Aero4gen dismantling advice.

[Chiliblue]

Hi,

I inherited a Aero4gen which has been working just fine.

I lost a blade over the winter and replaced it... it made the unit unstable (I should have replace the blades in pairs)

To cut a long story short, it seemed like it was time to take it from the boat for a service and a repaint. Once off it was obvious that it was in good working condition with smooth bearings, sadly however due to the way it was installed I had to snip the wires to remove it and as the installer had left no slack what so ever I will have to replace the wiring including the wires that go up to the contacts on the pivot.

To replace those I will have to remove that pivot which seems simple enough but I just can't the bearings to slide out from the body of the unit.ve

Can anyone recommend some where in the portsmouth or farnham area I could get the part extracted? Is there a place where people send these to be serviced? Or can you give me some tips on how to do it? I am following the instruction and clamping the shaft and hitting the body through a wooden block as described in the manual, I don't feel comfortable applying heat due to the nature of the device. No points for the 'hit it harder' tip which I suspect might follow.

Thanks in advance

Chiliblue

 

[GrahamM376]

The swivel bearings are an absolute pain to remove and some years ago I sent one back to LVM via Cleghorn Waring who suggested it needed the bearings freezing to get them out. LVM wrote and said a new body was required which, plus new blades was around £300!!! Fortunately, it wasn't mine.

 

[ELAiNe333]

The swivel bearings are an absolute pain to remove and some years ago I sent one back to LVM via Cleghorn Waring who suggested it needed the bearings freezing to get them out. LVM wrote and said a new body was required which, plus new blades was around £300!!! Fortunately, it wasn't mine.

Glad to hear that they cost that much, explains why fortunately they are only a few of the noisy things in the marina. (Grumpy O G mode)

 

[allanc]

Hello,
I recommend Ropewalk Marine in Lymington who solved exactly that shaft extraction problem two months ago when I needed to replace the bearings.
LVM are now owned by Cleghorn who will supply all the parts and spares but don't offer any servicing.
And as for the Aerogen being noisy, they are not. Other makes can be and are very annoying. Sitting in our cockpit, we have to look up at times to check that it is rotatating.

 

[doug748]

I have an Aerogen 25, which is an ancient precursor of your model, and can confirm they are very, very quiet.

When you replace a single blade it is best to balance the fan by filing bits from the tips. The new white blade looks very odd as it revolves but seems to do no harm.

When the mounting bearings get worn it does tend to rattle above 20kts. As mine are obsolete and very difficult to source, I have left them in; on a swinging mooring it only disturbs the seagulls. I have replaced the bearings a couple of times but can't remember any particular problem - you might give them a good soak and then try heat from a hot air gun to free them up.

The main rotor bearings are still good and they have revolved now for 20 years +.

 

[Chiliblue]

Thanks for all of that. I am going to give a local classic car workshop a go, they should be pretty adept at getting old bits apart and hopefully will save me the journey to Lymington. Its all really aggravating if the previous owner had put just a little thought in to how it was ever going to come off it would have saved me a lot of hassle.

Doug thanks for the balancing tip, I am thinking of just buying one more so that they are pair off which in theory (my theory) stop any imbalance.

I have found mine to be very quiet unless there is a gale blowing and then that has nothing to do with the bearings. I have found it to be a great piece of kit and a real comfort seeing my batteries at 100% when I return to the boat.

 

[Chiliblue]

Progress, local vintage car restorer... quickly got the pivot shaft out. Right tools and year of experience dismantling seized things that would be impossible or very expensive to replace. Note to shelf, buy a bigger clamp and hit things harder.

So next bit which is replacing the cables, it looks like I need to remove the bearing from the shaft.

If anyone has done that could they explain exactly how it is done.

Thanks in advance.

 

[agurney]

Progress, local vintage car restorer... quickly got the pivot shaft out. Right tools and year of experience dismantling seized things that would be impossible or very expensive to replace. Note to shelf, buy a bigger clamp and hit things harder.

So next bit which is replacing the cables, it looks like I need to remove the bearing from the shaft.

If anyone has done that could they explain exactly how it is done.

Thanks in advance.

I did it a few years ago. I can't remember the details, but recall destroying the inner part of the bearing then drilling/grinding/sawing the outer part that had frozen to the alu housing.

The upside is that the bearings are standard and can be had for a couple of quid (I probably have a note of the sizes somewhere)

 

[OldBawley]

“ Bought “ an Aerogen 4 from a sailor who had wreckt his boat on a beach in Rhodes. His catamaran was sitting on the beach with two holed hulls, the man wanted to stop sailing, had enough.
I gave him a very large sum of money for the windgen ( Who had a broken propeller shaft ) only so my friend could pay for a ticket home and some other basics.

First I made a new shaft. I have a miniature lathe on board, made the shaft out of bronze. Stainless steal is difficult to machine.

Some other little changes I made to the well made Aerogen :

For commercial reasons the Aerogen has a short tail. That makes the forward part a lot heavier than the tail part witch results in waddling of the unit in light winds and some waves. Our Aerogen stands 7 meter high, increasing waddling. So I made a longer, heavier, balanced tail. Supported by two tubes in stead of one. Waddling over, increased efficiency.
In very high winds, the one tube tail starts vibrating. I noticed a few times in 90 knot winds, a dangerous situation. The two tube tail will not vibrate.

The old blades had a very rough surface even microscopic glass fibres sticking out, so I painted them smooth.

Balancing : Since I build a low windage generator myself I have some experience with prop balancing. I use the fishing line method. On a lathe a perfect fitting dummy piece of shaft is made with a 1/64” whole in the centre. Some fishing line trough there, hanging up the complete assembly of hub and blades. Then balancing until the propeller assembly hangs perfectly horizontal.
Believe me, matching the blades is a very imprecise way of balancing.

In the old unit a bi metal switch protects the diodes from overheating by cutting the field current.
That results in free-wheeling and loss of charge. On my Aerogen 4, the switch was set incorrect, cut the current every few minutes in some wind and Mediterranean sun.
I reset the regulation ( bending a bit ) so output is now double on hot windy days.
Most people think a rotating windgen works fine..... measuring is the only way to know if the gen is working ok.

Last remark, everybody mounts his windgen on the “Spoiler” There they create shade for the solar panels who also sit on the spoiler and work in disturbed air. ( Boom, mast, spray hood )

I mounted the old Aerogen on top of the yawl mast. Not in front, on top. Even a mast behind a windgen results in disturbed wind, less efficiency.
The new low windage diy generator mounts in minutes on the port bow when at anchor and needed. No disturbance. Output three times the one of the Aerogen.

 

[Chiliblue]

I did it a few years ago. I can't remember the details, but recall destroying the inner part of the bearing then drilling/grinding/sawing the outer part that had frozen to the alu housing.

The upside is that the bearings are standard and can be had for a couple of quid (I probably have a note of the sizes somewhere)

Thanks for that. If you can find the note of the sizes that would be really helpful.

Looks like I will need a stiff drink before attempting this. The Pivot shaft and bearing came out surprisingly (possibly slightly embarrassingly!) easily, had to suppress the "I must have loosened it up for you" retort .

 

[OldBawley]

Do you want to take out the main shaft bearings ?

 

[Chiliblue]

OldBawley,

Wow, you obviously know your stuff. Pity you aren't in the solent.

 

[Chiliblue]

Do you want to take out the main shaft bearings ?

No the main bearings are fine, no noise or movement, its the pivot shaft bearings, which are also fine but due to the original install (previous owner some years ago) there was no way to remove it from the pole without cutting the cables... so I need to rewire the from the pivot down.

 

[OldBawley]

Removing the main shaft bearings :

Have the new bearings ready, ( Standard alternator bearings such as Lucas.. 35mm x 15mm x11mm
two side closed.)
Remove the retaining ring from the front shaft. Remove back cover.
Now put a hardwood block on the concrete, and bang the generator head with the shaft onto that block of wood, using the weight of the gen. The rotor will slide trough the bearings and get out on the back of the gen.
Now remove the bearings from the housing using a hammer and drive.
Put new bearings in.
Don’t have the rotor out long, the magnets loose power fast if no rotor in place. ( One or two hours is no problem )

Pivot bearings........ would like to know myself.