Axle removal - Jantar 3 - SZD-48-3

[Mike Pollard]

I've got a new-to-me Jantar 3 that was previously sitting in its trailer in humid Houston for 10 years.

I'm trying to remove the axle for the main gear in order to change the tire and fix the brakes.

I've removed the bolt/nut on the left and right side that would retain the axle. Beating on it from either end was not successful at getting the axle to move. I'm not even sure that this axle (slotted on both ends) doesn't need to be unthreaded out.

Before I get rougher with it (rotation and beating along axis), I was wondering if anyone had any hints as to how it should be removed.

Believe this is my first post. Looked for how to post photos, but can't find it, sadly. Would have been helpful for this.

Thanks,

Mike Pollard

[Dan Daly]

Two suggestions; the spare parts catalog at https://szdallstar.com/en/service/technical-documentation/szd-48-3-jantar/ near the bottom has exploded views of the parts which might assist (it has a download link). If you don't have the Technical Services Manual for your glider it would almost certainly help to get it.

I run the SZD-55 users group at https://groups.io/g/SZD-55usergroup but I've searched and there is nothing specific on wheel removal (there is the 55's TSM with exploded view). There may be a users group for the Jantar that could help - does anyone know if there is? There wasn't one for SZD-55 that I could find, and so I started one (free on groups.io), we now have 38 members (about 110 built).

In 2013 on r.a.s. there was a note:
"There is a link to polish glider forum:
http://forum.szybowce.com/szybowce/
You can ask a question about SZD gliders here . A lot of people from
forum speaking of english language. " It appears the forum is still very active.

Cheers
Dan

[John Sinclair]

Good luck adjusting that Jantar wheel brake! The shoes rotate with the wheel when brakes were applied……….never did figure out how to get more that crappy brakes!
JJ

[Mike Pollard]

Thanks to you both. With the spare parts catalog, I've now confirmed that the axle does not thread out. I just have to give it adequate persuation I suppose.

Brakes will be part 2. I pull the handle, the lever moves but the wheel is still free to rotate. Once I get this apart, I can see if some correction needs to be made. I sure don't want to count on landing short at our field every time and not need brakes. No doubt more on this later...

Mike

[Mike the Strike]

I had a Jantar-1 (19m) years ago, which I recall had the same or very similar wheel. A light tap with a suitable drift should do it, otherwise you just need a bigger hammer!

Mike

[Dan Daly]

I don't know how the Jantar brakes adjust; on the 55:
"Am 01.03.2021 14:55 schrieb name deleted for privacy:

Hello all,
I would like to add another advice: the wings needs to be rigged when adjusting the wheel brake. If the brake is adjusted too tight (or brake too soon) you are going to loose some range on your spoilers travel. It takes many attempt to make sure that you have enough brake power with full spoilers.

name 1

Le dim. 28 févr. 2021 22 h 21, another name deleted for privacy> a écrit :

When fuselage is on the trailer ramp, unlock brake adjustment, using 2 flat wrenches marked "34" turn clockwise break plate maybe 20-30 deg and lock with locking nut. Use both wrenches.
This will make internal discs 1-2 mm closer.
Inside the hub are 2 discs on the spiraling axle.
Lever with the brake cable is bringing them closer.
Don't try to adjust lever.
Those 2 wrenches should be sitting with main spar pins in the green pouch. Hope you didn't loose them. They get used once every 10 years.
It is very hard to explain unusual brake arrangement of 55.
Maybe someone has a drawing ?

name 2"

I have adjusted the disks by turning them about 45 degrees with the wrenches and it would absolutely put you on your nose when you brake... backed off to 20 degrees and it brakes well and controllably. This was before the directions above were posted. At some point, the internal disk ablative material will be worn off and the disks will need replacement, though I've never heard of that being done. I do see that Wings and Wheels has a TOST conversion to hydraulic disk brakes but it is spendy (but $700 lees than the SZD55 kit).

[Jj]

I would suggest backing up the gear structure, at the opposite end of the axle that you a massaging, with a bucking bar or similar.

JG

[Dan Marotta]

Use some penetrating oil and, after a bit, try rotating the axle
slightly before beating the crap out of it. You might also try a bit of
heat on the gear, not the axle.

Dan
5J

[ASM]

Contact me privately at jacek dot kobiesa at iCloud dot com.

[krasw]

Most glider annual maintenance lists include removal and lubrications of wheel main axle. My old ASW20 tailwheel was assembled without grease during 3000hr inspection. One summer of flying was plenty enough for axle and tailwheel to rust solid, could not get the apart even in bench after sawing axle in three parts for removal.

[Stéphane Vander Veken]

One of the problems with that design is that the wheel should always be able to move very slightly sideways on the axle when the brake is applied. If the axle is not well lubricated, this can and will lead to wear of the axle and eventually to the development of a groove with a rim on the axle. This groove and rim will limit the effectiveness of the brake and can make removal of the axle very difficult. We had this problem with a Puchacz, wich has the same system.

[mike maskell]

On Tuesday, February 7, 2023 at 8:40:46 AM UTC-6, launch...@yahoo.com wrote:

The comment of the glider sitting for 10 years in a humid environment is likely the cause of the axle becoming frozen in place due to corrosion. I would use a copious amount of rust penetrant (WD-40, Release-All etc) over a few days and be patient. The application of a bit of localized heat might allow some release, and as stated in another comment, backing up the opposite side with a bucking bar of where you are hitting from will allow for more direct force being applied. Use a brass punch large enough to fit fully on the head of the axle so as to not peen over the end of the axle. Good luck.

[Mike Pollard]

I want to thank all of you for your responses. Good info. No bashing, insulting or grossly off topic stuff like I've seen in so many other forums. Must just be better people :) My fancy screwdriver is being reviewed by a machine shop. In the mean time, I've ordered a shaft with a keyway cut in it and some key stock. Some grinding will be required, but think it'll be a good second attempt at getting this thing out. The best part is I'll have it for this weekend (I'm unfortunately not retired yet). If it doesn't break loose easily, I'll put a little heat on the structure that holds the axle and then hit the axle with water to cool it. Then penetrating oil. Then try a little more force. SOMEHOW this thing will come out. I'll let you guys know what all had to transpire once I get to that endpoint.

Mike

[Kari Mettinen]

Just did this on my Std 2. the SZD 55 stuff doesn't seem right, hopefully they made a better setup for that one. With regards to the axle, the suggestions here should work if anything's going to work. The brake adjustment is not hard, but won't make it great. I'm setting it so that without any squeeze on the lever it's just about to start braking, otherwise I don't get much braking at all Tost disc conversion is pretty high on my list of things to get eventually.

[Robert]

Mike,
Some time ago I removed the landing gear from my SZD-48-3 and overhauled it completely. Photographs of all the components in the album https://photos.app.goo.gl/RMFM3Nnd428AG5Qu9.
Note the obvious difference. Brake system in my SZD-48-3 has been converted from factory mechanical drum to hydraulic disk. The axle has been retained without any modifications.
Corrosion protection of metal parts on SZD gliders manufactured in the 80-s and in the 90-s is not as robust as what one would consider a modern standard. I think the axle in your glider is corroded and seized in the fork bushings (steel-on-steel contact). Penetrating lubricant and patience might be what's needed.
Well maintained axel can be removed by pushing with a finger after the safety pin is pulled out.

[Mike Pollard]

All,

Axle came out using a "bucking bar" of wooden posts and a larger hammer. I was ready with the heat gun, torch, fire extinguisher and a defeatist's expectations though. Took the wheel assembly home to look at in more detail with coffee hopefully tomorrow. Will probably start another thread based on what I find there, unless all is near-perfect and obvious. Thanks for all the good comments guys!

Mike

[Mike Pollard]

Robert,

I did look at the photos you had accessible by that link. Unfortunately I've gotten a 404 error every day this week when trying to access again. I think for this round I'll just see what my stock brakes can give me, but some time in the future could come an upgrade. I would like to be able to obtain/retain info from somebody who has done it before. Like photos, which kit was purchased from who, paperwork involved, weight and balance, method of restoration of other components, other components required or replaced, hints, comments etc. Don't know if you've done a writeup anywhere on this with some detail.

If you get bored some rainy day, I was wondering if you could do that (so long as access to a social media account isn't required to view). Of course a durable way to access this is key, and I don't know what the solution is there. Too many other posts in other groups where stuff can't be accessed at some later date.

Thanks,

Mike Pollard

[Robert]

Mike,
The best option I think is a brake retrofit kit available from TOST. It can be purchased from Wings & Wheels https://wingsandwheels.com/conversion-kit-jantar-swift.html

Hydraulic brake in my SZD-48-3 was installed by Williams Soaring Center. Original wheel was replaced with Cleveland .
Pictures in the https://photos.app.goo.gl/8p1jKTUdF4V8u2pv9

Robert

[Mike Pollard]

Robert,

Thanks. This link worded today. Took a screenshot and saved as a file on my hard drive. Is that kit from W&W you have linked the same kit that Williams installed?

If I recall correctly, Williams Soaring no longer acts as distributor or repair center for Jantars. Is there any US company that does that, or is it work with the factory?

Mike

[Robert]

Mike,
Williams Soaring installed the brake system in my SZD in 1999. They manufactured caliper bracket that is welded to the existing fork and used off-the-shelf aircraft components (wheel, cylinder, brake and hydraulic lines). Williams Soaring is an FAA approved repair station.
TOST kit has (EASA) airworthiness approval and is installed as a minor change.
https://www.tost.de/katalog/umruestsaetze-auf-scheibenbremsrad/?lang=en
In US the SZD-48-3 is an Experimental category aircraft.