Standard Jantar wheel brake assembly

On Thursday, April 12, 2018 at 8:02:37 AM UTC-7, wrote:
Does any have, or could anyone take a picture of the port side of of the main wheel on a Standard Jantar 41A? I’m having a heck of a time figuring out the trick to get it back together and adjusted correctly.

Thanks!


If it's the same wheel/brake as a 48-3 or a 59 then I can take some pics of the one I have, though it's no longer on the ship. That thing was simple enough assemble but I never found an adjustment point strong enough for the brakes to actually work without grabbing while not engaged.

It's a neat idea how it works in general but a poor design as applied and probably inappropriate on a sailplane. The wheel is allowed to 'float' on the axle to allow both clutch/brake plate things to engage equally even though it's actuated from one side. This also means if you do a taxi turn after landing but still able to keep the tail off the ground the brake can grab from the side load, with potential for a tail slam.

The only effective adjustment I made was to convert to a 5.00x5 Clevelend hydraulic. The biggest part of the job was the fork. Had to cut off the lugs that trap the brake plates to remain stationary, as well as machining a flange for the caliper and having it welded it on. Also needed an axle spacer/adapter and a bracket/lever for the master cylinder. Uses the same brake lever in the cockpit... except now it actually works.

If there's a Tost kit for it that's probably easier and way better than the stock contraption, but iirc that wheel was smaller and I didn't want to lose ground clearance. I have drawings of the parts that were made and specs for what was bought if you wanted to go that route.

On Thursday, April 12, 2018 at 11:36:50 AM UTC-7, sisu1a wrote:
On Thursday, April 12, 2018 at 8:02:37 AM UTC-7, wrote:
Does any have, or could anyone take a picture of the port side of of the main wheel on a Standard Jantar 41A? I’m having a heck of a time figuring out the trick to get it back together and adjusted correctly.

Thanks!


If it's the same wheel/brake as a 48-3 or a 59 then I can take some pics of the one I have, though it's no longer on the ship. That thing was simple enough assemble but I never found an adjustment point strong enough for the brakes to actually work without grabbing while not engaged.

It's a neat idea how it works in general but a poor design as applied and probably inappropriate on a sailplane. The wheel is allowed to 'float' on the axle to allow both clutch/brake plate things to engage equally even though it's actuated from one side. This also means if you do a taxi turn after landing but still able to keep the tail off the ground the brake can grab from the side load, with potential for a tail slam.

Yes - an undocumented feature of the Jantar brake! A sharp turn, including a half-ground-loop caused by a wing-tip snagging high grass, actuates the brake quite sharply. You may end up with some gravel rash on the nose, but it may save you a broken boom. I did this experiment on a Jantar-1!

Mike

How about fixing the wheel so that it doesn't travel on the axle? Only one shoe would apply pressure, maybe not enough to raise the tail...good compromise?

Better yet - a split washer or spring either side of the wheel. Sized right so that shoe disc can compress it as well, but would prevent wheel from binding without brake application. Experimental a/w certificate allows such experimentation...

On Thursday, March 14, 2019 at 5:54:42 PM UTC-7, wrote:
...Experimental a/w certificate allows such experimentation...

If it's experimental, I can put a Matco hydraulic disk brake unit in for you. Very effective yet progressive braking action. It will put the glider on its nose, but only if you want.

--Bob K.

On Friday, March 15, 2019 at 10:04:01 PM UTC-4, Bob Kuykendall wrote:
On Thursday, March 14, 2019 at 5:54:42 PM UTC-7, wrote:
...Experimental a/w certificate allows such experimentation...

If it's experimental, I can put a Matco hydraulic disk brake unit in for you. Very effective yet progressive braking action. It will put the glider on its nose, but only if you want.

--Bob K.

what would the cost be?

I'd have to see the glider to work up a proper estimate. But the ballpark is probably around $1500 installed and ready to use.

-Bob K.

Quote "Experimental a/w certificate allows such experimentation... "

Not necessarily. Read the operating limitations to see what it says about the maintenance requirements for the aircraft.