Dolly Launcher for Ripmax " Mustang "

I acquired this" Mustang" from the late Hugh Matthews last June and have only just got round to getting her into the air.
Most people are happy to have them hand launched but I don't fancy the uncertainty at point of launch depending on the
skill of the launcher.
Recent posting on the MIG / Sabre ducted fans have eluded to this.
In the past I've had success launching a large glider off a dolly, so using this design adjusted in size for the Mustang, a suitable dolly was built.
Fast taxi runs across the neighbours lawn were encouraging showing rudder control was effective through the dolly and
the model remained stable on the dolly.
In answer to the question, it's a snug fit on the dolly but will drop away when the model lifts off.( hopefully )
Watch this space for report of flight tests.
Three pics are attached.

Colin.

Nice Colin. I made a steerable dolly for a Weston Magnum a few years back; it had a couple of dowls that the wings rested against but the first outing these were too tight against the fuz and it did several circuits before falling off!!

On second look you seem to have quite a bit of down thrust Colin?

davidbright wrote: On second look you seem to have quite a bit of down thrust Colin?

Dave - If you are referring to the motor, it's how Ripmax designed it.
However, if you mean the "sit" on the dolly, the wing is at zero incidence to the ground when measured on a flat surface.
A little academic really since Cashmoor is not flat, if you feel it's needed I could lift the nose up a little.
Thanks
Colin.

I think Dave has a point there. To lift off the dolly the model must rotate about the rear mounting point, with the wing at zero incidence. Some packing at the front support would allow the model to fly off without the need to rotate.Look forward to seeing it go!

I was referring to the motor. I'm sure the dolly aoa will be fine. After all, these birds get rolling and go neutral.

Alternatively Colin install retracts like the ripmax mustang I have ....

I must point out previous owner did this not me, I’m not sure I could have bothered to do it, but they are great

Tuesday 25th June - Light wind down the runway so first trials of the dolly were " up hill "
So here we go for the models maiden flight - built up speed gradually tracking slightly left, onto 3/4 throttle still not unstuck, touch of up elevator and she jumps off the dolly.
A few trim inputs and she's flying rock steady, landing no problem, slight touch of up elevator and she touches down on the radiator intake with no damage to the fixed prop.
Second flight could not control left swing with the rudder and again jumps off the dolly when up elevator applied, no action shots since I was the only one there.
I was hoping that when she reached takeoff speed she would have just lifted off the dolly without elevator input.
The " jump off " is very sudden - any ideas how to achieve a gentle lift off would be appreciated.
I'm considering fitting a steerable wheel to overcome the left swing.
Thanks
Colin.

I would suggest that you increase the angle of attack on the dolly Colin, it's probably jumping because you're applying lots of elevator to get it unstuck, then when the speed is enough it jumps off