Skybug One

[Simon Chaddock]

I did add a 😉 concerning the gyro.

 

On the other hand I am not keen on white knuckle rides so when I maiden an own design with un proven aerodynamics I do fit a gyro but in rate mode so no positive stabilisation. Hopefully this slows down the plane reactions enough for my 'old age' eye/hand coordination to keep up. 

[Shaun Walsh]

1 minute ago, Simon Chaddock said:

I did add a 😉 concerning the gyro.

 

On the other hand I am not keen on white knuckle rides so when I maiden an own design with un proven aerodynamics I do fit a gyro but in rate mode so no positive stabilisation. Hopefully this slows down the plane reactions enough for my 'old age' eye/hand coordination to keep up. 

First time I enabled a gyro in flight, the model went crazy.

Memo to self, ensure gyro moves control surfaces in the right direction before flight!

[Lindsay Todd]

Hopefully this next week I can get the remaining work done and then get a final weight and assess the power setup properly, i am hoping to run on 3 cell lipo but there is space for 4 cell if required but the model has not been on the scales yet and the CG may need a little assistance in the nose as I want to be slightly forward of the mathematical position at least for the first flights. Hopefully we can be in excess of 125 watts per pound with a 11-12 inch prop. I have a 710watt 900kv sat on the shelf ready pending final weight checks, i am hoping just over half that would be enough. Linds

 

Edited November 5, 2023 by Lindsay Todd

[Lindsay Todd]

Ideal day for a test flight all complete checked and ready, final motor configuration updated to an Overlander thumper 900kv throwing a 14x6 prop at just under 400 watts and an all up weight of just on 4lb. An hours trip down to my test flight site, and a further check over and all the static shots done.

 

with no more excuses left i lined up for the first flight, good acceleration, V tail rudder working fine, up to flying speed and eased back on the elevator

 

As the model rotated it was clear something was wrong with the ailerons so with an inch or two off the ground i chopped the power. On inspection the left hand aileron servo had stripped its gears and explained the sudden loss of feel, any further and it could have been far more serious but so frustrating as from the photo above it was so nearly there but we can't yet claim a successful first flight.

On the plus side, I was able to satisfy myself re power, rudder and elevator authority. it will be a couple of weeks now before i get another chance but this is what test flights are all about and just grateful the brain was able to react so fast to something having happened so suddenly.

 

The servos were a couple of mini Hitec mini nylon gear items, I will upgrade both i think even though the load has not been the route cause, might have got knocked in transit and the cold will not have helped I guess. 

 

Linds

[Richard Harris]

Well done Linds,shame about the servo. You can almost taste it!

[Lindsay Todd]

Not the best image as it had some rubbish behind which had to be edited out but finally got airborne having waited since last November, a couple of trims and a bit more exponential on aileron but not to bad a test flight. Need a better day, brighter sky and can get some proper pics done.

 

Linds

[john stones 1 - Moderator]

Well done, video would be nice Linds. 😉

[Simon Chaddock]

Impressive

A very good example of "with enough power fancy aerodynamics are not required"

[Lindsay Todd]

Since the first flight i did need to resolve one major issue and that was ground handling, it was none existent and way beyond acceptable. The answer was a complete revised design for the two front axles as  did not want to loose the look. This took time to figure out although the end result is pretty basic, sometimes the brain cells just don't align. Eventually I realized I needed a steering set up so two center pivot points and a servo connection was required. The end result is two aluminium folded strips drilled to take 4mm wire axles, a link bar on one side and direct servo linkage on the other via a ball link. A bit of fiddling to mix a 5th channel to the V tail rudder channel and we have a result. Ok, no suspension and direct link may risk the servo gearing without a servo saver head which I will fit if the loads seem high.

 

Time for some taxi trials and more flights. Linds

Edited August 25 by Lindsay Todd

[Robin Colbourne]

Lindsay, the two front axles are probably trying to turn on different turning circles.  Geometry on a pair of axles is quite complex.  At one model club I went to, there was a chap who designed the steering geometry of the Panther Six Supercar, which like Lady Penelope's FAB1 in Thunderbirds, had two front axles.   He did describe how he made it work, but lost me at about the second sentence!



What you could do is to take a leaf from the Scalextric book.  They want the illusion of four wheels on the track, but not for those wheels to try and steer the car off course.  To achieve this, the front axle runs in vertical slots, so the wheels are on the track, but all the weight is on the braided electrical pickups.  If you made your middle axle with vertical slots instead of round holes for the axle, there would be no weight on it and the front axle should have better steering authority.

Edited August 25 by Robin Colbourne