J160 Kit#14 various with Photos

[Ross]

20081120

 

Hi Linda, Brian & Biggles I would be worried if anybody was using my experiences as a guide as what to do or what to do next. If I ever built another one I am sure that my experience on this build would supply me with many examples of what not to do!

 

How about you guys inserting some comments or suggestions based on your experience or advice from others - it feels pretty lonely out here!

 

As to my activity or rather the lack of it my health has been a bit off with bad chest colds etc aggravated by a former life of working in a number of bad for chest health industries made worse by smoking until I had a heart attack about twelve years ago.

 

However last week on 19th Nov I attended day surgery in Wagga to have a cataract removed from my left eye and a new lens fitted in place of the removed one. That now completes the set. The first few days feels like I had a bit of gravel behind the eyelid but is fairly good now.

 

Now all I have to do is wait for another month for the eye (and the brain) to stabilise after a follow up inspection by the surgeon in Wagga tomorrow before I can get new prescriptions for my reading glasses. That will make it about 27th December before I can try to get the prescription etc.

 

But how great it is now that I don't need glasses for flying or driving and already have got my driving license endorsed back to no glasses required-fantastic. I don't like my chances of getting the prescription and new glasses before February though and my old glasses are quite aggravating to wear now.

 

However I have decided to reline my wing tanks with the latest sloshing solution so that it can cope with all possible fuels including those containing alcohol (ethanol). It can be applied over the top of the existing sloshing material. Dan Mulder at Jabiru says that the contractors doing their tanks use about one litre of "Kreem" per wing tank. You need to do the header tank as well. I will feel better after doing this even if I don't use other fuels as it should seal around the points where the tank filler holes and drain holes in the wing tanks as well as the hole in the header tank for the float switch were installed.

 

I do not know when Jabiru changed to using this sloshing material. I think that it was relatively recently.

 

So I have ordered three 500 ml bottles at approximately $58 each not including freight from Jabiru (that price was in May 2008) and have asked Dan to send me an email explaining the process. He said that some acetone is used to thin the "Kreem" before application. Got an email today dated two days ago announcing that the sloshing liquid should arrive in Leeton tomorrow while I am in Wagga!! Will it get lost before we return from Wagga Wagga tomorrow afternoon?

 

I also occurred to me that if I was to shield the last 100 mm or so of the power supply to the strobe just below the strobe (where I had joined the new cable to the strobe short wiring) by wrapping some steel wire around that power lead and soldering it to the shield cover on the new wire just below it, it might have a large effect on further reducing the strobe noise that gets to the radio.

 

That last bit of power lead to the strobe is only a few cms from the top of the dipole aerial mounted in the back of the vertical stabiliser.

 

 

[biggles]

Hi Ross ,

 

Just joking , and are glad to hear that you are recovering after your op. I'm sure all former Jabiru kit builders have a wealth of information that would be useful for those following in their footsteps , just getting them to put their thoughts down on paper is the problem . Often after a frustrating day this takes a big effort , and there are always other demands which seem to take priority . Having said that ,I'm sure I speak for most Jab . builders/owners when I say that the effort you make to document your experiences is certainly appreciated . On the interference problem , for what its worth , I have found that placing a ferrite ring - (Dick smith R5120 for around $3.00 each ), had the most marked effect on reducing the noise caused when the strobe fires , when placed on the 12 volt supply to the strobe box , with only minimal noise reduction when placed on the discharge cable . Like most things it is a matter of trial and error , and what works for one may not work for another .

 

Bob

 

 

[brilin_air]

Hey Ross!

 

Glad to hear that you are ok. We thought you were madly working away at trying to get the 160 up in the air.

 

On the part of suggestions and such, Brian said you are most welcome to give a call (better and cheaper at night!) or him call you, for any help, advice etc.

 

I do know, that if he EVER built another one, there are so many things he would have done differently. There were many times when he become extremely frustrated with it....It took him 3 months to get the rudder set right! :faint:I was on the end of few late night profanities when he had to re-drill and set the hinges several times! .

 

Keep up the good work! :thumb_up:

 

-Linda

 

 

[Ross]

20081129

 

Hi Linda thanks. I had troubles with my rudder the first of which was because the fuselage was marked incorrectly for the cable holes and no actual hole through the fuselage into the cabin for the cable.

 

Nor could I get full required movement due to the non hinge side bottoming inside the vertical stabiliser when full right rudder was applied with the complication that the dipole aerial is glued in at that point.

 

Perhaps the aerial could have been put right in the right hand corner of the vertical stabiliser but I did not think of that until afterwards and it may not have been far enough anyway to give full movement.

 

So I drilled out the hinge rivets on the stabiliser side then "Araldited" an extension strip onto the hinge positions to extend them further aft and then drilled new holes and refitted the hinges.

 

The top rudder hinge could not be put in the correct position unless it was mounted with the rudder hinge pin going in upside down which makes it marginally less safe.

 

The instructions for the rudder offset were unclear with at least two alternative interpretations possible and not enough adjustment in the cable to fix it if the wrong interpretation were taken. I think I eventually decided that the rudder maximum deflection was to be each way starting from the offset position of the rudder. From memory, the adjustable length in the rudder cable is not as stated in the instructions making the placement more critical.

 

I think all these problems may have been resolved more easily with a more experienced builder. The new construction manual and probably some better quality control also probably helps on the later kits. Our J160 kit was #14.

 

The Jabiru parcel with some Resin & Hardner plus the "Kreem" sloshing liquid arrived yesterday.

 

I also ordered some exhaust wrap from Aircraft Spruce to reduce the heat load under the cowl area for wrapping the muffler and/or the exhaust header pipes.

 

See other posts on this subject under Jabiru users group. There are a number of possibilities of different materials available mentioned on the web site in those posts.

 

A piece of Heat Shield about 100 mm x 300 mm, Aluminium with a layer of very pliable sticky goo on it obtained from the local Holden dealer, was found to be highly inflammable when I applied an LPG gas torch to it. It readily caught fire then easily maintained a long flame (about 20 cm) with intense black smoke and dripping hot burning melted plastic like goo on the ground.

 

Radio and Strobe power lead

 

I think the noise in the radio from the strobe was cured this afternoon at least while the A/C was parked in the garage without the engine running.

 

I used some stainless steel lock wire to shield the last few unshielded cm in the strobe power cable. The stainless was wrapped around the new shielded power cable starting below the join and continued right up to the unshielded base of the strobe then continued back down over and past the cable join again. The SS wire was connected to the shield on the new power cable by scraping some rubber off the shield, inserting the SS lock wire between the rubber and the shield which also appears to be SS and wrapping it around the shield wire. It was not soldered. The whole was then wrapped in insulating tape before trying out the radio.

 

I think my wrapping gap between successive rounds of the SS lock wire was about one or two mm but was enhanced by returning back over the first layer with a second layer.

 

The radio was tried with the strobe back on top of the tail and the squelch knob hardly needed moving from it's no strobe squelched position with no interference to completely suppress all strobe noise from the radio while it was scanning all the 25 stored frequencies with the strobe then operating normally.

 

Fantastic at last!:thumb_up:

 

[ATTACH]6849.vB[/ATTACH][ATTACH]6850.vB[/ATTACH]

 

So I deduce from this that most of the noise came from the power lead in the last unshielded 15 to 20 cm of the power lead right up to the base of the strobe with the strobe itself apparently irrelevant.

 

I gather also from some reading, maybe irrelevant, that if the power lead core wires were twisted for their full length including the last bit into the strobe the interference might also have been suppressed.

 

The next step I had thought of was to mount the probe on a flat plate immediately below the strobe to shield the aerial and to connect that plate to the shield as well but it was so good that I did not even try that.

 

 

 

 

[Ross]

20081201

 

Strobe Noise I think we need digital radios in our aircraft.

 

Trying the radio again it was apparent that on receiving relatively weak signals the radio seems to have an automatic gain control that kicks in to amplify weak signals and any interference that is near or overlapping the selected frequency bringing up the strobe interference again.

 

Possibly the radio could be adjusted to reduce this interference. I think the adjustment has the ability to narrow the range of the selected frequency but I am no radio expert. It also appears that the interference from the strobe can drift/change depending on how long the radio has been running. Time for me to move along and leave it to the experts!

 

 

 

Closing the access holes

 

This afternoon, started closing up the access holes that were made to insert the tubing used to facilitate running the high voltage line to the strobe and the rudder cable to the slot on the port side.

 

The hole in the top of the rib leading to the vertical stabiliser had the tube coming up through a long slot from inside the fuselage into the space along the top of the fuselage.

 

So the entering tube was bedded in with a couple of layers of fibreglass and a layer of epoxy-flock on top of that from each side of the slotted hole.

 

Above that cable space, the next access hole was covered with three layers of fibreglass and will have some more layers tomorrow before the final V shaped cover is replaced over the final access hole on the top of the rib.

 

Some fibreglass was epoxied along the edge of the top/final access hole to make a better join for the final V shaped cover when it is fitted. This will have some more laid in there tomorrow to improve the joint.

 

The V shaped cover had a couple of layers of fibreglass laid inside it to reinforce it.

 

The port side inspection/access hole to the rudder cable anchor bolts, which are epoxied in place at the rudder end, can be seen and accessed through the inspection/access hole near the rear of the vertical stabiliser as well as the static air line and the radio aerial wire.

 

The tail end of the rudder cable is not seen here because it would normally exit the fuselage via a slot on the starboard side before reaching this access hole.

 

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The fibreglass base where the strobe is to be attached on top of the vertical stabiliser was epoxied in place and allowed to cure. It will require some more filling and smoothing around that area.

 

 

 

 

 

 

 

 

[Ross]

20081202

 

Despite the dates on the pics this work was done yesterday but not recorded then due to some unexpected interruptions.

 

Finished off sealing the hole in the top of the rib going to the vertical stabiliser and the join around the probe base.

 

Added another couple of layers of fibreglass over the top access hole made on the top of the cable space where the ducting was installed.

 

Made up some flock to do the cover join on the rib using plenty of flock on the fibreglass strips that were already epoxied in place along each side and the top of both V shaped ends of the access hole.

 

Once that was reasonably cured enough to not move, used some more epoxy to make up a small batch of epoxied microballs.

 

This microball epoxy was applied over the top of the join locations for the V shaped cover as well as the join area for the area under the strobe mounting on the top of the vertical stabiliser.

 

[ATTACH]6883.vB[/ATTACH][ATTACH]6884.vB[/ATTACH]

 

It could have been smoothed up more before it cured and some of the excess removed but I was unavoidably called away.

 

It looks pretty messy at this stage but is easy to dress up and get it smooth once it has fully cured.

 

 

 

20081203 Helped to test fit the tail group on Warren's Sonex mostly by lifting and steadying parts as well as checking the movement angles for the rudder. Some minor filing had to be done to ensure clearances for the elevator control and minor adjustments for the elevator stop and some minor filing of the skin in a number of places around the tail group. He has done a remarkable job on the Sonex so far.

 

 

 

 

[Ross]

20081206

 

Scraped and rubbed down the closed in access holes in the top of the rib leading to the vertical stabiliser as well as the strobe cut out and around the aft set of rudder cable anchor bolts.

 

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The photos show that some more filling and rubbing is still needed!

 

We also had some visitors for the last couple of days who stayed at the Leeton Caravan Park. See included pic showing the grasshoppers rising up from the lawn as we walked from the barbecue area back to their caravan.

 

[ATTACH]6891.vB[/ATTACH]

 

Richard has his head down because of the rising grasshoppers off the lawn. The grasshoppers can be seen as white flashes against the background of the darker trees.

 

Richard and I managed to get 1.1 hours in Wally's J230 at Narrandera on Friday morning. Even though we had taken off at about 9:45 am, the thermal activity was pretty severe despite the whole area having been completely overcast about fifteen minutes before the flight.

 

 

 

 

 

 

 

[Ross]

20081211

 

When the LH Main UC leg was lifted off the floor and the wheel rotated by hand it was apparently a fair way out of static balance so it was removed. The split rim was pulled apart with much difficulty even after taking it down to the local tyre man.

 

Eventually worked out that the two halves of the split rim were an interference fit and so were practically seized together. Would have been very difficult on the edge of an airfield.

 

So the pics show the aluminium anti-seize that I have applied to both halves in the area of the tightest fit before reassembly.

 

Removed the original foam liner that I had fitted and found it to be really squashed up to be fairly thin. I thought this was probably the cause of the imbalance.

 

I had purchased three tubes the same size as the originals 13x5.00-6 at $11-00 ea while at the tyre fitter shop.

 

The packed tubes were folded nicely so that the inside middle of the tube was the position of the fold. So the tube was cut along the fold. The valve stem was also removed.

 

Then inserted the good tube inside the fresh cut tube like an overcoat. One of the locals called it a Nullabor......? Applied a liberal coating of powder in the tyre and also between the tube and freshly cut overcoat tube.

 

Inserted the deflated tube combination back into the tyre.

 

Partially inflated the tube to prevent pinching on assembly.

 

Reassembled the tyre onto each split rim being careful to put on the rim with the valve stem hole last and to ensure that there is no strain on the valve stem and that the bolt holes on the rims line up. Aluminium anti seize applied to matching parts of rims. Bolts were inserted and tightened up carefully.

 

Tyre inflated to full pressure.

 

Fitted the wheel on the UC axle to find that it was still out of balance. The tyre was out of balance enough to move from any position except when the heavy point was lowest.

 

[ATTACH]6908.vB[/ATTACH][ATTACH]6909.vB[/ATTACH][ATTACH]6910.vB[/ATTACH][ATTACH]6911.vB[/ATTACH][ATTACH]6912.vB[/ATTACH]

 

Temporarily tried adding an extra nut to two of the split rim assembly bolts opposite the heavy point. It was not enough so tied a piece of lock wire (marvellous stuff) around the tyre and gradually added nuts 180 degrees around from the heaviest spot. After three nuts were added the wheel could be stopped in any position and would stay there. Adding one more nut would put that point on the bottom of the wheel.

 

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Trouble is I might have to take them off to actually take off or land. I'll see if I can get some tyre balancing weights to do the job tomorrow.

 

 

 

 

 

 

 

 

 

 

 

 

[Ross]

20081212 After the unbalanced wheel yesterday, I got some wheel weights from my tyre shop. I had not noticed this type before but he said he sells a lot to people like model makers etc.

 

They are in strips of seven with divisions that can be easily broken between each seven gram piece. Count them in the pic. They have a self adhesive strip on the back which probably works fine on a smooth or painted surface. Some super glue was used to help them along-maybe a thin smear of araldite might be better. The weights come in a pack of twenty one strips or so which came to $10 for 21 x 7 = one hundred and forty seven of the seven gram weights.

 

I took about 7 photographs of the LH UC wheel with the final set of four seven gram weights on it before the four weights showed up in the photo. One remains and it is not brilliant. I actually went and had another look at the wheel to make sure there were four weights on it.

 

Weights were added until the wheel did not show any preference for a rest position.

 

Once that LH wheel was balanced/finished, the RH UC Main wheel was removed and another tube split and refitted with the original tube inside it. For those who have noticed, yes I forgot to remove the previously fitted foam liner which I had not realised until I saw the other one later on the bench.

 

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The tyre and tube combination went on OK so I might reinstall the LH foam liner as well because the imbalance for the LH wheel with the tube liner did not seem to be any different from the original imbalance with the foam liner I had used.

 

It will give an improved puncture protection unless the J160 finds a "Castor Oil Plant". They are like a giant cat head and possibly could pierce the sole of a work boot.

 

Took no pics of the RH assembly aside from the freshly slit tube and the tube to go inside it. Finally woke up that a quick adjusting slide type G Clamp with about a six or eight inch throat is a great aid when assembling the Jabiru split rims. Might need a bigger a/c to carry the tools that might be needed.

 

Remembered to have some air in the tube while assembling the split rim to prevent pinching the tube with the split rims. There was still plenty of powder inside the second tyre and on its original tube.

 

In the morning it will be successful if both tyres are still up.

 

The tube manufacturer suggests to inflate a tube to about 10 psi then let it down and re-inflate to the desired pressure so that the tube will spread into place and hopefully not have any folds or creases in it when normally inflated which can also contribute to an out of balance wheel.

 

The RH UC main wheel bearing had a lot more drag probably due to the seals than the LH UC wheel making it very difficult to check the static balance. A series of small rotations of the wheel were tried which mostly seemed to show little preference for a rest position. It is not nearly as obvious as the freely rotating LH wheel.

 

A bolt used as a spindle was mounted in a large plastic cap off a plastic jar which was mounted in a battery powered 18V drill chuck and spun each tyre as fast as the drill's high speed setting would produce. A larger lid would be better providing the drill does not run out of power.

 

There was no bouncing but it was probably way below 60 odd knots. Driving the tyre on the tyre wall as close to the rim probably doubled the speed but I still did not know what that speed was. The Griffith based LAME can probably dynamic balance wheels as well as props. I shall find out eventually.

 

I think I calculated the RPM of the wheels for a particular ground speed in an earlier posting.

 

 

 

 

 

 

 

[Ross]

20081213

 

1. Inserting original foam liner+tube liner into UC Main LH wheel and then balancing wheel after installation.

 

2. Inserting Foam type liner only into UC front wheel & balancing wheel after installation.

 

3. Photographed the trickle charger with various loads on the J160 system.

 

..........................................

 

1. Lifted LH UC leg to facilitate wheel removal.

 

Removed the LH Main UC wheel, let the air out and split the wheel.

 

Removed the tube and tube liner.

 

Fitted a new foam liner inside the tyre. Dimensions 89 cm x 10 cm x 1 cm

 

Refitted the tube and tube liner.

 

Reassembled the split rim after inserting some air into tube and lined it up inside the rim then tightened up the bolts.

 

Inflated tyre to 30 psi & refitted wheel to UC

 

Removed old balance weights from wheel.

 

Checked wheel balance & fitted new set of weights.

 

.............................................................

 

2. Lifted front of A/C with engine hoist and sling under front of A/C.

 

Undid axle bolt through UC fork and front wheel.

 

Let air out of the tyre, Undo the split rim bolts, Prise the tyre down the narrower rim,

 

Split the rims apart, remove the narrower rim taking care not to damage the valve stem, remove the tube from the tyre.

 

Cut a new foam liner. Dimension 89 cm x 10 cm x 1 cm.

 

Fit foam liner inside the tyre. The foam has to be compressed into place as it overlaps a few cm in the tyre to keep it firmly in place.

 

Insert tube back into tyre taking care to place the valve stem in place. Put some air into tyre to prevent pinching the tube when assembling the second split rim.

 

Refit the narrower split rim taking care of the valve stem and careful not to pinch the tube.

 

A G clamp was used to hold some force on the rims to keep the two rims close enough together to get the bolts in and a few threads on the nuts.

 

Once the rims ere close but not tightened the tube was inflated and deflated a few times to get the tube to settle in place and remove wrinkles.

 

Once that is done the tube was inflated with minimal pressure but enough to keep a firm shape on the tube - maybe two or three psi.

 

[ATTACH]6925.vB[/ATTACH][ATTACH]6926.vB[/ATTACH][ATTACH]6927.vB[/ATTACH]

 

The split rim bolts were pulled up tight and then the tyre was inflated to 30 psi.

 

The wheel was refitted to the front UC forks and then the balance was checked.

 

Two weights were needed to achieve an approximate static balance.

 

............................................................

 

3. The A/C battery is permanently on a small charger as I was interested to see what load was on the charger for each item that could be selected from the panel.

 

The pics show the amps reading on charger meter and the items that are switched on at the A/C panel. Excuse the focus.

 

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[Ross]

20081215

 

Removed the rudder hinges from the vertical stabiliser to put another layer of fibreglass inside the rear of the stabiliser.

 

I drilled out the rivets and pulled their remains out/off with a pair of pliers. The tapered top of the rivets has been left in place for the moment.

 

The aluminium hinges were heated from the inside of the channel with the hot air gun until they were fairly hot to the touch but not enough to cook the fibreglass. They were then easily pulled off with the pliars without distorting them. They were marked T, M and B for top middle and bottom.

 

I did not do this originally because of the problems of clearance for the rudder as I had to put in a fibreglass strip under the hinges as the rudder had to be moved aft to clear the dipole aerial when full right rudder was selected which also caused a gap when full left rudder was selected. That gap has since been rectified some time ago by adding a thin strip down the starboard side of the trailing edge of the vertical stabiliser. The inserted strip under the hinges had also reduced the clearance between the rudder and the inside edge of the stabiliser on the starboard side.

 

Putting the dipole aerial in a corner of the vertical stabiliser channel instead of the middle of it before any glassing had been done might have solved both problems without the need to move the rudder aft or put a strip down the starboard side of the vertical stabiliser.

 

Also I think I have figured out how to hold a new piece of wet glass in place against the law of gravity.

 

Jabiru were at work today/yesterday and Jamie said he would send some more Tapered aluminium rivets when I rang or the next day.

 

 

[Ross]

Continued near new year - before or after........!

 

 

[Ross]

Just a note re the tyre & puncture problems.

 

Some people around here have used various goos in their tubes to prevent loss of air with punctures.

 

This usually resulted in violent shaking after lift off resulting in one case of a cracked windscreen. Applying the brakes immediately after lift off will help for the mains but not for the nose wheel on the Jabiru.

 

A local L2 commented that once these goos had been inserted resulting in a good coating inside the tube then the tube should be removed and squeezed and worked to remove any mobile goo through the valve teat. The mobile goo would have been contributing to the out of balance condition.

 

In my case (yet to fly it) I wanted to avoid the movement of goo in the tube by either using heavy duty tyres or inserting liners into the tyre to protect the tube. Any of these actions would probably contribute to putting the tyres out of balance, a scary experience, so I am interested in getting the tyres balanced.

 

I would think that they could be readily dynamically balanced by spinning them on the A/C at high speed and balancing them to compensate. My local tyre shop says that he cannot dynamically balance the wheels when removed from the A/C because his fittings will not match the Jabiru wheels.

 

I have managed to roughly statically balance them which would be a start but I would rather have a dynamic balance.

 

 

[BigPete]

G'Day Ross,

 

I've got a fair idea that the go-karting people balance their tyres on the axle. Might be worth investigating. :thumb_up:

 

regards

 

:big_grin::big_grin:

 

 

[Ross]

Hi BigPete

 

Thanks for that I shall check it out as we have a car club here.

 

Regards

 

 

[Ross]

20081230

 

We are now back from near the coast for most of last week where we saw lots of large screaming things overhead Concord mostly heading west and south-west. We do not see them as close up in Leeton but we can usually tell where they are going or coming from. Sydney traffic for Perth, Adelaide and Melbourne can usually be seen from here as well as Melbourne traffic for Brisbane or Coolangatta. At times we also see North South traffic very high and a bit west of here.

 

An order for some CSK rivets from Jabiru arrived while we were away sent on 19th Dec by Jamie just before they closed up shop for Christmas. A spruce parcel arrived this morning from USA as well. A sandblasting gun from the Supercheap Auto Store in Griffith was purchased this morning as well.

 

Saw a very dark plane similar to a Foxbat fly past last evening at 19:45. He had his front light (landing light??) on and it could only be seen in silhouette against the sky above. He appeared to be in a hurry.

 

 

[Ross]

20090105

 

Mix up epoxy for vertical stabiliser rudder rudder channel for adding the last fibreglass layer.

 

Prepare vert stabiliser rudder hinge area position for epoxy and fibreglass layer.

 

Pre-cut out a fibreglass layer to match the channel location on top of the radio aerial.

 

Scrape and abrade area with sand blaster, knife and abrasive cloth wheel mounted in a drill chuck.

 

Blow air on area to remove dust off the area.

 

Clean area with acetone and a rag

 

Prime area with a layer of epoxy applied by brush

 

Apply fibreglass layer

 

Use small clamps to hold glass after it is pushed in place from the top down trying to keep air out from under the glass.

 

Apply more epoxy by brush to wet up the whole glass layer

 

Use clamps, wooden strips over the hinge positions and peel cloth to hold down the fibreglass in place.

 

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Keep wiping up dripping epoxy periodically from the job.

 

Allow to cure

 

 

 

 

 

 

[Ross]

20090105

 

Pulled off the clamps, the wood strips over the hinge positions and the peel cloth.

 

The epoxy has not fully cured yet - but still curing - temperature still a bit over 33 degrees C in my carport at 9:30 pm.

 

Cleaned out the hinge rivet holes in the vertical stabiliser.

 

Remounted the rudder hinges loosely on the vertical stabiliser using 2 only AN3-4A bolts, nuts and washers on each hinge just to make sure it still lines up approximately and the rudder still has full deflection to the stops or close to it.

 

Refitted the rudder with the rudder hinge pins.

 

Made sure the rudder has full movement, clearance and no gap on full deflection to the left.

 

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It should only need some minor filing and perhaps some hot air heating to get a good free rudder connection once the countersunk 3/16" hinge rivets are replaced,

 

 

 

 

 

 

[Ross]

20090106

 

Removed the remains of the rudder hinge rivets from the vertical stabiliser.

 

There were too many air pockets mainly against the aerial in the channel of the vertical stabiliser trapped under the new layer of fibreglass.

 

So stripped out the middle of the fibre glass in contact with the aerial.

 

The right angle space between the aerial and the layer underneath it was filled with flock on both sides of the aerial for the bottom half of the vertical stabiliser.

 

The left hand side of this space was then covered with a layer of fibreglass which was pressed into the flock and a layer of freshly applied epoxy.

 

The right hand side of this space was then epoxied and a layer of fibreglass applied overlapping the previously applied layer.

 

Then both layers were brushed with a layer of epoxy.

 

[ATTACH]7013.vB[/ATTACH][ATTACH]7014.vB[/ATTACH]

 

As the temp outside in the shade was 40 degrees C decided to leave the rest.

 

At 17:30 hrs it was still 35 degrees C inside the carport. The fibreglass is substantially cured.

 

 

 

 

[Ross]

20090109

 

Prepared top half of U channel in vertical stabiliser for fitting a layer of fibreglass after removing the previously fitted layer. The main tool used was a 6 mm wide wood chisel.

 

Used an abrasive cloth wheel in a drill chuck to to roughen up surface for application of epoxy.

 

Blow out dust

 

Clean liberally with acetone.

 

Mix up batch of epoxy resin - and apply to surface to prime it.

 

Mix up batch of flock and fill each side of aerial to make a smoother contact for the fibreglass cloth.

 

Apply a layer of epoxy resin to the whole area to be covered in fibreglass.

 

Apply a layer of fibreglass over the aerial and the LHS of the U shaped channel.

 

Press in the fibreglass layer with fingers to wet it up completely and making sure to remove air pockets.

 

Apply epoxy resin to the top of the fresh fibreglass.

 

Apply the RHS fibreglass in the channel overlapping the fibreglass just laid.

 

Press in this layer to wet it up and to ensure no air remains under the layer.

 

Apply epoxy resin to the top of this fresh fibreglass.

 

Mix up a batch of micro-ball epoxy resin and apply it to the trailing edge of the U channel on the RHS.

 

[ATTACH]7026.vB[/ATTACH] Pic 1 [ATTACH]7027.vB[/ATTACH] Pic 2 [ATTACH]7028.vB[/ATTACH] Pic 3 [ATTACH]7029.vB[/ATTACH] Pic 4 [ATTACH]7030.vB[/ATTACH] Pic 5 [ATTACH]7031.vB[/ATTACH] Pic 6

 

Allow to cure - monitoring the micro-ball layer as it will droop & run so requires some manipulation as it slowly firms up as it cures.

 

 

 

 

 

 

 

 

[Ross]

20090110

 

Drilled out three of the rudder hinge CSK rivets in the vertical stabiliser as they were proud of the stabiliser - not enough countersinking.

 

Used the countersinking tool which I had bought after doing the original rivets on the stabiliser.

 

Mixed up some epoxy and flock which was applied in the countersink holes before inserting the rivets and pulling them.

 

20090112

 

Checking out the rudder stops. Started by reading the section from the new J160 construction manual.

 

Basically it says to find the centre position of the rudder by clamping some mixing sticks on the port side of the top of the rudder and let them align with the vertical stabiliser and the mass balance on the top of the rudder.

 

But my mass balance is slightly wider than the vertical stabiliser so I applied sticks on both sides and think that I have found a centreline.

 

Once the centreline was found and marked on the top of the tail end of the fuselage and on a plywood template an offset was marked 5 mm to the starboard side of the A/c on the template.

 

Using the offset as the zero position two lines were then marked - one 80 mm to port and one 80 mm to starboard from the offset mark.

 

(This is a much easier and far less ambiguous method than was published in the original manual.)

 

The stops were both allowing more deflection for each side as originally done by me which made it much more difficult to set the anchor point for the rudder cable.

 

I see that the J170 has a deflection of 100 mm each side of the offset line?? I note that there are other small differences in the area of the rudder hinges.

 

So the starboard stop was made adjustable by inserting A SS self tapper into the existing stop and leaving it proud of the stop.

 

The port stop was a bit low and had a gap when the rudder was in the correct position.

 

So the port stop was packed up with two small pieces of fibreglass and then flocked in place.

 

The preparation was to file the parts to fit and the site, clean it all up with acetone, prime the parts and the site with epoxy.

 

The remaining epoxy was mixed up with some flock and applied to the parts with the rudder set in the correct deflection for the port rudder stop.

 

Some peel cloth was applied to prevent the new work adhering to the rudder arm.

 

[ATTACH]7059.vB[/ATTACH][ATTACH]7060.vB[/ATTACH][ATTACH]7061.vB[/ATTACH][ATTACH]7062.vB[/ATTACH]

 

Then it was allowed to cure.

 

 

 

 

 

 

[biggles]

Ross ,

 

The instructions that came with my J160 kit , indicated that when setting the rudder movement , it should be 98mm +/- 2mm each side of the centreline . I agonised over this for some time and noted that , as the axial movement of the cable was only 80mm even with the advantage created by the horn , that sort of movement would be difficult to get . In desperation I rang Jabiru , who happened to have a new J160/170 out the back and , after measuring , confirmed that those coming out of the factory have a movement of 70 mm each side of centreline !!

 

Regards

 

Bob

 

 

[Ross]

Hi Bob

 

Yes I had the same problem with the same measurements quite some time ago and like you I had rung Jabiru and their response was not so helpful then at all. So I was pleased to see the new instructions in the current J160 construction manual.

 

The original measurements meant that the rudder cable anchor had to be located exactly in the right place. When it was there, there would be practically no allowable adjustment leeway left at the rudder end of the cable. I had originally mounted my cable anchor on the fuselage where the positions were marked by the factory only to find they would not work because of the angles and the position was out for cable length. After moving it again I eventually decided to put the cable in the top of fuselage strut but had to drill a hole out of it into the fuselage etc to get back to the control stick. I still had to experiment to get a mid adjustment location for the cable anchor on the rudder end.

 

It is a bit worrying that the J170 essentially the same A/C as the J160 except for the longer wings has gone back to that originally specified dimension for the earliest J160 of the allowed rudder movement.

 

So will we have a lower cross wind tolerance allowance for the J160 compared to the J170.

 

Will there be any effect on the J160's susceptibility to spin or the J160's ability to recover from a spin or a spiral dive.

 

Regards

 

 

[Ross]

20090125

 

It has been a bit warm here lately plus a few other excuses.

 

[ATTACH]7093.vB[/ATTACH][ATTACH]7094.vB[/ATTACH]

 

A few weeks ago decided to buy some spare spark plugs for the 2,200 motor. There were none in stock or ever had been in Leeton that I could discover. So ordered a packet of ten which came the next day for $45 for ten plugs.

 

Eventually opened a spark plug box to discover that that particular 12 mm plug comes without the nuts on top of the plug - the only plug in the whole range for that brand without the nut. This missing nut had been mentioned in someone else's post earlier on but I had forgotten.

 

After visiting a number of garages, I eventually found one that was willing to give me the nuts off ten as new plugs probably 20 years old hiding in a back store room.

 

It turned out that all the nuts from all the old plugs fitted the new plugs! I could hardly believe it.

 

I also thought that I should check out the compression tester that I had bought a year or two ago only to discover that it did not have a 12 mm adapter to fit the Jab spark plug holes in the heads. Eventually found a shop where I could get an adapter made to suit the Jab engine 12 mm holes but the turner who operates the lathe involved was on leave until this coming week. So with a bit of luck might have it by the end of this coming week.

 

 

 

 

[Ross]

20090131

 

The warm weather continued here, but not as warm as some others were experiencing. The air conditioner works well but is not in the garage. Last night at about 7:30 pm we had a bit of a southerly gale with thunder and lightening with heavy rain for about five minutes - it sounded like hail - all of two mm or 8 points. Immediately following that, the wind turned 180 degrees to give us a very hot northerly almost a gale until well after midnight.

 

[ATTACH]7132.vB[/ATTACH][ATTACH]7133.vB[/ATTACH][ATTACH]7134.vB[/ATTACH][ATTACH]7135.vB[/ATTACH]

 

Now having all the bits at last, decided to do a compression test on the motor. The new adapter to fit the Jab spark plug holes/threads was a bit short raising the chances of damaging the head cooling fins when tightening and removing the adapter. So might get another one made eventually a couple of inches longer. The bore of the adapter needs to be small so that it does not reduce the pressure excessively.

 

I just noticed that I entered the wrong size of the plug thread on the lid of the compression test box. The 14 mm should be 12 mm (actually measured 11.83 mm on a spark plug).

 

[ATTACH]7136.vB[/ATTACH][ATTACH]7137.vB[/ATTACH][ATTACH]7138.vB[/ATTACH][ATTACH]7139.vB[/ATTACH][ATTACH]7140.vB[/ATTACH][ATTACH]7141.vB[/ATTACH]

 

The pics of the compression tests are shown here in the order of cylinders 1,2,3,4.

 

The Jab engine book says to do the compression test with the engine oil temp between 30 degrees C and 80 degrees C. That was not a problem even at 10 pm in our garage on the night of 20090130. However due to a number of the pics being blurred due to not using the flash to prevent glare I did them again the following day arranging the garage lighting a bit better. When it came time to enter the results on the forum it was in maintenance mode. So they are going in this Monday morning.