Saturday, March 13, 2010

Need input on the Trike


The Trike demonstrator has not flown since we returned from Sebring. It sustained some very minor damage as we were loading it into the truck for the return home; the Superlite was a higher priority for us to work on after we got back. Also, the move into our new workshop location had consumed four weeks of our energy.

Based on the number of inquiries on the Trike, I know people want it and it's important to get this new plane up and running.

So here's my comments, and I want your feedback:

1) We redesigned the fuselage on the Trike to use an aluminum tail boom. You can see the black powdercoated tailboom in the photo above. It looks cool. It was supposed to save weight and reduce production complexity. It doesn't really save any weight, and the additional welding complexity on the tail feathers and rear landing (now main) landing gear largely offset welding savings on the rear fuselage. Should we use the original steel welded fuselage? Or stick with the aluminum boom?

2) The main gear of the Trike were designed from the ground up to use fiberglass rods. Although strong, this involved creating a couple more weldments that require fabrication. It would be easier to use an 'A' frame rear main gear similar to, if not identical, to our existing gear on the taildragger models, and forget the fiberglass rods. In other words, changing the gear design will save some money, and make this plane more affordable.

3) The nose gear works great; but we've discovered that the strength of the aluminum on the gear is a little marginal. Nothing really to discuss here; we're rebuilding the nose gear with some stronger aluminum.

4) The ground clearance is a little high, making taxiing tips slightly more likely.

5) I think many people want this with a bigger engine (think MZ-201 with 45HP) and light wings (think carbon fiber) so that it's weight legal in part 103. This would be an option, but would cost $$.

I have to make decisions on all of these over the next two weeks.

What do you think?

4 comments:

xaminmo said...

1) If the weight's the same, I'd say go with steel. The ease of welding steel vs aluminum, and the perception of strength with steel I think will add to warm fuzzies in sales.

2) I know it's a light plane, but I've seen fiberglass gear break. Metal MLG would improve the warm fuzzy feeling. With metal, you won't have a catastrophic failure all at once unless you have a bad weld. Also, all things being equal, simplicity in design is a big win for maintaining production quality and ease of maintenance.

3) I'm all for strengthening nose gear. While some people fly UL because it's cheaper/easier, some may not have enough training. Plunking it down might be more common, but UL reporting to ASRS or NTSB may be under reported. Not sure, but stronger nose gear would help prevent collapse/noseover.

4) I think shortening the gear would be a good thing. better balance, better ground effect. Alternatively, you could use wider gear, but I think you end up with non-optimal angles.

5) I think as options, maybe. I mean, a bigger engine and a climb prop would be fun, but not applicable to as many customers. I think low cost, simple, strong for the initial offering is the way to go. Alternatively, if you can maintain interchangeability between the planes and options, then it simplifies customization of features.

slattebo said...

tail boom is like a kolb solution. I prefer the origianl steel tube for simplicity.

landing gear should have one solution for both tail dragger the tri gear to keep design simple

the tri gear looks a little tall on it's ladding sticks like a gyro trying to achieve center line thrust. lower would 'look better' based on size and proportions . .

cowling does not look right yet .. .

dls - Green Bay WI

Harold said...

1) Since steel is same weight using a common fuselage for all versions makes sense
2) Metal gear seems again to represent standardization- a good thing
3)You have the nose gear mod in work
4)Gear length commensurate with prop ground clearance and better balance on ground
5) Basic aircraft with options unless weight is the critical factor

Personal bias for an UL aircraft is for STOL and climb performance thus lightest weight and highest power while holding at =<55kts

JimInMN said...

Like steel tail, simpler. Eliminates an "interface".

Likewise gear, transition from steel to glass adds complexity. I am also concerned about ability to disapate energy, not store it, rebound.