Metalastik coupling, large GU motors?

[Timleech]

Well if Tim Leech wants to get three, I'll definitely have one.

 

Although Trelleborg do not list it in their marine product range.

 

If Tim (Lewis) still has the details, I'll ask them what they can do.

 

Tim

[NB Esk]

It's often said that ordinary vehicle prop-shaft UJs shouldn't be used to carry thrust. In practice so long as they are generously sized and not working through a large angle it's not a problem. Unfortunately, 'not working through a large angle' can shorten their life as the needles in the UJ bearings then don't get moved around enough so you can't win Use good big ones, grease them regularly & they'll last for years

 

The point about taking thrust elsewhere than the gearbox is a very valid one, some gearboxes don't like it, Parsons used to specifically refer to it in their manuals.

 

Tim

 

Hi Tim, glad I followed this thread before installing my own setup.

 

What I was proposing, was a *plummer type* bearing, between the stuffing box & the propshaft flange, to take the thrust. I was then going to make up my own cardan shaft arrangement, whilst retaining the original vehicle sliding spline. The idea being that this will make fitting/dismantling easier & allow for any slight variation (for whatever reason) in driveline length.

 

It'll be a trad setup, vintage engine with a prm g/box.

Will this work, or have I missed something? Cheers...

[Timleech]

Hi Tim, glad I followed this thread before installing my own setup.

 

What I was proposing, was a *plummer type* bearing, between the stuffing box & the propshaft flange, to take the thrust. I was then going to make up my own cardan shaft arrangement, whilst retaining the original vehicle sliding spline. The idea being that this will make fitting/dismantling easier & allow for any slight variation (for whatever reason) in driveline length.

 

It'll be a trad setup, vintage engine with a prm g/box.

Will this work, or have I missed something? Cheers...

 

It should do, seen it done that way but if you're extending the splined cardan shaft the parts will need to be well aligned. I would check with PRM first that their box is OK with no thrust. I think most modern boxes are.

As I've said already, make sure your UJs are ample, maybe a size bigger than you would expect.

 

Tim

[NB Esk]

It should do, seen it done that way but if you're extending the splined cardan shaft the parts will need to be well aligned. I would check with PRM first that their box is OK with no thrust. I think most modern boxes are.

As I've said already, make sure your UJs are ample, maybe a size bigger than you would expect.

 

Tim

 

Thanks Tim, I work with trucks.....so you can imagine the setup...

[Chris Pink]

If Tim (Lewis) still has the details, I'll ask them what they can do.

 

Tim

 

Would assume it to be these geezers;

 

Customer Contact Centre

Trelleborg Industrial AVS

Westpoint, 4 Redheugs Rigg

South Gyle, Edinburgh

EH12 9DQ UK

tel: +44 131 338 6115

fax: +44 131 338 6712

industrialavs@trelleborg.com

 

unless someone else has the rights to this specific part.

[Timleech]

Would assume it to be these geezers;

 

Customer Contact Centre

Trelleborg Industrial AVS

Westpoint, 4 Redheugs Rigg

South Gyle, Edinburgh

EH12 9DQ UK

tel: +44 131 338 6115

fax: +44 131 338 6712

industrialavs@trelleborg.com

 

unless someone else has the rights to this specific part.

 

I was hoping Tim Lewis might be able to dig up some part-specific details, much easier than starting from scratch

 

Ta

Tim

[Tim Lewis]

I was hoping Tim Lewis might be able to dig up some part-specific details, much easier than starting from scratch

 

Ta

Tim

 

Still wending my way home from the Black Country Museum Working Boat Gathering - will try and find details when I get home tonight.

 

Tim

[madcat]

Sounds like Halsalls in which case I would be interested in a spare,better photograph the thing and see if it is the same.Havent learnt how to post photos on forums yet but may manage to work it out in which case I will put it on here.Wont be able to get to Hawne till next weekend though.

[Steve Priest]

Whenever we rebush a sterntube and replace the tailshaft we come up against this problem. When we come to re-instal the shafting we often find the engine is well out of alignment. I don't think that they were too fussy when the boats were built, let alone after several engine replacements. My reccommendation is that we fit a cardan shaft as part of the job. At least then the costs can be assessed properly, rather than spending an inordinate amout of time re-aligning the whole set up. I don't think that metalastic couplings can accommodate anything but a slight misalignment, nothing like the amount that we often encounter.

 

I would normally use a 3.5'' diameter tube with fixed 15/10 series ends (6'' flange diameter), and instal a carrier bearing on the tailshaft, just behind the coupling, mounted on an angle welded to the swim. Thrust is still transmitted to the gearbox. As has been said, if you relieve the gearbox of thrust you may need to replace the gearbox output thrust bearing, as they will fail, depending on the box.

 

As Tim Leech says, thoeretically the uj's are not designed to take thrust, and cardan shafts work best at a degree of deflection that is hard to achieve went installed in a boat where the shafting is close to being straight anyway, but having worked for years with camping boats with propshafts salvaged from scrapyards, doing 20 - 30 weeks work per season, with no problem, it does work in practice.

 

There have been problems with cardan shafts drumming and transmitting noise from the tube/prop, and gearbox, but recent Volvo research have dealt with this by lining the tube with - cardboard tubing!

 

Hence in a roundabout way I do have some used metalastic couplings spare

[Derek R.]

Cardboard? - Cheapskates! I'd thought of drilling a small hole in each end of the tube, and squirting expanding filler in. Wait for it to ooze out the other end, trim when set, fill, sand and paint.

 

I agree the cross-heads need some movement to get the needles working, and for all I know there probably is some, but greased often enough, and the occasional disconnect for a waggle around should see them out live me. Not like they are under the stresses that a lorry would take.

 

Derek

[Timleech]

Cardboard? - Cheapskates! I'd thought of drilling a small hole in each end of the tube, and squirting expanding filler in. Wait for it to ooze out the other end, trim when set, fill, sand and paint.

 

 

Derek

 

You'll probably need 2-pack foam for that to work reliably. The aerosol type from builders' merchants needs moisture to set it off, so if you're going to try that at least spray a bit of water in through your holes before the foam.

 

Tim

[Derek R.]

Morning - Ta, good point.

 

Derek

[Timleech]

For Fulbourne we obtained new Metalastik couplings from Robush. The minimum order quantity was 4, and they took about 3 months to arrive. The cost for 4 (in 2003) was £308.

 

David

 

Thankyou.

 

Have you any record of the 'official' description?

 

Cheers

Tim

[Tim Lewis]

Yes it was Fulbourne, we had to get them direct from the manufacturer. I think we had to get three (minimum order) and they were on something like a six week delivery.

 

we still have one spare but after we shredded another one last year we would be loathe to give it up.

 

Tim

 

 

As a matter of interest the below is a picture of our metallastik coupling arangement:

 

 

Tim

[madcat]

Woke this thread up because having been and looked at mine and took its picture I then got to thinking how old it might be and how long it might last .Then I got to thinking what might happen if it failed on me and then I started to worry.

Any other Town people out there who have experience of these things,any body else going to post a photo of theirs..

Edited October 7, 2009 by madcat

[Chris Pink]

Woke this thread up because having been and looked at mine and took its picture I then got to thinking how old it might be and how long it might last .Then I got to thinking what might happen if it failed on me and then I started to worry.

Any other Town people out there who have experience of these things,any body else going to post a photo of theirs..

 

I just took mine off to get the prop shaft out, I'll take some pictures if you like but not now 'cos it's pissing down.

[Tim Lewis]

Woke this thread up because having been and looked at mine and took its picture I then got to thinking how old it might be and how long it might last .Then I got to thinking what might happen if it failed on me and then I started to worry.

Any other Town people out there who have experience of these things,any body else going to post a photo of theirs..

 

A couple more pictures of an occaision when we had to remove ours

 

http://www.pbase.com/timlewis/mending_boat

 

Tim (Leech) - haven't forgotten you but we cannot find a record of the part number and the spare is on the boat which isn't local at the moment.

 

Tim

[madcat]

Tim interesting photos,I looked at the ballast photos as well .A very cunning plan.What were the bits of metal before they were "Fulbourned". Hope to catch up with you at a rally somewhere for a good chat.

[furnessvale]

What were the bits of metal before they were "Fulbourned".

 

I can see railway baseplates for flat bottomed rail held down by Pandrol clips with elastic spikes from baseplate to sleeper:-)

 

George ex nb Alton retired (now tug Sandbach out of retirement)

[Tim Lewis]

Tim interesting photos,I looked at the ballast photos as well .A very cunning plan.What were the bits of metal before they were "Fulbourned". Hope to catch up with you at a rally somewhere for a good chat.

 

Assuming that you are referring to the hold ballast (as shown here) the steel came via Mann & Buck from somewhere in the Black Country, looking at the sections we thought that some of it was destined to be used as the fork bits of fork lift trucks!

 

Tim

Edited October 7, 2009 by Tim Lewis

[madcat]

Hi Tim ,yes it was that I was on about,Iam currently on the hunt for more suitable ballast that I can put under the back cabin floor and in front of the engine.It needs to be neat to stash,dense and not heavier than I can lift on my own.I can lift quite big bits of metal if I need to.Yours looks handy for hiding out of the way but at the moment I rely on the blue plastic drums full of water to put weight in the hold.

Hi George,look foreward to catching up with you sometime.Good Luck with Sandbach

[Tim Lewis]

Woke this thread up because having been and looked at mine and took its picture I then got to thinking how old it might be and how long it might last .Then I got to thinking what might happen if it failed on me and then I started to worry.

Any other Town people out there who have experience of these things,any body else going to post a photo of theirs..

 

Was looking for some unrelated pictures this evening when I came across some pictures of the Metallastik coupling we broke in 2003.

 

http://www.facebook.com/album.php?aid=1296...mp;l=dc1f1c22a5

 

Tim

Edited October 8, 2009 by Tim Lewis

[madcat]

Thank you Tim, I have to admit I have just taken the thing for granted but maybe now... How did yours fail,just broke one day or were external forces invoved like a biggish bit of wood getting jammed in the prop?

Will have to be getting sorted on the spares front.

[mick110]

Thank you Tim, I have to admit I have just taken the thing for granted but maybe now... How did yours fail,just broke one day or were external forces invoved like a biggish bit of wood getting jammed in the prop?

Will have to be getting sorted on the spares front.

......sorry to butt in !...IMO it would seem to be a case of a tear started by a sudden prop foulage which then ,once weakened,turned into a fatigue failure?

[madcat]

Wondered if there was any history with it,cause and effect. Things dont always die instantly do they but sometimes they do.The rip is interesting [alarming],only had a quick look at it,had to look away I was breaking out in a cold sweat.Thanks Mick for your suggestion, I think maybe ye olde coupling will have to go on the "keep an eye on it list" especially after an incident with floating debris. As I have admitted previously I have been guilty of taking that coupling for granted till this thread started.

Also on the hunt for spares now