View Full Version : Gizmo prerotator and Dragon Wings
Resasi
08-30-2008, 10:09 AM
Would like to use Dragon Wings as we are trying for 103.
Does anyone have experience on using the Gizmo prerotator with these type of Rotors, and could you comment on it's effectiveness as I believe they are difficult!!! to pat up.
Any info on light prerotators also very welcome.
gyrojake
08-31-2008, 11:08 AM
Your gonna need 75 to 100 r.p.m. on the dragon wings before you start to taxi or you will flap the blades. Dragon wings are worth a prerotator because thay out perform any other blade I've ever flown. What is a gizmo prerotator never heard of or seen one? Good luck,
Jake
Timchick
08-31-2008, 03:09 PM
Here you go Jake. Gizmo hand recoil prerotator. http://www.starbeegyros.com/productdetail.asp?ID=181&kits=
gyrojake
08-31-2008, 03:37 PM
Is the white line the torque tube and is the black line the rotor head bolt?
Man, does that thing come with a box of Wheaties !!? :lol:
I wonder if the human body can deliver enough horse power to get the D/Ws up to speed.
I Know my old worn out body won't be able to do it.
Thanks Tim---never new about this.
Jazzenjohn
08-31-2008, 04:24 PM
I keep seeing the Gismo, and people keep mentioning it, but I've yet to hear from anyone that actually uses one to prerotate Dragon Wings.
How accessible is the rotor from the seat? DW's are more of a timing issue than brute strength.
Phil.
helipaddy
08-31-2008, 10:09 PM
You wouldn't have to add too much to the $840 gizmo cost to get a proven flex shaft pre-rotator that will work.
Oskar
08-31-2008, 10:40 PM
I've got a Gizmo with 24' SportCopter blades. Getting the blades to 50rpm is easy but anything over 60 is very hard work. For SportCopter blades 50rpm is all you need to get going, if you need 75 for DWs you will struggle with a Gizmo.
Resasi
09-02-2008, 11:06 AM
Thank you all for the input Tim for the picture of the Gizmo and Oskar for your experience
From all I have found researching, the performance of the Dragon wings is what attracts me to them.
The problem of hand starting though a problem as we will be struggling with the weight issue to keep below 254. Any prerotator would have to be light. The Gizmo is light but would seem not to be the best answer for DW's. Wunderlichts probably a heavy way to go, and do not know of any present light hydraulic system, or indeed of any other ultralight prerotator system. Have seen the picture of the French pulley system but did not like the idea of those long belts.
The DW's and Rotor Hawks are similar in weight, not much difference, those presently patting up on the Bensen I am training on without too much trouble. I of course have no way of comparing the performance though.
May have to trade performance for the weight involved.
Oskar
09-02-2008, 12:41 PM
You could also consider SportCopter blades with no prerotator. Weight wise they would probably be about the same weight as DW's with a Gizmo prerotator.
The SportCopters are very easy to handstart with a bit of wind, to handstart safely with no wind you would want electric start on your engine. Many handstart with the engine running, but I'm no longer prepared to take that risk.
I have DW's on my Mosquito and SportCopters on my GyroBee. Both are excellent, but for a gyro I would always choose SportCopter.
Georgi
09-02-2008, 01:36 PM
I have Gizmo and 24' Rotordyne blades. So I need only 45 RPM to start safely taxing. Without Gizmo I would not be able to fly my gyro in my sometimes busy airport for two reasons:
I can not reach the rotor from my seat to start (sitting too low for such tall mast) and (the same problem) if RPMs are slowing down while I am waiting for somebody's long final and there are nobody to help me there. Hopefully somebody will design very light rotors (weightwise and easy start) with rotorends weights for good inertia for landing. And if that new very light Air50(?) rotary engine will prove viable there will be plenty reserve in weight for any blades and prerotators.
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