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I also found that 1 of the 5 blades was much thicker at the outer end, making it way out of balance.
Had to use the belt sander there.
We're havin' Fun Now! :)
Had to use the belt sander there.
We're havin' Fun Now! :)
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Rick L.
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* Asking Questions is a 'Good Thing',
Since Learning is Always a 'Good Thing' * -
I've been looking at the gear-ratio question again and now I think a lower ratio may be better with that very light weight aluminum prop. 2.4 is better for a heavier brass version, which needs more torque, but I'm thinking about first trying a 1.95 ratio, which I have. With those very flat blades, a higher RPM may be better for acceleration.
I'm not trying for speed but I want acceleration for fast dynamic dives and surface.
I didn't realize how light weight it is before.Last edited by toppack; 07-02-2009, 01:35 PM.Rick L.
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* Asking Questions is a 'Good Thing',
Since Learning is Always a 'Good Thing' *Comment
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It's pitch and diameter that decides the RPM the prop should run at, not the density of the material it's made from.
The gear reduction sounds far too low to me for your choice of motor and a prop of that size.
Also bear in mind that the Disney Nautilius has some handling quirks that don't endear it towards high speed running. They cheated in the film.Comment
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Light weight props spin up faster and easier, so don't require as much torque as a prop made of a heavier material, of same size and pitch. Weight of prop greatly effects acceleration load on motor also.
I learned that when changing aluminum and wood props on experimental-aircraft, boat props have similar effect.
As I said, I'm not after Speed, only Acceleration, so I need to get the prop up to high RPM faster. That's why I'm using an aluminum one, not the brass version.
I'll probably try both ratios to see if there's any difference. Changing them is easy with this design.Last edited by toppack; 07-03-2009, 09:23 AM.Rick L.
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* Asking Questions is a 'Good Thing',
Since Learning is Always a 'Good Thing' *Comment
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I will second the wizards remark.Comment
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Rick,
What you need to do is stop posting so much and BUILD SOMETHING. And show us your work. That's what gets my attention.
Plans, schemes and expectations are one thing. Accomplishment is another.
Post when you have something interesting to say, that's how I handle myself.
David,Who is John Galt?Comment
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David,
This section of the forum is called 'Builders Treads'.
That's where builders like me talk about our project, ideas we have, and ask questions about it. Hopefully someone like me will offer a friendly suggestion or interesting comment in reply.
That's what I've always tried to do.
Please let this post last until David read it.Rick L.
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* Asking Questions is a 'Good Thing',
Since Learning is Always a 'Good Thing' *Comment
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There was progress on the Prop project until you told me to Stop,
I don't understand what was wrong with what I was doing, which was posting Info, problems and ideas on the new prop and replying to others comments. Not only a new prop to me but new to the Sub hobby.
I'd still appreciate an answer in the T-class thread, if possible?Last edited by toppack; 07-04-2009, 11:51 AM.Rick L.
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* Asking Questions is a 'Good Thing',
Since Learning is Always a 'Good Thing' *Comment
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Yes, I posted pics of it, as it was received, in a previous post (#43), where I said that I now had it.
It's sanded, drilled and balanced now.Last edited by toppack; 07-04-2009, 12:25 PM.Rick L.
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* Asking Questions is a 'Good Thing',
Since Learning is Always a 'Good Thing' *Comment
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I just wanted to add my own two cents, as I have seen the various posts in multiple threads on many other forums about this boat-in-progress.
First off, questions are good! I was a newbie once, and I asked all manner of crazy questions (maybe Dave remembers that?). The one thing that I have learned after years of building is that it is very easy to overanalyze an issue. Many times problems that you see are nothing of the sort, just small bumps or non-issues.
The biggest thing that I can say is that if you get stuck on the details, you miss the big picture. I have seen too many projects that die because the builders get bogged down in details, lose momentum, and finally lose interest. I've snatched up tons of half-started projects like that, and seen many more pass through the subswap forums of many sites.
I think you'll build a great boat, based on what I've seen of your WTC. Post up some pics of your hacked up hull and let's go from there! There's nothing you can do to that sub that can't be fixed. Believe me, I know!
BobComment
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