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Old Oct 24, 2010, 11:15 PM
Look out! The lever!
bobthenuke's Avatar
United States, AZ, Peoria
Joined Feb 2005
2,625 Posts
Martin,

I've also seen the wings held in by a turnbuckle. If I'm not mistaken the Multiplex Cortina wings are held in this way by design. Perhaps the LS3 was too? Just guessing. It must be mentioned, however, that Sean's method is probably the most common. Whichever way you go I would most certainly install a dowel or carbon rod across the inside of the fuse at the LE of the wings, and at the TE too if possible. This will prevent them from crushing the fuse in these areas should you come to an abrupt stop and the wings swing.

I have a Multiplex LS3 that I picked up and so far I've stripped the wings as they were a mess (he was not the greatest builder). The fuse is in good shape but the rudder needs to be rebuilt. I'm hoping to learn something about this model from your efforts. I have a number of MPX sailplanes and they are all great fliers.

-bob

PS I have too many projects going and a flying buddy just got himself my LS3. At least it'll stay "in the family". :-)
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Old Oct 25, 2010, 06:00 AM
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martinh's Avatar
United Kingdom, England, Fleet
Joined Aug 2002
544 Posts
Hi ,

Thanks for your advice.

@Sean & Bob - I guess the hooks and spring/turnbuckle need to be in front of the wing joiner for access?

My problem here is that there are the spoiler pushrods (and therefore the spoiler servo) plus the aileron wires exiting the wing root just where I'd need to put the hooks. Not sure if there's any spare room.

However, as Bob mentioned, I haven't got the front compression strut in yet... Doh

I think lack of strut may have been the reason for the damage done before I bought her.

If I put the strut in as per the plan, this should stop the wings moving forwards a bit. I'll try this tonight after work.

@Martini, I'm interested by your thread on the vinyl graphics, as I've got to get new markings too. Also interested to see if you will put a pilot in yours. I'm looking for a low cost solution - what about a GI Joe or similar 1/6 scale action doll? Maybe these are too heavy?

Cheers,

Martin

p.s. Bob, I've got the LS3 plan and instruction book, so if you need anything scanned and emailed, just ask.
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Old Oct 25, 2010, 11:34 AM
Look out! The lever!
bobthenuke's Avatar
United States, AZ, Peoria
Joined Feb 2005
2,625 Posts
Martin,

If it isn't too much trouble I'd sincerely appreciate a copy of the plan and instruction book. Quite frankly, I was *guessing* that the plane I have is an LS3 and wasn't convinced until I saw your pictures. Duh!

I have no doubt that the fuselage damage you have was the result of not having a compression strut at the LE. I don't know if this model was to incorporate a similar strut at the TE, but the later Multiplex models do, as well as a number of molded scale ships. Best not to put it in a position to stop suddenly but who's ever avoided that faux pas?

If possible I'd pull the wings together as close to the CG as possible but looking at mine, I see this would be quite difficult, not to mention the spoiler sservo in the way. Another method would be to use a set of Multiplex "Multilocs", the wing securing method they went to later on. These are simply a snap assembly, the female part mounted on/in the fuse near the front of the wing and the mate mounted to the wing. I use this method and it seems to work pretty well. I also tape the wing/fuse joint with white tape for streamlining, looks, and as a last ditch wing secure. I'm pretty sure that you can get these from forum member AirborneOne who used to be a Multiplex/Tangent dealer. It would take beefing up the fuse area where they would be mounted, but that's a pretty easy thing to do.

If the LS3 is anything like most of the Multiplex gliders you'll have to add some serious nose weight. I don't think a GI Joe will affect it's performance in the least. Ask anyone who has a Multiplex Alpina how weight affects it's flying... not much if at all. My first one was almost 12 pounds and flew beautifully.


-bob

PS - just took another look at my LS3 thinking about how to secure the wings and can't believe I missed this...does yours not have a rectangular bracket that surrounds the center of the metal boxes that secure the wing blades? The central screw in it which is used to tighten the boxes to the blades to secure the wings, the two outer ones hold it to the brass wing blade boxes. Here's a picture of mine: Also note the compression strut at the TE position. Hope this all helps.
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Old Oct 25, 2010, 01:51 PM
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martinh's Avatar
United Kingdom, England, Fleet
Joined Aug 2002
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Hi Bob,

yes, mine is the same as yours with the rectangle bracket. It works fine, but it doesn't "pull" the wings in like a spring or turnbuckle would. It just stops the wings from coming out when flying.

I think that with the front strut in place, it should be better. And yes, mine does have a rear strut permanently fitted.

Here's a pdf of the manual LS3 Manual 6. If you want a higher res copy, please PM me with your email address. Note that the german pages are also included at the front because that's where the diagrams are.

The plan is trickier, as it's huge and I can't scan it all. If you need a specific part, I can scan this and email it.

Cheers,

Martin

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Old Oct 25, 2010, 06:50 PM
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John Cole's Avatar
United States, CA, Santa Rosa
Joined Jun 2001
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Quote:
Originally Posted by martinh View Post
Hi John,

Thanks for your advice.

I'll try to get the fuselage splits back in line and then put a couple of layers of cloth and epoxy on the inside.

What do you think of removing the gelcoat completely and then repainting?

Your unbuilt LS7 kit must be pretty ancient - are you planning to build her?
[/B]
I didn't expect anything else back from them, but it was good to get a reply.

Martin
Martin,

Sorry for the delay in responding. It looks like you have the situation under control. As mentioned, the compression strut is very important, especially with blade connectors. My LS7 has a large rod, I believe. Airfoil is quite different too, and span is about 3.7m. I think it was kitted around 1992 or so. I hope to build it someday, it's a pretty glider!

John
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Old Oct 25, 2010, 07:13 PM
Look out! The lever!
bobthenuke's Avatar
United States, AZ, Peoria
Joined Feb 2005
2,625 Posts
Martin,

Thanks for the manual...that's all I really need at this time. I thought that if pushing in the wings and then tightening them down all would be well, but I guess I was mistaken. I really believe, however, that between the bracket and taping the wing/fuse joint you'll be fine.

-bob
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Old Oct 25, 2010, 08:46 PM
Chicago Mayor: A Terrorist
pilotfrank's Avatar
USA, CA, SoCal
Joined Sep 2002
404 Posts
If you can get a hold of the hard to get MPX Multilock system, it should do exactly what you desire.
There's a thread about it http://www.rcgroups.com/forums/showthread.php?t=824082

Frank
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Old Oct 25, 2010, 11:44 PM
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Martini's Avatar
USA, ID
Joined Jun 2004
256 Posts
Martin- I will add a reply about what I do with my graphics as soon as I find the right approach. I am hoping there is a decent vinyl shop here locally.

As far as a pilot - absolutely!! You gotta put one in for those photos. I am still looking for the right dude (or gal I guess). I got some ideas to look into my local record store - they have all sorts of figures that I'm guessing might work.

As for your wing movement - probably good to go with adding the compression strut and using some good tape. The tape works well and also lets loose if there's some major movement which seems to help absorb energy. Let's hope neither of us needs to test that one - at least not too soon anyway.

best regards, Jim
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Old Oct 26, 2010, 06:06 PM
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martinh's Avatar
United Kingdom, England, Fleet
Joined Aug 2002
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We're almost there...

Have now refitted the servo tray and the elevator, rudder and tow release servos.

Throws are as follows:

Rudder 40mm left + 40mm right.
Elevator 12mm up + 10mm down.
Ailerons 15mm up and 8mm down.
CG 90mm from leading edge at root.

I had to add a load more lead to balance her and the AUW is now 3kg (6.6lbs). That's about 200g more than design weight.

Required to finish:

- Secure the lead and battery up front.
- Make and fit the compression strut.
- Make a servo tray for the spoiler servo between the wings.
- Lateral balance (40g needed in left wing).

Found this spoiler servo solution on another forum:

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Note that the tray is removable for servo maintenance. Spoiler pushrods connect to the servo arm with ball connectors.

Looks like she could be flying this weekend!

Martin

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Old Oct 28, 2010, 07:38 AM
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christianka6cr's Avatar
Germany (Black Forest, Alps, Vosges)
Joined Dec 2009
63 Posts
Hello

Yeah, shes a dream! I love her!
Many years ago, around 20 i think, i got my first LS-3 and it was a real great glider. 3 LS-3s further, i found mine this spring at Ebay for 30€ without any scratches or breaks, complete with all servos. Now, half a year later and over 30 hours flight time with her, i dont want to miss her anymore!
Martin, I wish you many nice an happy hours in the air with her!

Greets Christian
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Old Oct 28, 2010, 08:03 AM
Chicago Mayor: A Terrorist
pilotfrank's Avatar
USA, CA, SoCal
Joined Sep 2002
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Quote:
Originally Posted by christianka6cr View Post
Hello

Yeah, shes a dream! I love her!
Many years ago, around 20 i think, i got my first LS-3 and it was a real great glider. 3 LS-3s further, i found mine this spring at Ebay for 30 without any scratches or breaks, complete with all servos. Now, half a year later and over 30 hours flight time with her, i dont want to miss her anymore!
Martin, I wish you many nice an happy hours in the air with her!

Greets Christian
30!!
Gotta love eBay Germany...I should have never moved here....
There, you have a category for r/c sailplanes, and tons of scale ships modern or vintage at great prices. Here in the US I think you see a scale glider once every 3 months, not counting all the chinese junk of course.
Christian, that is a great flying site and those pictures should be motivation for anyone's project to finish it in a hurry. Where exactly is that slope?

Viele Gre,

Frank
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Old Oct 28, 2010, 08:10 AM
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Germany (Black Forest, Alps, Vosges)
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Thank you Frank! This is at the Petit Ballon, in the Vosges-France, near Colmar. If it had clear view, you could see on the 3rd photo the Black Forest.

Greets Christian
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Old Oct 28, 2010, 12:10 PM
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martinh's Avatar
United Kingdom, England, Fleet
Joined Aug 2002
544 Posts
Hi Christian,

Thank you for your kind words and for posting your photos - looks great!

Can you describe her flying style - fast/slow, amount of lift needed etc? What would be the best wind speed range?

I can't believe you bought yours for 30 euros is such good condition. I just paid 30 euros inc postage for a replacement canopy for mine. Maybe we should all pack up and move to Germany.

So, now I'm even more excited about flying her. I need to find some good weather and a suitable slope. Sunday looks best but the forecast wind is SE -not good for the slopes near me. Hopefully, they got the forecast wrong again.

I still have some work to do though. I've made the compression strut and the wing rocking problem disappeared (hooray).

Just need to make and fit the spoiler servo tray and secure the receiver and lead.

Should be finished tomorrow evening.

Martin
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Old Oct 28, 2010, 02:44 PM
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christianka6cr's Avatar
Germany (Black Forest, Alps, Vosges)
Joined Dec 2009
63 Posts
Hello Martin

To describe how to fly the LS-3 is very easy: Shes a F3J-Amigo! Slow and easy without any bad qualities. You can fly her at zero wind or strong wind, but at the strong windy day you will not have much fun...

But if you want to go fast as most of the F3J can, thats not her style. Rolls, loops, turns, sunny side up , everything is ok, but shes a old wooden lady! Never forget it!

I wish you a successful maidenflight and much fun with your good old german lady

Greets Christian

PS: The foto is from our home-slope at the Black-Forest. 3 minutes away from my sofa
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Old Oct 29, 2010, 05:01 PM
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martinh's Avatar
United Kingdom, England, Fleet
Joined Aug 2002
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Thanks Christian,

That's just the sort of performance I'm looking for from my first scale-like glider. Thanks for the info and advice.

Tomorrow is looking reasonable for the maiden flight - especially as I've now fitted the spoiler servo and set everything up.

Regarding the setup, does the trim change when you put out the spoilers (pitch up or down)?

Also, I read on a couple of German forums (using Google Translate) about needing to adjust the EWD on this model - I think it's also called decalage i.e. setting the stabiliser angle relative to the wing angle. Do you have any experience of this for the LS3?

Cheers,

Martin
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