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BobS  
#1 Posted : 01 January 2019 00:17:17(UTC)
Rank: Member

Posts: 21
Location: Kirkcudbright

I wonder if it is inevitable that a Strongarm winch axle will seize on the drum due to the winch design. Unlubricated steel on steel in a marine environment, left unused for some months over the winter will presumably corrode and seize at some point. It certainly seems to be an ongoing issue in the forum and happened to my 285 Teal earlier this season. There was a horrible grinding noise on trying to lower the keel and oval slots on the housing appeared where the axle had chewed away the frame.

The repair, carried out by two fellow members of our sailing club involved removing drum and axle, making steel plates with half inch central holes and welding them onto the frame to take the new axle. The new axle was made from a stainless steel bar, cut to length with circlip on the clutch side and a D shape machined on the other end, so that a removable plate can be bolted alongside the new bearing plate to stop rotation. A modification suggested by Alistair, a marine engineer, was to drill a hole half way through the length of the axle shaft, drill another hole at right angles to meet it, etch a shallow depression on either side of the mid shaft hole and finally fit a grease nipple to the shaft end. (Photos available)

The winch now works again and I have been diligently pumping marine grease down the shaft, so with the grease and stainless steel axle, I am hoping that is the problem solved.

I presume I could have removed the drum and original axle to check and lubricate it as part of pre-launch maintainance, but hindsight is wonderful!

Ken Surplice  
#2 Posted : 07 January 2019 21:52:20(UTC)
Rank: Advanced Member

Posts: 212
Location: Basingstoke, Hampshire

Hi Bob, great write up, thank you. I know another engineering-minded association member has applied similar treatment. This has given me confidence to return, gradually, to an electric winch. It will be my third!

Ken

Ken Surplice
Martin Watson  
#3 Posted : 08 January 2019 12:27:31(UTC)
Rank: Advanced Member

Posts: 70
Location: West Sussex

I don't know if Peter Scrivens subscribes to the forum, but he has sorted out the problem for at least one of our members. I believe he uses Oilite bearings ( a sort of oil infused sintered bronze) and a stainless replacement shaft.

Although originally fitted with only a manual winch keel lift system on my Parker 27, I fitted a homemade hydraulic lift system which has worked well these last two years. It comprises a 400mm stroke hydraulic ram placed vertically along side the keel box in the fore cabin. Attached to the ram which is pointing upwards, i created a hanger for two Barton 3 series blocks. at the bottom, the ram sits on a stainless cage which has two more Barton 3 series blocks and an attachment eye for an 8mm Dyneema lifting strop. the other end of the strop passes through two turning blocks up near the coachroof top, so that the strop passes through the side of the keel box and attaches to the keel about 150mm down from the top of the keel. I therefore have effectively a 1:4 reverse purchase, ie when the ram travels 400 mm, the keel moves 1600mm. the hydraulic pump with built in reservoir is positioned in the void under the cockpit wherein also lives my start battery and Eberspacher, there being a reasonable amount of space which cannot be utilised for much else.

The keel is raised and lowered by a momentary action on-off-on switch located in the start panel housing. It takes 40 seconds to raise and about 35 seconds to lower, and for single handing is an absolute boon. To hide the hydraulic ram, I made a 1/4" teak faced ply housing with teak corner moulding, it is approximately 4" x 4". you would think it had always been there, it is so unobtrusive and blends in well with the teak faced bulkhead that it sits against. I had to get the small infill cushion modified to fit around it, but everything else I made myself, including the 5mm thick stainless hanger and cage which I then got my local stainless steel fabricator to weld together for me. If I recall the total cost of the installation was under £500, the most expensive part being the hydraulic pump which I think was £185 from a company called Hydra Products, who are also exceedingly helpful. If you tell them what you are trying to achieve, they will put together a pump to fulfil your requirements. My pump draws about 1/2 amp to raise and about a 1/4 amp to lower so power consumption is very reasonable. When running, the pump draws a maximum of 27 amps but you are using it fo less than a minute at a time. To deliver that amperage, the switch activates a double relay which I bought new on Ebay from a company that makes them in the USA, I think it was £36.

I was originally going to fit two limit switches but eventually found that I only needed a limit switch on the raising side, you can hear the keel hitting the bottom when lowering and also the note of the pump changes, the lifting side needs a limit, as the actual keel lift is a total of 1570mm so you need to stop it from travelling the full 1600mm which the the 1:4 purchase on a 400mm ram will achieve. Rams seem to only come in 50mm increments so the next smallest would have been a 350mm ram which would not have been long enough(1400mm @ 1:4)

The keel on a Parker 27 weighs about 200Kgs so the ram is effectively moving 800Kgs (1:4 ratio) but if my school era physics is correct, the pulley blocks are each only carrying 200Kgs and are sized accordingly. For a Parker 275/285, I believe the keel is 400kgs so bigger blocks and a more powerful hydraulic pump will be required (the next size up for both items as I recall when I researched it for a friend). The ram is capable of lifting about 2 tons or more, so is fine.

Edited by user 08 January 2019 12:34:54(UTC)  | Reason: spelling correction

Martin Watson
Peter Scrivens  
#4 Posted : 09 January 2019 23:45:20(UTC)
Rank: Member

Posts: 10

It is surprising that there are no proper bearings between the steel shaft and steel drum and no easy means of lubricating them. So the important thing to do, while the winch is still working, is to regularly squirt a grease from an aerosol into the gap between the drum and the shaft, hopeing capilliary action will get the solvent containing grease to lubricate the shaft before the solvent evaporates leaving the grease behind! These spray cans are readily available from motor accessory stores and preferably the grease should be waterproof (silicone or similar). Those with dry lubricants (PTFE) are not so good. Once the shaft has seized it is a devil of a job to free it and then it chews it's way through the side plates until the teeth are no longer in contact.

The other problem is that salt water is brought up with the cable and then this runs along the drum and corrodes the teeth building up rust which puts further strain on the gears. So again it is important to regularly apply a good waterproof grease to the teeth on the drum and primary shaft. The reduction gears from the motor to the primary shaft are well engineered and so it is surprising that the winch has this inherent weakness in it's design.

When the winch is working it provides a luxury to be able to raise and lower the keel at will, unfortunately the price for this is that it does require regular maintenance to keep the winch working and it is not just a leave and forget to the start of the season. A seized shaft can be repaired but as previously mentioned it is lot of work

Peter (Zephyr)

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