Crane Fly Light , Autotogyro Trainer , For experienced pilots trying autogyros for the first time.

[bees]

Okay will do, feel sure it's something simple. That's staring at me. Glen

[Tom Wright 2]

If it is I cannot imagine what .

[bees]

All this afternoon spent trying to solve the problem to no avail. Did manage to get them up to something like speed but i had a fraction over 1mm shim. Now i have started adding shims and i reckon iam around 0.4 mm shim but no spin up. Just about had enough for today and a little frustrated that i cannot solve this problem as i was ready to order the Firefly 11 as my next step up but at the moment i have stalled. Glen

Edited By bees on 29/05/2014 17:29:32

[Tom Wright 2]

Glen

I view of your previous experience and success with the CF SFH I cannot imagine that you have missed any of the the obvious points that effect spin up.

If you eyeball a blade from the tip can you see any negative blade incidence relative to the plate? and are you sure the blade bolts are not over tight and causing plate distortion ? Could you confirm the current shim thickness and the distance the shim l/e is from the bolt centre.

I am clutching at straws here, so it would probably be a good idea to meet up and get the model flying, I am available this Saturday if it's any help .

Tom.

[bees]

When eyeballing from the tip you can see some slight negative pitch. I reckon I am about 0.8 at the moment and have tried shims from less then 0.4 up to about 1mm shims. I put the shims 4mm from ct go bolt hole. I like to go flying my fixed wing on Saturdays but aim determined to solve this problem by myself as this will hold in good stead for future projects but if I find I cannot I will send you a pm. Glen

[bees]

Down at the field today again and with a breeze the blades will spin to speed but only if I hold at 90 degrees and find when levelling out to launch they tend to slow down a little but enough to launch , is this normal never took much notice when launching the CF. Any how when I launched the wind seems to act against the CFL and it seems to go backwards into the wind. Do you think I should add a little more weight to the nose to penetrate the wind . I have started with probably 0.9 to 1 mm shims and have been sanding them down slowly and the spin up seems to be getting better.

[Tom Wright 2]

Glen I think you might be be expecting a higher rotor speed than the actual speed necessary for getting away successfully, but of course a rotor not up to speed is a guaranteed crash.

The pitch up and apparent blow back you describe can be due to several things . Firstly was sufficient power applied and available, if so what effect did lowering the nose with elevator have? some down elevator to check the climb angle would probably be needed if full and rated power was applied.

Added nose weight may appear to improve things but this could just be masking the need for other adjustments.Shims set at 0.8 mm should give very easy spin up and for the next try I would suggest elevator down trim and plenty of power for the getaway but do reduce power to cruise setting once above 50 ft .

This may or may not be the correct solution as I would need to see model and observe it in flight to make a positive suggestion.

Tom.

 

 

Edited By Tom Wright 2 on 31/05/2014 21:24:44

[bees]

Tom, Launched and the CFL flew for about 40 yards with some height gained but when any roll input is applied more so left it just wants to drop its nose and roll to the left violently any ideas . Glen

[Tom Wright 2]

Hi Glen

Questions again .... Did it climb out hands off ? What power setting was used?

My first thought would be that the climb angle was to high for the power available and the control throws are on the high side . To much rudder throw could certainly make things tricky as the response is immediate with the rotor response following slightly behind.

Try the same climb out then lower the nose to a very slight nose up angle and reduce the power so she makes a positive slow cruise speed, at this point any need to hold roll and pitch on the sticks should be noted followed by a gradual reduction of power to land straight ahead. Adjust the trims and repeat the exercise.

Any turns at least until you have got used to the model should be progressive with application of up elevator to keep the nose tracking slightly above the horizon .

I flew three CFLs at the weekend and found one in particular was so ridiculously easy that it flew like an intermediate fixed wing trainer, I know you like the challenge of sorting these things out but the interactions between vertical cog thrust line , lift vector , and elevator trim can be perplexing if things don't go to plan.

It is usually quite possible to sort out problems without damaging the model as long as the approach to adjustments is done progressively by way of short in to wind sorties so I would fix the shims at 0.8 mm set 6 mm behind the bolt hole centre and assuming the flex plate is as per the Coolwind and pdf specs your rotor should behave identically to my sample model. The CFL will easily carry a 1.3 A so it may be worth a try ,my only reservation is extra weight can result in damage if arrivals are less than dignified .

Tom,.

[Tom Wright 2]

[bees]

Sorry Tom but i think my auto gyro days are over. Just about got fed up of going to the field trying it and bringing it back in pieces. I think this time was the last straw. I can not keep asking you questions all the time when i can not sort it out myself so i think i will just stick to flying the CF on occasions when i take my fixed wing to the field. Thank you for your time and help over the last 12 months and at least i gave it a try. Glen

[Tom Wright 2]

Take a breather Glen and don't give up, as you are not to far away I would be happy to come over and sort out whatever the problem is. most afternoons and evenings in the week are OK for me.

Tom.

[bees]

Hi Tom , will be away on hols for next week so will give it a rest and see how I feel after . Thanks for your offer but if I Decide to carry on will come over to your place if that is okay as I would not expect you to come to my place. Glen

[Tom Wright 2]

Glen if you can get over just bring the model as is, I have all the spares and can fix any crash damage very quickly and leave time to have a flying session at the field which is only a few minutes away

It is quite important for me to establish why you could not get the model flying as it might be of benefit to other builders.Enjoy the break and I hope to hear from you when you get back.

Tom.

[bees]

Actually it would only take me about 15 mins to repair so will get back to you after my break . Glen

[Tom Wright 2]

Great stuff Glen ,but check for a bent rotor bolt as even a slight bend can cause "hair tearing " variable roll trim .

The stainless steel bolts seem much more prone to bending so I no longer use them. pm me for address and phone number ,

Tom.

[Tom Wright 2]

David from NZ sent me this photo of his CFL build, best of luck with the maiden .

[Deyrick Gibbins]

Have been flying mine quite a bit over the last week, still going well.

Have just gone through the thread on the Atom from Richard Harris for RCME, looks nice, may have to make one now I have some flying experience with Gyro's.

Edited By Deyrick Gibbins on 21/09/2014 19:02:22

[Tom Wright 2]

Deyric

Glad to hear you are still flying your CFL , the Atom should fly very similarly, but of course is much better looking Regards

Tom.

[Deyrick Gibbins]

Another half dozen flight today and 3 on the AutoG, first time in ages for that.

Have to wait for the heads to come in stock as no one seems to have any at moment, for the Atom that is.

[Richard Franks]

Hi ,

I am new to this scary world of model autogyros having been an aeromodeller most of my life flying fixed wing. I have had limited success with an AJ autogyro (managed some circuits and building confidence).

I have scaled up x 1.5 a cranefly 2 and have a question.The mast height on the scaled up model looks far too long is there any reason why I cannot reduce the mast height?

Richard (Kent).Pleased to say I am the only club member turning to this dark side.Any help on this and flying would be a great help.I will never give up.

[ken anderson.]

hello richard...i had a go and built two of tom's...he's your man for the cranefly as is young rich harris....for his design's..

ken anderson...ne...1 foodmixer dept.

[Tom Wright 2]

Hi Richard

Well the most important thing here is your resolution not to give up.

Attempting a new design by scaling up is perhaps a little ambitious until a good few hours of successful auto gyro flying experience is gained . IMHO the AJ is an easy to fly model so at this stage any difficulty encountered should be revisited and considered carefully.

As I have said many times before early days flights are often terminated by disorientation flying to fast , and not having a full appreciation of the trim factors that result in a model that can be managed by a rotary newbie.

To comment on your scale up would require some data on blades,shims, plate, AUW, and power but if its any help I do have a scaled up CF with a mast height of 14" measured from the fus bottom to the pitch pivot point .

If you live within practical driving distance from North Nottinghamshire I would be happy to help[ get you flying with any auto gyro, I also have several CF based trainers that you could have a go with.

Regards

Tom.

[Richard Franks]

HI and thanks for the replies,

Had a great day today with my AJ autogyro.The thing actually flies well.Did circuits and landings.One landing a bit heavy and minor damage received (now fixed ready to go again). It actually flew on my home made blades(thanks to Rich Harris you tube tutorial).

The changes I made to see an incredible difference was (1) reduced down thrust by a couple of degrees and (2) Reduced rotor shim thickness to 0.4mm This made a massive difference.Must get used to rudder turns !!

My scaled up cranefly mast height is similar to what you have done so I will leave it alone.I must thank you VERY much for the invitation but I am in Kent near Folkestone.

I felt a big improvement today and will not fly the larger one until proficient with the AJ autogyro.The thing seems almost indestructible!!.

Thank you all very much.

[Malcolm - coolwind.co.uk]

Well Done Richard,

Good to hear you are getting there !!

Malcolm