Autoprop vs Maxprop

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Now I'm really confused. I went to LIBS yesterday to buy an Autoprop - but heard some negative comment and was advised to look at Maxprop as well. I've heard out both firms now - and they were both impressive and provided credible arguments for each of their respective products.

Before I toss a coin to decide which to go for (I can't see any other way of deciding!) has anyone got any positive/negative experiences with either product? - I'd be very grateful to hear first hand user experience.

rob
 
I have an Autoprop and am very pleased with it, does what says on the packet, ie .5 to .75 knot on boat speed in light airs sailing, frugal motoring costs and better directional steering in reverse. I am also impressed with the pre and post sales service offered by Brunton's, the manufacturer. I bought it on the advice of peeps on this board and the collective view of the Rival Owners Association, quite a few members have them fitted.

Have no experience of maxprop.
 
I have owned a two-blade Autoprop for about 4 years. Mine is the later type that has greased bearings, not the water lubricated one. I have absolutely no negative comments to make about it. Performance under engine definitely better than with a fixed prop, especially astern. No faults or defects. No corrosion that I can detect. I suspect that the improved performance under sail is somewhat over-sold but this applies to any feathering prop. Maybe depends on underwater shape and gear. I do like the simplicity of the design, eliminating gears and other components that may be prone to failure or being jammed.

One feature that may have been a one-off but was a distinct bonus. Last season I picked up a length of 1/2 inch polypropylene that wrapped itself several times around the prop, breaking the fixed part of my Stripper in the process. Despite this I was able to motor for about 5 miles with no detectable loss in power. The rope was found to have wrapped without causing the blades to move. I suspect that the long forward extension of the prop allowed an accumulation of the rope that might otherwise have got into the blades.
 
Very pleased with Brunton 3 bladed which came with our current boat, by comparison with an identical boat/engine but std fixed 3 bladed ours is faster for the same revs and yet uses less fuel. Under sail I believe it has to be at least partly responsible for the superb light weather performance we have, thoroughly recommended.

I don't have experience of Maxprops, but they will I believe fit in smaller gaps ahead of the rudders on some boats than will Autoprops. However one boatowner I know had enormous difficulty getting the pitch correctly set (it required a lift out each time) and I don't believe it was ever really sorted before the boat was sold on, he never got anything like the expected performance. Others I know are well pleased with theirs.
 
I endorse everything said about the Autoprop. Have a 37 ft Cat with an unusual engine arrangement. 32HP central main engine and 10HP wing engine in one hull. Prior to fitting Autoprop I had a 2 bladed folder on the wing engine. Best speed with this was about 3 knots and it was useless as an aid to motor sailing. Now I can get about 5 knots and when motor sailing it increases my speed from say 2 knots to 6-7. I looked at maxprop when I bought autoprop too and rejected it on the basis that it would not automatically adjust pitch to suit conditions. Very glad I made the choice I did.
 
Before you toss that coin, look at Kiwi prop.
Lighter,cheaper and you adjust the pitch with an allen key, while snorkelling
if necessary!
 
Another satisfied Autoprop customer. Improved performance allround when we replaced our 17'' fixed 3 blade with a 19'' Autoprop.

On passage through the French canals last summer we barely had to increase revs over 1200-1300rpm whereas I would have expected to be doing at least 2000-2100 for the same progress with the fixed prop.
Better brakes meant I could be last in to a crowded lock and still maintain plenty of steerage if there was any crosswind.
Reduced prop walk, though it is still there.
Once in the Med we could sail in lighter winds than before.
The blades really do feather under sail - I've body surfed from the stern ladder to satisfy my curiosity.
Greasing at lift-out was simple clean and quick.
Excellent customer service.

Whilst I am sure we are sailing faster for a given wind I can't be precise because this year we have become semi-liveaboard and so the boat is more loaded than ever before.

Following LIBS 2005 Bruntons were more keen for my business than Darglow, if you get my meaning.

One thing I have found is that I have to keep dropping in and out of neutral for really slow speed manouvering. Not really a niggle, more a change of technique.

All in all very pleased, though I know people who are similarly satisfied with the Maxprop. IIRC there was a slight chance that the Maxprop might not be pitched right first time, and as we were in a hurry to launch and head for the sun I had neither time, inclination or wallet for another lift-out/adjustment.

Steve
 
I have had an Autoprop fitted for the last two years and am very pleased with the performance. A friend has a Maxprop fitted to the same type of boat and he has yet to get the pitch adjusted correctly, and as already stated you hae to lift out to adjust the Maxprop; however the Maxprop performance under sail is as advertised.

The only "negative" thing that I have to say about (my?) Autoprop is that when going from neutral to either ahead or reverse it makes a loud "clunk" which is much louder than a Maxprop (al least on my boat). Mine is water lubricated and has only done 200 hours, so I doubt it needs new bearings yet .... but will check adjustment at next lift out.

If I had to choose again, then I would go for something where you can adjust the pitch without lifting the boat out (Kiwi, J-Prop e.t.c.; or like Autoprop where there is no adjustment).

Alan.
 
Don't have any experience of the Autoprop, although a friend (who liked it otherwise) found a wear problem with his rather sooner than seemed reasonable.

We have a Variprop, which is very similar to the Maxprop, but has the advantage of being adjustbale in situ, i.e. with an allen key, by diving/snorkelling.

We have covered around 20000 Nm over the last 4 years with it, and have been very pleased. Less drag, and good grip ahead and astern, and no wear to mention so far.

We have had similar niggles to the Maxprop that I have heard from owners of that unit, i.e. anodes dropping off the prop very quickly (ludicrously expensive anodes, too) and some "grumbling" when under power.
 
I have just purchased an Autoprop from Bruntons but have yet to try it in anger. I sailed with a friend to Gibralter last summer and he had a Brunton fitted to his 41 ft Westerly. I must admit I was very impressed with the difference in performance - having sailed with him when the boat was fitted with a 3 blade fixed prop. The performance both motoring and sailing was quite impressive, with a distinct lack of prop walk in reverse.

I researched both theAutoprop and the max prop before deciding on a Autoprop for my Moody 38. I considered the Max prop very serously as i have read good reports o it but went for the Brunton based on what I had experienced, and the price. Bruntons were offering a 15% discount, which made it quite a bit cheaper than the Max prop as quoted in September. They may however, be offering deals at LIBS. The price? Well the Brunton H5 model suitable for my 38 is around £1600. Certainly not cheap, but a long term investment!
 
I have a maxprop (it is actually the third one in two boats) and am very pleased with it, reading what other people have said I think they are comparable in efficiency

one thing you might bear in mind is what kind of inverter you have: if you have a mechanical one you may choose whatever propeller you fancy, if you have an hydraulic gearbox a propeller which does not turn when stopped might be preferable (you may always fit a shaft brake but sometimes it is very difficult)
the max prop does not turn when stopped (except if you stop the engine while astern), I do not know about the autoprop but others will know

also, if you plan to fit a shaft alternator is might be useful to consider if/when the feathered propeller can turn
 
Probably gearbox dependent. Mine continues to rotate in forward with a Yanmar 30 but is locked in reverse. Problem then is that after some hours of sailing the lever needs considerable force to disengage the gearbox. We normally start the engine with the prop still in gear, then select forward via neutral.

Agree about the 'clunk' when going from forward to reverse. Helps if you do it slowly. Not sure of the reason, I don't see how it can be the prop as there is no play in it. I thought it might be the gearbox but, as I have an Aquadrive, it can't be. One of life's mysteries.
 
Vyv,
That's interesting because I lock the box in forward, or to be more precise stop the engine with the box in forward, 'cos that's what the manufacturers recommended to ensure that the prop feathered properly.
Chris
 
I have a maxprop myself, which I'm pleased with. Another boat on my pontoon has an Autoprop and is thinking of moving to a Maxprop.

The reason he sited was that the Autoprop sometimes does not set properly. It seems that the blades can get a bit sticky and therefore don't set, or don't set properly. I had heard of this before, which was why I went for maxprop in the end.

Just relaying what I heard, but suspect that both are good products that need maintenance to operate at top efficiency.
 
I have a MaxProp, partially because my prop aperture wouldn't accommodate an Autoprop. No complaints, but if size/space is an issue, there are other options requiring less space - some of which permit pitch adjustment without dismantling the prop (just a mask, snorkel and screwdriver). YM did an article a couple of months ago. If you haven't already, have a look at the Darglow website. The Kiwi-Prop is also well worth a look and a lot cheaper.
 
The manual discusses this. It's only a matter of setting the bearing clearance correctly. Can't remember whether it's with shims or something else but it isn't a big deal. I believe fouling could possibly account for it with the water lubricated ones but not the greased version.
 
We do the same, stop the engine whilst it is still in forward gear. We have shaft drive Yanmar 44 and it doesn't stick in gear at all so we can put it in neutral easily to restart. Paradoxically the Volvo MD22L we had in our old boat ALWAYS stuck in ahead under sail and we had to give it a quick blip on the starter which freed it so neutral could be engaged, that was a new MD22L and it is quite normal I understand. Our Yanmar clunks going into gear which Yanmar say is normal with the Hurth gearbox but it is exagerrated slightly by any kind of folding/feathering prop where the load comes on suddenly as the blades open or set.
 
Setting Autoprops and how They compare with Maxprop

The bearing do sometimes "jam" if done up too tight or if the race-face is worn. I've once had it happen when the mooring went through a tremendous fouling phase.

I had one of the original Autoprops and after 14 tears of use have just replaced the bearings (a simple job). the bearings are adjusted quickly and easily by simply tightening the race faces and re-locking. That needs doing about every 1200 hours of use.

Both have their advantages and disadvantages. But to summarise the Maxprop probably has less drag and less drive than the Autoprop but is probably slightly less expensive.
The strongest point of the Autoprop is it's superb effectiveness when motorsailing.

Users of early KiwiProps confirm their effectiveness but bemoan their short life span.
 
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