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[tobyker]

And, further to my last, another disadvantage of the HUCO type UJ is that the plastic bits are a very tight fit on the brass ends, so it is impossible to disassociate shaft end float from motor end float. I suspect a double cup and pinned ball arrangement might be more satisfactory all round -  cups on both the motor shaft and the prop shaft, with a free floating dogbone in the middle.

[Peter Fitness]

  Do belt drives tend to wear the bearings more Peter?

I suppose they would, Martin, but I've never had a bearing fail yet. I guess that's mainly due to the fact that they are only used for an hour or two a week. Also, as Ian said, the tension is light, just enough to stop slippage.

Peter.

[oldiron]

And, further to my last, another disadvantage of the HUCO type UJ is that the plastic bits are a very tight fit on the brass ends, so it is impossible to disassociate shaft end float from motor end float. I suspect a double cup and pinned ball arrangement might be more satisfactory all round -  cups on both the motor shaft and the prop shaft, with a free floating dogbone in the middle.

Like so.......
.......or , one can run the next size larger drill through the hole in the red plastic coupling to allow the freer movement of the brass block in the yoke.

John





Dumas dog bone style coupling with a nylon dog bone


Scratch built

[derekwarner]

Goodness oldiron   ...I knew this was a subject for discussion & that is why I suggested it be put under one tutorial thread

We now have an extra 25 comments from members with their thoughts & experiences...which naturally I respect.......... .

However   ...we still need to sort the fact from fiction or the good from the not so good  in the final washup tutorial......

regards to all ....Derek

[oldiron]

Goodness oldiron   ...I knew this was a subject for discussion & that is why I suggested it be put under one tutorial thread

We now have an extra 25 comments from members with their thoughts & experiences...which naturally I respect.......... .

However   ...we still need to sort the fact from fiction or the good from the not so good  in the final washup tutorial......

regards to all ....Derek

Really started something here. I think we need a moderator to combine both threads. Its getting a little unwieldy with two going on the same subject.

John

[HS93 (RIP)]

 Do belt drives tend to wear the bearings more Peter?

Yes I know you mean the nice peter not me , but I use toothed belts because you don't have to have them as tight, I run stainless steel ball races anyway so no problems with side forces except if you run a motor with bushes just make shore that the bushes are oiled.
peter

[tobyker]

Oldiron - right on, Mate. Happy Christmas and where can I get some?
(I usually "ease" the holes in the UJs too!)
Happy Christmas.
This is a really useful thread addressing a problem common to many of us.

[oldiron]

Oldiron - right on, Mate. Happy Christmas and where can I get some?
(I usually "ease" the holes in the UJs too!)
Happy Christmas.
This is a really useful thread addressing a problem common to many of us.

  Thanks......Merry Christmas your way too.
  I bought the Dumas couplings at my local hobby store. Here's the web site for Dumas:        http://www.dumasproducts.com/index.php?cPath=39_86
  The unit in the other picture I scratch built since I have a lathe. Helps a bit, but not everyone is as lucky.
I'm surprised how wide spread the problem is

John

[Peter Fitness]

To further complicate the issue  , here is a photo of some scratch built couplings I made from brass rod, turned in the lathe, and a short length of speedo cable for flexibility.

They are fitted in my Armidale class patrol boat and work a treat.

Peter.

[irishcarguy]

Very clever design Peter, also John I think your design solves the problem about 95% as well. There would still be a slight friction on the pins I would think, but a very big improvement on what most of us are using today. Who would have thought when this thread started that so many problems existed, How many boats are running with misaligned shafts/motors ?. your writeup is very timely John, certainly needed from reading the posts on here. A question Peter, did you soft solder the speedo cable into the brass couplings,?.Mick B.

[Norseman]

Hey Peter (HS93)

That motor arrangement in your first picture above is really neat and compact - it looks great. 

Dave

[HS93 (RIP)]

I use this method for setting up a mount I have a spare long shaft that has a point turned on the end I fit the piece of metal I am using for a mount  and push the shaft till it Marks the centre for the motor I then drill it etc then re fit and put a small flange on the end of the shaft bring it up to the mount and adjust till the two faces are the same, I also have some flanges the same dia that will fit motors so I fit one and if they line up with no gaps then the motor is spot on , I then put in the normal shaft and fit the coupling, I found this to be the most accurate , bits of tube can be used but if the angle is wrong on the mount it will still tighten up but be out of line when finished.
Peter
this took 5 attempts had to load each part separately picture at a time or I got the normall 504

[Martin (Admin)]

Really started something here. I think we need a moderator to combine both threads. Its getting a little unwieldy with two going on the same subject.

John

We can do that John but when we merge topics, they merge according to the time stamp on each post so it may get quite confusing!

 Martin

[derekwarner]

Hullo Martin & oldiron.........

It may be a little confusing at the first read when the two threads are combined..........but still far better than as two seperate threads.....


However   ..."we still need to sort the fact from fiction  or the good from the not so good  in the final washup tutorial" ...... & we should leave this up to oldiron as he is doing a great job.........

Derek

[Circlip]

But he hasn't mentioned pin and disc or Leather disc couplings - - - -  Yet.


    Regards   Ian.

[Norseman]

Hey Peter (HS93)

Now that last post was worthy of a standalone thread in itself  and having such a
nice clear explanation with the pictures, made it really easy even for me to follow.
From looking at the ply base you must have worked out all the dimensions in advance
so it looks perfectly built rather than just an ad hoc assembly. Any more posts like that
and I just might have to free up a few tired old brain cells to absorb your demonstrations.

Dave

[NFMike]

Hmm. Another hour gone! As is the way of the web, you go looking for answer to A, end up getting answers to B, C and a lot of other stuff you didn't know you wanted to know. (I love looking in tool catalogues - just to see the tools for jobs I never knew needed doing.)

Anyway, back to topic, I have acquired (by default really) Raboesch 'single' universal joints, which having read all the above I will probably convert to doubles. However the splined brass inserts to go to the shafts are not a very tight fit in the couplings. I'm thinking from some of the above that they are meant to allow for the half mm of longitudinal play in the prop shaft (between ahead and astern) and so the motor should be installed with a little bit of clearance between the shaft ends and the coupling parts. Or should one or both of the splines be glued in place?

If I do double them I'm thinking it would be a good idea to glue at least the link insert into the centres of the couplings, to ensure it's a solid shaft there. Opinions?

[old shrimper]

great info

subscribed

[Norseman]

Having started in model boating early this year I joined the forum in August, I ordered parts for my Smit Nederland from Cornwall Model boats. Malcolm sent me the double Huco setup without me asking,(I just told him I needed motors & couplings) so I would assume that he knew that was the correct setup to use, that is double Cardan joints .I am not sure if everyone knows as pointed out by John(oldiron) they MUST be installed in proper alignment ( I wonder John if you could put up a picture of the correct way to install them, thanks) As an aside the guy that really helped with all the rest including wiring diagrams was Dave from ACTion. When I first saw the couplings I was not impressed coming as I do from the auto trade, the couplings did not look up to the task required of them.Lack of a place to lubricate them was the first red light. However as time went on & I saw this was what most of us were using & basically forgot about it until I heard the noise they made, which prompted the question I raised on the forum. Now we have a problem to solve & I have no doubt that we will collectively do so.

Now I love 'a man who can' and Mick (Irishcarguy) is certainly one of those who can 'engineer'. Having been less that satisfied with what he had found on offer he went away and arrived at a solution (not that he has yet finished with all possible improvements yet). I am sure he will reply and explain all, but basically he has taken a constant velocity joint from model car racing and adapted it to usage in a boat. You need to machine the correct shaft diameter and thread when converting but you'd expect that. Mick very kindly made me one for a Tosher I have in mind. I couldn't stop twiddling with it - nice weighty thing compared to the Hucos I have used. I should have posted pix by now but have been extremely busy visiting hospital this week. I have taken a couple on the iPhone and if I can't get them up in the next hour I will email them to Pettyofficernick before I go to work. .... So hopefully pix will appear later this evening.

Dave

[Norseman]

The info ended up at http://www.modelboatmayhem.co.uk/forum/index.php?topic=41338.msg415414#msg415414

Dave