Soft start your prerotator

[asra]

OK....we might have the answer here, 2 are currently being tested on machines, 12v starter motors are being used.No need to even flick the blades prior to engaging the electric starter, blades begin to turn as soft as.Costs approx $60, thats all.Blades will spin up to approx 140rpm, or better.As my machine is a trainer, this soft start will get a good workout quickly. Photos and how to do will follow if it works out as expected.[] I'm feelin real confident.By the way thanks to Max at Tennent Ck....NTRDC

[birdy]

The smartest auto sparky I know is ol Max.Ignorance is bliss............but only till you realise you were.Ingratitude stinks.......be generous carefully.

[asra]

Great Russell. Look forward to the news. Have you got your slider head yet?Aussie Paul. []www.firebirdgyros.com

[asra]

Come on Russel, what is its principle of operation?John EvansThink logically and do things well, think laterally and do things better.

[asra]

Come on Russel, what is its principle of operation?John EvansThink logically and do things well, think laterally and do things better.

[asra]

G'day Paul.....NO, hope to have it fitted for easter though.John.....You maintain your existing elec prerotator and it's switch etc, you fit a special solenoid and resistor into the main wiring , with it's own switch, a little bit of wiring is required to loop into system. So initial startup you press the new switch installed, which soft starts the blades, then you release that switch and engage your original prerotate switch, works a treat. Will give part numbers etc when this prooves its self.And photos . Yes Dave, Max is a whizz[]RDC

[asra]

Geez Doc, you really want to know eh? Two posts!!! LOL[]It sounds just like your Harp resister system though. I wonder if it is a carbon pile resister?[?]I just have not had time to sus out the carbon resister yet. What are your thoughts on it Doc?[?]O.B. Aussie Paul. []www.firebirdgyros.com

[asra]

The double post was due to my usual finger problems[:I]Yes it sounds very much like another version of my original design.I don't know much about carbon piles [ seems it has nothing to do with haemorhoids that have been cauterised ]. Possibly they could allow variation of resistance by varying the pressure applied, much like the principle of a carbon microphone.The good thing about the 'Harp' is it's simplicity and and ready availability of components cheaply.I would make the point here that in my view it is not necessary to have more than one level of torque control, my experience indicates that the single resistor provides this so long as the multiple strands can stabilise their resistance quickly, Nichrome does this very nicely.John EvansThink logically and do things well, think laterally and do things better.

[asra]

[asra]

Russell,Do you want to see a unit that realy works?, a system that has been in use for nine years, Email pjbarsden268@ozemail.com.au and I will send you photos and details.All the bestPete Barsden

[Waddles]

Gidday Russell,This sounds similar to the unit I have fitted to the Monarch. It works in 2 stages as you say, but the torque applied to the rotor head is still significant. Have someone balance the machine on the mains only, then engage the soft start, then the full charge. If the nosewheel tends to be deflected by the torque, then, in my opinion, it is too much.I have seen Peter Barsden's set-up first hand, and it is a gradual torque applied at a rate determined by how quickly a knob is turned, thus the power to the motor and therefore the torque can be infinitely varied.I hope to have one fitted in time for Cooma, provided I can locate the pre-rotator to eliminate the minor stick shake it causes.Regards,Waddles.

[Brian]

Waddles, you are probably way in front of me but I will tell you my limited experience in regard to 'stick shake' due to location of pre rotator, I happened to buy a new set of rotors and experienced a lot of stick shake which I didnt have with my other set of rotors so I contacted the rotor builder and he told me it was due to where my pre rotator was located, I had Rosco double check the head, still no better then I tried another set of rotors from the same builder, guess what ??? no shake, smooth as you could possibly get.I suspect you didnt have a pre rotator and have fitted one and now have a shake and if thats the case you are going to have fun getting it smooth. Seems the extra weight up there really makes any small imperfection in the blades show up.Brian.You never know how far you can go, till you get there !

[asra]

Dumb question here...whats wrong with useing a automotive V-belt drive from eather your electric starter or mechanical pre-rotator ? it will inherantly slip as all v belts do...I have one on my modified bumble bee and it works great .... I ease the pre rotor in and it slowly starts spinnin'er up .... no shock at all for an electric starter arrangement just use a 12" v belt pully mounted beneth the berring block... and a 2" pully on the starter... tension on the belt is the key.... alow it to slip some and your good to go.... belts are cheep to replace when they finally burn out ...... but mine is 3 years old and shows no ware at all but an electric starter would probly tax the belt a bit .just a thought ....Bob....

[asra]

Difficult to visualise your set up without a photo...I wonder if you'll need a sprag bearing somewhere?salutations []André Martin.Québec; CANADA.