Best of Dominator Modifications Edypaul - Joe Pires

[scottessex]

Running a 2 stroke @ 120* will not hurt it at all, Running a 2 stroke @160* will make a little more power. When I talked to the Arctic Cat racing guys they said keep the engine cool, I have a 120* thermostat. I had 2 different radiators on the Dom with the rotax 582 one ran@140 the other 160* I could not tell any difference.

 

[Edypaul]

It probably does'nt matter much what temps you run from 100 to 200 Deg. Most of the engines made today are aluminum with liners and I think they run close to 200 for better emissions with no problems. If mine blows I'll let you know!

 

[scottessex]

4 strokes yes, don't run a 2 smoker over 180, they get very unhappy.

 

[cesphil]

Nitrogen for shocks

Nitrogen for shocks

Here is a little more detail.

I Got the regulator on ebay for $55. It is a Uniweld RHP 400. There are plenty of sellers at that price. I also got a high pressure hose with an air chuck on ebay for $10.

I bought a used 20 cu ft bottle for $40. I have just over $100 invested.

You can get a 20 cu ft bottle for about $100 from a welding supply store or a gas supplier, where they will exchange it for a full bottle for about $10. A fill should last for years if it does not leak as it holds 2000 psi. You can also use it for your tires.

Also, harbor freight sells a complete outfit for 179.99.

Replace the valve cores and make sure they are tight. Let the air out and fill with nitrogen. Its easier than replacing the shocks. They still need to be checked visually before each flight and will require occasional topping, but it is easier than air and holds the charge longer.

Attached is a photo of my nitrogen charging station.

 

[Edypaul]

I'll keep that in mind. If it hits 100 deg OAT here in orlando I might hit 180 deg.

I just bought a small nitrogen bottle at a garage sale with reg. for $25.00

 

[cesphil]

Rotax 582 Thermostat

Rotax 582 Thermostat

My gyro and engine are very new. Approx. 25 hours on my Rotax 582 Blue Head. I have a Rabbit radiator which is oversized but with a thermostat, it should not matter. I have never gotten my operating water temp over 140 deg. and on the last two flights, I never got over 118 deg.

I have been told that Rotax ships the engines without thermostats and mine certainly operated as though it did not have one. Today I opened the thermostat housing and found that it did have a Rotax factory thermostat. See the photo.

The thermostat appears to have been designed for the Blue Head as it has a spring loaded disk on the back side that appears to close to the bypass port as the thermostat opens to the radiator. This would appear to be the best thermostat for the Blue Head but as my temps were too cold, I replaced it with an OMC 982554. I needed the Rotax gasket model 230-800 to install the OMC stat. The gasket on my Rotax stat will not work on the OMC stat.

I could not fly today due to inclement weather, but I ran the engine on the ground for a few minutes and maintained temp between 156 - 158 deg.

Looks like the OMC stat is better suited to the engine than the Rotax stat (that cost $95). I will let you guys know how it performs in flight when the weather permits.

 

[helipaddy]

Best mod I made was to move the prerotator lever to the throttle.

 

[Joe Pires]

Best mod I made was to move the prerotator lever to the throttle.

Show us what you mean.

 

[helipaddy]

I'll have a look for some photos Joe, I won't be down to the hangar for a bit, I got an extension made that bolts onto the standard throttle assy. It's about 8" long and the dia of a bicycle handlebar. The lever is attached to this and then a normal bicycle handgrip is put on.

Very natural operation and no changing of your hand position on the cyclic stick.

Joe, I'm in Florida all next week, I'll draw it on the back of a beer mat while we discuss it over a pint if you are around. Staying on Titusville.

Paddy

 

[EI-GYRO]

From 30 seconds in;

Dominator Gyroplane Flying in Ireland - YouTube

 

[Vance]

That is very cool Fergus.

That is very cool Fergus.

Thank you for sharing your clever idea.

I only recently identified a similar challenge on The Predator.

The small button up front in the second picture is the Pre-rotator and I can’t operate the throttle and push the button at the same time.

When I am cleared for takeoff I richen the mixture, advance the throttle a little and push the pre-rotator button. As I pull the cyclic full back at 120 rotor RPM I have to let go of the button to advance the throttle to begin my take off roll in earnest. I release the button at 150 rotor RPM.

This is awkward but I have learned to manage it so well I forget it could be done better.

I worked most of yesterday making my first attempt at my new switch panel. Around 6:00 I figured out why it would not work and started over. One of the challenges is where the mounting bolts intrude into the switch area. The rear bolt was right in the middle of my new magneto switch location and if I left a washer off or used too long a bolt it would break the switch. Considering who will be working on this those kind of easy to make mistakes should be mitigated before they cause a problem. The end of the bolt, the nut and the switch are not visible when mounting the panel and it is done by feel.


If I had to charge for my time this would be a very expensive seven inch piece of aluminum.

The two rectangular holes in the back of the panel were for the electric trim that doesn’t work with my Sport Copter blades. The large button is the starter. I need to add a power outlet for my Garmin 696 and I want a panel plug for my helmet. The other outlet is for power to the active noise canceling of my headset. The two protected switches are the left and right magneto switches.


This all seems so simple and yet I have around 12 hours invested in the project so far and I have been working around it since I purchased The Predator in November of 2008. I have over 1,300 takeoffs in my log book.

I feel it will make the take off sequence more natural when I can work the throttle with the pre-rotator engaged.

I love progress and the devil is in the details.

Sorry if I got off track.

Thank you, Vance

 

[EI-GYRO]

Sorry, Vance. Paddy's clever idea, not mine. I just knew where to find the video of his machine.

Ergonomic ease of operation and coordination of throttle, prerotator and brake
seem to be a common problem. I never got used to the ELA setup, and I
think the MT-03 is the same.

I'm sure you get the hang of it eventually, but it is most unhelpful for a
student to grapple with.

 

[j bird]

Vance, would it be easer to use a on-off toggle switch ?

 

[Joe Pires]

I'll have a look for some photos Joe, I won't be down to the hangar for a bit, I got an extension made that bolts onto the standard throttle assy. It's about 8" long and the dia of a bicycle handlebar. The lever is attached to this and then a normal bicycle handgrip is put on.

Very natural operation and no changing of your hand position on the cyclic stick.

Joe, I'm in Florida all next week, I'll draw it on the back of a beer mat while we discuss it over a pint if you are around. Staying on Titusville.

Paddy

Paddy I live just a few minutes from there. Come visit.
i will put my contact info in pm.

Joe

 

[cesphil]

Prerotator - Thermostat

Prerotator - Thermostat

Attached is a photo of my pre-rotator lever. I attached the bicycle brake lever to the handle on the quadrant throttle. The pre-rotator lever moves with the throttle handle. I am very pleased with the setup. As with the other setups, you don't need to change hands on the cyclic stick and it is very easy to engage. The two parallel levers look like they may be a little awkward to manipulate.

Also, I have 4 flights on my 582 with the OMC thermostat. It maintains temperature at 158 deg. with the oversized rabbit radiator.

 

[helipaddy]

Philip

That's almost exactly the way my prerotator lever is set up, works really well

Paddy

 

[SWaRC]

I have the same setup. The most natural feel to the operation of a pre-rotator in my opinion. Ditch the wooden handle and replace it with a pipe so you cal attach a lever on it. Done.

 

[j bird]

SWaRC, Sweet!. If I didn't have a hydraulic set-up with elec.actuator, I would sure do it the way you did.

 

[GyroRon]

For what its worth..... I am not a fan of that. The throttle quadrant on most dominators is not attached to the machine in what I would call a " Robust " way. I wouldn't want any excess weight or stress put on it. It does seem to work for others though

 

[MikeBoyette]

Ron very good point. I see people hanging their helmets and such from them. I caution them about this. It doesn't seem to matter to them I hope the throttle doesn't break off.