Ambassador rope cutter?

[macd]

Thankyou Elecglitch and dom.
With your help the conclusion I have drawn, which seems both more logical and less disingenuous than that expressed in post #34, is never to buy anything from H4 Marine.

 

[Tranona]

Is it possible that the Quickutter is used on the larger RNLI vessels on the basis that the calcs are materially different up around the 100bhp+ territory, from those relevant to yachts which overwhelmingly operate in the 25-125bhp space?

Personally, there is no way I would buy a product from a manufacturer who declined to provide clear and specific reasons for not partaking in a test, which attempted to realistically mimic my intended application.

As a matter of interest, every time you go to the IOW on a Red Funnel cat, you will be pleased its prop is protected by a Stripper!

Many other high powered boats - French lifeboats (sybarite will be pleased to hear), patrol craft, superyachts etc have them fitted. Standard sizes go up to 4" shaft, and custom designs for even bigger. www.ropestripper.com has all the details.

 

[dom]

As a matter of interest, every time you go to the IOW on a Red Funnel cat, you will be pleased its prop is protected by a Stripper!

Many other high powered boats - French lifeboats (sybarite will be pleased to hear), patrol craft, superyachts etc have them fitted. Standard sizes go up to 4" shaft, and custom designs for even bigger. www.ropestripper.com has all the details.

Wow they build them that big! It seems like Ropestripper's good reputation has been hard won and well deserved.

Pity one of those babies doesn't regularly ply the, Looe channel, inner-Portland route, etc

 

[dunedin]

Zincsmart has been my source of saildrive anodes for several years and they will drill the guide pin hole and machine the lip edges for a modest fee. (I have done it myself but i had a machine shop at work then and it requires a pedestal drill to accurately drill the hole)
Total cost - a fraction of what you can pay elsewhere.
Michael.

Very helpful thanks. However, whilst zincsmart sound very good at anode adaption, they aren't so hot at websites - slightly odd navigation, and found anodes for Volvo 100 and 120 saildrives but not for 130/150, even before adaption for a stripper
http://www.zincsmart.com/index.htm

 

[Neil_Y]

1. If you're addressing a particular post to an individual and hope for a response, I suggest you use some method, such as the quote facility, to make that clear.
2. If it was aimed at me, I wrote that UK magazines test rope cutters "every few years" for no other reason than that they group-test rope cutters every few years. If you consider the tests not exhaustive enough, I suggest you take it up with the magazines in question.
3. If you're so concerned about comprehensiveness and balance, perhaps you'd be so kind as to identify the anonymous cutter to which you refer? Readers might also be glad to know whether they're available to the public and where they might source them.

Sorry you feel that way Mac, I should have quoted, but I wasn't looking for a response just to let people know the tests are old and not comprehensive. The impression people get is that there have been regular revues and tests when actually the last group test was 8 years ago and the report has been re printed. I'll explain the situation of why this cutter wasn't tested back in 2008 in an answer to the other post.

My initial comment was to add that there is another type as only two types were discussed by one poster. I do have a commercial interest (I thought that was clear in my footer), and that's why I prefer not to name brands as it seems against the spirit of the forum. The cutter is available through other suppliers and is lisenced as an option on some stern gear systems. If people go out and search I hoped they would find more information to make an informed choice. I am not the manufacturer.

 

[dom]

Sorry you feel that way Mac, I should have quoted, but I wasn't looking for a response just to let people know the tests are old and not comprehensive. The impression people get is that there have been regular reviews....

The cutter is available through other suppliers and is licensed as an option on some stern gear systems. If people go out and search I hoped they would find more information to make an informed choice. I am not the manufacturer.

I have been searching for just such information and posed the question in post #39 as to whether the Ambassador's scissors type arrangement is more suitable for smaller engines as opposed to the Kwickutter which appears to require the trapped rope to be dragged across a cutting surface.

As a non-engineer, I can for example imagine that it would be much easier to cut a piece of string with a scissors than by trying to pull it across a serrated blade. However, if I had 1000hp in my arm I might not care!

Any thoughts?

 

[Neil_Y]

I think he might be referring to this bit of kit: http://www.h4marine.com/QuicKutter01.htm

This is the comment from the 2015 test (http://www.yachtingmonthly.com/gear/propeller-rope-cutter-test-30012):

We explained to all eight manufacturers how our tests would be conducted and invited suppliers to send us samples and attend the test. Plastimo couldn’t provide us with a unit, so we bought one. We were unable to test the Quickutter shaver – its maker declined to participate, citing concerns over the suitability of out test tank and rig for evaluating the performance of a shaver. We would be pleased to hear of any readers’ experiences with shaver-type cutters. It’s worth noting that the RNLI has fitted Quickutters to its entire fleet of Tamar-class lifeboats.

IMHO this doesn't justify his sarky post though. I assume from his picture he's hardly unbiased and it's interesting that he chose not to point that out.

The test was not 2015 but 2008.
And for Dom a clear as I can make explanation as to why we didn't take part.

We were asked to take part in that test which was in November 2008 we provided engineering drawings of how the cutter should be installed (in Feb 2008), the testers were unable to carry out the work required. We were eventually asked to sort it in less than a week and there was not enough time to get a local engineer to carry out the work.

The basic problem was that the test rig you see in the video was designed for a shaver cutter so it has quite a large gap between the prop hub and the bearing carrier, the quicKutter works best with as small a gap as possible. This alone would compromise it's operation had it just been bolted to the bearing carrier as the other cutters are. Our response at the time was I quote..."In summary

The test rig, having been designed with the scissor cutter in mind, had a prop blade root to bearing carrier gap far larger, (over 60mm for a 38mm shaft) than that suitable for a conventional and straight forward quicKutter™ installation. The difference in diameters, bearing carrier to prop hub also presented some problems. Had the gap been 20 -25mm with similar hub and bearing carrier diameters we would have been happy to have participated. The ideal gap of around 10-15mm from cutter blade to prop blade root, allows one or two turns of the most common sizes of debris to wind on to the spool before cutting. Increasing this gap increases leverage loads and reduces cutting efficiency.

One of the reasons the cutter has been such a success in commercial vessels is its robustness, even in a test we wouldn't want to compromise this, so the only solution looked to be an extensive modification of the test rig.

If a vessel had actually had these dimensions there are engineering options available to allow us to provide a customised solution. However, customising the test rig in question within the allotted time is not practical

Thank you for your help, if you want to go ahead with a practical test on MBM's boat let me know. We will provide the cutters free of charge."

We also weren't that happy with the test methodology as it didn't demonstrate a rope caught by the prop, the rope was fixed at the base of the P bracket/strut
and then the free end was sucked into the prop. In practice trouble starts when a rope is caught by a prop blade, so the fixed end is now on a blade and rotating, winding the rope tightly against the shaft between the prop and the bearing carrier. The rope is rarely going to be pulled tight along the length of the shaft unless it is first caught by the strut or something on the boat (a dropped sheet may replicate this) The scissor and discs work well in this situation as the debris is pulled across the cutting action and the rope is stationary relative to the shaft and pulled tight so the discs get a chance to saw through as they rotate. The shaver cutter works when rope is caught by a prop blade and is then winding up on the space between the prop and bearing carrier and rotating with the shaft. The test did not allow this to happen as the end was fixed in front of the P bracket. So we suggested they carry out two types of test when they had the cutters and tank where one end was fixed to the prop blade and it was winding with some resistance around the shaft in front of the prop. Sadly they had not given themselves enough time to even fit the quicKutter as we suggested or carry out different tests.

Perhaps I should refrain from commenting on areas that I have a commercial interest in?

 

[Yngmar]

Zincsmart has been my source of saildrive anodes for several years and they will drill the guide pin hole and machine the lip edges for a modest fee. (I have done it myself but i had a machine shop at work then and it requires a pedestal drill to accurately drill the hole)
Total cost - a fraction of what you can pay elsewhere.

Thanks for that tidbit. Just ordered two machined anodes from Zincsmart for the spares box. Half the price of what Ambassador marine wants. I did try drilling it myself last time but without a drill press the drill wandered off in the soft zinc and left a crooked hole.

 

[Angele]

Thanks for that tidbit. Just ordered two machined anodes from Zincsmart for the spares box. Half the price of what Ambassador marine wants. I did try drilling it myself last time but without a drill press the drill wandered off in the soft zinc and left a crooked hole.

Out of interest, did you do that online or by ringing them? I'd like to buy anodes cheaper than the cost of them direct from Ambassador but, as dunedin says, that is a pretty rubbish website.

 

[Yngmar]

Out of interest, did you do that online or by ringing them? I'd like to buy anodes cheaper than the cost of them direct from Ambassador but, as dunedin says, that is a pretty rubbish website.

Rang them like it says on the site. Payment on receipt of goods, so no risk.

 

[Angele]

Rang them like it says on the site. Payment on receipt of goods, so no risk.

:encouragement:

 

[cagey]

Agree with comments about Zincsmart ,been using them for a while for hull,shaft and pencil anodes, quality and delivery always good only downside is clunky website but prices more than make up for that. Very helpful on phone as well.
K