AJAY Autogyro Build

[Big T]

Hi everybody! I have been asked by AJ Blades to do a step by step build of their new trainer Gyro the AJAY Autogyro. The kit is on sale now at their shop http://www.ajblades.co.uk/blades-20-c.asp for £59:00 plus shipping. I understand from AJ that this is a pilot run of kits to test the market so stock will be limited for the first run. If it is a success then production will be stepped up and laser cutting used instead of CNC.

The kit comes in a large triangle shaped box and is very complete. The only additions you will need are a motor, esc, Rx and LiPo or LiFe battery around 3s 2200mah, 3 servos, glue and covering. On inspection the quality of the packaging, wood, accessories and CNC machining is very good and the instructions are included on a CD Rom in MS Word format.

I intend to build this model with the parts supplied so as to give a fair assessment of the fit and quality of the machining, supplied parts and the design.

First Job after checking that the contents matched up to the parts list is to fettle the rounded edges from the locating tabs on the fuselage base and centre spine. The rounded edges are a feature of CNC and are there on all CNC kits I have built in the past. A few swift strokes with a Permagrit or file soon have them fitting snuggly. The floor and spine come in two halves and are joined prior to fitting together. The recommended adhesive is Aliphatic but I guess you could use anything from PVA through to Cyno if you want. The spine and base are brought together, squared up and left to dry.

The small T you can see is important as it marks the Top of the floor. Get this upside down and you will have left side thrust not right

[Big T]

Next I chose to fit the front bulkhead/firewall to the floor and spine. Important to mark a centre line on this to aid alignment later on. The Firewall is made from 2 halves. The centre faces are machined to take the undercarriage so it is important to get the larger one to the rear.

A tapered doubler is then pushed in from the left side. This is marked B1. Trial fit this before adding glue as it may need slightly sanding.

[Big T]

Next we move onto the mast and mast support. This is rather clever in that the spruce mast is replaceable should it get damaged in a crash. The Gyro uses the well tried and tested Hobby King control head a feature of which is that this type of head control keeps the push rods in tension whilst in flight but your radio will need to be able to do either a flying wing mix or similiar.

[Big T]

The Fuselage Spine is supported by 2 ply doubler's. The instructions are very clear about the order in which these are assembled. There are two options to fitting the mast. It can be either glued in place or held in situ with 2 screws which will allow easy replacement if you should snap it off in a crash. I elected to go for the second option, so 1st the mast is pushed into the slot in the spine from the top. It is very very important that the mast is pushed in from the top and not from the side. If you push it in from the side the Spine will split! You have been warned. One of the doublers is then trial fitted and the top of the doubler is marked on the mast and the mast position is marked on the doubler. Two holes are then drilled in the doubler, the dimensions are in the instructions. With the mast in position the doubler is then glued to the spine. I normally use a contact adhesive to glue doublers but in this case I used 30 minute epoxy so I had plenty of time to adjust the position and clamps. To prevent the mast getting stuck in place I sprayed the mast with Silicone Baking Release. This is a product used in the catering industry but any oil would do.

Doublers with centre line and holes drilled

!st Doubler Fixed with mast in position

Top Of Mast Marked so you know how far to push it in when you are fitting it. Note: notch goes to front.

Next you fit the front and rear balsa fillers to either side of the mast making sure they support the mast along its length. Then fit the other doubler.

Next job is to fit the outer front bulkhead which holds the undercarriage in place. This must be glued using a 2 part epoxy and firmly clamped whilst curing. On my kit I took the time to trial fit the undercarriage and relieved the slots slightly to enable the 2 halves to fit snugly. Next fit the 2 bulkhead supports. A really nice feature is that these two pieces are pre angled to fit.

The hole is for the centre line of the motor.

Next we fit the bass wood frames for the servo mount, battery tray, esc and side rails. It is important to have the servos in your hand before doing this as the mounts are tailored to the servo.

[Steve Jones 2]

Hi Tim,

Long time no hear, hope all is well with you. Build looking good and great detailed pics

Steve

[Big T]

Before I move on to the next stage I would like to compliment AJ on the quality of this kit. The quality of the wood, accessories and production of parts is better than anything I have experienced. The design is an easy build for a novice builder and challenging enough for a first plan builder. Frankly I don't know how they do it for the money.

_____________________________________________________________________________________________

So, onto fixing the servo rails and mounting blocks. These pictures say it better than words.

This is the 2 hard wood blocks that also form the mounts for the false floor. Then using your servos as spacers you fix the second and 3rd rails in line. Then the mounting blocks for the servos to screw into.

The rudder servo took a small head scratch and beard pull to work out but it is very simple in fact.

There is a slotted bearer and solid bearer. The slot is to enable you to screw the servo onto the bearer.

All beares in and the false floor fitted. The false floor is even cut with the motor thrust taken into account!

Next we fit the side rails and cut out the access for the servos.

Servos fitted and linkage installed with supplied hardware.

Tail wheel assembly which is assembled as per the instructions and stuck to the recess with epoxy.

The tailplane is made up of 3 components which glue together with your favourite adhesive. The fin and rudder are assembled as per instructions. At this point I chose to change the mounting of the tiller arm as I have a particular way to do it. I chose to mount the rudder to the fin using the Fuzzy Hinges supplied in the kit, then mount the rudder onto the tail plane, then mount the assembly onto the fuselage and get this perfectly lined up and square. I then stuck one of the GRP plates onto the rudder in the location of the "tiller". I then marked the tiller onto the rudder and cut a slot in the balsa through to the GRP. Then I slotted in the tiller and glued the opposite GRP plase in place. I then drilled and mounted the Horn which is supplied with 2 cap bolts and nuts. Another lovely touch.

[Big T]

[Big T]

I have to admit to making an error of measurement here! The instructions give the dimension of 17mm for the center of the tiller. Please note that this is from the top of the nylon mount not from the bottom of the rudder. This is why the GRP doubler on mine was not level with the bottom of the rudder.

This picture shows the route of the rudder push rod which has a double offset. Remember to put the guide tube on the rod before bending!

The Head

Take the rotor head and remove the blade mounts reserving the nuts and bolts. Assemble the supplied AJ GRP blade plate onto the spindle carrier. Make sure that you get it the right way up as the blade mounting holes are offset to give an easier mounting of the shims. The unit is supplied by the manufacturer with all the nuts and bolts loose so make sure that you nip them all up and use a light thread lock. The rotor spindle assembly is mounted onto the rotor shaft. The mount needs shimming onto the shaft with sections of the blade shim.

Note the blade mounting holes offset

Pushrod mounted into the keeper on the servo and cut to length.

[Big T]

Blades

The blades are the usual excellent AJ Blades product. For those of you who may be put off from trying a Gyro due to the complexity of making and balancing blades then this is the answer. In fact many of the "die hard's" who made their own in the past now use blades from these guy's. Preparation starts with determining the span wise CogG. Just follow the supplied instruction's or refer to Rich Harris's You Tube video if you are unsure how to do this. After determining the CofG, glue the top GRP reinforcing plate in place, I use cyno for this. Now, very important for everyone, even you experts, make sure you stick this on the ROOT end not the TIP. Remember the blades rotate Anti Clock!!!

The lower GRP brace is then glued as shown below.

 

Then using the top plate hole as a guide drill a hole through the complete assembly and cover using your favorite method. I used HobbyKing heat shrink film but you could use a thin adhesive sticky back plastic or even reinforced parcel tape.

  I then balance each bladed length ways to establish the CofG.  You can see the pencil mark on the blades in the picture below.  If the centre's are a long way of then add tape the root end to get them together.  As you can see these are very close without any adjustment at all.

 

I then pair up the blades and balance them until they are all the same.  If needed you add tape to the CofG of the lighter blade.  This is important if you want to have a smooth Gyro.  Some might skip this bit but it pays to be thorough.  The blades can then be mounted on the head plate with the supplied cap bolts.  Do not over tighten the bolts.  The correct tension is just so that the blade can move with a small amount of friction holding them in place.  Too tight and they will "hunt" shaking the plane in flight. Too loose and they will not track correctly.

 

 

Edited By Big T on 17/09/2014 09:04:43

[Big T]

Next I will mount the motor, Rx, ESC, battery, do the radio mixes and throws as per the instructions. Then break it all down and cover the model. My choice will be to film the spline, tailplane and rudder and paint the floor , bulkhead and tray.

[adrian lawrence 1]

It's looking good, tempted to place an order soon for one, although I have yet to finish my Scout that I bought from AJ's (decorating interruptions).

I am looking forward to seeing yours completed.

Cheers Adrian

[Big T]

STOP PRESS

I have mounted the lower blades supports incorrectly. The next sequence will show the correct method.

[Big T]

Then using the top plate hole as a guide drill a hole through the complete assembly and cover using your favorite method. I used HobbyKing heat shrink film but you could use a thin adhesive sticky back plastic or even reinforced parcel tape.

I then balance each bladed length ways to establish the CofG. You can see the pencil mark on the blades in the picture below. If the centre's are a long way of then add tape the root end to get them together. As you can see these are very close without any adjustment at all.

I then pair up the blades and balance them until they are all the same. If needed you add tape to the CofG of the lighter blade. This is important if you want to have a smooth Gyro. Some might skip this bit but it pays to be thorough. The blades can then be mounted on the head plate with the supplied cap bolts. Do not over tighten the bolts. The correct tension is just so that the blade can move with a small amount of friction holding them in place. Too tight and they will "hunt" shaking the plane in flight. Too loose and they will not track correctly.

Edited By Big T on 17/09/2014 09:04:43

[Big T]

I have now moved onto the covering of the model. As this is a trainer it is most important that the nose and tail are easily identified in flight. ALL model gyro pilots get disoriented in a turn at some time or other. One of the key helps its if the tail stands out from the nose. Don't worry too much about the blades as you normally don't look at then in flight. Once you get used to them spinning at the correct speed for flight, that's all you need. Usually if you get to see the top of the blade in flight it's all over anyway! SO I have chosen an easy to do colour scheme of white iron on film for the spine, silver paint for the ply floor and bulkhead and a floro yellow for the side strakes. The tail is in the same checker film as the blades. So while I wait for the motor to arrive I am going to get on with that.

[Tom Wright 2]

Nice work Tim , my Ajay was a breeze to build and flew off the board with no fuss at all. Alan really has done a great job producing the kit.

Regards

Tom.

[Big T]

Posted by Tom Wright 2 on 20/09/2014 20:01:08:

Nice work Tim , my Ajay was a breeze to build and flew off the board with no fuss at all. Alan really has done a great job producing the kit.

Regards

Tom.

Hi Tom, I totally agree with both those statements. I maidend the proto and after a few trimming hops it was hands off take offs. Very easy in the turns both left and right providing the pilot used throttle, rudder and roll control correctly. Very tolerant of hang angle and stable in pitch.

One important pilots note for any experienced fixed wingers looking for a Gyro trainer, Gyro's do not respond well to "yank and bank" flying. The rudder and throttle are your primary controls, elevator is not how you climb but how you slow down. In many cases you will find yourself giving opposite roll to yaw and throttle to maintain height.

[Big T]

SO here is the finished model ready to go

 

 

 

 

The layout of the battery and Rx. Stock motor with a 10 x 6 E prop pulls 30 amps at 330 watts at full throttle. AUW is 1.2kg so it should go OK. Neutral Trims are set to the listed figures in the manual for the test flight hops. I will set the throws to 100% and 50% on rates with - 10 expo on roll and pitch (- Futaba + for Spectrum). Forward pitch or down elevator will be reduced to prevent accidentally stopping the blades in flight.  Hang angle is about 14 degrees.

 

Final Comments On Build

The instructions are well written and clear, with the exception of the blades supports which where missing from my set of instructions. This will be corrected from now on. The materials and machining are superb and are exceptionally good value for money. Attention must be given to the HK head as they are supplied with non of the bolts tight, thread lock should be used.

Next post will be after the maiden.

Edited By Big T on 21/09/2014 18:10:27

[Big T]

First test hops followed by a successful test flight yesterday. The wind was about 10 to 15 mph, a bit too strong if you have never flown a Gyro before. The flight characteristics of a gyro are effected in a big way by small adjustments so take your time and follow Tom's thread on first flight and trimming. As usual with Gyro's each one has it's own character, even if they are from the same litter, and this is no exception. The blades spin up very quickly and the head plate is soft enough to give a good "cone". What I did find was that as lifting rotation is achieved and the tail comes up I had to put in a small amount of back stick to get the nose up and lift off. Only a small bit, over do it and it will go vertical and you don't want that. On the next flight I decreased the down thrust on the motor by the thickness of a 1 new pence which reduced the effect. If a smaller prop or smaller motor is used then that would be the same as reducing down thrust. The rudder is very effective and ground handling is perfect. Full power in level flight is not needed, in fact you don't want to fly this model too fast or you will get some nasty handling as a result of the soft head plate making it very twitchy. Just remember that this is not a "bank and yank" model, try and keep the rotor flat in the turn by using all the controls.

It was easy to hold the model into wind and get into a steady hover with back stick, then reduce the power slowly until a perfect 3 point landing, just apply power at the end to keep rudder control.

On the 3rd and 4th flight I was soon cranking the rudder turns and touch and goes.

Final Settings

I ended up with a 3s 2200 all the way forward, Measured with the fuse floor as a datum: Trims at 9 degrees neutral back tilt, 2 degrees left roll and 4 degrees down thrust on the motor which had a 10 x 6e prop. Futaba -20 expo on aileron and elevator, nothing on rudder. End point on roll and elevator reduced to 50% . 14 degrees hang angle.

[Big T]

Yesterday I have the Tx to a couple of club members who had never flown gyros before just to test how the model performed with a true gyro Virgin. Given that the model is trimmed and sorted. I have to say that both did really well and found the AJ very satisfying to fly and both performed perfect landings and take offs. My caviat is that I taught both to fly and both learnt rudder control in the early stages.

[ray staerck]

Getting there. Had a hop yesterday before i covered the blades but loads of vibration. I think this was due to me forgetting to fit the 0.4mm spacers on the mast sides. I've covered the blades and will cover the model this week and try again. Kit quality is fantastic. I got one for another club member who has flown his and is very very pleased.

Ray

[Al - AJ Blades Ltd]

Hi Ray,

Just to clarify,it is the 0.8mm FG strip (same colour and thickness as the head plate) that fits both sides of the mast but I`m not sure that is the cause of the vibration.Apart from the obvious checks, blade balance and correct tightness etc.,try reversing the nyloc nut so that the nylon end faces towards the head plate and adjust it to take up most of the play but still allows the assembly to rotate freely.I`m sure you will get it sorted and you will find that it flies great.

BTW what power plant are you using?

Al - AJ Blades Ltd.

[ray staerck]

Thanks yes you are correct its the 0.8mm FG strip i forgot to fit.

I weighed the blades today at work after covering. These were 20.7g, 21.2g and 21.7 so i've added some tape on the CoG of the lightest blades to make them all 21.7.

I also think i may have over tightened the blades on the intial hop but will remove any slop in the head assembly

Anyway, thanks for your advice, really enjoyed bulding the model

Ray

[Big T]

Hi Ray can you describe the vibration or better still post a video as it makes diagnosis simpler. If the blades are balanced correctly its Most likely the mounting bolts too loose or too tight. The way to test is to hold the model so the blade is parallel to the ground and give the model a downward shake. The blade should drop but not under its own weight. The other major source is the head assembled incorrectly as some are shipped from manufacturer very loose

[ray staerck]

Flew th AJAY this morning with 0.8mm shims in head as per instructions and balanced blades

-------------PERFECT-------------------

Only had one battery but really impressed. Flies lovely with no vices

Can't wait to get a few more flights on this beauty

Thanks all for the advice

Ray

[Tom Wright 2]

Congratulations Ray .

Tom.