Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Lifeboats => Topic started by: hama on October 26, 2008, 07:04:20 pm
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Hi!
I thought that I for some reason needed a side project to the build of Smit London. I wanted the FSB Tenby when I first saw her, I very much wanted to try a waterjet propelled boat. With limited budget there was one obvious solution, combine the two. :D So, I modified the hull to take the Graupner mini jet. The prop tunnel in the hull was "filled in" to get the waterjet at the right waterline, this also gave me more buoyancy. The bath tub tests were very successful, there seems to be quite some speed in her and the manoeuvrability is superb. She spins on the spot! Now I cant wait for the sea trials! %%
Hama.
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A Brave Man!
Well done mate,looking good ,can't wait to see this go myself.Just wait for the flack from the lifeboat purists (get a hard hat).but in my humble opinion a great idea and keep us up to date!
Kind wishes
Andy.
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Hi Andy and thanks!
Well, brave or stupid. Perhaps I'll get the hard hat on then, and there is always the North sea between us so I think I'll be safe. Will let you know how she runs as soon as I get her in the water, I'm very curious my self.
All the best!
Hama
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Ha,ha, maiden voyage!!
Took her out for the first time today. First tried on a 6v lead battery and to be honest it wasn't a rocket, but boy how fun it was to manoeuvre! Then tried on a 9,6V NiMh battery and off she went, almost like a rocket. Now I need some advise as I'm totally new to "fast" electrics. The motor is the supplied graupner speed 400 6-7,2V, so I can't use the 9,6V battery without damageing the motor right? On 6V she was to slow to be any fun. I could get a 7,2V battery which I think would give me a descent speed. I could also change motor to a speed 500 or 600 cause thats what the mini-jet is designed for. I think I rather have moderate speed and long run time than "warp speed" and short run time. Any ideas anyone?
Here are some pics from the test runs.
Hama.
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hama - that's fun and impressive - thanks for posting it :}
<<The motor is the supplied graupner speed 400 6-7,2V, so I can't use the 9,6V battery without damageing the motor right?>>
Oh yes you can :}. This seems to be the marine version of a Ducted Fan, where you need revs, revs and more revs to get any excitement. The voltage on a "Speed" motor is really a code about the winding wire and resistance, not a restriction on voltage. (It is more like a middle voltage for medium (aircraft) propellors)
I'm not sure which S400 you have, the S400 6V is different to the S4007.2V.
You can run either of them on 9.6 V or more AS LONG AS YOU LET THEM REV HIGH, and keep the Amps below 10! (in other works keep the loads low)
There is another thing - this is a simple motor, and if you run it at high speed or close to 10A it has a limited life. I'm not sure how boaters feel about this, but before the days of brushless motors hard flyers sometimes would change them after 5 flights, in the extreme case. Having said that, I have never cooked a S400 despite running a S400 6V at 12V in a ducted fan.
Before thinking of a bigger motor, try more voltage
after that you could go to a S480 motor - similar size, longer case, more speed, or an inrunner brushless suitable for EDF use as S480 replacement.
More volts and more photos please
andrew
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Hi Andrew!
Thanks for the answer, really appreciate it. :-)) Great news on the voltage! I'll try again with the 9,6V battery then which is great as I have the battery and charger already. Next thing to find out is run time, she can take the load of two of these battery's with no problem.( I used an old battery for ballast on the trials ) If it works OK I guess I could get a second battery and put them in parallel. And as you state, it's not the end of the world IF the motor should break. I hear what you say, keep the revs up! O0
Cheers!
Hama.
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Hi,
A new member here from the other side of the pond (USA).
If you do decide to change motors I would suggest a Graupner Speed 600 to go with this Graupner Mini Jet Drive. Next year I plan to build the American Enterprise by Dumas. It will be powered by two Graupner Mini Jet Drives(#2349) connected to Graupner Speed 600 9.6V motors(#1786). These motors can supposedly handle up to 12V and 17 Amps. Battery will be a 3 cell Lipo to keep the weight down.
You might want to look into a motor like this for your boat.
Regards,
Richard
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Hi Richard, and welcome to the forum!
Thanks for the advise, I'll keep that in mind. I'll try to get some colour and details on her soon and then do some more test driving. That is if there isn't any ice soon! I guess I will be tempted to try a 600 motor sometime in the future, even though I think she has good enough speed as is. Please be sure to show your American Enterprise build here, sounds very interesting.
Cheers!
Hama.
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Hi again!
I've started on the railings. They are made of brassrod. Once I got started it's very fun to solder this together. I use a small gas burner as my solderingiron didn't do the job. I'm quite pleased with the results so far as it's the first time I build up the railings like this. I use a little artistic freedom on the design as I've already deviated from the original when I put the jet propulsion on her.
Hama
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Hi again!
Some more railings, next will be the mast I think. This is fun!! I've learned so much.
Hama
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Nice job on the railings hama, and the boat looks good too. With the extra volts it will really look the part (maybe the full size chaps might take notice with the jet drive) :-))
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Thanks Steamboatphil!
I must say that they look a bit better on the pics than in real life, but thats OK. Like I said, I'm quite happy with them and it's a real joy making them. I thought I'd hate making them.
Merry Christmas!
Hama.
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Mast! :-)
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A little more...
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coming along nicely, keep up the good work and keep the pictures coming :-))
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Thanks! I'm afraid the shipyard will close during Christmas though, or? %)
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Actually got some more done before Christmas. Cut out the windows, made up a protective bar for the waterjet. One is made of ABS and the other of brass. Haven't decided which one to use yet.
Hama.
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Some very nice and tidy brasswork there
Mark
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Thankyou Mark!
Got some more work done this evening, made the davits and screwed on the waterjet protection. Painting is getting closer!
Hama.
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Made a mess of the plastic tube for the towingbar in the stern. {:-{ Didn't manage to bend it or glue it so I made it out of brass tube instead. Better stop soon before I sink the boat though, after all it's supposed to rescue others in distress. :embarrassed:
Hama
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Almost done!
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Hi again!
Found some open water at the beach for a test run with "colours". A bit difficult to take the photos as you drive though. Regret I didn't bring the Dicky tug as well because there was perfect modelboat ice to break!
Hama.
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Happy with the speed?
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Hi there Martin!
Yes, I think so. Unfortunately it was a badly executed testrun as I had almost no batteries in the transmitter so I lost the signal all the time. I have two battery packs in her, one is for ballast only at the moment. Will do further tests later and figure out the best battery solution for speed and endurance. I'm having major problems with my internet at the moment, I'm being kicked out all the time.
Have a nice weekend!!
Hama.
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Some more details added...
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That's a nice we model. Interesting concept (jet propulsion).
I'm a firm believer that life boats are made for choppy water. Whats the highest wave you have sailed her in? How was the stability?
Thanks for answering.
Mark
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Hi there Mark, and thanks for your interest in my model!
Well, I intend to test her in heavier weather when she is completed. I need to find a way to fasten the superstructure and also make sure that no water can enter the hull that way. I think she would perform better in high seas with props, but I'll have to find out what shes capable of later. I will post pictures when time comes. As for heavy weather, I have a bad habit of putting my boats through some nasty weather so this one will most likely meet the same destiny! I have some threads here on the subject, one is called "Rough weather" I think.
All the best! ( BTW, what is we/wee model? I've seen it here sometimes and I guess it's a not so detailed/semi scale boat? Or?)
Hama.
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Wee is a Scottish word for small, nothing to do with detail.
I forgot to ask, what's the beam?
Regards
Mark
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Hamma,
But be careful if you use "wee" as it also is a colloquial/childish word for urine!
Roger in France
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OK, thanks a lot both of you! :-)) Well, better be careful then because you don't want to get them mixed up! You know, even if I believe I understand most of what you're all saying I'm totally lost on the fine lines and details sometimes but you help me to improve! OK, so this wee boat is about 17cm wide. She seems quite stable but time will tell. She will definitely drift away in the wind, that I have noticed already.
All the best!
Hama
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10/10 hama wd
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You are too kind, thanks a lot!
Hama.
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I need to find a way to fasten the superstructure and also make sure that no water can enter the hull that way.
Hi Hama,
Sorry if you already know this and have discounted the idea.
One option is high coamings. I have also used clear plastic for part of my coamings where there is window.
See reply #16 http://www.modelboatmayhem.co.uk/forum/index.php?topic=2716.0
And then attach a hook(s) to the inside of the superstructure, and an eye(s) to the inside of the hull near the keel.
Next attach a big rubber band(s) to the eyes(s), when you put the superstructure on attach the other end of the band to the hook(s).
This will hold down the 'lid' snugly.
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Hello tigertiger!
I have thought of raising the existing coaming, and the rubberband thing would probably work perfect. It would pull the superstructure firmly on place, I shall think about that. The kit supplied a pair of clips that should work with a modification for the raised coaming, but I think I like your idea with the rubberband better. I also have a pair of magnets but I think it might be tricky to get them in correct position horizontally to each other, rubberband solution again seems superior. I'll see what I come up with, thanks for the advice!
Hama.
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OK, now I've made a raised coaming. Next will be securing device for the superstructure and the battery pack. Then I can test her in her right environment!
Hama.
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Update! Made a box in the hull for the battery, superstructure secured with two small strong magnets. Took her for a test ride with new battery, lot more power! To quick for me to capture as you can see on the pictures. Guess my old 9,6V battery was tired of age or something. Still have to figure out how to arrange the ballast. Used no other ballast than the battery this time and she is fast and seems very stable, but I think I maybe got her a little bit stern heavy. Will try that out on a warmer and sunnier day. Unfortunately after about 15 mins drive the motor got loose from the motor mount. I have modified it to take a smaller motor than the jet drive is designed for and obviously I made it to week. I'll see if I can get to the motor and fix it tonight. Please forgive me for the poor pictures but I wanted to give you some idea of how she looked today!
Hama.
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Looking good Hama! :-))
(Video clip too next time please!!)
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Looks real fast!
I still want to hear how it goes in ruff water, easier to say when it's not your own boat.
Mark
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Hello and thanks!
Martin, I've tried to use the video function on my cameraphone but it doesn't look good. You can hardly see what it is jumping around on the water. I promise to try and take better pictures though, as soon as I have her running again. I have managed to remove the old motormount so I'll see if I can make a new improved one tonight.
Mark47, I promise to try her out in the real stuff but I will take it gradually. Must say that I feel confident after todays run in some choppy water, I think she will do fine in wind and waves. The waterjet offcourse loses water when she jumps on the waves, but I guess even props would if you drive to fast!
All the best!
Hama.
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:-)) Looking forward to the report.
Mark
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Hi again!
Well, she is up and running again. Added a little ballast to the bow as a test. I gave up trying to take pictures of her, to fast to me to both control and use camera. Only orange stripes on the screen! I did shot two short videos though. I managed to get them in my computer via Adobe photoshop?. How can I show them to you here? I also have something called Windows media player and Real player, perhaps one of those is better? Can someone please help me here, I don't have a clue.
Hama.
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Windows media player and realplayer will only show videos on your computer,upload to youtube then you can share
Mark
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Hello Mark!
Youtube you say, is that the only option! I'll have to think of that. One thing to show it to you guys, a bit scary to show the whole world! :o Anyway, thanks for your help! :-))
Hama.
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Up load to photobucket then paste the link on the thread and we get to see the vid's :-)) :-))
there are other jobbies on the net for the same thing but I use the above
R,
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(http://i566.photobucket.com/albums/ss110/hama-01/Jet%20Tenby/th_MOV01229.jpg) (http://s566.photobucket.com/albums/ss110/hama-01/Jet%20Tenby/?action=view¤t=MOV01229.flv)(http://i566.photobucket.com/albums/ss110/hama-01/Jet%20Tenby/th_MOV01228.jpg) (http://s566.photobucket.com/albums/ss110/hama-01/Jet%20Tenby/?action=view¤t=MOV01228.flv)
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Is this the right way to do it??? {:-{
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(http://i566.photobucket.com/albums/ss110/hama-01/Jet%20Tenby/th_MOV01229.jpg) (http://s566.photobucket.com/albums/ss110/hama-01/Jet%20Tenby/?action=view¤t=MOV01229.flv)(http://i566.photobucket.com/albums/ss110/hama-01/Jet%20Tenby/th_MOV01228.jpg) (http://s566.photobucket.com/albums/ss110/hama-01/Jet%20Tenby/?action=view¤t=MOV01228.flv)
That's really maneuverable with the jet, nearly turning in her length.
How far away were you sailing her from you in the video?
Now to see her smashing through waves. The reason I want to see this is because I'm thinking of getting my son one to sail in loch Lomand, so it needs to handle waves from 6" (light breeze) to 18" (if a private cruiser passes to close to shore).
Mark
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Wow, this was so much fun! A shallow beach with small breaking waves, she handled perfect. A real lifeboat! I got a camera for my birthday in February and its so much faster than my cellphone was, so now you can actually see whats on the pictures. Next time perhaps I can make a video as well. I'm still experimenting a little with the ballast, but I think it's OK now. She felt very safe and no water at all inside! Hope you enjoy!
Hama.
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Wow, this was so much fun! A shallow beach with small breaking waves, she handled perfect. A real lifeboat! I got a camera for my birthday in February and its so much faster than my cellphone was, so now you can actually see whats on the pictures. Next time perhaps I can make a video as well. I'm still experimenting a little with the ballast, but I think it's OK now. She felt very safe and no water at all inside! Hope you enjoy!
Hama.
:-)) :-)) :-)) :-)) :-)) :-)) :-)) :-)) :-)) :-)) :-)) :-)) :-)) :-)) :-))
That's what I like to see!
It makes sailing a lot more interesting, learning the skills to sale in rough water. Negotiating breakers, ridding waves, increasing and decreasing throttle to keep control.
That's what lifeboats do in real life, that's what the models should do. O0 O0 O0 O0 I find it much more pleasurable to sale in these conditions, rather than going round in circles throttling up and down.
Great job on a fine craft. O0
Looking forward to seeing a video in these conditions.
Many thanks for an interesting topic.
Mark
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Hi Mark47!
Thanks for your kind words! Yes, this was great. One good thing about being on a beach is that should something fail, you just have to wait for the boat to wash up! Have a really nice weekend!
Hama.
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Hi Mark47!
Thanks for your kind words! Yes, this was great. One good thing about being on a beach is that should something fail, you just have to wait for the boat to wash up! Have a really nice weekend!
Hama.
Thanks. Hopfuly be working on the Trent this weekend O0 O0
Mark
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looks great fun, and the model looks great to!
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Thanks dantheman! It was fun, I will certainly do it again! Perhaps I can have someone to drive the boat for me so I can take better pictures, or someone to take pictures so I can drive the boat better cause it's quite difficult to do both! Have a nice weekend!
Hama.
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Hello!
Done some more testing and found out a few things. The shaft started to leak a little water and it squirted on the steering servo, the servo didn't like that and went nuts. Let it dry out and then put a protective sheet over the shaft so thats fine now. After a little longer drive period than I've done before I took up the boat and lifted off the superstructure just to find white smoke coming out!! I thought something had started burning, it turned out to be the overheated motor!! I was afraid it should melt loose from its mount, but it was OK. I guess I'll have to install some kind of cooling to it. Also did some testing with homemade trimtabs made from scrap plastic. I think she goes better with her nose down a bit. So, the progress continues! Here are some pictures, hope you don't mind.
Best regards.
Hama.
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Some short videos, the "foggy" one is with trimtabs added.
Hama.<embed width="448" height="361" type="application/x-shockwave-flash" wmode="transparent" src="http://s566.photobucket.com/flash/player.swf?file=http://vid566.photobucket.com/albums/ss110/hama-01/MOV00157.flv"></embed><embed width="448" height="361" type="application/x-shockwave-flash" wmode="transparent" src="http://s566.photobucket.com/flash/player.swf?file=http://vid566.photobucket.com/albums/ss110/hama-01/MOV00190.flv"></embed><embed width="448" height="361" type="application/x-shockwave-flash" wmode="transparent" src="http://s566.photobucket.com/flash/player.swf?file=http://vid566.photobucket.com/albums/ss110/hama-01/MOV00194.flv"></embed>
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Hama, can you please tell me more about the kit? Who makes it, size, and where I might order one? What scale does it work out to?
Thanks in advance for any information you can provide.
An excellent job on building her by the way...I'm insanely jealous of your skills.
Cap'n Jack>>>>sends
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Hi there Captain Jack!
Thank you for your kind words. This kit is from Model Slipway so if you check out there site you will find all you need to know. It is a simple kit aimed for beginners I think, it contains all you need to finish it including one motor, rudder and propshaft. I'd say it is semi scaled at 1:32 and supposed to simulate a Tamar class lifeboat. I think the hull is based on another class of lifeboats, The Trent class, but the end result can be very close to a Tamar if you want to. Check out the image gallery on Model Slipways site. They have the same kit with the Trent boat as well, called "Small rescue boat" I think. I have seen some people that put two motors and shafts in her as the original, but I choose to rebuild her with waterjet, just for the fun of it, and i don't regret it. All in all, a great kit for the money! Hope this helps, and good luck!
Hama.
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Thanks for the reply, sir. I have two of the Graupner mini-jets powering my American Enterprise conversion, and am very happy with them. I am considering building a Tenby for my next kit. I live on the Gulf of Mexico, and want something to play with in the surf.
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Hi Captain Jack!
American Enterprise you say, have you showed her to us? Would be very interesting to see her perform. What motors do you use, SPEED 500? I've gone for the smaller 400 motor that came with the kit but if I don't manage to install a cooling system I might have to change. Do you have water leaking from the shaft sealing on your Mini Jet? I didn't have problem with this at first but I suspect that the shaft is rusting inside the rubber seal and perhaps the surface roughness on the shaft makes it leak. It's not a big issue though, just a teaspoon or two after a run. I try to grease it every now and then but it's a bit fiddly to get the shaft out.
Hama.
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No videos of her underway, but a few pics of the heavily modified kit here:
http://s238.photobucket.com/albums/ff33/road_hard72/American%20Enterprise/?start=0
There are also pics of the real vessel as she looks today. After an exhaustive search of over a year, I literally found her almost in my own back yard by chance.
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Wow!! :o
What a cool boat, looks fantastic. Please put her in the water!
Hama.
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I had planned to sail her this weekend, but a class on anti-terrorism tactics got in the way.
At any rate, the weather here turned out to be attrocious. Tornadoes, flooding, the whole ball of wax.
I'll see what I can do for next weekend. If I had not been otherwise engaged, I could have sailed her in the roadway right in front of my house.
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Oh boy, what a mess. Hope everything improves for the better soon. Even if it would be nice to have a pond outside your frontdoor!
Hama.
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Don't envy you the weather. Last time I was in Texas there was a drought and we couldn't sail a 1:1 boat because the launch crane couldn't reach the water it was so low. :((
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Hi Hama,
I noticed that you're using trim tabs. I don't know about the Graupner jets, but most of the 1:1 real ones are angled downward by 3-5 degrees to counter the bow lifting. So it's not just a model problem.
Tony
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Hi Tony!
Thanks for that information. I think this jet drive is pretty much 90 degr to the inlet/bottom. Part of the problem is my rebuild of the hull bottom, that I think puts the outlet in a small angle upwards. Its not a big problem, more about how she looks on full speed. I think it looks better when shes a little bit more horizontal, and it felt like she was a little bit faster with trimtabs. It could be wishful thinking. I've just installed a small fan for ventilation. Found a cooling coil on internet that suites 400 motors, perhaps I'll go for it. The trimtabs I found searching the net were to big so I think I'll have to make my own.
All the best!
Hama.
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I finally got to test the cooling that I built in to her. I made a pick up from the jet nozzle so when the motor starts the circulation starts. There is a cooling block that I bought attached to the motor. Tested in the bath tub and it works! I also built a lubricating device, a small container with oil feeds the shaft, seems to keep the water out. Time will tell if it works. Will try to test her out in the water soon.
Hama
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Some more pics. I bought some self adhesive letters and named her -99, hopefully they wont build so many Tamar's! Unfortunately they only had black letters so i had to paint them white on the hull sides. I'm afraid I got them to far forward on the hull sides, if I cant stand it I'll have to do it all over. Also a pic of the small fan and the in/outlets. The fan has a nozzle on the inside thats pointed towards the motor.
All the best.
Hama.
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Hello again.
Took her for a short testrun today, both cooling of the motor and sealing of the shaft seem to work. Time will tell if it works in the long run. I really like the little fan, will definitely install some kind of ventilation in my future boats. Made some windscreen wipers the other night and put on some more letters just because it was fun. :-)
Hama.
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bumping slightly...
Tempting to try twin jets
%%
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This boat looks to handle very good.
Nice to see someone do something different.
How big is the boat and what is the weight ?
I too have a jet drive and i like the idea of doing this
BUT if it goes wrong then ill have a big hole in my boat.
Big decision to cut up a nice boat
phill :-)
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come on, we need more vids of this little boat
its real good to watch it go along so well
phill :-))
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Sorry I haven't answered earlier, I missed your replies somehow. Thanks for your interest in my little boat, unfortunately she's been stripped of her speedcontrol at the moment. Was thinking about testing a 12V battery next time, the need for speed you know! It's a great boat and the jet is really fun with it's superb manoeuvrability. I saw that Graupner has released a Pilot boat with two minijets, that should be fun!
I'll let you know next time I put her on the water, but right now a big tug is taking up my time! ( fingers crossed SHE will hit the water this spring )
All the best
Hama.