tag:blogger.com,1999:blog-903444638046674243.post3067337433058754881..comments2023-10-23T19:46:33.401+01:00Comments on nb Lucky Duck: Day Twenty-Six- Worse things happen at sea. Apparently.Amyhttp://www.blogger.com/profile/13190832458135017656noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-903444638046674243.post-82472822068829885882008-08-28T21:24:00.000+01:002008-08-28T21:24:00.000+01:00James said: "At the moment, there's an oil seal w...James said: "At the moment, there's an oil seal which, whilst it isn't being used to seal the shaft, is I think acting as a bearing of some sort, as it's securely bolted to the sides of the swim. However, the prop moves in and out if it's levered (with a mooring pin in one of the holes) which suggests that there isn't a flange or anything bolted to the shaft to transmit the forces."<BR/><BR/>This is the slightly rusty thing on the left, yes? It's difficult to see, but that could be a thrust bearing. If the it is, and the shaft moves freely through it, that may well be the problem. What's breaking your grubscrews is not the rotational forces, its the propeller pulling the whole boat backwards using those screws. Can you look very carefully at the "oil seal" and see if theres any way to lock an inner, rotating part to the shaft.<BR/><BR/>It might be better to take this to email: simon@thekelleys.org.ukAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-903444638046674243.post-58477492148637526632008-08-28T19:43:00.000+01:002008-08-28T19:43:00.000+01:00The coupling and oil seal, btw, are visible here:h...The coupling and oil seal, btw, are visible here:<BR/><BR/>http://3.bp.blogspot.com/_FXLjgqnOPag/SLRnccrnIBI/AAAAAAAAAYM/LHk_sYgbLCI/s400/24082008928.jpgJameshttps://www.blogger.com/profile/16646174143519854448noreply@blogger.comtag:blogger.com,1999:blog-903444638046674243.post-5427561716094315452008-08-28T19:41:00.000+01:002008-08-28T19:41:00.000+01:00At the moment, there's an oil seal which, whilst i...At the moment, there's an oil seal which, whilst it isn't being used to seal the shaft, is I think acting as a bearing of some sort, as it's securely bolted to the sides of the swim. However, the prop moves in and out if it's levered (with a mooring pin in one of the holes) which suggests that there isn't a flange or anything bolted to the shaft to transmit the forces.<BR/><BR/>The coupling itself is, I think, a Flexidrive (I think that's the brand name) with a big spun aluminium housing and a brass cone inside it.<BR/><BR/>Jim suggested a possible fix- my uncle has offered to machine us a new propshaft, so we could have it extra long and bolt it directly to the gearbox, dispensing with the flexible coupling for now until we can afford a new one, or get the old one apart and fit it.<BR/><BR/>At the moment, the coupling is bodged with the grub screws; three little ones to transmit 40 h.p. or so just isn't working. They will hopefully hold until we can get to Bill Fen, where we can attend to it properly and make a proper repair.<BR/><BR/>BTW, we're hoping to be in Uxbridge on Sunday with Jim and Sarah, so perhaps we'll see you there!Jameshttps://www.blogger.com/profile/16646174143519854448noreply@blogger.comtag:blogger.com,1999:blog-903444638046674243.post-25111508836636413542008-08-28T18:52:00.000+01:002008-08-28T18:52:00.000+01:00Does your propshaft have a thrust bearing? In case...Does your propshaft have a thrust bearing? In case you don't know, spinning the prop pushes (or pulls, in reverse) the prop and shaft. There has to be some way to transfer that force to the rest of the boat. <BR/><BR/>In installations with solid propshafts (ie no coupling) the force is transfered to the back of the gearbox, and there is a thrust bearing there. I know that at least some sorts of flexible couplings don't cope with thrust, and there has to be a separate thrust bearing bolted to the hull and to the prop shaft between the prop and the coupling. <BR/><BR/>If your coupling is that sort, and the bearing has been omitted, that could explain everything: going into reverse is pulling the prop-shaft out of the fixings in the coupling which are intended to transmit rotation, but not pushing and pulling forces.<BR/><BR/>So, it's worth looking and checking to see if your coupling needs a thrust block: something like this:<BR/>https://simplybearings.co.uk/shop/i/ucp_200.jpgAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-903444638046674243.post-44620430393256658832008-08-28T10:44:00.000+01:002008-08-28T10:44:00.000+01:00We were thinking just the same - that it would be ...We were thinking just the same - that it would be good to go to Bill Fen and get it out of the water. Loads of people there who would be keen to help (some more productively than others) and John himself of course with his wealth of experience and workshop full of parts. We're staying in Little Venice today, leaving for Uxbridge tomorrow morning, so if you need picking up let us know before tonight; otherwise we'll see you in Uxbridge at the weekend...<BR/><BR/>Never fear Moominpapa, Warrior will get the Duck there somehow!Shttps://www.blogger.com/profile/14207397235093098621noreply@blogger.comtag:blogger.com,1999:blog-903444638046674243.post-81883618314232428992008-08-28T09:41:00.000+01:002008-08-28T09:41:00.000+01:00If you need to machine the end of the prop-shaft, ...If you need to machine the end of the prop-shaft, you will probably need to remove it from the boat, which means coming out of the water (unless you're _very_ brave!) In that case bear in mind that the boat-crade/slipway at Bill Fen is much cheaper than craning: the prices are on the website. If you talk to John Shotbolt in advance he may be able to organise the machining too. Of course this implies making it up the GU and down the Nene first. I don't know how possible that is.....<BR/><BR/>MPAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-903444638046674243.post-14267153514671460762008-08-27T23:40:00.000+01:002008-08-27T23:40:00.000+01:00Did you get our email before about getting in touc...Did you get our email before about getting in touch? Steve says he'd need to see it, but even perhaps talking to him may be a help. If you are going to be where you are for a while we could speed up to try and get there if there's a possibility we could help. We'd still be a good two weeks getting there though. Give us a ring.Steve and Clairehttps://www.blogger.com/profile/14036563146190483777noreply@blogger.com