Weight of Tracy Obrien Gear Legs

[ededoad]

I used Tracy Obrien gear legs and got a little surprise today. I new my Sonex was going to be a little bit heavy but after weighing today I found it to be 20 lbs or so heavier than I expected. Any one else experienced this? I can only think that this is the gear legs.

[rizzz]

What does it weigh?
Is it polished or painted? What engine? Tail dragger? Instruments? ...

You say heavier than expected, what did you expect and why?

[ededoad]

I am using a O-200 with light weight starter mag and alternator. about 210 lbs. All painted because of the gulf coast. Expected about 710 -720 lbs ended up at 764. Engine monitor, airspeed, 10000 foot altimeter and skid ball.

[fastj22]

When I converted from tri gear to conventional, I also went from the stock titanium to TOB legs. My weight didn't change significantly. I doubt your weight is due to the TOB legs.

[kmacht]

How did you weight the plane and what did you use for scales? The titanium legs aren't very light and I suspect that the TOB legs may be a pound or two heavier but no way is it 20lbs.

Keith
#554

[ededoad]

I used electronic shipping scales and spirit levels. Used tire pressure to set center bubble. Don't think its the gear anymore. Just don't know where it is. Got emails from builders using similar alternate engines and I am still 20 lbs heavy. I am going to start weighing separate parts.

[fastj22]

I used electronic shipping scales and spirit levels. Used tire pressure to set center bubble. Don't think its the gear anymore. Just don't know where it is. Got emails from builders using similar alternate engines and I am still 20 lbs heavy. I am going to start weighing separate parts.

The O200 is at LEAST 20 lbs more than the Jab 3300 or the Aerovee turbo. Probably more like 40 to 50 lbs. I think you will find your weight gain there. How is your CG? Is it really forward?
There's a reason the O200 is not a recommended power plant for the Sonex. And its not reliability or serviceability.

[sonex892]

Do you have bigger tires and hydraulic brakes? They will add quite a bit of weight.

Mine originally weighed 655lbs, but after a few minor mods. Big tires (McCreary Airhawks 5:00x 5)/ hydraulic brakes (Great plains) / new vents / dial a rudder trim, I re-weighed. It had fattened up 20 lbs to 675lbs. The big tires were the biggest contributors probably followed by the brakes.

Steve
Sonex 892

[kmacht]

Not just the motor but what about the motor mount? The aerovee mount is pretty simple and light. Not sure what you have to mout the O-200 on.

It also might be worth trying a different set of scales just to confirm you really have a weight issue and it isn't a measuring problem. You said that you used electronic shipping scales. What is their weight range? Most scales don't measure accuratly in the first third of their load range.

Keith
#554

[ededoad]

I understand that paint will add up to 20 lbs so there it is. This is primed in and out and painted. Also larger tires and a couple of lbs for the gear. It all adds up.

I guess I have to live with it now.

Thanks for all the input.