sponson shape

[Boris Mazor]

Needs opinion: what is the best bottom shape of front sponsons ( rigger, hydro ).

I completeted FIRE FIGHTER Gas Rigger and ROCKET Retro Hydro with #1 shape of sponsons. Now is timer to make improvements. Thanks. Boris

 

[rhomodel]

I'd go for #4, but it really depends on the size of the boat I think. A gasser would benefit from #4, but a small 2.5 cc would do with #1 .

 

[Don Ferrette]

Definitely not #3, it will trip on the overhanging edge in the turns.

 

[Grimracer]

#3.... Don.. it wont trip on that edge..

For sure 3.. when in doubt go with 2

Grim

 

[Don Ferrette]

#3.... Don.. it wont trip on that edge..

Tell ya what. Put that on the left sponson of a rigger & then tell me what happens when you throw it hard into a corner at speed. I'll give you a hint, you'll get to know the retrieve boat real well..........

 

[FloridaScaleBoater]

Put the overhang on the inside of the port sponson, How's it gonna trip?

I think you are just "assuming" the overhang is going to be put on the outboard side of the port sponson.

Or am I assuming Boris would be doing it the correct way?

Rick

 

[Don Ferrette]

Put the overhang on the inside of the port sponson, How's it gonna trip?
I think you are just "assuming" the overhang is going to be put on the outboard side of the port sponson.

Or am I assuming Boris would be doing it the correct way?

Rick

Rick, you're correct if it's only on the inside (right sponson) but Boris did say sponsons as in plural.

I have seen this attempted on the left & right side sponsons together and the results made for quite a show every time the person hit the turns with any speed. :huh:

 

[Mark Leyde]

#3.... Don.. it wont trip on that edge..

Tell ya what. Put that on the left sponson of a rigger & then tell me what happens when you throw it hard into a corner at speed. I'll give you a hint, you'll get to know the retrieve boat real well..........

Don my .12 rigger is like #3 on both sides with a stepped bottom. I can turn my rigger so tight it will spin your head and it never trips on the edge. That little overhang keeps the sides of the sponsons from wetting up and creating drag. Maybe it is different for larger boats . But it works great on the light little .12's. hitting near 50mph.

Mark

 

[Boris Mazor]

Put the overhang on the inside of the port sponson, How's it gonna trip?
I think you are just "assuming" the overhang is going to be put on the outboard side of the port sponson.

Or am I assuming Boris would be doing it the correct way?

Rick

Rick, you're correct if it's only on the inside (right sponson) but Boris did say sponsons as in plural.

I have seen this attempted on the left & right side sponsons together and the results made for quite a show every time the person hit the turns with any speed. :huh:

Hi, Don! what you did on your ROCKET? On the kit sponsons are #1. Thanks. Boris

 

[Grimracer]

Don... One word.. NINJA

4 US-1s and all with sponson #3

did you feel it EVEL!!!!!!!

Grim

 

[Don Ferrette]

Don... One word.. NINJA
4 US-1s and all with sposnon #3

did you feel it EVEL!!!!!!!

Grim

Well I don't know what to tell ya, maybe it's because two of you are talking about smaller (.12 & .21) boats? I watched it attempted on a fast 40 rigger & it was a complete disaster. The guy who was trying it never got the boat to stop tripping until he removed all of the overhang on the left sponson. He tried leaving it on the right sponson & it was fine as long as he didn't make any left corrections. Needless to say after a few weekends at the pond he removed it from both. :huh:

Grimmy, turn on your spellcheck.

 

[Don Ferrette]

Hi, Don! what you did on your ROCKET? On the kit sponsons are #1. Thanks. Boris

Boris the sponsons on my Zipp Rockett are STONE STOCK & the boat corners great!! B)

 

[Grimracer]

Don.. I have run them on all kinds of boats.. My scale boat has them too...

Spelling fixed..

Grim

 

[Don Ferrette]

Don.. I have run them on all kinds of boats.. My scale boat has them too...
Spelling fixed..

Grim

Well that's interesting for sure. How much dihedral and sponson AOA also might play into it. If you look at the top end production heat racing riggers you don't see it and I'd have to think guys like Stu, Andy & Ralph have gone down this road already. Glad it works for you though. B)

 

[Rigged]

Boris what does your FF do that you are wanting to make improvements over #1? My FF is built to the plans (other then tub is only 4.5" inside/5" outside) with the 3* or whatever angle in the sponson, but i havent got to run it yet.

 

[Grimracer]

Don,

1 to 1.5 left and 0 right..

My AOA are typically higher however. Up to 5.5 running.

Grim

 

[Boris Mazor]

Boris what does your FF do that you are wanting to make improvements over #1? My FF is built to the plans (other then tub is only 4.5" inside/5" outside) with the 3* or whatever angle in the sponson, but i havent got to run it yet.

My FF runs great at 50 mph. Makes sharp right turn and big radius left. One problem I saw it is low speed! I even afraid to slow it down - it will not run!!. I desided to set booms 1" higher and hope it will help. Boris

 

[Rigged]

Boris what does your FF do that you are wanting to make improvements over #1? My FF is built to the plans (other then tub is only 4.5" inside/5" outside) with the 3* or whatever angle in the sponson, but i havent got to run it yet.

My FF runs great at 50 mph. Makes sharp right turn and big radius left. One problem I saw it is low speed! I even afraid to slow it down - it will not run!!. I desided to set booms 1" higher and hope it will help. Boris

with what prop? 50mph... are you running a stock zen?

 

[Boris Mazor]

Boris what does your FF do that you are wanting to make improvements over #1? My FF is built to the plans (other then tub is only 4.5" inside/5" outside) with the 3* or whatever angle in the sponson, but i havent got to run it yet.

My FF runs great at 50 mph. Makes sharp right turn and big radius left. One problem I saw it is low speed! I even afraid to slow it down - it will not run!!. I desided to set booms 1" higher and hope it will help. Boris

with what prop? 50mph... are you running a stock zen?

The prop is PRATHER 275, SIKK-27 with ligted up piston (I remove ~3g from 31g). Boris

 

[Don Ferrette]

The prop is PRATHER 275, SIKK-27 with ligted up piston (I remove ~3g from 31g). Boris

Shorten the pipe & put a 6719/3 blade on it.