Crane Fly Trainer Autogyro

[Olly P]

not for a while yet methinks...

[Tom Wright 2]

Hi Tony .

I should be able to post the complete material and hardware list before the weekend ,the build was started ahead of the intended schedule and some design changes were also anticipated that could have changed the material list.

 

The model will be finished and weather permitting test flown by the middle of next week the object of the exercise is to produce a simple inexpensive and practical model that could get fixed wing pilots going with autogyros ,its a tall order in some ways as Rich has put a lot of effort into similar projects to find most duck out when it comes to the crunch.excuse the pun.

 

So if its quick and easy to build cheap and works ,hopefully the drop out rate will be less,if you have never flown one you don't know what you missing .

 

HI r Active

A foam ply hybrid would be possible ,but key areas need to be torsionally rigid along with good alignment accuracy between principle components.and the weight must be kept low to reduce the damage when things go wrong.

 

 

All

OMO the key to initial success is based on a light slow flying design ,combined with an understanding of trim requirements ,suitable weather for first flights and a pilot that does not rely on automatic model stability to avoid the ground.

In other words you blokes have no excuse not to be flying autogyros ,unless of course you just don't want to .I will be very disappointed not to see some successes from this thread. At least I will end up with another design to fly next season . It would be great to see others having fun as well.

 

Tom.

[Tom Wright 2]

This is the result lo far when the Crane fly parts are put together ,not to bad as it was started less than two days ago and included some new design work.

 

In case the gyro clutter is confusing its the one in the foreground.

 

 

Edited By Tom Wright 2 on 05/01/2012 16:33:07

[Dean]

Hi Tom

Loving this build, it looks quite simple to put together i am very tempted to build one. gyrocopters really fascinate me so this could be a good way to try one out.

I will hang on until i know the whole material list much like TonyS I don`t really have any spare wood laying about (only built one ARTF and part way through one traditional build).

This might be a daft question but what do you use for the rotors? is it normal rc helicopter blades from the LMS?

 

Cheers

Dean

 

 

[TonyS]

Tom,

Promise I won't be a drop-out (well, in this anyway!)

Look forward to the materials list.

T

[Tom Wright 2]

HI Dean

Thanks for the post the answer to your question is a very definite no.

The blades are simply made from standard balsa leading and trailing edge .

 

Tony

Thanks for that,hope to get some more done this evening.

Tom.

[Tom Wright 2]

Crane Fly Autogyro

 

Front fuselage sheeting material 2mm lite ply

 

Its important that the every thing is kept nice and square the sheeting will will make the box section rigid so I used a weight to keep things in line .Cyno or PVA can be used .

 

 

 

[simon burch]

Will definitely be building one. Like a few others, once I see all the bits I need I will get them order.
Could you please include motor, ESC and prop info as well as the stuff needed for the rotors etc.

Really enjoying the posts. Can wait to get stuck into mine.

Regards,

Simon

[Tom Wright 2]

HI Simon

 

Here is some more info ...

 

Crane Fly Autogyro.

 

Rotors....Material Qty 2 ...40mm x 10 mm preformed t/e.

Qty 2 ...9mm x 9 mm preformed l/e.or use 10mm x 10 mm square section and sand to shape.

 

 

 

 

 

Edited By Tom Wright 2 on 05/01/2012 20:08:48

Edited By Tom Wright 2 on 05/01/2012 20:28:49

[Tom Wright 2]

Crane Fly Autogyro.

 

Rotors

 

I used PVA to join the two sets of l/e and t/e this results enough to make four blades ,three to complete the model and one spare .

 

When the glue is set the blades can be sanded to a flat bottomed section with a fairly sharp l/e .

 

Edited By Tom Wright 2 on 05/01/2012 20:26:58

[Tom Wright 2]

Crane Fly Autogyro

 

Rotor blades

 

Less than 15min work to produce the blades including a spare ready for sanding to section as soon as the glue has set.

 

 

 

[simon burch]

That's a clever idea, much closer to the final shape.

[Tom Wright 2]

Crane Fly Autogyro.

 

While the glue is setting here is what I used for the power train.

 

Motor Keda TR 28-30-18 1300 KV from GC.

 

ESC any rated at 25A or above ,mine is a cheap one from GC

 

Prop 8x6 flexible slow fly type from GC

 

Lipo Gens Ace 1000 (1A) three cell from GC

 

You will also need a V tail delta mixer £2 from GC look in the esc section for this item.

 

This set up is very economical but of course any out-runner that will produce 250W continuous will do ,don't rely on any info or specs use a watt meter to choose a prop that produces the power indicated for the model,in this case 250W and don't over prop a motor that's to small as that results in a current reading above the motors rating and burn out.

Don't be tempted to use a larger lipo for test flights as the extra weight increases the chance of damage during a crash landing.

 

 

 

 

[Richard Harris]

Tom,

Excellent work

 

Hope you don't mind me making a comment about the blades which I feel is important?

 

 

It is surprising how each piece of balsa can differ in weight, when I select wood for blades I can be quite a while sifting through the stuff at the LMS. In fact they do laugh at me with my digital scales, this is a bit extreme I know! But it is important to get your wood with roughly the same weight, grain density and most importantly straight! They will be balanced after but the closer you can get the weights the easier the process is.

The blades are the most critical part of an autogyro, get them twisted in any plane or a heavy blade and you will get an out of track rotor disc.

An out of track rotor disc is basically when the blades do not spin in line when viewed from the side, It is pretty easy to spot. It causes unwanted stress on the head bearings ,servos and airframe. It always kind of reminds me of when you stroke a dog on his belly and you see one of his legs going, on an autogyro if they are not right the UC does something similar

Very much like running an out of balance prop.

Ok....enough of my rambling on

 

Sorry

Rich

Edited By Richard Harris on 05/01/2012 21:50:48

[Tom Wright 2]

In case you have not used a v mixer before this is what it looks like ,the two servos plug in on end and the leads go to the rx elevator and aileron plugs.

 

[Tom Wright 2]

HI Rich.

Thanks for the input its good advice and covers the blade material selection points not yet mentioned.

My experiments with very light weight autogyros have often shown the effects of lack of blade balancing and other inaccuracies resulting in the classic "shake rattle and roll" I believe the detrimental effect gets much worse when heaver faster models are flown.However while every attempt should always be made to address all the relevant issues the object of this exercise is to get flying and learn about the pilot input required to go flying again without rebuilding the model,

If a newcomer to autogyros can get around with a bit of "shake" and down in one piece there is then a whole big bag of finer points to consider before progressing to finer things.But having said that your advice should be taken by the builder as its very relevant to producing a set of rotors that perform well as opposed to ones that work but shake.

 

Just come away from the keyboard to weigh the rotors made for the Crane Fly this evening and they come out at 25 g 25 g 24 g and the span wise balance points are within a 1/16".But this is prior to sanding so this will need to be done again.

 

Tom.

[simon burch]

Do you need the mixer if using a computer tx ??

Will get ordering at the weekend.

[Lazygit]

I was just about to ask about the blades as I have just made some 19" long and 2" chord which weigh 29g and they have a 16mm wide spruce leading edge, but then mine are only 6mm thick. As I made a sanding jig for them, I'm going to use this as a standard section for a while, and just vary the length. One day I'll do another jig. (But then one day I might get an autogyro built too ).

[Tom Wright 2]

Most of the autogyros I currently fly have thetype flapper plate shown below which to some extent goes against convention in terms of the rotor attachment position , also not everyone has the g/f material in the spares box so this raises two issues ...one would it be right for me to suggest using an unconventional rotor fixing method and two....how can I make it easy and economical for builders to get the correct material?

Well re issue two I have had a word with Pete and he is willing to lay up a big sheet of g/f and cut into pieces sufficient to make the flapper plate etc so if that's any help pm me with your address and I will send (UK mainland only) free of charge as its not worth peeps writing a cheque for under a pound.

Similar considerations apply to the control mechanics I am trying to avoid special materials ,soldering,or precision engineering requirements,so I will try and build a simple spruce and bolt system based one the ones I have flown for a while now.

That just leaves the bearings and housing i do have some at hand that could be sent at cost for £5 including postage if that's any help the g/f bearings and housing could all be sent together .

 

The photo below is an example of the flapping plate mentioned in the text.

 

Edited By Tom Wright 2 on 05/01/2012 23:25:27

[Tom Wright 2]

Posted by simon burch on 05/01/2012 22:55:22:
Do you need the mixer if using a computer tx ??

Will get ordering at the weekend.

Simon it might be better to spend the £2 on the mixer so we are all singing from the same sheet.

 

Tom.

[Tom Wright 2]

HI LG

Those blades should be fine cut down in span enough to give tail and fin clearance.

Tom.

[simon burch]

Will add it to the list, just ordering at the moment. I have some gearboxes which I bought previously but I think they might be a bit heavy duty for your machine.

[Tom Wright 2]

Simon I have use the gear boxes on this type of model , I removed the nylon cog though.

Tom.

[Tom Wright 2]

One strong contender for the bearings and housing is shown below if I can get some more bearings, that would give me a few to send to builders who required them.

 

 

 

[Tom Wright 2]

The model in the video is my scaled up LA using the bearing and housing as shown above ,the "Crane Fly" is in effect a rationalised revamp of this model to eliminate the carbon components and other special parts.

The carbon based model is in fact even easier to build if you have the parts to hand but of course more expensive. this one also uses 1.6mm g/f formers,a dedicated mast mount and control mech that requires a fair amount of soldering skill,so the Crane Fly is an attempt to eliminate all the expensive parts and tricky jobs.