Crane Fly Trainer Autogyro

[Tom Wright 2]

This is an easy control mech to make if you up to the soldering skills.

 

[Tom Wright 2]

Or this one Pete made from a polypropylene cutting board .....its bomb proof.

Whatever you choose to use it does not effect the airframe design other than a small change to the mast fork which has not yet been covered in the build blog.

 

 

 Will make the spruce and bolt version tomorrow then builders can choose the option that suits.

Edited By Tom Wright 2 on 06/01/2012 02:14:56

[Lazygit]

Hi Tom, don't forget this for bearings. Their p&p is a £1 per order and they have a good stock of metric and imperial. Even over the Xmas hols I got my bearings next day.

[Lazygit]

Posted by Tom Wright 2 on 05/01/2012 23:31:53:

HI LG

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

Tom.

You know me, never march in step . I'm going to make a short fus so the tail is well under the blades and will not get hit too often. I think I will use EPP as it can take a beating with out much damage.

[Tom Wright 2]

Posted by Lazygit on 06/01/2012 10:44:11:
Hi Tom, don't forget this for bearings. Their p&p is a £1 per order and they have a good stock of metric and imperial. Even over the Xmas hols I got my bearings next day.

Yes thanks LG a good link will send for some to fit the bell motor mounts, by the way in case I run out HK stock the bell motor mounts as a separate item.

 

Tom.

[Tom Wright 2]

Here is the third option for a control mec ,all you need is spruce and ply off cuts and a small brass hinge from a hardware dept.

This one does work very well to say its so low tech,more details on how to make it on request.

 

Edited By Tom Wright 2 on 06/01/2012 12:39:37

[Olly P]

Please consider this a request Tom.

 

Think I can see how but a photo of the other side would also be helpful.

[Richard Harris]

Posted by Tom Wright 2 on 05/01/2012 22:48:26:

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.

 

Tom,

Yes the loads are increased with larger models, but I have had first hand experience of the dangers when out of track/balanced blades have been used.

This has happened to me twice and I know of a few others. The first time was with a model that weighed about 3lbs, this had been flying with a shake for well over a year. At around 100' the rotor shaft (5mm diameter) sheered completely off, the model hit hard but there was very little damage due to the UC taking the impact. The rotors however carried on and did a great landing.

The second was my micro Nellie, due to imbalance of the rotor system the 3mm ID bearings collapsed, that model was totalled even though it weighed around 400 grammes. Both failures happened at least 12 months into the models life.

Now the models to me are just material things that can be replaced. If ever one of these models had hit someone due to my incompetence over a simple task I could never live with myself.

I don't care whether a model is 10 grammes or 50lbs, if a rotor comes off or airframe/mechanics fail and it hits someone it is dangerous.

This is the reason why I feel so strongly about the subject and why you will see me over engineer mechanics and scrutinize blade design, it is the heart of any autogyro and care must be taken and considered.

Up until that first failure I had the same attitude that if it shakes but flies who cares. Sometimes it takes things like that to appreciate just what is happening, luckily for me just my pride was hurt.

I have crashed mine more times than you could ever imagine in the few years I have been playing with them, and if there is one piece of advice I would be that above. Not because I think I know what is right and wrong but because it has happened to me (embarrassingly more than once).

 

  This a video of a larger type autogyro and what happens when a rotor decides to depart. Even if the model was lighter you wouldn't want it to hit anyone.

 

 

 

 I hope you do understand what I mean. 

Rich

Edited By Richard Harris on 06/01/2012 14:31:58

[Tom Wright 2]

HI Olly.

Here is another view ,will do a detailed build if needed

 

.

[simon burch]

Be good to see details of all the options if you have time. I would assume the head and hinge are the most complicated part of the model.

Cheers

Simon

[Tom Wright 2]

Rich

If any model pilot is flying over or near to persons property or animals then the most fundamental rule of all is broken.

As we know pilot error, radio problems,ect can cause models to go out of control and represent a danger ,it is the pilots responsibility to ensure the flight is not a danger to others even when things go wrong.This of course also applies during ground maneuvers as well .Props do part company with models,so we all avoid the danger area ,and the pilot will/should not operate motors or rotors close to other people and should make appropriate allowance should things go wrong.

My experiences with auto gyros suggest that uncontrolled crashes due to disorientation are by far the biggest single danger.

I doubt any one would say a light autogyro is any more or less dangerous than any other powered model and we should of course all endeavor to minimise any risk that can be identified and rectified.

If every under 7kg model that ever flew was engineered to a public category type approval schedule our hobby would be confined to a handful of boffins.

I have worked in a professional capacity on full size aircraft type approval and designed full size aircraft so I do have some idea and appreciation of what component may or may not be suitable for a particular application.

IMO in view of the huge amount of information available to autogyro builders ,I would be surprised if a pilot allowed "shake"to continue beyond initial flights,as most would soon want to know what to do about it ,furthermore I would be very surprised if a newcomer to autogyro flying made his basic trainer last a year,having mastered a very basic machine most would soon want a "looker" like your Panther design.

In technical terms I would not argue with anything you have posted but come on mate it came across a little heavy handed on my low tech build thread ,.

Don't want to fall out with a fellow autogyro pilot as we are to thin on the ground a pm might have been more appropriate as the people following the thread could now be under the impression that autogyros are not a good idea.or need to be graduates in enginering to build one.

The "Crane Fly" will be completed and rigorously test flown before any on the forum have made a start ,so if it does anything that concerns me or does not withstand the rough and tumble the builders will be the first to know.Rich you know your input is always appreciated so lets go forward as friends.

 

Tom.

 

 

[simon burch]

I think you have both made good points, but it's good to make people aware of the care needed with rotary components. I fly more helis now than planes and I still see models with obvious vibration issues being flown even though the outcome could be a catastrophic failure.

If this is someone's first autogyro, they maybe completely unaware of how important the balance of the blades will be. If made badly, the maiden would be short lived.

This is going to be my first flying autogyro (hopefully) but feel I have a healthy repect for balancing blades etc from the years spent playing with heli's. Maybe a link to the method for balancing blades would be good. I'm sure I've read one of Richards posts elsewhere which cover this in detail?

Keep up the build pics, this is a great thread.

[Lazygit]

I agree Simon, although tracking I think is more difficult than balancing with an autogyro (I'm happy to be corrected), and is as important.

 

It may sound OTT to some, but rotors can store quite a bit of energy, and though not as dangerous directly as with helicopters, they can at least damage the aircraft itself. I used to be involved with vibration testing in a previous existence and a small amount of energy can wreak havoc at the right frequency.

 

As someone once said, we need to learn from mistakes of others, as there isn't enough time to make them all ourselves.

Edited By Lazygit on 07/01/2012 00:24:03

[Richard Harris]

Tom,

No worries mate, just giving my opinion on something that I believe is important through mistakes I have made that's all, I just thought I was trying to be helpful.

But I cannot just sit here saying nothing when someone politely tells me I am wrong or makes disparaging comments about my models (on the first page). This I would respect and understand if I knew the comments were from first hand experience but I am sure (and I apologise if I am wrong) that you haven't flown one of my models?

Its just not something I would comment or 'presume' but the world would be oh so boring if we were all the same.

 

Your model is coming on very nicely, it is surprising how quickly its coming together. May just have a go at one myself It just speaks out Night Flier to me!

 

 

Rich

[Tom Wright 2]

Rich

I find it hard to believe my comments on page one could be taken as criticism ,we seem to have some crossed wires here ,I explained the reason your name was mentioned in the first place in a PM to you .

I had mistakenly thought comments made by someone else on the thread were an unfair criticism of your plans so I responded in your defence,and then went on to say that generaly speaking your autogyro designs were aimed at the more accomplished builders and pilots eg Little Nellie. Rotodyne,Panther,I was not aware that your portfolio included very basic models that fit the criteria I have set for this thread, so my remarks were entirely innocent and without a trace of malice....why would I want to do that to a mate?

Your further response on this page took me totally by surprise and within minutes the phone was ringing with people asking why Rich had bombed my thread.

Further more your advice although welcome was premature as the build sequence had not yet got to the point were balancing blades would have been covered,you obviously assumed that my comments about shake suggested that balancing etc would not be covered.

Clearly a case of small misunderstandings on both sides resulted unnecessary upset this is a shame as I had just come back from a realy good autogyro flying session.

We should have had this conversation privately but no harm done ,I certainly offer my apologies to you if any my comments came across in the wrong way I repeat criticism or malice were not in the frame.

I would be happy if you could post a link to your latest blade balancing tutorial this would help me to get on with the last part of the build.

 

Tom.

 

 

 

[TonyS]

Tom / Rich,

Glad that you've kissed and made up. Let's get on with the build thread and don't worry about giving us safety lessons etc along the way. As I guess that we're all model fliers we've pretty much got that one covered (even I can work out that loose whirly things could be dangerous).

T

 

[Tom Wright 2]

Sorry about the hold up Tony but is all good stuff, If we were all had an identical personality it would a a very boring world indeed ,it also highlights how communication on the forum is made all the more difficult due to lack of face to face signals.

 

Just to recap, my build so far has resulted in the parts shown below ,sanding and balancing will be left until final stage as I have not yet decided whether or not to include my rotor tongue idea see ( last page on six different.....) for more on this.

 

As this is a low tech design I feel that the simple ply /spruce control mech should be the one to build this eliminates the requirement any special materials or skills .Comments on this would be welcome before I resume.

 

Edited By Tom Wright 2 on 07/01/2012 14:44:08

[Tom Wright 2]

[TonyS]

Tom,

My vote's to go ply/spruce as it looks fairly straightforward and I can probably knock up all the bits. The only question I'd have is the hinge in the middle - is this more of a 'rocker' and, if so, how did you make that please?

T

[Tom Wright 2]

If I understand your question correctly Tony the roll hinge will be centered on the pitch pivot bolt as will the rotor bolt,which will be screwed into a threaded brass long nut which I can send if not found in the bits box ,PMs if required.

The example shown was just a quick try out with every thing off centre works fine but will do a better one for the build. Full details to follow but will have to be later tomorrow as I will be entertaining friends tonight.

 

Tom.

[simon burch]

I would have thought a Mylar hinge would do the job, or a couple of heavy duty robart hinges. The metal seems a bit ott for a small machine?

[Tom Wright 2]

HI Simon

Some model hinges will take the flight loads but don't generaly do as well when subjected to rotor ground strikes or crash loads.Many types have been tried but the tearing loads are much greater than control surface applications.

I can only recommend what a has worked for me ,the hinge in the photo only weighs 3g.a lot depends on how easy such an item is to buy .Other suggestions are always welcome of course.keeping in mind that the main part of the control head is quite small and has to accommodate the hinge -pitch pivot,- control arm and threaded anchor for the rotor bolt.

[simon burch]

Hopefully wood arriving next week. Bit short on time as I'm trying to finish a project which I've had for over a year, but shouldn't take long to get the bits to the same level as your photo above.

Cheers,
Simon

[Steve W-O]

Just looking at the pictures of the head, and can't help wondering if the roll ball joints shouldn't be inline with the pitch pivot point, and the pitch ball joint be inline with the roll hinge pin.

 

this could stop interaction and stress on the roll servo and linkages.

[Tom Wright 2]

Posted by Tom Wright 2 on 07/01/2012 17:33:42:

If I understand your question correctly Tony the roll hinge will be centered on the pitch pivot bolt as will the rotor bolt,which will be screwed into a threaded brass long nut which I can send if not found in the bits box ,PMs if required.

The example shown was just a quick try out with every thing off centre works fine but will do a better one for the build. Full details to follow but will have to be later tomorrow as I will be entertaining friends tonight.

 

HI Steve the above post should at least partly answer your question.

 

Tom.