problem.
 
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