26in predator outrugger help
07-17-2009, 02:22 AM
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RE: 26in predator outrugger help
I am keen to help
Riggers are fun and that is why I now have two. Both drawn and built by me.
The tub size you have is almost exactly the same as my bigger rigger which is on 4S power and will currently clear 55mph.
Over the last two years I have done a LOT of reading on rigger design and now have a few basic formulas to pass on.
AoA of the sponsons. 3 to 5 deg if you can make them adjustable, if not then set them at 4 deg and wedge ride pads can be added later.
Tub AoA. 1 to 2 deg .
CG ( centre of longitudinal balance ) This is commonly given as a distance from the rear of the sponson ride area to the prop, also known as the afterplane.
I suggest setting the hull up so that it will balance somewhere between 10% and 20% rear of the sponson. Both of my riggers run 20 to 25% rearwards CG.
Strut height For a hull of this size I would set the strut so that the bottom of the tub is parallel to a table when it is sitting on its 3 points. Sponsons + strut. From here allow 3mm (1/8”) down ward movement and at least 5mm upward adjustment. This will allow you to lower the rear and increase the AoA at the front if needed.
Motor I do not run anything on 6S so I have taken some data from FECalc to give you an idea of what you can expect.
Fiegao 10XL 1668kv on 6S
440 prop = 32,500 rpm, 70A, 1402W, 57mph
640 prop = 31,000 rpm, 86A, 1700W, 63mph
These figures should be used as a guide as I use FECalc to compare power setups.
If you need to know more about riggers from me then call out, I’ll help where I can.
Here is my bigger one before it hit the water.
Riggers are fun and that is why I now have two. Both drawn and built by me.
The tub size you have is almost exactly the same as my bigger rigger which is on 4S power and will currently clear 55mph.
Over the last two years I have done a LOT of reading on rigger design and now have a few basic formulas to pass on.
AoA of the sponsons. 3 to 5 deg if you can make them adjustable, if not then set them at 4 deg and wedge ride pads can be added later.
Tub AoA. 1 to 2 deg .
CG ( centre of longitudinal balance ) This is commonly given as a distance from the rear of the sponson ride area to the prop, also known as the afterplane.
I suggest setting the hull up so that it will balance somewhere between 10% and 20% rear of the sponson. Both of my riggers run 20 to 25% rearwards CG.
Strut height For a hull of this size I would set the strut so that the bottom of the tub is parallel to a table when it is sitting on its 3 points. Sponsons + strut. From here allow 3mm (1/8”) down ward movement and at least 5mm upward adjustment. This will allow you to lower the rear and increase the AoA at the front if needed.
Motor I do not run anything on 6S so I have taken some data from FECalc to give you an idea of what you can expect.
Fiegao 10XL 1668kv on 6S
440 prop = 32,500 rpm, 70A, 1402W, 57mph
640 prop = 31,000 rpm, 86A, 1700W, 63mph
These figures should be used as a guide as I use FECalc to compare power setups.
If you need to know more about riggers from me then call out, I’ll help where I can.
Here is my bigger one before it hit the water.
