thai boat plans needed..

[Frosty]

I think I talked to you last Sunday. Your is the shop with one with the Arneson in the window? opposite the hard stand.

[HakimKlunker]

Yes. That is right You see: it is a small internet world. Unfortunately this does not bring our friend closer to his lines plan

[Peter VE]

I am involved with WaterFire, a cultural/art installation in Providence, RI. http://www.waterfire.org/about-waterfire/welcome
We have several small Pangas, donated to us, which we use to take guests amongst the fires. The largest of these can only take 4 guests. I have a plan (fantasy?) to build a slightly larger version to carry six people, over this winter, scaling up from the 4 seater. I will post pix, as we move forward.

[HakimKlunker]

Hi Peter,
just as a suggestion: there are many ceremonial boats and also racing longboats around here and in Malaysia with often rich decoration. Perhaps this can inspire the artist aspect. I am more of a sober artisan ...

[tomac]

Originally Posted by Frosty

They use wood bearings,even on big trawlers with shafts of 6 inch or more lumps of wood sat soaking in big smelly tanks are removed and fitted into a 4 jaw chuck and turned down.

I asked the guy how long the bearing would last ,--he said 3 years.

Thats 3 years trawling most days.

Hi Frosty, I wonder where the thrust bearing is situated on the longtail shaft.
It seams to me that the shaft i connected directly to the gearbox. What part is taking the axial thrust force?

//Tomas

[HakimKlunker]

Hello. Although I am not 'Frosty', I can maybe contribute a little here:

If you have no thrust bearing, the load goes via the engine into the mounts and from there to the engine carrier and further to the hull skin.
That means that you need strong engine mounts (!) and the flexible type will not do here. As a result, vibrations go straight into the body.
But the major disadvantage is, that the prop thrust loads all bearings in this 'chain' (gearbox, engine and whatever else) and so they wear much faster than wanted.
A thrust bearing usually is mounted inside quite close to where the shaft comes through the hull. The bearing is carried by a convenient construction (can be integrated in the hull, hull liner, stringer or else).
So the rest of the drive train is free of load. If you have space left, you can think of a flexible coupling: This reduces vibration and also compensates mis-alignment of a certain degree.
Practical hint: When you have mounted the engine, let it rest for a while - especially new rubber bearings will settle under compression.
After the boat is launched, you should check the alignment again; hulls are a little flexible and in the water you have different conditions than on the hard stand.

[tomac]

Originally Posted by HakimKlunker

Hello. Although I am not 'Frosty', I can maybe contribute a little here:

If you have no thrust bearing, the load goes via the engine into the mounts and from there to the engine carrier and further to the hull skin.
That means that you need strong engine mounts (!) and the flexible type will not do here. As a result, vibrations go straight into the body.
But the major disadvantage is, that the prop thrust loads all bearings in this 'chain' (gearbox, engine and whatever else) and so they wear much faster than wanted.
A thrust bearing usually is mounted inside quite close to where the shaft comes through the hull. The bearing is carried by a convenient construction (can be integrated in the hull, hull liner, stringer or else).
So the rest of the drive train is free of load. If you have space left, you can think of a flexible coupling: This reduces vibration and also compensates mis-alignment of a certain degree.
Practical hint: When you have mounted the engine, let it rest for a while - especially new rubber bearings will settle under compression.
After the boat is launched, you should check the alignment again; hulls are a little flexible and in the water you have different conditions than on the hard stand.

Thanks for the answer. Do you know if there i any manufacturer i thailand able to send parts for longtail, props, shaft, etc to Europa ?
I find one called SPS on the web, maybe there is more options?
//Tomas

[Frosty]

Hold your horses here, the shaft is not connected straight to the back of the engine, It has a reduction chain drive, where the thrust is taken up? I have no idea.

Thais dont worry about vibration, they have special elbows and no teeth.

[Wetracer]

Hello all, is there any up date info on this thread. I want to get one of these water taxi's to use on the river here in my town (Oregon USA) to give tours in. Any help would be appreciated. Thanks. Mike

[HakimKlunker]

I know a Malaysian producer of these boats. Quite cheap and reasonable quality.
Or do you intend to make the boat/s yourself?

[brian eiland]

I think I have some more photos of close-ups of a few of these drive line variations. I'll try to find some time to post them. If I remember correctly most of these long tail shafts connect directly the the engine/gearbox or to a chain/bearing system mounted to a plate that is attached to the engine. So its the engine mounting system that ultimately transfers the thrust loads to the vessel.

BTW, these are pretty rudimentary drives that could be fashioned quite easily by most 'back yard' amateur shops.


PS: Have you looked thru some of those photos that both Frosty and I provided? In particular look at posting #41

[HakimKlunker]

Brian, I have the impression that all these drivers were made in some backyard. Built, from what was found behind the backyard.
Thinking of safety requirements in the old world (let us include the USA here) it will perhaps be difficult to get a license or certification?

[HakimKlunker]

Sawadee kap also from me.
Just as Frosty said: the local way of making boats is simply to make them No offense, but in a culture where until 'recently' boat builders and similar could not even read, it makes little sense to draw plans. And so the younger ones learned it from the 'old cracks' - skills were (and are ) forwarded on the job. Jay Dee's offer is very friendly. I can support you with details in scantlings and dimensions if you like, or when you get stuck somewhere.
If possible, I would like to see the drawings, too: Would like to find differences or similarities of the Malaysian small fishing boats. Of course, I will return this favour with own contribution, too

[brian eiland]

Quote:

Originally Posted by Originally Posted by Frosty

They use wood bearings,even on big trawlers with shafts of 6 inch or more lumps of wood sat soaking in big smelly tanks are removed and fitted into a 4 jaw chuck and turned down.

Originally Posted by tomac

Hi Frosty, I wonder where the thrust bearing is situated on the longtail shaft.
It seams to me that the shaft i connected directly to the gearbox. What part is taking the axial thrust force?

It really is quite amazing how well some of these old simple bearing technologies worked. Certainly workboats with big props and lower RPM shafts help with those wood bearings.

Thrust bearings can be a different matter. I'm doing some research on belt and chain driven outdrive legs (C and Z configurations), and along the way I'm discovering some surprises in the amount of attention give to this thrust subject. All to often it appears as many marine drive lines do not appear to provide really adequate bearing surface areas over which to allow the trust loads to be applied. This can result in very significant load density on thrust surfaces.

[HakimKlunker]

There are excellent products available.
Often it is the customers who request low purchase prices. That leads to less 'solid' constructions.
On the other hand: Most boats and their equipment last quite long compared to other modern products.
Most of us may make friends to buy a 15 year old boat, but a 15 year old car would be much out of discussion.