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. A newbyprop weight

Old 12-23-2005, 05:53 AM
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Default . A newbyprop weight

Hi folks! A newbie here so please be patient. I'm building a 1/8 scale miss bud hydro. Where on the net, can I get info on prop weight?

THX

Norm
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Old 12-23-2005, 07:19 AM
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Default RE: . A newbyprop weight

Two words that you just typed scared me, newbie and hydro. I hope that you're not new to boating as a hydro isn't a good first choice for a complete new boater.
To answer your question, I've never seen anywhere a place that shows the weight of a prop. It generally doesn't do much good as when you're dne sharpening and balancing a prop it will be much lighter depending on how much was removed in the process.
Old 12-23-2005, 11:39 AM
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Default RE: . A newbyprop weight

Ron, there is another definition of prop weight. He may be refering to the weight of the back of the boat that the prop needs to lift to get to a "good" running attitude. If that's the case, chinslip, you need to be around 1.5 pounds when you balance the boat on the rear of the sponsons. I do have some questions for you chinslip:
1) Is this your very first boat?
2) Which Budweiser are you working on and if scratch building, who did you get the plans from?
3) Do you have a CLUB OR EXPERIENCED BOATERS in your area?
I'll explain why I ask after I see your answers
Old 12-23-2005, 12:36 PM
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Default RE: . A newbyprop weight

I got to thinking after posting if that was what he was referring to. I had first heard of that term over a year or so ago on another site. Before that, I had never thought about it but I wasn't messing with hydro's at that time either.
Old 12-23-2005, 04:08 PM
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Default RE: . A newbyprop weight

Bingo hydro junkie. That's exactly what I was referring to. When I called myself a newbie, I was referring being new to the site. This is my 2nd hydro built from R. Newton's plans. The first one was 8 yrs ago and let me tell all you guys...newbie and hydro don't mix!!! I'll admit that much. I had the plans blown up 1 1/2 times to 66" long. That would not have been so bad, had the boat been kept at a reasonable weight. It was a turd. I basically sold it to a kid down the street that liked the look. This one will be researched fully before starting construction. This is why I'm asking about prop weight. Anyone who scratch builds a hydro will know what prop weight is before starting. By the way 1.5 lbs seems light!!!!! Then again my first boat was way heavy...so 1.5 could be right. What I was hoping for was a % based on the total weight of the boat including engine.

I live in northern Canada and there is no one anywhere near that knows anything about r/c boating. This boat will not be raced competitively and will not follow any club racing regulations. I am building this boat for fun at the cottage. I do have one requirement however...it must be fast!!!! This is why I'd like to drop in a .90 OPS engine. No rules to follow...no rules broken. This is a 1994 Bud hydro...T3 I believe. I've been a machinist for 20 yrs and familiar with details and precision. The mistake I did with the 1st boat was, I didn't know how far to take details and precision. This is why I'm asking questions. Prop weight is the first of many question. Weight saving will be another. The plans call for 1/16 ply throughout the construction including the skin. However I would love to hear what you (more experienced builders) have to tell me regarding lightness and strength? I've read about "lite-ply" being super light vs regular aircraft ply. What do you use? Micro balloons, Epoxylite for fillets? West systems epoxy for sealing the wood?

I'd like to build a symmetrical boat ...no rules to follow...no rules broken. It would turn equally good left or right. The rudder will be directly behind the prop. Anything you can add will be taken very seriously towards construction.

That's it for now.
THX
Old 12-24-2005, 08:49 AM
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Default RE: . A newbyprop weight

Do you plan to put on two turn fins, 1 left and one right? It might make it turn both ways good, but what about extra drag, and the affect each fin would have on each other while turning?
Old 12-24-2005, 10:55 AM
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Default RE: . A newbyprop weight

Yes 2 turn fins. Extra drag?... maybe so, but with a big honkin' engine...I'm not too worried about drag. I think that the fin on the outside of the turn might make that side want to lift thus making the one on the inside bite a bit more. Does this make sense? What can you suggest in terms of weight savings?

THX
Old 12-24-2005, 09:35 PM
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Default RE: . A newbyprop weight

FORGET TURNING BOTH WAYS AND DROPPING IN A 90!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1) First off, dual turn fins only make the boat likely to flip in a turn. The boat is designed to slide through a corner, not turn on rails, hense the dihedral on the left sponson and anhedral on the right. The left side skid fin will upset the balance of the boat, not let it turn both ways
2) STAY AWAY FROM LITE PLY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Lite ply is basically balsa with a 1/64th birch veneer. IT WILL NOT HOLD UP TO BOAT USE If you build the boat PER THE PLANS it will weigh out in the 12 to 16 pound range and be plenty fast
3) Don't use a .90. You will still be in the 100 KPH+ range with the .67, not to mention much richer. The .90 will only make the boat unstable and prone to blowing over by pushing it beyond the speeds the boat was designed to run at
4) Leave the rudder offset behind the left engine bay side. You will get better rudder response due to less pushrod flex by pulling the pushrod rather than pushing.
5) Be sure you use a 100 inch ounce or stronger servo for the rudder. Anything lighter will self destruct
6) The 1.5 pounds is the optimum weight on the prop. Any lighter, the prop won't stay in the water enough to get a good bite. Any heavier and the prop won't be able to lift the transom. Having said that, you have to remember that all boats are diferent. A little more or less weight may be better, but it will take experimentation to find out
Old 12-24-2005, 09:51 PM
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Default RE: . A newbyprop weight

Let me show you something.
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Old 12-24-2005, 10:27 PM
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Default RE: . A newbyprop weight

Picture 1(top left)...The Pico is running at over 100 KPH with a 8 to 10 meter rooster tail
Picture 2...............Notice the amount of water coming off the skid fins. A skid fin on the other side would only lift this sides out of the water and probably flip the boat
Picture 3...............Notice, two people involved with starting the boat, the guy with the starter(right) and the kid with the transmitter(background). The kid actually drives this boat and was a rookie(at the time), while the guy starting it is a 10+ year vet and spotter for the boy. The boy's father is the guy on the left, waiting to launch the boat
Picture 4...............Launching a boat with a throw start. These things don't start really well from just placing them in the water. They will usually die from an overloaded engine. You will also note that these guys DO NOT have the transmitters with them. The transmitters are with the driver, on the drivers stand(out of the pic to the camera's right).
Picture 5...............Note the boat stands. This club REQUIRES a stand that totally encloses the prop for safety. I have never seen anyone hurt by a spinning prop in the pits
Picture 6...............Again, note the stand. Also, see how crowded this boat is with only the .67? The lay out is (bow to transom) the radio box, the engine, the tuned pipe, a silencer. If you look closely, you can see the twin fuel tanks under the left deck aft of the engine
ALL PICTURES.......Every one of these boats was built from Roger Newton plans
As for how much I know about 1/8th scale hydros, and hydros in general, I was involved in rebuilding the full size 1951 Slo-Mo-Shun V, the 1960 Miss Thriftway and have worked on the 1957 Breathless 2. For R/C hydros, over the years I've had around 20 boats, ranging from 30" .20 kits to 62" G26 powered scratch builts. I've been a member of R/C Unlimiteds(the largest 1/8th scale hydro club in the United States) for at least 10 years and known Roger Newton personally for over 20 years, including working under him on the Slo-Mo-Shun V and Breathless 2(he was the crew chief). Any Questions?
Old 12-25-2005, 08:31 PM
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Default RE: . A newbyprop weight

THX hydro junkie...that's the kind of info I was looking for. I really appreciate it. Where do you get your hardware...rudder prop and shaft and that stuff? What about he canopy? Better to build from scratch or buy new in hopes of saving a few onces or lbs? And the cockpit where do I start with this? Ohhh and the uprights and horz. wing....(ok Norm take a breath) Do you guys buy all this stuff or do you all build from scratch? I was thinking of buying those build videos from Mock. Any opinions on this? What is your input on getting the boat blown up to 50" and putting in a bigger engine? The boat might be a little more stable at speeds. But that blows out the idea of buying any finishing parts like canopies and stuff like that!!! You know that I don't have to follow any race rules?

THX for now
Old 12-26-2005, 02:32 AM
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Default RE: . A newbyprop weight

Where do I start............................................. .
Hardware: I have several sources that I use. A Jensen Marine Strut for starters, custom rudder bracket by a machinist friend of mine, and Prather/Octura/Prop Shop for props. Haven't found a good source for skid fin brackets yet to meet what I want for my boats, though Aeromarine makes good stuff, among many manufacturers.
Cowling/Vertcal Tails/Rear Wing/Turbine Exhaust Pipe: All my fiberglass parts I've gotten from an R/C Unlimiteds member who makes them.
Don Mock Videos: Never seen them, though I've known him almost as long as I've known Roger Newton. I've seen the boat he built in that video run, very competitive. I have heard through others that he uses other materials in this video besides wood, but that's just heresay.
Enlarging the Plans/Boat: Not recommended for a beginner, WHICH YOU ARE. Takes more wood, custom added framing, and all scratch built parts. Stay with the 1/8th scale boat with the .67. A larger boat is hard to launch for one person, requires a larger engine, requires a larger fuel load. Net result= more cost and hassle for a little speed gain(been there done that. Let me show you another pic. This one is a 1/6th scale of a late 1950's round nose. It's 60" long, 24" wide and powered by a Zenoah 230. So far, this boat hasnt gotten much past 60KPH
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