Jabiru wheel wobble

[Guest watto]

I am training in a J 170 at the moment and I have noticed that it gets a vibration through the front wheel after it has just left the ground, is this normal? it did not do it when I started training!

 

 

[Guest Macnoz]

Hi again Watto

 

are you sure its the front wheel?

 

Vibration on the Jab via the main wheels is very common almost to the point that a momentry touch of the brake is needed after take off partucularly TnG.

 

How goes your 230 plans?

 

 

[Guest watto]

I have the 230 already but am punishing the undercarriage of the training school whilst doing my landing etc haha and hen I go solo will start using my aircraft!

 

Am very pleased with the 230 though.

 

 

[Guest Rocko]

Used to have terrible probs with vibrating front wheel, just after takeoff. Turned out the wheel desperately needed balancing.

 

Made up a jig to balance the wheel, on 2 adjustable rails. Some lead from a tyre wholesaler, balance nicely, and all was well

 

Fixed nicely the problem.

 

Have use the jig on several aircraft since...proved very handy. Admittedly, I loaned it out, and never got it back, so guess others find it helpful too ;>

 

Scotty

 

 

[robinsm]

Any chance of getting a drawing of the jig???

 

Cheers

 

Maynard

 

 

[Guest Rocko]

Tyre balancer

 

No probs. It's a quick sketch, but hopefully you'll get the idea.

 

The key thing is to have both rails nice and sharp, to minimise friction between axle and the jig, and they must be dead parallel to each other, or all goes to heck ;)

 

Make it big enough, so can use on any tyres and rims. Then someone'll nick it ;>

 

Set it up on a stable bench, use a spirit level to make it absolutely level horizontally across the top, using the threaded bolts to adjust. Once level, either remove the axle with the tyre to use across the rails, or use an equally thick diam metal rod of some sort. Threads screw it up, as we found ;)

 

When put on, the tyre will self-rotate so the heaviest part is down. We used tape to temp stick the lead weights to the rim. Then redo over and over, until it doesn't tend to want to stay at any one point. Clean the rim thoroughly with appropriate solvent, and use the self adhesive on the lead weights to stick in place. The ones we bought only cost a few bucks from any tyre retailler, in all different weights, and have never come off so far.

 

The tyre we did was pretty out of balance. Had to use a surprisingly large amount of weight for an apparently new rim.

 

Took all the wobble from the front wheel on takeoff tho. It was pretty bad before we did it, and annoying as hell in the air as it rotated. Can use on all wheels, but it was the front we really were having probs with. As said earlier, some brakes will stop the others.

 

I really have to track mine down ;>

 

 

 

[Guest Rocko]

Again, it's one of those things you'll make up, and only use once in a never. But, when you need it, it's excellent. Then again, it's cheap to make. $10 in angle, and a fewbolts and nuts, and a bit of time with the welder and angle grinder.

 

 

[brilin_air]

Thanks for that Rocko :thumb_up:

 

We are having the exact same problem. It occurs with lift off and it vibrates the whole of the dashboard. We even changed the tyre on it thinking that it may have been caused from a flatspot on the wheel because it had been sitting for so long.

 

-Linda

 

 

[Guest Rocko]

We ended up finding it was the rim itself out of whack. Put it on by itself, and it still was well out. Rotating the tyre made little difference.

 

 

[Modest Pilot]

You may be able to get a tyre shop that does Go Kart tyres to balance them.

 

The local Cooper dealer can do it, strangly the only small wheels I saw there were off Ride On mowers. Watch out for racing lawn mowers in Cooroy!!!:big_grin::big_grin: