YOUR JABIRU AND "THE JACK"

[Captain]

Help needed.

 

I've been mucking about with the brakes on my 230 today and jacking the thing up once fully painted was a bugger.

 

I have had a quick look in the manuals and can't find any procedure specified.

 

How do you blokes do it?

 

In particular, what is the best way to jack them up to change a tyre if you are away in the sticks ..... and what items do you carry in the aircraft to make it easier.

 

Regards Geoff

 

 

[Guest DonC]

Good question , Captain. I made an angle iron bracket and used the stub axle bolts to fix it to the inside of the gear legs , then used a low screw type car jack - bit heavy to carry around but all I could think of. By the way , what do you think of the twin caliper brakes - mine are pretty useless at any sort of speed

 

 

[Guest brentc]

I have a stand made up that a mate made for me. It's Mark-1 of Mark-3. That being said, you do need a couple of people to lift the aircraft up in the first place to get it on the jack.

 

What I have done in the past is undo the required bolts and have someone lift the aircraft up and then lower it onto a block of wood / stump or rag or similar. Fix the flat then lift the wing and slide the wheel back on.

 

It's not a problem at my local field, as I just drive under the wing with the forklift and lift away!

 

 

[theoy]

Timber Jack

 

I have tried the car jack method, a bit tricky, it works OK. I'm not keen lifting my wet wings so now we use the good old fashion wood lifting method,yes just 3 pieces of wood I use a 4X2 timber about 1/2 M long place one end under the wheel leg. Next jam a wide piece of wood about 4 inches back from the wheels leg under the 4x2. Lever the 4x2 other end down, just lean on it, lifting the wheel up jam more wood under the leg to keep it up. At all times making sure the wheel and disk brake spin free. The good old fashion wood lifting method most times works well but can get hairy on soft ground. LOL

 

cheers

 

Theo

 

 

[Ross]

Hi Geoff

 

My brother has made up some kind of lever type jack that works by starting with the jack frame top under the UC, the foot of the jack frame on the ground and I presume lifting a lever one stroke thus lifting his Kit Fox.

 

Once it is lifted far enough the lifting frame goes over centre against it's built in stop with the wheel off the ground..

 

I am guessing that it folds in the centre (so folded it is short) and goes over centre just past the vertical (so over centre it is long or extended) and can not go any further. (The jacked up position).

 

The lever and jack section are made of folded sheet metal that is lightened by holes cut in it.

 

It would have to be made to suit the lift height.

 

Obviously it is meant for reasonably light AC - the heavier the AC the longer the lever required.

 

The major advantage is that it can be operated by one person and is light.

 

 

 

I have not seen it and am working from a vague description that is at least two years old.

 

 

If you are interested contact me for his phone number.

 

Regards

 

 

[Captain]

Thanks to all that have replied so far.

 

I wonder if a reasonable solution might be to source the 4 X 2 system as described by Theo ..... but in aluminium and then keep them in the aircraft with the tie-down kit.

 

Will Brent or others please confirm whether you think it is easier to lift one wheel off the ground when the wings are on (which mine aren't yet) ... even with full tanks?

 

However even if that is easier it does no good if you are alone & it seems to me that we need a reasonable system that a pilot can use, alone, if you puncture or similar on a reasonably remote strip. Has anyone tried a moose type system of Finelec or the like?

 

Any comments would be most welcome from anyone who has already addressed this issue.

 

To answer DonC's question about the brakes ... mine are perfect ;) but I haven't used them yet as I am still building :clown: . See Roger's post on another thread near here as he is not real happy with his after 100 hrs ... yet Brent thinks his are OK. My plan is to try these out with the std 4 calliper arrangement and the removable pads ... and if that is no good I'll probably fit something like a Matco conversion. By the way, I reckoned that the geometry of mine was all wrong as originally supplied in the kit and would have needed the backing plate to bend about 1.5 mm each time ...... unless the small SS pad backing plates was added on each side. Do DonC & Roger have that SS plate installed on each side between the large main backing plate and the pad ... as I'm buggered if I can see how they would work well without that? Let me know if you want me to post a photo to show further what I mean.

 

Regards & thanks again

 

Geoff

 

 

[Guest brentc]

I know what you mean!

 

You are supposed to bend the backing plate (which is crap if you ask me). You may find that the wheel is hard to get on if you don't. If you have the quick-swap brake pads, you will need to possibly put 2 bends into the backing plate to get a flat braking surface onto the pads. I told them I was not amused with this solution, to which I was told that 'nothing ever fits on a jabiru out of the box.' I had never had issues to date with anything like this not fitting.

 

It is also a little strange that you are expected to put your axle bolts into light aluminium, rather than straight onto the stub-axle.

 

On another note, I think I will be purchasing one of Boyd May's Carbon Fibre 3 blade props. I've been told to expect miracles when it's fitted, so I'm purchasing a ready-made miracle.

 

As for lifting the aircraft by the wing. I'd say a big fella like yourself would manage ok. I (at 5'10")find I can't quite lift the wing up enough to be of use to put a chock under but you'd be amazed at what you can lift when there's no-one around and you need to to get home before dark, but then again, that's why I got a night rating :-) Luckily I've never had an issue when nobody is around.

 

I would advise to continue with your lightweight jack idea, although blocks of timber or aluminium are feasible for a 2 person operation.

 

 

[Wilfred]

I think the lever type jack is definitely the answer. I have been intending to make one for the Jab for a while now. They were quite common years ago in vehicle workshops a lot larger naturally. Its quite a simple idea , easy to make if you are not overly concerned about weight, I was intending it for hanger use.

 

At the same time I was intending to make a lightweight stand for use away. Intending to lift the aircraft with the wing, it really is quite easy and then plonk it on the stand. It is a two person job though.

 

Brent how does your insurance company view the Revolution Prop. Ours has said that the fitted prop must be approved by Jabiru.

 

Cheers

 

Peter

 

 

[Captain]

I think Peter is right.

 

I noticed that Jabiru's position re alternative props has hardened since the loose flywheel issues and one of the AD's states that only Jabiru approved props must be used.

 

I have some sympathy for Jabiru's position on this as the crank & flywheel attachment are directly effected by how soft or hard are the forces exerted by the prop and there is little doubt that some of the props on the market are not as soft or forgiving on the engine as the timber originals.

 

Those 3 blade carbon units look the berries .... but Boyd told me at Wings-Over-Wagga that it doesn't go any/much faster and doesn't use less fuel, so what is the miracle other than that the pointy bits look sexy?

 

One more point re the jacking ... if the tyre is flat as a pancake, can you still get a 4 X 2 under the leg to start the leverage process if alone?

 

 

[theoy]

HI Captain

 

I like the idea of a 4x2 X 1/2 m aluminum instead of wood and maybe have the long piece lever folding into one or maybe use 1x1inch aluminum I haven't used it on a flat tyre, I don't see a problem as all you need is a gap under the leg of about 2 inch. The 4x2 is a one man show, try it. Iam definitely up grading to a cool looking aluminum set.

 

Cheers

 

Theo

 

 

[rodknee]

Is there any more news on the evolution of a jabiru jack or maybe even some photos ????

 

 

[Guest Andys@coffs]

With my 2nd hand Jabiru I got a jack that appears (I havent yet had to use it) to be the bees knees of jacks.

 

The bottom part is a normal scissor jack with a 1/4" drive welded to allow lift by rachet drive, and a welded on reciever for the top bit.

 

The top bit uses the narrowing of the undercarriage leg as it goes down to the wheel to allow an interference fit for lift. Inside the welded shape is carpet to stop leg scratching (Note that in the 1st photo the scissor base is probably at 90 degrees to that shown)

 

Photos as follows:-

 

[ATTACH]1565[/ATTACH] [ATTACH]1566[/ATTACH] [ATTACH]1567[/ATTACH]

 

 

 

 

 

[Guest brentc]

Ahhh Captain, the 3 blade prop issue.

 

Revisit this discussion in 100 hours or so when your timber prop is out of whack and we'll see what you think then!

 

The benefits are: - some partially repeated

 

1. SMOOTH running, all year round.

 

2. No out of balance propellor

 

3. Adjustable to get more RPM and more power to suit your needs

 

4. Able to fly in the rain with no damage

 

5. It's UV protected

 

6. It looks good

 

7. Increased climb-rate

 

8. Shorter takeoff

 

9. Faster acceleration

 

10. Aluminium spinner that is perfectly balanced from day 1

 

11. Less airframe vibration thus component longjevity

 

If you think Jab timber blades are even pitch, think again!

 

Downsides:

 

1. Cost

 

2. Possible loss of speed

 

 

[Captain]

Ahhh Brent, the 3 blade prop issue.

 

Please don't paint me as THE champion of Jabiru timber props .... for I am not and don't have enough experience to champion anything in this Ultralight caper .... and I bow to your conclusions on this.

 

The 3 blade-ers sure look the business.

 

All I ask is, if they offer all of those benefits, particularly smoothness of operation, are they yet approved for use by Jabiru on their engines?

 

Being "Mr Conservative" I can't help but support the logic that when a firm like Jabiru are churning out heaps of aircraft and even more engines, they get to see or sort out all of the consequences of what owners do, so when they put out an AN that talks about only using approved props then I feel that it is prudent to take that on board.

 

Having said that I note that Jab USA are offering Sensenich (excuse the spelling) props over there.

 

Are Jab or Mr May progressing approval of whatever model 3 blade-er you have?

 

Best regards

 

Geoff

 

 

[Guest brentc]

There's no approval by Jabiru and there probably won't be. Too many props out there to test and so little time to do it and to be honest they are probably making more than enough money to have to worry about this kind of testing. Technically speaking the warranty (mine has run out anyway) is void with this prop. There is a rumour that it's been tested by Jabiru but I can't confirm that. When you're home-built you can pretty much do what you want and to be honest if the flywheel breaks off, it won't break the bank!

 

Stick with your timber prop till the warranty runs out, then see how others are going and then make your decision. But me, I like the idea of a 50 tonne breaking strain on each blade!

 

The AN was caused by people who didn't keep their props tensioned. I have seen school aircraft with loose props on the odd occasion too. Doesn't appear to be as much of a problem on 6 cylinders however.

 

 

[Wilfred]

Brent

 

Have you got a new prop fitted yet

 

Two or three blade

 

I notice your discussion seems to focus on a three blade

 

if so why a three instead of a two?

 

As another aside we recently fitted the "wavy "discs and although its still the single calipers and pads as supplied by Jabiru they seem to be getting more hours and need adjusting less.

 

 

[rodknee]

Thanks Andy for the photos but I was hoping for photos of a smaller jack(lifting device ) that could be carried in an SP jab and not take up much room .Still cant work out how the 4x2 works with one person but that's truck drivers for you

 

 

[Yenn]

There are wooden props and there are wooden props. Some people consider the Jab prop to be of poor quality and I am not buying into that argument, but their props are made of softwood whereas there are props out there made of hardwood and they appear to be longer lasting. Mine is a Sweetapple and first class, it holds its tension in the bolts and is smooth.

 

 

[Guest brentc]

I haven't got the prop yet, but I have been in the same aircraft with the 3 blade for a test flight.

 

Yes, 2 blades are more efficient and the aircraft will go faster, however the 3 blade will be (is) smoother and it has a greater ground clearance because the 3 blades are shorter, so less gravel / stone damage and hopefully a longer life.

 

The distributor claims the extra for the 3 blade will be worth it in terms of smoothness, however I will lose a knot or two in the cruise. The main thing for me is the climb rate and takeoff. I'll get a J430 takeoff and climb with the higher cruise speed of the J400. That's the theory anyway and from what I've seen, definitely possible.

 

 

[Guest brentc]

That's a good idea actually. Light on weight. Stuff it in the back of the plane, I like it! Need a small air compressor to blow it up which aren't heavy.

 

 

[rodknee]

Not a jack but I made a stand to put under the leg on my sp to be able to change a flat out in the wilds.Place the stand at the front or rear of the leg after removing the spat then a shoulder under the outer end of the strut with a lift and move the wing towards the stand and if you have lifted enough the leg bottom would be on the stand and wheel off ground :;)3: .The stand is 75x100x2.5 & 130 (mm's) high & fits in the tool box under the pilots seat with enough tools inside to change a tyre also doesnt weigh much

 

 

 

 

[turboplanner]

The method Ross is describing is used to quickly lift race cars off the ground. If you imagine something with the dimensions of a bag trolley, but at a smaller angle than 90 degrees. The lifting tip can be made to suit a particular part of the aircraft, and the crosspiece (axle in the bag troller) can be heavy duty folded sheet metal to provide a wide footprint for soft ground.

 

 

[Guest ROM]

Every job needs a lazy man! He will always find the easiest way to do something.

 

Jab jacks. This ones hangar use only and built because we always seemed to be taking wheels off or putting them on until we got the bindi tolerant tyres.

 

One of our mob got some 4x2 pine, can't make it too heavy now can we, and made up a frame about metre wide and about 10 / 15 cm's higher than the bottom of the J230 wings.

 

A bit of that tin strip cross bracing to hold it square and lots of foam tied around the top cross piece.

 

Slip it under and across the wing right against the strut and pull / slide the bottom in until the frame is vertical.

 

Wing goes up with aircraft attached.

 

One man operation without busting the phoofer valve and the wheel is 5 or more centimeters off the ground and the aircraft can't go anywhere unless it tips the frame over and with a metre width on the ground that is unlikely.

 

Crude but it works with minimum strain on everything concerned and no aircraft falling off tendencies.

 

 

[Modest Pilot]

We use a piece of 3/8" steel about 2" wide by 4" long with a lip on one end. A 5/8" hole is drilled close to one end.

 

The hole is used to bolt the metal to a cheap trolley jack. This is used under the end of the u/c leg; the flange stops it slipping off! The trick is to bore the hole so the jack just clears the wheel, other wise the jack tips up. Still works O K if you get it to far out but it's a nuisance if you are trying to use it by yourself.

 

 

[bushpilot]

Off topic

 

I know what you mean!On another note, I think I will be purchasing one of Boyd May's Carbon Fibre 3 blade props. I've been told to expect miracles when it's fitted, so I'm purchasing a ready-made miracle. quote]

 

Care to expand on this Brent? Is there a thread elsewhere on topic?