Air Trap Sponsons

[Charles Perdue]

Hello John, I haven't tried the shingles spaced out. I have only tried the stacked design.

Part of the reason for the stacked design was to create the tunnel to channel the air for the ground effects and the other reason was to help break the suction. An added benefit of the stacked design is to allow a greater angle of attack over progressively smaller areas of each shingle as they are stacked closer together toward the rear of the sponson. This helps the sponson to transition smoothly and quickly from the sponson flat area, to the shingles, to the ground affects.

If you are not looking for the ground effects, a single strip of stacked shingles can be used for a running pad. This also works quite well.

Charles

 

[carlnoki]

how thick are the shingles and are they each tapered to a pointed section? (can't tell by the pictures very well.)

carl

 

[Charles Perdue]

Hello Carl, the shingle thickness that I use is .030. Thinner shingles do not work as well and I haven't yet tried any that are thicker.

The shingles are a constant thickness, they are just stacked one on top of the other at an angle.

If the bottom of the sponson is flat, the shingles can be glued together on a flat surface and then attached to the sponson. If the bottom of the sponson is curved, I place a layer of Saran Wrap on the sponson and build up the shingles on top of the Saran Wrap so the curve of the strip matches the sponson bottom exactly. I use medium super glue for the adhesive.

I also build the shingled pad in a piece wide enough that I can cut it into strips, that way all of the strips are the same.

Charles

 

[John Finch]

Hello Carl, the shingle thickness that I use is .030. Thinner shingles do not work as well and I haven't yet tried any that are thicker.The shingles are a constant thickness, they are just stacked one on top of the other at an angle.

If the bottom of the sponson is flat, the shingles can be glued together on a flat surface and then attached to the sponson. If the bottom of the sponson is curved, I place a layer of Saran Wrap on the sponson and build up the shingles on top of the Saran Wrap so the curve of the strip matches the sponson bottom exactly. I use medium super glue for the adhesive.

I also build the shingled pad in a piece wide enough that I can cut it into strips, that way all of the strips are the same.

Charles

Thanks for the info. I will be experimenting with the shingles soon.

 

[Terry Keeley]

Isn't there some sort of stick on mylar that acts like this? Think it looked like fish scales or sumpin'...

Here it is:

http://www.sharkskincoating.com/indexe.asp

 

[Rokieboater]

Mark and I have had the shingles on my sport 21, Crapshooter 101 hydro and on SGX60 and my SST twin 90's. There was marked inprovement in the launch and getting up on step and the acceleration is greastly improved. The boats also seem to handle the rough water better.I will atest to Mark's statement on the fact that he did not borrowed the idea. His account is correct because I was at the same Nats, running partner, and we discussed the concept at length.

The tunnel spnsons have been around for a long time. The first that I saw was years ago at a race in New Orleans and the O'Donnell's had a baby blue hydro with the tunnels and many other innovative concepts in the boat. They ran a Picco that was air cooled.

Another amazing boat at that race was a black guy who came all the way from California and he had a bueatiful black twin that he would "rope" start.

I wonder how many folks have seen motors started with a free hand ROPE?

Could have been Gene Adams, I don,t think Jim henry raced Twins.....

Robert Holland

 

[carlnoki]

ThanksCharles

am going to order some carbon in .030 thickness and experiment on a 20 rigger.

as well as going to 0% on it and see what i can get out of it.

Carl

 

[AndyBrown]

Tossing out a idea. Very rough sketch of sponson. Lighten and maybe add some downforce with less drag???? B)

Ray,

Cal Lang did that to his Gator and Cayote sponsons. He made the hole ahead of the front boom tube. His boats always ran very well.

I used a leather shoe string or a rope to start my boats until about 1982. Don Pinckert started his twin 45 gator with ropes.

I've seen a number of guys Thumb start the old Rossi 60's.

 

[Dasboatman]

"Cal Lang did that to his Gator and Cayote sponsons. He made the hole ahead of the front boom tube. His boats always ran very well."

Hey Andy,

I think this is an example of that. Found it in some of Phil's Old Pictures files. We all used ropes, leather shoe strings, and thumbs because that's all we had. I still have an old Stinger rudder assembly that I should post pics of. Hey, We thought it was GREAT at the time. Marine Specialties stuff was state of the Art - Har, Har !!! I pull it out periodically when someone gripes about the CNC produced stuff. It's all GOOD. CHEERS !!! Bob

 

[Ron Saxvik]

is the rudder being held on with a rubber band?

While attending the World Championship (full sized hydros) races at Lake Alfred,FL

this fall I saw a more refined arrangement for some of the turn fins. I talked with

one of the Swedish crew members and he told me that they run a lot of rivers with

a lot of floating debris and this was to get the fin back in the water in case they

hit something and kick it up. They run extremely tight courses over there and

they need all of the turn fin in the water.

This makes much more sense than our brass shear pin idea.......how many times

have you had a rudder kick up and you have no choice but to shut the boat

down and watch the others finish while you sit on the beach waiting on the

retrieval boat to get it back to you ?

 

[AndyBrown]

"Cal Lang did that to his Gator and Cayote sponsons. He made the hole ahead of the front boom tube. His boats always ran very well."

Hey Andy,

I think this is an example of that. Found it in some of Phil's Old Pictures files. We all used ropes, leather shoe strings, and thumbs because that's all we had. I still have an old Stinger rudder assembly that I should post pics of. Hey, We thought it was GREAT at the time. Marine Specialties stuff was state of the Art - Har, Har !!! I pull it out periodically when someone gripes about the CNC produced stuff. It's all GOOD. CHEERS !!! Bob

There ya go Bob! I think that was Cal's twin K&B 6.5 powered Gator. Twin 40's were very popular in those days.

Speaking of rubber band rudders and Marine Specialties made one of their rudders with a Spring on it. You've probably got some of those kicking around too Bob.

 

[Bill Gibson]

Tossing out a idea. Very rough sketch of sponson. Lighten and maybe add some downforce with less drag???? B)

Ray,

Cal Lang did that to his Gator and Cayote sponsons. He made the hole ahead of the front boom tube. His boats always ran very well

...

I used a leather shoe string or a rope to start my boats until about 1982. Don Pinckert started his twin 45 gator with ropes.

I've seen a number of guys Thumb start the old Rossi 60's.

I think Cal called em "vented sponsons".......

 

[carlnoki]

Charles;

how wide are the small shingles?

carl

 

[Charles Perdue]

Charles;how wide are the small shingles?

carl

Hello Carl, see post # 6 .

Charles

 

[carlnoki]

Charles;

can yo say DUH<<<<<<<<<<<<< :lol: :lol:

thanks i over looked that.

carl

 

[Scott Schneider]

Ok guys .... been most of a race season for R&D on "Tunnel" & "Stepped" sponsons.

What were the findings, Lets get this thread up and alive with input again

 

[jetpack]

You will see a fish scale design on the bottom of cross-country ski's along the same lines as the domino effect mentioned.

In this case it also helps the kick as well as the glide on waxless ski's.

 

[dr gary turner]

OK

Charles,

Do the shingles need to be one right after the other to work on breaking up the water or can they be spaced far apart like the aeromarine cat hulls if your not looking for the air trap, just breaking the suction?

Mark's and my shingles are one after the other. When you pull the throttle back the boat does not immediately slow down. It just keeps going. Gary

 

[Scott Schneider]

Come on guys ... share some findings Pictures etc ......

 

[Scott Schneider]

Link not active ... see newer posts