Badger
Well-Known Member
Anyone had any experience of fitting and using one of these ? Is it a nice to have or a must have ? Anyone tried the new Moduline Aquadrive ? Thanks in Advance.
Aquadrive from Halyard Marine
- Thread starter Badger
- Start date
Talulah
Well-Known Member
Aquadrive
I have bought and fitted 2 Aquadrive units. The later I think is a moduline.
The main issue is "Do you have space to fit one?"
If you do and can afford the price tag I think they are great for the following reasons:
Engine alignment no longer an issue.
Heeled over with the engine running the engine mount rubbers move and the Aquadrive accomodates the movement. No images of the shaft grinding against the cutlass bearing as the boat is healed.
Changing the Volvo stern seal is made easy.
Extracting the prop and renewing the cutlass bearing is straightforward.
When you size which Aquadrive unit to get it's worth phoning them and having a discussion. They carry a 10 year warranty but as our boat clocks up a huge number of engine hours we opted for a much bigger Aquadrive then would be specd for a leisure user.
I have bought and fitted 2 Aquadrive units. The later I think is a moduline.
The main issue is "Do you have space to fit one?"
If you do and can afford the price tag I think they are great for the following reasons:
Engine alignment no longer an issue.
Heeled over with the engine running the engine mount rubbers move and the Aquadrive accomodates the movement. No images of the shaft grinding against the cutlass bearing as the boat is healed.
Changing the Volvo stern seal is made easy.
Extracting the prop and renewing the cutlass bearing is straightforward.
When you size which Aquadrive unit to get it's worth phoning them and having a discussion. They carry a 10 year warranty but as our boat clocks up a huge number of engine hours we opted for a much bigger Aquadrive then would be specd for a leisure user.
andygc
Well-Known Member
I have an Aquadrive fitted by the previous owner. Given the vibration of a Yanmar 1GM10 I think it a great way to prevent an engine beating an old wooden hull to death. On your shaft seal thread Tranona suggested "needs a lot of engineering to install". The engineering needed is to fit a thrust plate. How difficult that will be depends on the shape of your boat, but all the plate needs to be is thick plywood firmly attached to your hull.
My Aquadrive is beginning to rumble quite badly, but it's over its 10 years now, so fair enough. I'm about to re-engine because I can't cope with getting any deafer with the Yanmar and there will be a new Aquadrive going in with the new engine.
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PS, if anybody wants a well-maintained 1GM10 in good running order, complete with Vetus strainer, exhaust box, engine mountings etc just send a PM for full details.
My Aquadrive is beginning to rumble quite badly, but it's over its 10 years now, so fair enough. I'm about to re-engine because I can't cope with getting any deafer with the Yanmar and there will be a new Aquadrive going in with the new engine.
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PS, if anybody wants a well-maintained 1GM10 in good running order, complete with Vetus strainer, exhaust box, engine mountings etc just send a PM for full details.
D
Deleted member 36384
Guest
Excellent Devices
I fitted one last winter to a big Perkins 80 HP on a 41 foot yacht. The gearbox is hydraulic.
Vibration has been eliminated. I can just turn the prop shaft by hand in neutral, so the bearings are great.
I replaced the Cutlass bearing, prop shaft and engine mounts at the same time.
The big advantage for me is that when the old engine dies I do not have to worry too much about realignment issues with the new engine.
Point about hydraulic gear box - unless you have a shaft lock the prop will rotate quite fast when sailing (putting it in gear does not lock up a hydraulic gear box). My old arrangement didn't allow prop rotation because of the stiffness of everything.
Well worth the investment. The best modification I have made.
The yard fitted a mini bulkhead to attach the thrust bearing too. It is located under the sole about 12" from the back of the gearbox.
I fitted one last winter to a big Perkins 80 HP on a 41 foot yacht. The gearbox is hydraulic.
Vibration has been eliminated. I can just turn the prop shaft by hand in neutral, so the bearings are great.
I replaced the Cutlass bearing, prop shaft and engine mounts at the same time.
The big advantage for me is that when the old engine dies I do not have to worry too much about realignment issues with the new engine.
Point about hydraulic gear box - unless you have a shaft lock the prop will rotate quite fast when sailing (putting it in gear does not lock up a hydraulic gear box). My old arrangement didn't allow prop rotation because of the stiffness of everything.
Well worth the investment. The best modification I have made.
The yard fitted a mini bulkhead to attach the thrust bearing too. It is located under the sole about 12" from the back of the gearbox.
earlybird
Well-Known Member
I fitted an aquadrive to my previous boat, which had been re-engined from an old petrol engine with virtually solid mounts, to a Yanmar 2GM20. The Yanmar, being 2 cylinders, wants to jump all over the place on its soft mounts, and was putting a lot of radial loading on the stern-tube, esp. at low engine speeds. The overall reduction in noise and vibration transmitted to the hull was dramatic.
Engines of 3 or more cylinders are much better balanced, and, in this respect, the value of an aquadrive would be less IMHO, but the ease of alignment is still a big plus.
Engines of 3 or more cylinders are much better balanced, and, in this respect, the value of an aquadrive would be less IMHO, but the ease of alignment is still a big plus.
Tranona
Well-Known Member
earlybird;2225605 said:
earlybird
Well-Known Member
It was a while back. I did consider a Bullflex, but, IIRC, although it catered well for angular misalignment, it didn't really accomodate radial movement, so I concluded that the Aquadrive was the better engineering job. Must agree that it was fairly pricey and considerable effort.
Tranona
Well-Known Member
I solved the movement of the shaft by having a cutless bearing on the inboard end of the stern tube as well as the outboard end. That way the shaft is effectively fixed and the Bullflex absorbs the movement of the engine only. Line it up absolutely spot on so it does not deal with any angular misalignment either. Result of three iterations of layouts and very pleased with the final result.
Gunfleet
Well-Known Member
shaft
Could I ask how long that shaft was, Tranona?
Could I ask how long that shaft was, Tranona?
Tranona
Well-Known Member
The overall shaft length from memory is just about a metre with less than 200mm inboard of the stern tube. Take out the 110 mm for the Volvo seal and there is not much left to fit the coupling! About 40mm exposed shaft.
The stern tube is a Stuart Turner which I had to keep because it would never have come out of the deadwood and skeg. If you remove the inner bearing which was originally white metal and a stuffing box there is insufficient clearance for the engine to be fully flexibly mounted - the shaft hits the tube. Final solution was to machine the inboard bearing carrier to take a cut down (about 60mm long) cutless and the outside diameter to take the Volvo seal.
At tickover you can watch the 1GM auditioning for come dancing and the shaft stationary!
Neil_Y
Well-Known Member
As others have mentioned space issues the alternative might be a seatorque system? which comes with shaft and bearings. Replacing the cutless bearing, stern tube bearing and through hull fitting whilst taking thrust loads and coupling with a cardan shaft to the engine.
Neil_Y
Well-Known Member
Although many people are talking about vibration reduction from the ability of a UJ, cardan shaft, flexible couplings ability to allow misalignment or the engine to move. All systems still run within tolerances of a few mm and even the double UJ 4degrees at higher revs, paying careful attention to the individual angle of each joint and not the combined angle between shaft and engine.
Many of the benefits come from taking the thrust loads through the hull/bulkhead rather than allowing the shaft to push the engine out of alignement as soon as the prop is pushing or pulling.
Tranoma is correct in sorting out the shaft support with sufficient length and placement of bearings, which is often minimal with long unsupported lengths which encourage shaft whip. This is also why rigid bearings help reduce vibration.
Many of the benefits come from taking the thrust loads through the hull/bulkhead rather than allowing the shaft to push the engine out of alignement as soon as the prop is pushing or pulling.
Tranoma is correct in sorting out the shaft support with sufficient length and placement of bearings, which is often minimal with long unsupported lengths which encourage shaft whip. This is also why rigid bearings help reduce vibration.
OAF
Well-Known Member
i have owned several boats with Aqua drives and they have all been excellent, had to have a twenty year old aqua drive overhauled recenty, costly but it will still be going strong in another 20 years, i use these guys http://www.twmarine.co.uk/ excellent service
I also use something very similar called a python drive, very much cheaper than the aqua drive and nearly identical in design, i use this company http://www.midlandchandlers.co.uk/PYTHON-DRIVE-P60-K-1-1-2-C-W-ADAPTOR-4-5-FLANGE_A1GK5.aspx
I do still own some hire boats with the python drive fitted with 42 hp engines and they have done around 3000 hours and have given no problems what so ever.
Good luck with what ever you choose as the difference from a standard coupling is amazing as others have said.
Regards
I also use something very similar called a python drive, very much cheaper than the aqua drive and nearly identical in design, i use this company http://www.midlandchandlers.co.uk/PYTHON-DRIVE-P60-K-1-1-2-C-W-ADAPTOR-4-5-FLANGE_A1GK5.aspx
I do still own some hire boats with the python drive fitted with 42 hp engines and they have done around 3000 hours and have given no problems what so ever.
Good luck with what ever you choose as the difference from a standard coupling is amazing as others have said.
Regards
PCUK
Well-Known Member
Depends if you want to cure misalignment or reduce vibration. If the latter then Centaflex couplings are the best.
davey
Well-Known Member
There are other ways of doing things! A diesel engine that I bought for amusement was an air cooled Kirloskar. Some ingenious person had built up a frame for this which carried the engine mounts. The gearbox was bolted solidly to the other end of the frame and there was a drive shaft complete with CVJs joining the two. Quite a good idea really as the gearbox can be solidly mounted to take the propeller thrust whilst the engine can jump about as much as it likes. I find it amusing that somewhere along the line marine engine designers (thousands of them) lost the plot! The ideal place for the "Aquadrive" type of device is between the engine and gearbox.
D
Deleted member 36384
Guest
Indeed by removing the gearbox mass from the engine the mass that is subject to vibration and hence the loading on any thrust bearing is also reduced. Further, as the gearbox is some distance from the mounts, the displacement interval would be reduced if the gearbox was moved as you suggest and was replaced by a thrust bearing.
However, its not that simple. A good number of engine arrangements are mounted where the hull tapers and to move the gearbox back towards the shaft log would not be possible has the hull taper reduces both available width and depth. Hence, there is not that much room. This is certainly the case the case on my boat.
The CV type thrust bearings are relatively long but small enough in diameter that they fit in the space between the shaft log and gearbox, albeit with modification to the shaft. So perhaps they have not lost the plot after all but are working to real world constraints.
This is an interesting subject, so why not start a new post, this one is quite old from 2009 and so probably not so relevant to the original poster now.
Regards,
BlowingOldBoots
However, its not that simple. A good number of engine arrangements are mounted where the hull tapers and to move the gearbox back towards the shaft log would not be possible has the hull taper reduces both available width and depth. Hence, there is not that much room. This is certainly the case the case on my boat.
The CV type thrust bearings are relatively long but small enough in diameter that they fit in the space between the shaft log and gearbox, albeit with modification to the shaft. So perhaps they have not lost the plot after all but are working to real world constraints.
This is an interesting subject, so why not start a new post, this one is quite old from 2009 and so probably not so relevant to the original poster now.
Regards,
BlowingOldBoots
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srp
Well-Known Member
I've got an aquadrive in my Corribee, again with a 1GM10. I bought it for my previous boat (a 1938 gaffer), specifically to reduce the vibration transmitted to the hull, but didn't get round to fitting it as it was a bit tight for space. When I installed the Yanmar in the Corribee I designed the layout to give enough space for it to fit. Expensive, but well worth it.
Have a look at Vyv Cox's site, which shows a couple of examples. Link
Have a look at Vyv Cox's site, which shows a couple of examples. Link
john_morris_uk
Well-Known Member
I fitted one to our current boat and can only echo others remarks on the dramatic improvement in vibration and noise.
Its wasn't too difficult and fitting the dwarf bulkhead was not too fiddly, although I did beef it up with a stainless plate subsequently.
Its wasn't too difficult and fitting the dwarf bulkhead was not too fiddly, although I did beef it up with a stainless plate subsequently.
eagleswing
Well-Known Member
centa coupler vs. aquadrive...
had an aquadrive on last boat coupling to a yanmar 2Gm20F 20 hp diesel. it was quite an expensive proposition and it also required a specialized adapter for the yanmar. i now have a CENTA coupling on the yanmar 3jh4E 40 hp which was original equipment installed by nauticat . the centa is much less costly, requires an adapter which is much less $. the Centa is much easier to work on than the aquadrive. here in the USA yanmar markets the aquadrive for tis engines at about $2000 compared to $800 for a Centa or Vetus.
i recently had to replace my bent propshaft which required detaching the old prop from the centa M127 gearbox coupler. the detach and install of the new prop with the CENTA coupler was a piece of cake: remove 6 M8 13 mm coupling mounting bolts around the circumference of the Centa. take off 3 black plastic plugs covering 3 jackholes on the centa. insert 3 M10 17mm jackbolts into the 3 jackholes. slowly tighten the jack bolts working each one tighter a little at a time. the jackbolts' tightening forces the centa coupler out of its hub, then you can remove it easily from the prop shaft..
had an aquadrive on last boat coupling to a yanmar 2Gm20F 20 hp diesel. it was quite an expensive proposition and it also required a specialized adapter for the yanmar. i now have a CENTA coupling on the yanmar 3jh4E 40 hp which was original equipment installed by nauticat . the centa is much less costly, requires an adapter which is much less $. the Centa is much easier to work on than the aquadrive. here in the USA yanmar markets the aquadrive for tis engines at about $2000 compared to $800 for a Centa or Vetus.
i recently had to replace my bent propshaft which required detaching the old prop from the centa M127 gearbox coupler. the detach and install of the new prop with the CENTA coupler was a piece of cake: remove 6 M8 13 mm coupling mounting bolts around the circumference of the Centa. take off 3 black plastic plugs covering 3 jackholes on the centa. insert 3 M10 17mm jackbolts into the 3 jackholes. slowly tighten the jack bolts working each one tighter a little at a time. the jackbolts' tightening forces the centa coupler out of its hub, then you can remove it easily from the prop shaft..
davey
Well-Known Member
One engine that I bought on impulse had been destined for the previous owners wooden boat but he had lost interest. The engine was a hand-start air cooled Kirloskar but the neat thing with it was where the gearbox was i.e. the gearbox was not bolted to the engine! An angle-iron frame had been built and this had the gearbox bolted to it. The engine was also on the frame some distance back and was mounted on rubber mounts. Between the engine and gearbox was a modified Citroen drive shaft. Simple!
