Sport 20 Shovel Nose design

[missbudpilot55]

OK Wade,

My bad I didn't see the dimension, the wetted area or width of the sponson is your 1.5" as shown in 12/14, make the ride pad aprox 5/8" - 3/4" wide and approx 60% of the distance from the rear of the sponson forward to the bow, 1/8" tapering to "0" over that distance.

I would make the tunnel 7" wide and the height of the transon aprrox. 7/8" to 1" tall, any shorter and rudder mounting becomes an issue. About the absolute minimum would be 3/4".

I would plan on having a forward radio box with the tanks mounted to the right of the engine rails. I think that the maximum fuel capacity should be 8 oz, but probably could get away with 6. Might be able to use the R/H tank that "Grim" has for Brian Blazer's Sport 40 if it is 6 - 8 oz. Ok all you 20 mono & hydro guys, how much fuel do you cary for a normal heat race?

Strut mounting, bottom of hull or transom? "BUILDERS OPTION", RUDDER TO THE LEFT (turns better with less effort from the servo, and also keeps rudder out of the slip-stream of the turn fin. Turn fim from the Power Surge Racing Products stable also. Have sent e-mail about tank capacity & measurements to Mike.

Over all I think you are on the right track for the "Round-Nose" Sport 20 design.

Only wished the background color of black wasn't there as it's hard to see when you print it from my PC. Wade could you print me a full set of the plans when they are finished, I'll be glad to cover the cost of printing & postage.

On the dropped sponsons request maybe that could be design #2, I'll send you some pictures of my "Miss Chrysler Crew" currently under construction.

 

[wswatzell]

Bill, Thanks again for all the great info!!

What color would you prefer for the background? I can make it any color I want, I am just used to modeling with a black background, so I stay with it.

How far below the transom should the CL of the strut be? I am designing it in "level flight" so that will determine where the bottom of the transom needs to be.

The fuel tank dimensions would be a big help, so if I have to tweak the height under the deck, I can at this stage. (easier to modify right now ) ( have a Nova Rossi .21 I was going to model up for the engine position, with the wrap around header, I would assume that the pipe would have to be routed along the side of the cowl. The shovel noses that I have seen have a very narrow cowl over the engine. I will try to keep the pipe below deck though.

 

[Paul Pachmayer]

Drop Sponson Shovel

 

[wswatzell]

Oh, I see. It would be easy to modify my design when I am done for a Drop down sponson design.

 

[missbudpilot55]

WADE

Are you going to transom mount your strut or tuck it under the hull? According to what has been posted in another thread by Bill Zuber:

"NO PART OF THE STRUT SHALL HAVE A WIDTH GREATER THAN 1/2 INCH OR A LENGTH LONGER THAN 2 1/2 INCHES"

The height of the tunnel is 5/8" (.625") as per dwg 12/14 that is what I would use as a starting point. The strut under the hull is going to be tucked close under it, I would like to get some measurements on the strut Tom is usng on his Firefighter 21. Do you like to use a flat bottom strut or a rounded bottom strut?

 

[not2bright]

you need to carry at least 8 oz of fuel. my dads sport 20 sucks a 6 oz tank down in no time at all. damn italian motors!!

 

[Jerry Wyss]

you need to carry at least 8 oz of fuel. my dads sport 20 sucks a 6 oz tank down in no time at all. damn italian motors!!

77344[/snapback]

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SSSHHHHH! They gave us PIZZA!! :lol:

 

[missbudpilot55]

WADE & JERRY,

Talked to Mike "Grimracer" @ Power Surge Racing Prod. this evening and here are the dimensions of the tanks for Brian Blazer's Sport 40.

L= 4.75"

W=2.25"

H=1.18"

Capacity 8 ozs.

Mike said if we wanted to have a single or double custom tank set up let him know the dimensions you would require and he would be glad to make them for us. He also said that 8 ozs would be the minimum for Sport 20 heat racing he would recommend.

 

[Jerry Wyss]

Tank or tanks are gonna be determined by how wide and deep the center section

is, We can't know about one without the other :blink: Yeah,,thats right. I think

"The Cattle Are Herdin' the Cowboy" on this one,,,Wade probably feels like He's

bein' "rubbed down" in between rounds at a "Prize Fight"

 

[wswatzell]

Do you like to use a flat bottom strut or a rounded bottom strut?

I don't have any preference. The only boat I have that is close is an old Dumas Drag-n-Fly 60. It doesn't qualify as a 1/8 scale, so it can't be raced so I just play with it. Anyways, I have never set one up for racing, so I don't know.

Wade probably feels like He'sbein' "rubbed down" in between rounds at a "Prize Fight"

As long as I don't have to endure the part in-between the "rub downs" :lol:

I can work with those tank dimensions, & if I can't get them to work, I'll design something up with 8oz capacity & send it to Grim.

I am going to be out of town until next week Wednesday (going to Las Vegas) so not much in design will happen after today until I get back. I'll try to make a few more tweaks & post them before I leave though

 

[missbudpilot55]

[SIZE=14pt]Wade,[/SIZE]

On your drafting program when you get ready to print your work, what happens to the black background.

I

am going to be out of town until next week Wednesday (going to Las Vegas) so not much in design will happen after today until I get back. I'll try to make a few more tweaks & post them before I leave though

[SIZE=14pt]Have a great time, safe flight and don't take any wooden nickles. LOL[/SIZE]

 

[wswatzell]

Wade,On your drafting program when you get ready to print your work, what happens to the black background.

The CAD software will only print the geometry. I think what you have tried is printing the picture of my CAD file. From now on, I'll make the background white when I capture the image of my design so you can print it out if you would like.

I wasn't able to get anything done today on the design; I had too many things to button up before I leave.

See you all Wednesday!

 

[wswatzell]

Well, I'm back. I'll try to update some more today.

 

[Jerry Wyss]

Glad to see your back Wade

 

[wswatzell]

Sorry it took so long to make an update, but I got swamped at work

Anyways, I made the tunnel width 7". If all is fine with the design, I can start designing the internal structures.

https://www.intlwaters.com/gallery/thumbnails.p...lbum=100&page=2

 

[wswatzell]

Bill, It was great talking on the phone with you last night.

 

[[email protected]]

Wade,

how does the CAD design software work?? Does it print out blueprints?? or only help you get the dimensions??

 

[wswatzell]

Rodney,

It does both. I make a 3 dimensional model of the design in CAD, to make sure everything fits properly, and then I can generate plans ("blue prints") from the model. With the software I use I can spin it in all directions to look at it from different angels. I can hide different components so I can see how things fit better. I can shade it & spin it around to better see how the real thing will look.

 

[wswatzell]

Well, I increased the transom height to 1" at the center, & it tapers off to the sides. Since no one has anymore changes in mind, I am going to start the internals after I design the ride pads.

I'll update the pictures after I get the ride done,

What thinkness should I use for the deck, & sides? what about the bulkheads? I was thinking 1/16 for the decks & sides, & 1/8" for the bulkheads; 1/4" for the engine rails.

 

[Brian Blazer]

Looks good...

A couple of things that I saw that you may want to think about.

The sponson ride pads are not parallel at the back. If they are parallel, it will be less drag. I would say the last 2-3" should be parallel.

Your break point is at the rear of the sponsons, as with most boats. Move the break point forward, about half the distance to the front, then go up towards the nose. This will suck the nose down, thus making the boat less prone to blowovers.

Dropped sponson round nose boats are a little harder to think up, but it is easier to lay the deck. There are compound curves with a roundnose, and dropping the sponsons helps relieve it. Looks cool to. I have two of them if you would like to see.

Keep up the good work!

Brian