How will yours work regarding soft start and speed regulating, will it all be in the controller and then just a switch to activate?
the RC command brushless controllers can be controlled by a pod ( a sevo tester)
I will put the servo tester on a lever with a micro switch under so that I need to push on the pod to power it
the controller does not send current to the brushless until you turn back the pod to zero ( to avoid any brutal start)
the controller also has a soft start
plus I will install a timer relay that will send the current from the pack to the controller only for 2 minutes
so to pre-spin i will have to
- place stick fully ahead
- pull back the rotax throttle to idle ( coz I will use the left hand to control the pre-spinn process)
- push the timer relay button still with left hand
- push the pod down, zero the pod, and then turn it smoothly ( it as 300° from 0 to 100%) to increase rpm applying the wheel brakes at the same time ( the lever is on the stick)
- as soon as I get 140 rpm stick back fully
- finish the pre-spin
- realease the pod and the brakes and full throttle
in fligth the timer will cut the current so that there zero chance for the pre spinner to start while flying
I don't want an automatic system for the moment ...
YES !! When time and money permit, there are some new outrunner motors that provide much torque and it is my plan to put one around the rotor head for testing. I know, Chuck, we don't want to add more weight up there.I often wonder if i could be possible to (somehow) integrate the electric pre-rotation motor in the rotor axle, with co-axial induction coils, hence eliminating all moving parts...
It has been done, that German manufacturer (gyro tech I think ) were building there gyro's with that style of spinner but they seem to have disappeared. I think there later models they went back to a more conventional engine driven system for some reason.I very much admire your efforts concerning the electric pre-rotator. I often wonder if i could be possible to (somehow) integrate the electric pre-rotation motor in the rotor axle, with co-axial induction coils, hence eliminating all moving parts...
Yes I totally agree with you, I definately don't like having a sliding spline etc joining the head to the mast.Hi,
I think that the manufacturers have no interest in developing an electric pre-spinner when you know that existing systems just work good
home builder are the only one that are crazy enough to design and machine such a system.
however it is nice to try , the benefits can be interesting, for me the more important is to get rig of any mechanical link btw the rotor head and the gyro frame, secondly I am totally tiered of occuping the runway 4 minutes on average before taking off, thirdly I hate the feeling of mechanical where the brakes and the rest of the pechanical parts are under pressure the propeller pushing the gyro , with all the vibrations and so on , all of this is not satisfactory for me etcetc...
If 200 rpm of the electric spinner seems sufficient to you, why do not they seem sufficient to you with the mechanical spinner, since then the thrust of the propeller and the gripp of the wheels discharged by the rotor, do not yet create problem ?Electric is independent and from 200 while rolling will accelerate rapidly.
Required power varies with (diameter)^4
So, talking about rrpm prerotator, without specifying the diameter makes little sense.
For only 1.5 kw mechanical produced by a car starter you need 3 kw electrical.
This electric power requires:
ordinary car battery: 30 lbs
Odissey 625 15 lbs
Lithium 3 lbs
With electric once at 200r rpm the engine can be advanced almost instantly to full power to accelerate instantly.If 200 rpm of the electric spinner seems sufficient to you, why do not they seem sufficient to you with the mechanical spinner, since then the thrust of the propeller and the gripp of the wheels discharged by the rotor, do not yet create problem ?
200 rpm instead of 300rpm requires only 44% of braking, while the grip of the tires increases by 50%
For the reasons stated in my last post I think it's easier to do with electric rather than mechanical, unless there is a overload clutch for the mechanical.You are right Wolfy. I love Birdy's technique where he keeps the pre-rotator engaged during the t/o roll. I do it regularly with the AR1. Of course, there is a lot of torque reaction in the process. But the results are amazing. Unfortunately, that is difficult to do with an electric spinner.