Plans built Dominator

[turbodog]

Construction is underway on my single place Dominator, I plan on using a 670 rotax and b box for power and of course 24' DWs, mechanical prerotator, will be trying to keep weight to a min. Any comments, or ideas will be appreciated.

 

[turbodog]

More Pics

More Pics

Still new to posting pics, try these.

 

[scottessex]

Just a FYI, the "B" box might be a little weak for the 670. A "C" box would probably be a better choice.

And you could resize your pictures not quite so small. I don't know what program you have, I usually size mine to around 8-9 inches, or around 125kb

Some people say 600x400 pixels or what ever.
The gyro looks good.

 

[MikeBoyette]

Carey,
Be careful not too much luck around here with the 670. Do an archive search on the 670 on this conference you'll see a few problems with it on gyros.

 

[gyroman]

welcome

welcome

Welcome to the Forum Casey... Congrats on the build, looks great. Wish I was closer I'dd love to take a look..

 

[gyromike]

There seem to be a lot of bolts in the cluster plates.
Are they phillips head?

 

[jdalexa]

Carey,

The choice of gearbox is determined for the most part by the prop moment of inertia. A "B" box can handle a 60 inch prop, but with the sort of power a 670 will provide, I'm betting it will not last.

The pictures attached will tell the story of why. The first picture is the big gear and the dog gear from a B-box. The big gear meshes with the small gear on the crankshaft of the engine and reduces the engine rpm to something good for the prop. The propshaft fits into the dog gear splines and it in turn fits onto the ears of the big gear and is loaded to around 1800psi by springs. Impulse dampening from engine and prop takes place by the 2 pieces rocking against one another. The 2nd picture shows them together.

While the B box can handle the size prop you would likely be putting on, the sheer power of the 670 would hammer the dog gear. A C-box has a hard rubber "hardy" disk to absorb the impulses and can handle much larger loads.

Then again, there is the issue that the 670 is a snowmobile engine. The case and other bits are not built to withstand the specific and special stresses involved with having a propeller attached. On a snowmobile, if the engine stops, you just pull over. In an aircraft....

Do yourself a favor and find a 582 to hang on it. You will very likely be happier in the long run.

I've got a 582-90 that I replaced with a blue head, if you're interested. P.M. me if you wanna talk.

 

[turbodog]

Mike G. The bolts are an-4 and there is 4 in the lower keel, and 4 in the
mast, and 8 in the forward keel, as per Ernie's plans. My pics are not the
best.

 

[turbodog]

John A., I agree with your comments on the gear box, right now a C or
E box are not in the budget and I do have a B box to use. As for the 670 it
is a 618 lower crankcase with 670 crank and cylinders, coated pistons,618 exhaust, I had this engine on a Kolb firestar and it has 71 hrs on it. I have been building two stroke engines and Rotaxs for about 15 years.

 

[turbodog]

Does anyone flying a dominator with an engine other than a 2 stroke rotax have the original motor mounts that they would like to get rid of? Thanks

 

[jdalexa]

Wasn't aware of your experience with Rotax's, hence the explanation. Hopefully it will be helpful to others though.

It's quite interesting to see the pictures of it coming together after having stripped mine bare last winter.

 

[13brv3]

Cool pics Carey!

If you don't mind me asking, are you doing all this work just because you like to fabricate stuff (a perfectly valid reason BTW), or to save some money?

I bought the plans for a single place, with the intention of building all the parts myself, but when I look at the modest prices of the pre-fab stuff Ernie sells, I just can't justify the time to do it myself. Of course I haven't quite jusfied buying yet either, but I'm getting there

Cheers,
Rusty

 

[Timchick]

Rusty,
You need to hook up with Blake Avant. He has a Sport Copter over in Navarre. His screen name on the forum is RazorBlake.

 

[13brv3]

Rusty,
You need to hook up with Blake Avant. He has a Sport Copter over in Navarre. His screen name on the forum is RazorBlake.

Hi Tim,

What I really need is for Blake to quit flying around my airport.

Why do you think I'm back here looking at gyros again? The gyro condition was in remission, and I was perfectly happy to tinker with fixed wing planes, but noooooo, Blake has to come around making me want a gyro again. I really don't need another toy. Just ask my wife

Seriously, it's almost a certainty that I'll build a Dominator. It's just a matter of when.

Cheers,
Rusty

 

[turbodog]

Rusty, I do enjoy building and then actually flying it, man that is the lick!! Gyros are in my opinion are so much easier construct than a fixed wing, not to mention the thrill ride a gyro gives. I have all the equipment for fabrication at my business, a repair and fab shop. Just buying someones gyro and then having to worry about the construction or having to rebuild parts is something I perfer not to do. So if you do decide to build good luck with you project. Carey

 

[13brv3]

Hi Carey,

I guess if you have a repair and fab shop, this sort of work isn't that much of a challenge for you. I'm still on the learning curve for welding, so I'll certainly let Ernie supply the pre-welded parts, then I'll concentrate on the engine conversion, which is my main interest at the moment. Maybe I'll get started later this year when the current RV-8 project is flying.

Cheers,
Rusty

 

[turbodog]

Rusty, my fab shop is a one man operation, after 25 years of being a master tech in porsche and audi dealers, I quit working for others and opened up a shop fabbing street rod parts and building u/ls. Sometime the income is slow but there is always something fun going on.
Carey

 

[turbodog]

on wheels finally

on wheels finally

My baby has new shoes, all welding done except top mount for rudder.

 

[turbodog]

More pics

More pics

Thanks to Tom Milton for an excellent seat tank, the construction is the best I have seen.
Carey

 

[MikeBoyette]

Carey,
Looks good keep up the good work. Are you going to make your own tail or buy one from my dad.