Blowing over

[larcor69]

I have an older wood kit built from newton plan 1983 Atlas, is a heavy hull about 18lbs., but when she is running good, all she want's to do is FLY!!!..LOL, I though I had it worked out from last time, but I guess not, it has canard wing's bent up at a good angle, I lowered the strut and put even more neg. angle on it, but didnt really get to try that set up due to an engine tuning issue the last heat today, and some set up recomendations would be greatfuly helpful, Thanks..Corey

 

[t_hedlund]

Where is the CG? When is it blowing over?

 

[glenng]

I have an older wood kit built from newton plan 1983 Atlas, is a heavy hull about 18lbs., but when she is running good, all she want's to do is FLY!!!..LOL, I though I had it worked out from last time, but I guess not, it has canard wing's bent up at a good angle, I lowered the strut and put even more neg. angle on it, but didnt really get to try that set up due to an engine tuning issue the last heat today, and some set up recomendations would be greatfuly helpful, Thanks..Corey

Hey, You're doing a lot better than me-took my old 83 AVL to the lake last Sunday.Started in reverse didn't have to go get it-just backed it up to the shore

 

[Russell Bear]

Corey, if it was built as per the plans, it probably has way too much angle on the bottom. It is collecting too much air and this is what's making it blow over. Roger's plans are drawn very scale and those angles don't work too well at 1/8 scale.

The fix is to either fill in some of the bottom angle with foam and sheet it or do the fix that many others have done, add an air dam with some aluminum angle or a wiper blade up near the front of the air trap. This will "kill" the air underneath and will help with your problem.

Good luck......

 

[Bert Dygert]

Corey,

Are you racing at Sumpter next weekend ? If the angle of on the tunnel is too much you are packing air under the boat, an aluminum angle under the boat use 3/4 X 1/2 and two sided foam tape until you find the right height to block the air. Next we need to look at the prop. With that much angle in the tunnel the prop has to lift the transom out of the water or you will pack more air under the boat. Then look at is the sponson depth. It hull maybe to high off the water. Is your Atlas a Dumas kit?

If you are racing next weekend. Pit by me. We can see what we can figure out and get a game plan for next year. Doug Sheperd will be in town as well he will have some good input as well.

Just some thoughts.

Bert Dygert

 

[larcor69]

she only want's to lift off at speed, but saturday before the race day she was rockin!, but there was hardly no wind, then again the wind sunday was coming across the lake into your face on the driver's stand, Burt, you may have seen my boat almost blow off during mill time during the second round heat 1 I let off the gas when I seen the turn fin out of the water then the nose slamed down which caused it to stuff the nose and go belly up, like a dead fish..lol, then the last round it was just outta wack with the engine tune??, and yes I will be at sumpter!!

 

[larcor69]

Corey, if it was built as per the plans, it probably has way too much angle on the bottom. It is collecting too much air and this is what's making it blow over. Roger's plans are drawn very scale and those angles don't work too well at 1/8 scale.
The fix is to either fill in some of the bottom angle with foam and sheet it or do the fix that many others have done, add an air dam with some aluminum angle or a wiper blade up near the front of the air trap. This will "kill" the air underneath and will help with your problem.

Good luck......

This hull was built per the plan's 20+ years ago, it's a good solid hull, but dated, I am running a like new Picco exr .67 with a slight mod to it, with a x455 prop, it's really fast for an 1/8th scale of it's weight, I just might try some blades under her for a test run before next weekends race!!

 

[GRoth265]

Get rid of the X455 prop it has no lift! try a 3 blade or maybe a 1460. It sounds like you need a prop with more lift. Also a 1455/3 may be worth a try. Greg

 

[larcor69]

Get rid of the X455 prop it has no lift! try a 3 blade or maybe a 1460. It sounds like you need a prop with more lift. Also a 1455/3 may be worth a try. Greg

You Know Greg, your most likely RIGHT, the boat was good with the x452/3 blade, then I put a newer .67 exr in it, with a x455/2 blade prop then it started having the blow over issue again!!!, I just need a 3 blade x455 or something like it..Corey

 

[larcor69]

have a 3 blade prop, and she's is all set now!!, woo,hoo, after a few test run's and setting the needle she was gettin with the program, Thanks all!!