Topic: Filipino Long Tail boat (Read 48332 times)

vnkiwi · « **Reply #75 on:** July 12, 2014, 01:10:45 pm »

Hi Rich,
better, but the whole tail, is supported on the motor bearings, which will not last long.
The outer propshaft tube, should really be supported by the motor mount, leaving the shaft free to run in the tube bearings.
To say that another way, the motor mount plate and the outer tube (inside which the propshaft runs) should be as one, onto which you mount the motor, and the propshaft then can be inserted into the tube, with a solid coupling to the motor. I'd remove the top plastic bearing from the tube as well.
just my thoughts
cheers
vnkiwi

U-33 · « **Reply #76 on:** July 12, 2014, 02:06:58 pm »

Point taken, VNK...I should have realised that. I'll make up some brass supports, solder them to the prop shaft, and bring them back and attach them to the motor mount plate.

Thanks for that,

Rich

U-33 · « **Reply #77 on:** July 12, 2014, 04:24:31 pm »

Following on from VNK's advice, here's the brass rod which will be eventually soldered together to prevent prop shaft whip. It does need shortening, I'll do that in a bit.

Rich

Neil · « **Reply #78 on:** July 12, 2014, 04:55:53 pm »

good luck rich, old mate.............I hope it works well...........you deserve an A* for thought, concept and effort.

neil.

U-33 · « **Reply #79 on:** July 12, 2014, 05:07:43 pm »

Cheers Neil. It's like me... different.

Ok, I've removed a slice out of the transom to clear the supporting rods and to allow the motor to turn, I've seen full size versions with exactly the same piece removed, so I'm claiming it's a scale job.

Rich

Netleyned · « **Reply #80 on:** July 12, 2014, 05:16:30 pm »

Does the prop shaft have a centre bearing Rich?
Tubes with a centre bearing cut the shaft whip
considerably on long lengths of shaft.

Ned

U-33 · « **Reply #81 on:** July 12, 2014, 05:19:05 pm »

It didn't, Ned...but it has now. I made one from a piece of that ultra slippery plastic stuff(can't remember what it's called now)

Rich

geoff p · « **Reply #82 on:** July 12, 2014, 05:26:38 pm »

Spot on, Rich. Can you raise the pivot a bit higher in the boat? It would give you a lot more steering-type rotation.

You mentioned planking the rear-end - could you mount the pivot on top of that planking. It would be very realistic.

Geoff

Netleyned · « **Reply #83 on:** July 12, 2014, 05:30:13 pm »

PTFE Rich

Ned

U-33 · « **Reply #84 on:** July 12, 2014, 05:30:57 pm »

PTFE...that's the stuff, Ned !!

Possibly Geoff, but it's getting a bit top heavy...mind you, I haven't tried it with the battery in yet.

And yes, I can plank under the pivot, it's only a nut and bolt fixing.

Rich

Jonty · « **Reply #85 on:** July 12, 2014, 10:28:19 pm »

And it wasn't just boats they used drop tanks for...

U-33 · « **Reply #86 on:** July 13, 2014, 12:51:58 pm »

A dry run of the prop tube 'anti flexing system' I came up with at 0300hrs this morning(couldn't sleep...

)

It's all just tacked together at the moment, it will be soldered up properly in a bit...medication is just kicking in, and I'll be fast asleep in a couple of minutes, but it seems to work ok, and the prop shaft angle is about right too.

I'm also going to plank the motor mouting plate, and make up a wooden slatted floor, as I see a lot of the full size ones have like a duck board running the length of the floor.

Rich

derekwarner · « **Reply #87 on:** July 13, 2014, 11:46:41 pm »

Rich....does the triangulation have a larger leg to shaft spacing with the legs toward the top of the motor? ...or than with the legs near the motor base?

Same principal for stability as a tripod......or the wheel nuts on a Renault car ...last reference is for Stavros......Derek

Klunk · « **Reply #88 on:** July 14, 2014, 07:59:47 am »

http://www.dumasproducts.com/product_info.php?products_id=1056

U-33 · « **Reply #89 on:** July 14, 2014, 09:02:04 am »

Close...but no cigar.

Rich

malcolmfrary · « **Reply #90 on:** July 14, 2014, 09:23:03 am »

I suppose if a gondola got one, it would have a Ferrari V6 by the driver?

U-33 · « **Reply #91 on:** July 14, 2014, 10:14:51 am »

This is driving me mad...I have troubles soldering two wires together, let alone great lumps of brass.

I have an idea that I may shorten the prop shaft some, and use a section of brass U shaped channel to support it midway. The shaft I'm using is 9'', so I'm thinking that removing 3'' from it might be an idea. I've seen pictures of full size craft with much shorter shafts and square section steel strengtheners, so if it's good enough for our Thai cousins, it's good enough for me.

Rich

vnkiwi · « **Reply #92 on:** July 14, 2014, 10:42:41 am »

Rich,
think your thinking is more on the right track now.
An interesting build, good luck
cheers
vnkiwi

U-33 · « **Reply #93 on:** July 14, 2014, 10:53:50 am »

Thanks VNK...we shall see if I'm on the right track in a bit when I get the hacksaw out.

Whilst plucking up courage to start cutting the shaft down, I found some coffee stirrers for the duckboard on the floor, just need to trim the ends up.

Rich

U-33 · « **Reply #94 on:** July 14, 2014, 11:43:52 am »

The worst has happened...I sort of felt that the boat may be unstable with the motor that high, so before I went any further with the build, I decided to put it in the bath and see what happened.

It fell over straight away. ''Oh gosh and bother it'' I said...or something similar. The weight of the motor mounted that high is obviously far too much, even with a 7.2v battery pack low down in the hull it still fell over.

So, it's back to square one. Now I'm contemplating converting it into a more conventionally built boat with an inboard mounted motor, conventional prop shaft and rudder. The motor can be hidden under a box, and piles of fishing 'stuff' will hide the rest of the radio gear. Shame, but I've learned a lot from this so far.

Rich

vnkiwi · « **Reply #95 on:** July 14, 2014, 11:54:28 am »

Hi Rich,
Most of the Thai long tails are flat bottomed.
The VN ones I posted, are heavy displacement hulls, and the weight of the long tail is a fraction of the total.
Maybe, and I don't know your displacement, you just need some lead ballast along under the floor boards.
Keep up the good work
cheers
vnkiwi

U-33 · « **Reply #96 on:** July 14, 2014, 12:00:26 pm »

My hull is a styrene moulded one, it's one of two hulls from a small catermeran yacht (Lesro Gemini), round bottomed, 23'' x 3''...maybe I should have started off with something longer/wider/flatter bottomed.

I have had a look round for a replacement, maybe a river steam launch type of thing might be a better alternative. Something like this:
http://www.kingstonmouldings.com/pdvictoriansteam.htm

I don't want to give up on it just yet...

Rich

vnkiwi · « **Reply #97 on:** July 14, 2014, 12:21:04 pm »

your wee hull is only about 400 gms, so not a lot to play with in ballast.
Be interested in what you come up with
cheers
vnkiwi

U-33 · « **Reply #98 on:** July 14, 2014, 12:51:21 pm »

It gets worse...it's just been back in the bath with added lead ballast. I can get it somewhat stable, but it's so low in the water that the waterline is practically level with the stern edge. And that's without any radio, battery, etc. Put it this way...I certainly wouldn't want to take it out on open water.

I think I may abandon this hull, and buy something longer/wider, like the one in the link I posted above, and start again. I thought this may be a learning curve...I didn't realise it would be a vertical learning curve!

Rich

vnkiwi · « **Reply #99 on:** July 14, 2014, 01:04:45 pm »

With some sheet styrene, you could actually construct a flat bottomed hull on the outside of the hull you have, would increase your displacement. Keep the inner hull (the one you have now) intact and you have built in bouyancy, place your components along as you have and you just might have a boat that works
cheers
vnkiwi

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Author Topic: Filipino Long Tail boat (Read 48332 times)