Rigger with Saito 180

[Craig Hollingshead]

So, I think I will build a outrigger with my Saito 180. Any ideas as to how to fit a drive line? Need a flywheel, and collet. Will probably go with a wire drive.

Any thoughts would be appreciated.

Craig

 

[RaceMechaniX]

You did not say if you have the Nitro or Gas version. The tricky part will be finding a M7x1 collet. I would advise against a wire drive, just use a standard 1/4" flex cable. That motor is close to 30cc and likley has tons of torque. That's rough on a wire drive.

If you are building the rigger from scratch consider building a 5" tub so you can use standard rubber damped motor mounts from Speedmaster or Aeromarine.

Octura still produces some giant flywheels including a large brass one which should have enough inertia to keep the Saito idling. You may need to ream open a standard conical "olive" to 7mm from 1/4" to get the right fit. Call up Octuta and ask about the flywheels.

 

[Amp Eater]

Saito 180 has a 8x1.25 mm thread
This is steel and heavy made for the OS 81VR, should allow the engine to idle, given the additional mass of the drive line and prop.
You have to be prepared to buy worldwide for certain parts desired.

OS ENGINES FLYWHEEL NO 7 81VR-M ABC - 71805400​

6.5oz mass will work for Saito 180 speed projects the 2 stroke 81VR made good power for it's day.

 

[RaceMechaniX]

Thanks for correcting the crankshaft thread, I was looking at a smaller Saito in the manual which listed the M7x1 thread. A M8x1.25 should be readily available.

 

[Mike Byer]

does this engine turn the correct direction? CC viewed from the flywheel end?

 

[Craig Hollingshead]

Thanks for your replies...still pondering the choice of the 180.

 

[BruceHartmann]

Saito 1.80 is an awesome motor. I love all of my big Saitos. They are beasts running 30% heli fuel in an airplane.

 

[Roxyflash]

Being they don’t turn a lot of rpm’s do you use a gear box to double the rpm’s?

 

[Craig Hollingshead]

It will spin at 10000 rpm...not fast enough?

 

[Roxyflash]

I run mostly gas and usually turn 18000 or more

 

[rhomodel]

It will spin at 10000 rpm...not fast enough?

No, you need revs, loads of revs. Sorry to say but a 4 stroke is more for a tugboat. In order to get any decent speed you need a huge prop, and teh propwalk in a rigger is already huge, let alone if you proip it up to accomodate 10k revs, rather than 18k.

 

[Grimracer]

To me.. it COULD work but controlling prop torque would be important.. AND likely difficult.

would be fun to try...

I have seen a skidaddle with a 4 stroke in it.. it was no slouch! Was quite cool! (Not talking rigger here I know.. but it was still cool!)

DO IT.. do all you can to make it work the best you can.. would be fun to see it run!

Grim

 

[Mark Anderson]

How will you cool it?

 

[Amp Eater]

My lanky / wide stance 4 stroke rigger had no issues with prop walk / pure 3 point no ramp.
Given the hull design I had to try a few prop sizes before getting a handle on what the OS Alpha .52a does well with.
Once the needed thrust was obtained the rest of the power went to pitch. The fuel ended up with some castor and 45%
nitro to reduce heat and hold a good needle. Engine well exposed did just fine air cooled given the rigger was always moving.
3ft L / 3.14lbs. lean design. On the bench 3.6k to 15.8k rpm.

180 rigger loaded on the water should have a shot at making 11k -rpm is higher compared to mass / load with air props.

 

[Bill Eilers]

I'd like to see a scale with a Sato radial. Bet it would sound good