Crane Fly Trainer Autogyro

[Malcolm - coolwind.co.uk]

Bob,

Its a Hexagonal spacer normally used for spacing circuit boards or other items in electronic building projects. Search on ebay for "Hexagonal Spacer" and you'll get lots of options for different sizes.

I've used an eBay shop called Brimal components for most of mine

Malcolm

[Bob Bertram]

Hi Malcolm,

Yes, of course it is! Thanks for reminding me and putting me out of the agony of wracking my brains!

I may have some floating about in my shed somewhere which is probably nearly as big as Tom' s nice new one but is chock a block with all sorts of useful junk. May have to build a new one soon.

Regards

Bob

[Tom Wright 2]

Thanks Malcolm for the spot on answer to Bob's question .

Bob .

Why not go for the single function home made head ? it will simplify the build even further .All you need is a pivot ,and an arm, which is operated by one servo ,with no TX mix or mix component required. . This can be achieved in a variety of ways one of which is posted on the previous page .

One of our local lads flew another head variation to day and it was just made from spruce off cuts, and a bolt. I will knock one up this evening and post a photo to give you lads inspiration to make your own. Make the rocker arm between 95 - 110 mm long and the rest is easy .

The hex long nuts can be handy to make convenient pivot points and rotor bolt anchors .The ones I have are 3 mm thread 15 mm long , and can be used for duel or single function heads ,although not essential for the single function option, A rotor bolt threaded anchor can be made by simply drilling and tapping spruce and then soaking in thin cyno to produce a strong job.

Tom.

[Bob Bertram]

Hi Tom,

Thanks for that, I have been watching the posts with great interest and may go down that route. It does seem a lot quicker and of course easier for low time r/c-ers. And they don't come more low time than me at the moment! It may be a while before the maiden due to the lack of flying experience on my behalf but I am taking in all the progress and developments and have bookmarked your thread and of course Richards too. Amazing what you all come up with and many thanks to all for your input. Didn't realise that all this could be so much fun.

Regards

Bob

[Tom Wright 2]

Here are some photos of the single function ( roll only ) spruce control mech as flown today by Pete .The rotor bolt is screwed into the spruce via a tapped thread .

The roll pivot is simply a 3mm bolt through the mast and arm,which has a brass tube sleeve.

 

 

Cick on the photos to see detail .

 Tom.

Edited By Tom Wright 2 on 13/12/2012 20:54:08

[Tom Wright 2]

I mentioned using the Hobbyzone Cub tail and rudder set on a Crane Fly which can be purchased from most LMS for well under £10 . The set comes complete with horns, tail wheel , and ready hinged control surfaces.

We flew a single function head Crane Fly today with this set up and it was fine .

See the two previous pages for more ideas .

Tom.

Edited By Tom Wright 2 on 13/12/2012 21:09:57

[Maxy]

Hi Tom

I am about to start on the 0.8mm GF Delta Plate you suggest a 3"" size with 9.5mm centre hole for the top of the bearing to fit through. The blade screw holes are for 3mm position as previous delta plates proportionally. The HK C 30 blades I presume to be drilled for 3mm about 16mm from the blade root at the highest point of the camber or should you go for the balance point, is bushing necessary or do just put a 3mm screw through with washer and stiff nut. I can see you have been very busy with the E-Mails.

Max (single function head)

[Tom Wright 2]

Max , I like your single head sign off it helps a lot .

Go for a 4" 0.8 mm plate, with the rotor bolt hole positioned to give 27 mm between the bade bolt centre and rotor bolt centre. This info assumes that you use the the ready made hole in the HK blades ( note the hole is concealed by covering ) and also note there are actually two holes the one nearest the root is the I have used . If you prefer more "meat" between the blade hole and blade root then you could drill one further in but then make allowance for the plate hole which would need to be nearer the apex , or use a 4.5" plate if this still gives rotor to rudder clearance.

I have done plenty of flying on the the factory made hole and despite the fact it is a bit close to the root no problems have been experienced .

Tom.

[Tom Wright 2]

If all the time saving options are used on a single function head Crane Fly , it leaves very little to do other than time at the field to learn to fly Autogyros . I have flown and compared the options shown in the previous few pages and found no difference worth mentioning . All the current flying was done using the HK C- 30 blades and due to the current out of stock situation I will make a set and if they fly the same.... the construction details can be posted .

The principle requirement is to chose even grained medium to hard balsa that will result in even blade weight . Adding a hard l/e should bring the blade cg to or in front of the rotor bolt position ( chord wise cg ) followed by a balance check along the blade length .

Another easy way to produce such blades would be to use preformed 1.5" balsa trailing edge which would further reduce sanding , a little ingenuity can be used to add a low cross section l/e that enabled chord wise c/g to be achieved.

 The Auto - G blades are available and do work well but when postage is added I feel the cost is prohibitive against getting two sets out of one sheet of 3/16"and  some l/e material.

Tom.

 

 

Edited By Tom Wright 2 on 13/12/2012 22:39:35

[Tom Wright 2]

I have ended up making three sets of blades as substitutes for the out of stock HK C-30 blades.

One set is made from preformed trailing edge . Another from 3/16" sheet . And the third set from 1/8" sheet with no section other than a chamfered trailing edge . Yes the third set is pushing the boundaries but if by chance this works it would make it very easy for the constructor to produce blades .

Looking at the previous three pages you should see that I am doing my best to eliminate all special components, tools ,and materials so more can have a go with out been confronted by the problem of hard to get parts. The sole aim is to build the simplest possible air frame that will enable those first successful flights and open the door to the world of Autogyro's .

Tom.

[Grasshopper]

Tom, pressing on with my 'single function mod. kit' for the Crane Fly while waiting for the weather to improve. Yet another day of strong gusts and heavy showers with the same forecast tomorrow!

I have completed a replacement tailplane which plugs in in place of the elevator-less version and am now working on the simple head as per your photos of 13.12.12. I note that in an early carbon mast version you used a 2mm piano wire rod between the ball joints which were 95mm apart . You commented that this gave smooth roll control.

In this later one with a wooden mast, measuring from the photos you seem to have reduced the distance bwteeen the ball joints to about 68mm.

Any suggestions as to the best distance I should use please?

Peter

Edited By Grasshopper on 15/12/2012 14:52:05

[Tom Wright 2]

Peter.

The 95 mm between ball joints is the dimension on my machine, and the I would suggest you use . The other dimension you referred to was on one of Pete's models . This was just to show a another simple control mech option that works well . You were not far out in estimating the shorter arm length it was in fact 75 mm ,and probably set to suit a different servo arm length , and to suit Pete, as he is an experienced Autogyro pilot.

The longer control arm allows both the roll clevis to be positioned at the servo arm last outer holes , this seems to result in better resolution.

Tom.

[Grasshopper]

Cheers Tom it will be done/copied!

Just looked at the forecast again and same rubbish now until Thursday so building it is.

I have an EDF Concorde to repair as sand and EDF blades do not mix. I also have a Luna 2m mouldie sloper with a cracked fus near the tail which needs attention so I will not be idle.

Keep up the good work, bar the flying bit you have me hooked.

Peter

[Tom Wright 2]

Peter.

If you can get you Autogyro wings then the weather is not at all critical ,I have been out to the field today testing flat section blades in a nasty gusty wind and managed to bring the model back in one piece . But getting through the first stages can be quite a challenge requiring patience and perseverance that involves identifying why a flight has not been achieved .

Simple things like an un noticed bent rotor bolt can cause confusion when a second attempt to trim fails . A lose servo mount , bent control rod , chipped servo gear , or any part of the system that changes roll trim settings can leave you wondering why things are not going to plan .

Of course lack of familiarity with the flying characteristics may well involve crashing a perfectly trimmed and serviceable model , this situation is par for the course closely followed by disorientation which often happens just when pilots were congratulating themselves on a successful flight .

I must not sound to negative as gaining the upper hand with these machines is a very satisfying flying experience not to be missed. And strangely when you understand what the requirements are to achieve success , you are left wondering what all the fuss was about .......dark side ? not really .

Tom.

Edited By Tom Wright 2 on 15/12/2012 19:20:29

[Grasshopper]

Sounds familiar. I self taught here in France as the locals all fly mode 1 and as I had (long time ago) a gliding licence - although I tried mode 1 it was just not 'me. Several years and 'planes later I was good enough I thought to tackle slope soaring which was the reason I got inot the hobby. Here in Brittany it is all cliffs-soaring so one fine and blowy day I arrived at the cliff edge with a 2,6 metre balsa soarer I had made and, encouraged by some other flyers, lobbed it off the edge and to my amazemenet I was able to keep it in the air. In fact the problem was not letting it climb too much. The first flight was nearly an hour long as I was so pumped up I wanted to keep on and on. Brilliant - and no fuss thereafter

I suspect that with autogyros it is going to be the same but please oh please let this weather break so I can get the tears out of the way and get some stick time in.

Along the way one of the other Club members had caught the bug and has built an ag using an old heli head he had in his shed. It is a pusher but to my eye, tuned to your work, it looks like it might fly. We'll both have our fingers crossed. (yes the French use the expression as well)

Peter

 

 

Edited By Grasshopper on 15/12/2012 19:33:50

[Tom Wright 2]

Hi All .

For those who might be pondering over blades ,and especially as the HK ones are out of stock ,then after a couple of days experimenting it looks like the simple answer is preformed 1.5" trailing edge.

Marking a line 0.5" in from the l/e and using a balsa knife to remove the excess takes about 5 min per blade leaving very little sanding to complete a very reasonable section . The added complication and work involved in adding a hard wood l/e is avoided by adding 5 grammes of lead mid span and near the l/e ,this brings the chord wise cg on, or in front of the blade bolt .

Just timed how long the sanding took and it comes out at less than two mins per blade..

Using this method is inexpensive ,quick ,and can result in accurate trainer blades for minimum work . Will fly a set tomorrow or Monday to confirm suitability and then post full details.

Tom.

Edited By Tom Wright 2 on 15/12/2012 21:49:28

[Tom Wright 2]

Completed the blades made from preformed t/e this evening will fly tomorrow.

[Tom Wright 2]

Substitute HK-C30 blades for the single head Crane Fly .

The blades were made from 1 1/2" x 1/4" hard preformed balsa trailing edge ,as shown in the photo above . Lite ply wedge pads were added at the roots and the chord wise cog was achieved by securing 1.5 mm piano wire with glass tape to each blade leading edge . this proved to be easier than adding lead .

The rotor 3 mm bolt holes are located 0.5" from the root and on the one third chord line , with 0.8 mm gf fingers used to re enforce the bolt hole on the root top surface .The blades were then mounted on to the delta plate to check dynamic balance ,one blade was slightly heavy so 2.5 gm of lead was added to the two lighter blades .

Test flights were very successful and all at the field agreed the performance was equal to the HK blades.

If any single function head Crane Fly builders are stuck for blades let me know if more details are needed.

Tom.

Edited By Tom Wright 2 on 16/12/2012 17:04:19

[Kevin Flynn 1]

Hi Tom I have a question does the piano wire run all the way along the blade?

I have cut out all the pieces bent the landing gear and built the single function head. Going to try the blades next, then assemble everything at one go, hope to be ready for first flight this coming weekend

regards.

Kevin

PS Merry Xmas to all.

[Tom Wright 2]

Hi Kevin.

Best wishes to you to . Yes the piano wire on my blades is full length. I also added chord wise tape at the tips as an extra precaution . Obviously the method used must be secure , but my tests today did not show any problems.

Tom.

[Tom Wright 2]

Plate details as flown, for substitute HK blades as described above .

The blades as test flown are made from preformed balsa t/e are currently mounted on a a 4" 0.8 mm plate with a spacing of 43 mm from centre bolt to the rotor bolt .

If a 4.5" plate is used for the same blades then 50 mm between the centre bolt and blade bolt should be ok.

The "Blue Wonder" bearing holder was fitted with a flange bearing at the top and two standard bearings underneath . Or a flange bearing can be used top and bottom with one standard bearing in between .The rotor bolt has a 3mm lock nut underneath the bottom bearing ,but leave a little vertical play as over tightening the nut can compress and damage the bearings.The lock nut should not be allowed to rotate when tightening the rotor bolt , as this could damage the bearings .In a perfect set up each bearing should have a thrust washer to transfer the bearing centre loads but I have yet to find a suitable component .

Tom.

Edited By Tom Wright 2 on 17/12/2012 03:05:22

[Tom Wright 2]

Just a note about securing the wire to the blade l/e . The glass tape seems fine for the first flights but for longer term service it might be an idea to make 90 degree returns at the root and tips, or use other methods, and add cyno to all points of wire contact with the blade.

Tom.

[Tom Wright 2]

One of the Crane Fly single function heads ,that I am using to fly the home made blades as shown above .

[Tom Wright 2]

Kieth.......e mails sent .

Tom.

[Grasshopper]

Tom,

loving your progress on the single function design.

Sadly I am still waiting for my head bearings to arrive so have resigned myself to a mid-January maiden. (after 2 weeks in the sun!)

Quick question: what throws do you have on your elevator. It has a big surface area so I guess nothing large?

Peter