NAMBA strut question

[Matt Smith]

Agreed.

Maybe a dumb question being that I'm the Scale Director for D14 but how easy is it to find documentation on length of the real boat for the drive dog rule?

Is it documentation based on photos?

Sam,No documentation that I know of, I;ll pull some pics from home to show 3-4 typical examples of current and old struts.

Matt, if you use the leading edge of the prop as your datum point, it doesn't matter what size your drive dog is in length.

Youre right Joe. I think this would a great change to the IMPBA rules.

 

[Samuel Hagan JR]

Agreed.

Maybe a dumb question being that I'm the Scale Director for D14 but how easy is it to find documentation on length of the real boat for the drive dog rule?

Is it documentation based on photos?

Sam,No documentation that I know of, I;ll pull some pics from home to show 3-4 typical examples of current and old struts.

Matt, if you use the leading edge of the prop as your datum point, it doesn't matter what size your drive dog is in length.

Youre right Joe. I think this would a great change to the IMPBA rules.

I have some boat plans of a modern day era boat. I can come up with some drawings.

 

[Lennard Cuenco]

recent build had several photos with strut extending past a transom extension

 

[Joe Wiebelhaus]

As promised, strut photos ! HOT

As you can see, most of these struts extend beyond the transom anywhere from 2" to 6" max, or just under the bottom of the boat.

 

[Samuel Hagan JR]

Joe what's a good way to get in contact with you email or phone. I need both.

 

[Joe Wiebelhaus]

Joe what's a good way to get in contact with you email or phone. I need both.

pm sent

 

[Ray Sametz]

As promised, strut photos ! HOT

As you can see, most of these struts extend beyond the transom anywhere from 2" to 6" max, or just under the bottom of the boat.

Just curious guys, is there any advantage to having two blades mounting the strut then one vertical like most hardware? IE flow and turbulence to the prop.

 

[shann harrison]

Joe here is what I built my hull at and heres a pic of the real hull.I should be fine but need your imput Thanks Shann

 

[Hydro Junkie]

As promised, strut photos ! HOT

As you can see, most of these struts extend beyond the transom anywhere from 2" to 6" max, or just under the bottom of the boat.

Just curious guys, is there any advantage to having two blades mounting the strut then one vertical like most hardware? IE flow and turbulence to the prop.

Not really. The twin blade strut went into use when boats started running turbine engines due to the single blade struts bending, or worse. Since our power plants haven't gained that much power, relatively speaking, we don't have the same issue. Then again, even when running a 3500+ HP twin turbo Allison instead of the original 2000 HP Merlin, the 7325 Pak hull still ran a single blade strut.

What a twin blade strut will do is prevent you from adjusting the prop depth or thrust angle since it would have a fixed setting on it, just like the full sized boat struts do

 

[Samuel Hagan JR]

Joe here is what I built my hull at and heres a pic of the real hull.I should be fine but need your imput Thanks Shann

Perfect example of what different people interpret the rule.

 

[Joe Wiebelhaus]

Joe here is what I built my hull at and heres a pic of the real hull.I should be fine but need your imput Thanks Shann

Shannon,

So what is the dimension from the transom to the forward face of the prop hub, with spacing for the flex shaft ?

See my pdf example sheet.

Take a pic with a ruler next to the strut. (ruler, what an old term)

 

[shann harrison]

Joe here it is its 7/8" aft of transom.

 

[John Borden]

As I race scales.

I would go to my district director submits my boat information.

At that point the you will get your answer if you can race the boat.

It is not up to us to make the boat legal.

Only NAMBA or IMPBA can.

We all have a opinion that does not matter.

Just submit your boat per the rule book turn in $5 and you will get [emoji106]or[emoji107]

See you at the pond

Sent from my iPhone using Tapatalk

 

[Mikemalloy]

We have been running this strut that we made using the articulated hard shaft in our 1/8 SCALE FE hydros in R/C Unlimiteds. We also have a couple of nitro boats using this same strut. We presented it to the R/C U board with pictures and scaled down measurements from a modern type hull, since the drive dog is past the transom of the hull. It works and has Scale appearance . So I'm sure in other clubs ect.. if they provide proof that's how the real boat was configured, then present it to who is in charge and it shouldn't be a problem. Just my 2 pennies worth IMO.

 

[Samuel Hagan JR]

What is that about 1" from the transom to the front of the drive dog?

 

[Mikemalloy]

When I go back to the shop I will get a accurate measurement and let you know. I don't remember off the top if my head, old age lol.

 

[Joe Wiebelhaus]

As I race scales.

I would go to my district director submits my boat information.

At that point the you will get your answer if you can race the boat.

It is not up to us to make the boat legal.

Only NAMBA or IMPBA can.

We all have a opinion that does not matter.

Just submit your boat per the rule book turn in $5 and you will get [emoji106]or[emoji107]

See you at the pond

Sent from my iPhone using Tapatalk

John,

We will pursue this for clarity matters, possible IMPBA rule addition.

It appears to be a concern for some.

 

[shann harrison]

After looking at my last post I put the boat strut back in cause I'm getting ready for paint so here is a pic of my strut and the pictures I started this build off of that was sent to me by Kevein Eacret about strut placement being at the rear of the sponsons and not the transom but I really would like to know if this fits into IMPBA rules?? I should BUT there is always that 1 person to complain I've had it in the past and would like no arguments about this one that's all easy peasie

 

[Samuel Hagan JR]

According to John It doesn't matter. The ScaleDirector for your district is all that matters. I would get in touch with them.

 

[Mikemalloy]

I was able to kinda hold a tape measure and snap a pic for a measurement, its roughly 3/4 - 1 " from transom to back of drive dog. This measurement was scaled down from one of the real boats by the builder of our hulls.