Michigan Wheel Marine rope cutter....any experience?

[Tim O]

Hi, has anyone fitted or even seen a Michigan Wheel Marie ropecutter? I've just bought one but there are no fitting instructions. Wanted to fit it tomorrow and of course their office is closed!!!

Anyone know which side....the side with the "boss" or the flat side, should face forward and how it should be spaced between the shaft bearing and the propeller hub? Flush against the hub? With a gap???

I have about 10cm exposed shaft, this thing is 18mm thick.

 

[pvb]

As it's essentially symmetrical, I can't see it would matter which way round you fit it. I'd position it a few cm forward of the prop.

 

[duncan99210]

When I first saw this, I thought it was a version of the Ambassador cutter, with one fixed and one rotating disc to cut rope. On looking a little more closely, it's clear that it's a single fitting with no scissor like cutting action. As pvb says, it would appear to be able to be fitted either face forward. I might be tempted to use a drill bit to put a small, the emphasis on small, dimple into the shaft to ensure one of the grub screws has a really secure grip on the shaft, otherwise it'll simply spin if you get a rope wrap.

 

[Tim O]

I wondered too about a dimple in the shaft....spoke before purchase to the manufacturer they reckoned no need. It has six grub screws......i'm tempted to drill at least one dimple as it can't harm surely?

This is a half way house between the ambassador type and the simple discs.....a disc with more aggressive cutting action. Didn't fancy the expense and fitting of the ambassador so thought I'd give this ago..... apparently very well established in the USA but new to UK market

 

[Tranona]

Despite its fancy edge it will suffer from the same problem of all such devices. It does not cut in the conventional sense but slash. This type was popular for a while because of its low cost and seeming sharpness. However, they have faded away because they are relatively ineffective. At least it is unlikely to do any harm.

As in most things, you get what you pay for and a scissors type cutter works! - hence their popularity.

 

[pvb]

Despite its fancy edge it will suffer from the same problem of all such devices. It does not cut in the conventional sense but slash. This type was popular for a while because of its low cost and seeming sharpness. However, they have faded away because they are relatively ineffective. At least it is unlikely to do any harm.

As in most things, you get what you pay for and a scissors type cutter works! - hence their popularity.

Interesting that the OP mentioned that it was "apparently well established in the USA", but it doesn't feature on their USA website at all. I'd guess the European office in Devon is selling left-over stock on eBay.

 

[Tranona]

Yes, far from being well established (although Michigan Wheel is) the product is very new and they have been scratching around trying to find a UK importer for some time. Not an attractive market - low value, not very effective product.

 

[Hydrozoan]

Despite its fancy edge it will suffer from the same problem of all such devices. It does not cut in the conventional sense but slash. This type was popular for a while because of its low cost and seeming sharpness. However, they have faded away because they are relatively ineffective. At least it is unlikely to do any harm.

As in most things, you get what you pay for and a scissors type cutter works! - hence their popularity.

Yes, I recall that you (and some others) gave a similar view on ‘disc-type’ cutters (albeit plain, not serrated, ones) here http://www.ybw.com/forums/showthread.php?426367-Rope-Cutter&highlight=rope+cutter and here http://www.ybw.com/forums/showthread...ht=rope+cutter

But others were less critical of them – e.g. Vyv Cox pointed to some potential problems of the ‘scissor-type’ with P-brackets – and I linked to this video of a YM test, test in which IIRC a disc-type performed badly only with copper wire: http://www.yachtingmonthly.com/archive/watch-yms-rope-cutter-test-12700

I know that you keep pretty well abreast of technical developments, whereas I am more likely to have missed them. Do you know of any later tests than the one by Yachting Monthly shown in that video?

 

[Tranona]

No - and that test had its limitations. Very difficult to simulate in a test tank what actually happens when a prop gets fouled as there are many different scenarios. The key difference is that disc cutters are sharp, but only slash at the rope whereas a scissors cutter actually holds the rope while it cuts. Just try cutting a hanging rope with a sharp kitchen knife without holding it against something solid and you get the picture. then try cutting the rope with a pair of pinking shears with serrated blades and see the difference. So, of course it will cut at times, particularly if the rope is held stationary against it, but that is not typical of the types of fouling that cause the damage.

As to P brackets - the Sadler has a particularly "fragile" P bracket, much thinner than most and the recommended cutter is the smallest size rather than the next size up which some fit. The screws holding the striker on are the weak link. On the rare cases where the cutter does get overwhelmed the danger is that the sterngear can get damaged (as it often does without a cutter) so the screws will pull out rather than pulling the shaft aft for example. However, with small HP engines often the engine stalls before any of this happens.

 

[Hydrozoan]

No ...

Thanks for that. I do understand the different mechanisms, and your reservations and concerns. But however flawed you think the YM test was, it was at least a practical assessment which is worth something in my view.

 

[Tim O]

Thanks for your answers guys....I knew when I asked the question Id get people saying "fit an Ambassador, the disc-type cutters are rubbish"!!

I too have read the YM test result...and various others, and while in general the scissor type cutters come out tops, the general opinion also seemed to be that ANY cutter was better than none. Also, as with everything n a boat we are always balancing
What we can afford
What we have the technical ability to do
What we can afford to pay others to do
What the risks of not doing anything are
What other priorities we have!

So.....with all that in mind my thinking was this...I'm doing up this boat to liveaboard on a tight budget which is already overspent...I'm too cautious to set to sea without ANY cutter (even though the previous owner seems to have sailed the Bristol Channel happily for years without one), but too skint to be able to afford an Ambassador and not technically confident enough to fit one myself anyway...I also have other things I need/want to purchase such as high-end lifejacket and PLB ( as I'm likely to be singlehanding often), solar charging set-up, etc etc......so I figured this is relatively affordable, easy for me to fit, and will give me at least SOME peace of mind that if I pick up a prop wrap it might not be terminal! ( At last it did before I read some of your answers....

 

[Tranona]

Like many preventative measures or equipment, you only appreciate their value when you have suffered the consequences of not having it fitted!

Where it fits into your list depends on two things. Firstly whether you are sailing in an area where fouling is common and second the consequences of picking up something that will foul the prop and disable your boat. The heavy fouling areas are well known and plotted. So, for example the western Solent and Poole Bay west to St Albans has a high density of poorly marked pots. So you will find a high proportion of boats kept in that area fit rope cutters - mostly scissors type as it is the only effective defence.

You are right - your disc MAY cut some ropes but there is a sound reason why scissors cutters, despite their seeming high price are the most popular, and have been for 30 years.

Of course there are many people who never have problems of fouling and in many parts of the world it is not an issue anyway. If you went back in time and got a copy of PBO November (from memory) 1987 you will find an article that I wrote about the consequences of picking up a piece of net in the middle of the channel. I subsequently re-engineered the rudder and sterngear of my boat so that I could fit a cutter - which had plenty of work in subsequent years.

BTW not difficult to fit one to the sort of stern gear you have.