long slow process, the Autoflight 700

uniflow

Newbie
Test flying the Autoflight 700 twin,
And it's me testing it. Runs smooth (internal balance shaft) and powerful (80HP) with the internal gear reduction proving robust so far. Still single ignition for the moment and runnimg carburetors. I've got a second engine here that will be set up with TPI injection and burning E85.
https://youtu.be/8pS4KhsTtoo

https://youtu.be/8IA3Xth6jXc
 
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Kevin_Richey

Yamaha gyro...Oregon, USA
Neil: Thanks for sharing the twin engine project. It has been a long time since we've heard from you on this forum.

As an aside, a fellow PRA Chapter member has a SparrowHawk gyroplane, w/ the Subaru 2.5 l. engine. Stock belt drive. He'd like to convert it to a gear reduction, exactly as Brock Steiner here locally did to his same gyro, using one of your gear reductions. Will you sell him one?
 

Kevin_Richey

Yamaha gyro...Oregon, USA
Neil: Does that vertical shaft prerotator on the front end of your new engine have a clutch somewhere inside the engine case?

Pretty nifty to have a reduction drive built into the engine.
 

uniflow

Newbie
yes, a cone clutch, all built in as part of the engine.
Internal reduction drive was designed to make the engine lighter and shorter, various ratios are available. Especially designed for autogyro use.
New engine with TP injection is cleaner and more fuel efficient. TP injection is is simple, reliable and cheap.
 
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Kevin_Richey

Yamaha gyro...Oregon, USA
Is the cone raised up by the pilot to engage the prerotator? Varying the cone nestling inside another cone to slowly bring the rotors up to speed?
 

uniflow

Newbie
the female cone is connected to the end of the balance shaft, spinning all the time. The male half is connected to the angle drive, angle drive is able to slide in and out via a lever and cable, operated by the pilot.
Pilot uses a clutch handle ( like most gyros) to engage the cones. Some slippage is nessasary for a start but not for long then one to one drive. Works well.
 

Cresco750

Newbie
Very cool. I love the safety ‘Stubbies’! What’s your ultimate goal for this engine, Neil; do you hope to put it in production or is it one-off for your own use?
 

uniflow

Newbie
Obviously for the moment it has to be just a one off ( or two or three off) but eventually I would like to do a production run. I'm sorting production tooling for the cylinders now and a production sand molding machine.
I have all the CNC machining sorted, cranks cases etc and I have a gear hobbing machine ready for production runs.
BUT I want more time on this one first and perhaps a second engine ( I have a second complete engine minus the cylinders, thats what I'm trying to sort at the moment).
And I have a third engine unmachined, also missing cylinders.
I must say I'm enjoying the test flying, a little nervously at times as I'm only low hours, not that much more than the engine. Every landing is a practice engine out. All flying is close circuits and the airstrip is long and wide.
 

uniflow

Newbie
Purchaced another four litres of twostroke oil, optimistic?
Perhaps, but I hope not, off to run the gyro again this weekend. More tight circuit's.
 

uniflow

Newbie
two and a half more hours, still just circuits but plenty of fun.
This engine was never supposed to fly, ground run only but its going so well, why not do circuits. Have been careful to run it up to only 6000 rpm, flys nice at that. This weekend I turned it up to 6800, what a difference, it sparkles. Should be good for 7500 all up. But we won't be going there yet.
 

uniflow

Newbie
another two hours today, Starting to relax and feel quite confident on an out landing now if needed. Did my first cross country ( over size circuit😆)
Might have some video on line soon.
 
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