prop weight for a rigger

[Rick Pirrone]

hi all

can someone please explain prop weight and how to calculate for riggers

or is there a general weight for 20 40 90 size boats ???

cheers and thanks rick

 

[wayne middlemiss]

rick the best answer i can give is build as per you do but not try to take too much weight off the prop or you loose all your drive when comes time for heat racing. if the your running 14-16 series props and the boat is happy not hopping its ok but if your doing a new boat and remove too much weight of the prop you've got another problem = lots of hopping & loss of speed. ive always worked around or close too 40/60 balance of the whole boat.

 

[Rick Pirrone]

hi wayne

i know find im have too much lift in the back end and yes im running 14 - 16 series props

prior to the vac rebuild and this was its first time back in water it has started to hop more offen with every prop i tryied last sun

1 have about 1.25oz of prop weight

so im tryin to decied if i need more weight and how much \

or do i play with strut angle or hight and see if it gets better

all part of the learning curve

cheers rick

 

[Rick Pirrone]

hi wayne

i know find im have too much lift in the back end and yes im running 14 - 16 series props

prior to the vac rebuild and this was its first time back in water it has started to hop more offen with every prop i tryied last sun

1 have about 1.25oz of prop weight

so im tryin to decied if i need more weight and how much \

or do i play with strut angle or hight and see if it gets better

all part of the learning curve

cheers rick

Rick 1.25 oz of weight on the strut is waaaaaaaaaaaaaaay to light

to give you an idea my 20 firefighter had 310g on the strut ( 11 oz ) and it was light in the rear

and lost some drive if the water got up

i just checked my SGX .45 and it has 25oz

how are you measuring it ?

Greg

hi greg

i had a hard day i meant to say 1.22lb which it 19.60 oz

heres a pic just lifting the rear buy 1/8 is this ok ???

maybe a little more in the back might fix this then

thanks mate

 

[wayne middlemiss]

rick get some stick on wheel weights to add in bit by bit or a few at a time from tyre service that will help you sort it out.

maybe go and get 3 sets of electronic kitchen scales for checking your weght distibution over the whole boat more accuratly

 

[Rick Pirrone]

rick get some stick on wheel weights to add in bit by bit or a few at a time from tyre service that will help you sort it out.

maybe go and get 3 sets of electronic kitchen scales for checking your weght distibution over the whole boat more accuratly

thanks wayne

i was going to try that next sunday and see how it works out maybe aother 5 oz like greg said might be the ticket

cheers rick

 

[aaron alberico]

Prop weight ain't the problem!

19.60oz approx 550grams

My old boat( Clint's) had lass then that

Did not have that problem....

Work on set up and propeller..

 

[wayne middlemiss]

i did have a pinkert coyote that never like 14-16 series but loved x series imo was to light on the prop altogether so i moved it.

 

[dr gary turner]

It depends on the type of boat. A "ramp" boat needs prop weight to off set the lift of the ramp. A "4" point hydro needs less prop weight. A hydro that has standard rear sponson set up needs the least prop weight, because the prop not only pushes but lifts the boat.

 

[Terry Keeley]

Though static weight on the prop is one factor I think you'll have a better picture of what's going on thinking more about for to aft balance, both static, aerodynamic and most importantly, hydrodynamically.

At least that's what my engineering department said! :lol:

 

[SayMikey]

hi wayne

i know find im have too much lift in the back end and yes im running 14 - 16 series props

prior to the vac rebuild and this was its first time back in water it has started to hop more offen with every prop i tryied last sun

1 have about 1.25oz of prop weight

so im tryin to decied if i need more weight and how much \

or do i play with strut angle or hight and see if it gets better

all part of the learning curve

cheers rick

Rick 1.25 oz of weight on the strut is waaaaaaaaaaaaaaay to light

to give you an idea my 20 firefighter had 310g on the strut ( 11 oz ) and it was light in the rear

and lost some drive if the water got up

i just checked my SGX .45 and it has 25oz

how are you measuring it ?

Greg

hi greg

i had a hard day i meant to say 1.22lb which it 19.60 oz

heres a pic just lifting the rear buy 1/8 is this ok ???

maybe a little more in the back might fix this then

thanks mate

That boat looks a lot like a Crapshooter put a 1657 on it and be sure its sharp enough to cut you if not put on with a rag

 

[Tim_Duggan]

Work on set up and propeller..

Hi Rick,

What Aaron said worked for me - try some tip cupping on a 1460,1462 or an ABC 2314, 2414 - worked a treat on my 45 that was blowing out the prop with the strut at neutral. Adding lead is an easy band-aid to use as a way to confirm (thats what I did at first, but lighter accelerates faster )

On my latest 21 I tried a different approach - changed the afterplane length and raised the tub a little. Now the front end is too loose!

Tim.

 

[wayne middlemiss]

rick try some of aarons wheels on it at the lake next your there with him. like tim said too little changes to boats change them in other area's . its alot of research building boats to make them better than the last boat you built

 

[Rick Pirrone]

thanks guys

i will be working on boat setup next sunday my strut is level so i will change that

for memory i had a little bit of neg angle before i went to the natts when it was preforming good

enjoying this learning

thanks everyone

cheers rick

 

[RodneyPierce]

Hey Rick, you have some of the best help right there buddy. Tell Aaron to give up his prop box, and start testing

 

[Terry Keeley]

That rudder looks awful thick...

 

[Ian Inverarity]

That rudder looks awful thick...

Who makes a good thin 45 rudder these days?

 

[dwilfong]

Lenny Blake at Rum racing makes a killer thin rudder.

 

[Rick Pirrone]

terry it is quite thick its just a cheapy from ebay

hi ian thanks for asking the ????

david does lenny operate from iw or does he have a web siite to order from ?????

cheers rick

 

[Terry Keeley]

terry it is quite thick its just a cheapy from ebay

Think that might be why the back end wants to lift?