Topic: side thruster idea (Read 7739 times)

portside II · « **on:** February 05, 2009, 01:46:01 pm »

Another build on the floor of the workshop (no room on the bench too many boats) and this time its an oil tanker type .
To give this as much manoverabillity as possible i thought a bowthruster or two would be good , been a tight Yorkshireman i looked at the commercial ones available and then turned away , i also thought of the home made variety by minni steve which are great , but what about clearing obstructions as the tube would be 16" long.
So i decided to make my own ,

not knowing the finished draught of the tanker i did not want to have the exit above the water line so i made an angle cut in the hull side 50mm and the base 100mm ,sanded and fitted sides and top to cover inside ,it looks like a anchor howsing but on the angle below the water line , from this i drilled a hole for the prop shaft and made a wedge for the motor to mount to with an angle to allow the prop to turn freely within the recess . The shaft was then fiberglassed in for a hopefully watertight seal . i have done this on the other side .

Untill i get the rest of the hull watertight i will not know if this is a sucess or a frothy maker, but what do you guys think ??

andrewh · « **Reply #1 on:** February 05, 2009, 02:04:51 pm »

portside,

Looks well carried out and practical - thanks for passing it on.
The water has a bit of a turbulent path to get into the prop - but for this occasional duty we don't need peak efficiency
Maybe bonding in length of aluminium can of the right diameter (having cut a round trough would be another version of your idea)

Yorkshire? Do you have any Scottish blood in you?
and the protruding screwheads could avoid needing to pay FLJ for a sound card!

andrew

Martin (Admin) · « **Reply #2 on:** February 05, 2009, 03:09:02 pm »

Looks great! Can't wait to see the results!

portside II · « **Reply #3 on:** February 05, 2009, 06:25:49 pm »

Err , yes the coupling screws need to be shortened .
daz

Martin (Admin) · « **Reply #4 on:** February 05, 2009, 11:08:09 pm »

Naaa, just use bigger batteries!

catengineman · « **Reply #5 on:** February 07, 2009, 06:56:41 am »

Hi looking at your pictures I see only a small item to bring to mind,

the arrangement may not be very efficient as I don't see a good water flow area to the props, and at that acute angle with such a small "inlet" area you may well have a great coffee frothier but not too good thruster.
This is where the model proves me totally wrong

I find some of the fun of this hobby is doing things that you don't know if they will work and the experts say they don't until you prove them otherwise.

keep us posted..
R,

tobyker · « **Reply #6 on:** February 07, 2009, 11:38:47 pm »

Looks crude but effective (no harm in that) but will produce some drag in fwd motion. I'd bridge the gap at the outside edge of the hull, to protect the props from weed, sticks etc as the hull goes over them. It might also give some direction to the jet. You could of course get a far finer angle if you offset them a bit, ie put one a bit further aft than the other. Remember the Renault 4- different wheelbases each side because the rear torsion bars were about 2" apart!

hopeitfloats · « **Reply #7 on:** February 08, 2009, 08:16:44 am »

i wonder how they would work instead of being at 90 degrees to the hull they were at say 45 degrees and then redirected to 90 degrees. that way there may be a less turbulent area for the intake? just a thought

roycv · « **Reply #8 on:** February 08, 2009, 10:18:49 am »

Hi can I put in my two pennorth?

What about having the props in normal line i.e. not at 90 degrees, at extreme edges of hull.

Then have a sloped intake underneath for smooth water to the prop and the propeller pushing water on to a 45 degree angled part of the hull.

This would push water away at 90 degrees to hull side. giving the side thrust.
just a thought and best of luck, Roy

tigertiger · « **Reply #9 on:** February 08, 2009, 10:24:00 am »

Dumb question.

Would they work better with the water flow in the reverse dirrection.

A bigger patch of water to suck from (the sides), pushed into a smaller channel with the jet exiting the bottom of the boat, so any cappuccino will be less vissible..

grasshopper · « **Reply #10 on:** February 08, 2009, 02:28:39 pm »

Portside,
you are to be congratulated for thinking outside the box and I look forward to the results.

portside II · « **Reply #11 on:** February 08, 2009, 06:38:05 pm »

Thank you lads for your imput , TT the thrusters will work in both directions as i intend to connect them to one esc , i did think of them clogging up with weed, thats why they are open and may still fit guards under the hull and ports on the side mainly to protect the props , the underside of the hull has skids either side to keep the bottom clear and act as keels . Fitting the props at 90 deg may give a better thrust but i don't know as they are normally contained within a tube , i am now waiting for the paint to dry with the weather been so cold it takes longer, and apart from that the pond has been frozen so requires clearing first, we did however have a good afternoon pushing icebergs (not the lettuce type) and trying to beach the boats on the ice

Just above the pusher is a weed rake holding back a massive piece of floating ice .
daz

hopeitfloats · « **Reply #12 on:** February 10, 2009, 05:57:08 am »

portside. i cant wait any longer. please put it in your bath to try it. its an amazingly simple idea if it works and made me wonder why after dozens of sketches of my own trying to simplify standard thrusters i didnt think of it.

portside II · « **Reply #13 on:** February 10, 2009, 02:39:27 pm »

Your more impatient than i am , the paint is still wet (tacky) i dont have a bath and the pond has frozen over again

.
be patient , i have to be

.
daz

hopeitfloats · « **Reply #14 on:** February 11, 2009, 06:16:19 am »

OK

portside II · « **Reply #15 on:** February 26, 2009, 04:24:58 pm »

It's been a while now ,and since the ice has gone and i think the paint has had time to dry i thought it would be a good idea to try the side thrusters .
So today i loaded up the bike trailer and headed off to the pond , once the two halves were in the water i noticed two problems ,
1st i had left the securing bolts at home so found a couple in the club lobby that would do.
2nd there was a small amount of water in the rear section (it had only been in the water about a min)
Back to the thrusters , once i had connected all the wires up and switched the radio on it was time for fun.
with a lean on the radio stick to the left both motors kicked in and ...............YES IT WORK'S

the hull moved off the pond side , ok not the fastest thrust i have seen but there was a side wind counteracting the movement . The motors seemed a bit under powered even on 12 v so i have a couple of faster ones in the shed to try next time maybe without the esc ,just switched on/off .
by this time the water was a couple of inches in the rear section and the main leak was from the lower bolt hole wher the two halves connect so a dry out and get ready for the next trial.
daz

Martin (Admin) · « **Reply #16 on:** February 26, 2009, 05:43:57 pm »

hopeitfloats · « **Reply #17 on:** February 28, 2009, 12:37:01 am »

:-)well done. just goes to show sometimes the simplest ideas are the best.

portside II · « **Reply #18 on:** February 28, 2009, 12:49:57 pm »

I have now up graded the thruster motors and done away with the esc (just switched) ,i am just sorting the water ingress (leak) and then another trial .
daz

portside II · « **Reply #19 on:** April 01, 2009, 11:03:44 pm »

Finally the better weather is here and i have some time to play.
So you all wanted to know if it works ,YES YES YES, well it did brilliantly until one of the wires to the port motor broke off , too much vibration but it works.

this is how i got it to the pond.

and once it was bolted together a quick balast check, this is when i realised the main drive motor was playing up , so i had to make a quick visit home (good job its only down the road) for a replacement motor . I also had to replace the electronise esc with a MTronics one as that was playing up too.
Once all was sorted it was time to play .

I have some video footage of the thruster in action , but you will have to wait for it to upload (my broadband is running at 12kbs), first one is 80mb and after 40 mins i am at 30%

.
daz

portside II · « **Reply #20 on:** April 02, 2009, 02:15:14 pm »

Me back again , after two hours of uploading i have the video's done they are a but ameturish to say the least as all i have is a little camera

And a link to you tube as this one was too big for photobucket and i have not worked out how edit the video's as they are in quicktime, any ideas .
http://www.youtube.com/watch?v=Ex6F47SjLlM

daz

Andy K · « **Reply #21 on:** April 03, 2009, 03:43:53 am »

Nice one Daz, glad to see it worked.
Andy

portside II · « **Reply #22 on:** April 03, 2009, 10:04:54 am »

Thanks Andy , it was plauged with problems most of them brought on by me rushing . the boat was drawing about 3" when it was first in the water but there is still an issue with water leaks , so by the end of the trial the draught was nearer 4" with about a gallon of water in the hull ,but as its so big it was not a problem .
I will give the inside a lick of bitumen once it's dried out and fix the other thruster motor for more trials this weekend .
Apart from that i am pleased with the results unlike the wife who is cossing because of this 8 foot boat on her lawn .
daz

hopeitfloats · « **Reply #23 on:** June 06, 2009, 10:48:25 am »

how did you go with the leaks etc.

portside II · « **Reply #24 on:** June 06, 2009, 04:56:29 pm »

Once i had sealed up the leaks ,with more paint

the thing was fine so no probs there .
As a latest update the hull is laid up at the back of the club shed awaiting dismantleing .
It was only a concept

.
daz

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Author Topic: side thruster idea (Read 7739 times)

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