Aussie Flying Saucer

Outboard designs up to 14'

Moderator: ttownshaw

polarisman14
Posts: 223
Joined: Tue Oct 04, 2011 7:04 am

Re: Aussie Flying Saucer

Postby polarisman14 » Sun Aug 17, 2014 4:16 pm

That boat looks awesome. Your progress was really staggering over a short period of time. I probably asked this already, but any tips or tricks on the fairing? Once I get past that my next hangup will be the butt-to-lap-joint transition toward the bow and that should be about it.

I'm at my wits' end with my Chrysler 35hp and our boats are the same exact size and should be similar hull weight. Good to know I should be able to hit 30+mph with a new 30hp outboard--if I can get the Honda with remote controls I may go that route as the short shaft is ~150lbs and I wouldn't have to modify the transom. Just need to figure out how to come up with $5,000USD to do that if that's the case.

I'm interested to see what you can get out of it once it's fully broken in--planning on playing with any different props? Keep in mind trimming up and decreasing the wetted surface of the hull will up your top speed albeit at sacrificing the ride quality. Pulling the trim tabs off will make it more difficult to get on plane but creates less drag in the water which should help your top speed a bit too. I'm willing to bet you'd be able to hit 35mph with the right prop and right trim setting, by yourself.

miyot
Posts: 55
Joined: Tue Jul 22, 2014 10:23 pm
Location: WV

Re: Aussie Flying Saucer

Postby miyot » Sun Aug 17, 2014 5:29 pm

Your boat is a beauty. A couple of questions. Are your trim tabs adjustable or are they always pushing down. I have read about the gas filled tabs that always apply pressure downwards, sort of self adjusting to your speed. I'm considering these for my boat and wondered if you like their performance?
Dave

Mojo
Posts: 141
Joined: Tue Jun 11, 2013 2:56 am

Re: Aussie Flying Saucer

Postby Mojo » Mon Aug 18, 2014 1:21 am

I didn't use any fancy techniques for fairing. I think I started by fairing the chines at each of the frame locations. I then went by eye and also used a sheet of ply about 8" wide x the span between the keel and chine. The craftsmen will shudder, but thickened epoxy can always be your friend when it comes time to gluing on the planks.

Swapping props becomes an expensive game to play. I'm not sure finding an extra mile or 2 is worth the cost to me. I'll keep trying to optimise the setup I have and see how I feel when I get to the end of that road.

I've used 30lbs Smart Tabs. They are like a spring loaded tab that point down 25 degrees when not under load. The idea is the water pressure raises them as the boat gets up to speed. This must cause additional drag at top speed. You can adjust the load settings, but not while moving. From the small amount of experience I've had with them I think they are good for keeping the boat level across the speed range and reducing fuel usage at lower speeds. I think they will also be handy when I dump a couple of passengers in the back. I'll give a more detailed report once I've got the boat a bit more sorted.

Cheers
Mojo

miyot
Posts: 55
Joined: Tue Jul 22, 2014 10:23 pm
Location: WV

Re: Aussie Flying Saucer

Postby miyot » Mon Aug 18, 2014 7:26 am

polarisman14 wrote:That boat looks awesome. Your progress was really staggering over a short period of time. I probably asked this already, but any tips or tricks on the fairing? Once I get past that my next hangup will be the butt-to-lap-joint transition toward the bow and that should be about it.

I'm at my wits' end with my Chrysler 35hp and our boats are the same exact size and should be similar hull weight. Good to know I should be able to hit 30+mph with a new 30hp outboard--if I can get the Honda with remote controls I may go that route as the short shaft is ~150lbs and I wouldn't have to modify the transom. Just need to figure out how to come up with $5,000USD to do that if that's the case.

I'm interested to see what you can get out of it once it's fully broken in--planning on playing with any different props? Keep in mind trimming up and decreasing the wetted surface of the hull will up your top speed albeit at sacrificing the ride quality. Pulling the trim tabs off will make it more difficult to get on plane but creates less drag in the water which should help your top speed a bit too. I'm willing to bet you'd be able to hit 35mph with the right prop and right trim setting, by yourself.


Not to jump on Mojos thread but I have a couple of tips on fairing that have helped me some. A lot of times the inexperienced or new to fairing needs to look at his tools. They must be sharp, and sharpened often during the fairing process. I'll take a lot off with the electric planer, but you must be careful and sure to stop before you take to much. Then switching to a Jack plane, block plane or my favorite for small boats a spoke shave.

Your tools have to be like a razor. After finishing a strip of end grain plywood perhaps 3 to 4ft long its time to sharpen the blade. End grain ply really takes the edge off your tools. Watch planing a crown into your bevels. They need to be flat. This is one of my problems due to inexperience. Check your angles often and take a break now and then. Funny how some problems begin to appear, walk away and take a break, come back later and you work it out.

Bevel your irons to the proper angle and keep them sharp. Perhaps 5 minutes to touch them up often rather than let them get dull, making you struggle and fight during fairing and then spending a half hour trying to get them sharp again.
Dave

User avatar
Andy Garrett
Posts: 1275
Joined: Tue Aug 31, 2010 11:44 pm
Location: Nampa, Idaho

Re: Aussie Flying Saucer

Postby Andy Garrett » Mon Aug 18, 2014 8:25 am

Looks great!

I VERY interested in more details about the Smart Tabs. I have an uninstalled set with 60lb pistons for my Zip. I have not put them on because I think they should be lighter like yours.
Andy Garrett

Perhaps the slowest Zip build in Glen-L history...

Flash
Posts: 80
Joined: Mon Feb 03, 2014 10:56 pm
Location: Eagan, MN

Re: Aussie Flying Saucer

Postby Flash » Sun Aug 31, 2014 9:21 pm

Hi Mojo,

Your boat is beautiful. Should we assume that you will tie it up better from now on?

What are you building next?

Take care,
Flash
Yellow Submarine II - Flying Saucer
Summer Wind - Zip

Mojo
Posts: 141
Joined: Tue Jun 11, 2013 2:56 am

Re: Aussie Flying Saucer

Postby Mojo » Tue Sep 02, 2014 2:03 am

Not sure what the next project will be. I do have a mate who has just bought an old 16ft timber clinker ski boat with a Ford V8 engine. The hull is worn out and needs a lot of work. Not sure if he will keep the hull or get something else to use the engine in. So, I guess my next project will be helping him. It's much cheaper having someone else pay the bills.

Cheers
Mojo

Mojo
Posts: 141
Joined: Tue Jun 11, 2013 2:56 am

Re: Aussie Flying Saucer

Postby Mojo » Sun Nov 23, 2014 11:21 pm

I've had a win!
I've managed to resolve the porpoising issue. I flipped the boat and refaired the aft 3ft of the bottom. Most of it was good, but the last 6inches needed some filling. I added up to a 1/4" in places. The boat now rides beautifully. I still have the smart tabs, but keep them up unless I have passengers in the back. With passengers in the rear they help for getting on the plane at lower speeds. It's a good feeling when you can solve an issue.

Whilst upside down I also took the skeg off as I thought I could get better cornering performance changing to a fin. I haven't put the fin on yet, but went for a run without anything. It actually tracks much better then I expected. Does slide a little bit in the turns, but can still turn reasonably tight and maintains speed through the turn. The skeg used to disturb the water to the prop during a turn and it would cavitate, not anymore.

Top speed is sitting around 33mph.

Cheers
Mojo

User avatar
jenko
Posts: 796
Joined: Sat Mar 19, 2011 2:50 am
Location: Pine Mountain . Vic . Australia
Contact:

Re: Aussie Flying Saucer

Postby jenko » Sun Nov 23, 2014 11:28 pm

good news :D and interesting info about the skeg

Flash
Posts: 80
Joined: Mon Feb 03, 2014 10:56 pm
Location: Eagan, MN

Re: Aussie Flying Saucer

Postby Flash » Mon Nov 24, 2014 12:50 am

Congratulations Mojo!

That is a great solution to an aggravating problem. You will probably help a lot of people now and in the future.

Same with the skeg. I will not be adding the skeg. I don't need to turn on a dime and I sure don't want to risk cavitation issues.

Thanks for the update,
Flash
Yellow Submarine II - Flying Saucer
Summer Wind - Zip


Return to “Small outboards”

Who is online

Users browsing this forum: Yahoo [Bot] and 13 guests