Arcus owners not monitoring the Arcus newsgroup...

[Dave Nadler]

Assembly info here:
https://groups.google.com/d/msg/schempp-hirth-arcus/3exDnET5nTw/7Ufemdv0BQAJ
Enjoy!
See ya, Dave

[[email protected]]

I have been assembling and disassembling the Arcus "J" (jet engine conversion by Desert Aerospace) using the WingRigger I specifically built for this application. The prototype unit went to Al Simmons, who appears to be satisfied and pleased with it. To counteract the high spring forces necessary to handle the heavy Arcus wing, the gas spring is augmented by a remotely controlled 12 volt 225 lb. capacity linear actuator. Not only does it make height adjustments effortless, it also enables the user to easily lower the saddle to the lowest position so that the second wing can be removed from the trailer. So far, we have had excellent results. For more information, please contact me through info (at) mmfabrication (dot) com. Photos and video are not yet available on my website, but will be coming soon. www.wingrigger..com

[Dave Nadler]

On Tuesday, August 23, 2016 at 10:51:19 PM UTC-4, wrote:
> ...To counteract the high spring forces necessary to handle the heavy
> Arcus wing, the gas spring is augmented by a remotely controlled
> 12 volt 225 lb. capacity linear actuator.

With a properly sized electric linear actuator, the gas spring is
unnecessary, and adds additional weight/complexity...

The wing dolly as I modified should now be available from IMI.
It is beautifully built, has an adequate axle that does not bend,
and is very light weight.

Thanks,
Best Regards, Dave

[[email protected]]

Gee, Dave- when we were corresponding last year about an Arcus model WingRigger, you were adamant that the linear actuator was "too complex and unnecessary." Now it is the gas spring that is too complex and unnecessary. How things change. I find that a combination of the spring and actuator is preferable.

[Dave Nadler]

On Wednesday, August 24, 2016 at 8:42:29 PM UTC-4, wrote:
> Gee, Dave- when we were corresponding last year about an Arcus model
> WingRigger, you were adamant that the linear actuator was "too complex
> and unnecessary."...

Unfortunately, the proportionality of a gas spring that fits inside the
IMI structure is too high - otherwise gas spring would be preferable.
If you can fit a gas spring with more constant force, that would be best.

> I find that a combination of the spring and actuator is preferable.

Using both is just unnecessary complexity, cost, and weight.


Now, how about a thank-you for repeatedly providing you with engineering
data and measurements, instead of snide comments? Really now.

Thanks,
Best Regards, Dave

[[email protected]]

Dave, your "engineering data and measurements" were not needed nor used. I am satisfied with my solution. The extra 1.1 lb. of the gas spring means I can use a lower capacity actuator (thus less costly) by using a properly sized gas spring as a load assist. I am sure the IMI unit is satisfactory, but it is not the only solution.

"Thanks" anyway.

[[email protected]]

On Tuesday, August 23, 2016 at 5:17:52 PM UTC-4, Dave Nadler wrote:
> Assembly info here:
> https://groups.google.com/d/msg/schempp-hirth-arcus/3exDnET5nTw/7Ufemdv0BQAJ
> Enjoy!
> See ya, Dave

Alignment suggestion: how about a simple sight gauge? A removable fixture sitting on top of the fuselage (maybe 1” pvc pipe attached to a FG saddle) which "fixes" two vertical “whiskers” aligning perpendicular to the fuselage center-line. These “whiskers” would be spaced as far apart as possible without interfering with walking out the wing. With the fixture on the fuselage top “sweet spot", just "gun sight" the whiskers while out at the tip until properly aligned with a reference point on your wing. Wing should then be positioned close enough to align dead on within the adjustable travel of the rigger base if needed. KISS rocks.

More important suggestion: the thought of lifting any wing tip and carrying its load to full extension while stepping over a mid-way pivot rigger is inviting a probable trip/fall/damaged wing and SCREAMS oh my aching back. With rigging aids becoming the norm and the linear actuators proving to be so helpful, pilots with bad backs and especially “bus” or “big bird” pilots need a dual purpose rigging aid. First it would serve as a “wingout” device; it would be used to capture wing tip handles and lift the wing tip so the wing could be rolled straight back to full extension. Once fully extended, the linear actuator would transfer the wing tip load to a purpose built tip stand. Once on the tip stand, the aid would be converted into the current wing cuff pivot rigger and manage the positioning and rotating of the wing until the wing root is seated into the fuselage. I think a dual purpose rigging aid could use the existing IMI or Enstroj (another well designed pivot rigger) actuated base and reengineered to offer easily interchanged “wingout” and pivoting wing cuff “heads” to handle all the lifting loads.

Proof of concept should develop an easy process which eliminates any lifting heavier than what is required to lift the trailer clamshell roof.

(Dave, please share the sight gauge idea with the ARCUS group.)

And ya’ll quit slinging cow piles at each other.

[Casey[_2_]]

>
> And ya’ll quit slinging cow piles at each other.

And I thought I was the only one that got cow patties thrown at me.

[Dave Nadler]

On Friday, August 26, 2016 at 2:32:43 AM UTC-4, wrote:
> Alignment suggestion: how about a simple sight gauge?
> A removable fixture sitting on top of the fuselage (maybe 1” pvc pipe
> attached to a FG saddle) which "fixes" two vertical “whiskers” aligning
> perpendicular to the fuselage center-line. These “whiskers” would be spaced
> as far apart as possible without interfering with walking out the wing. With > the fixture on the fuselage top “sweet spot", just "gun sight" the
> whiskers while out at the tip until properly aligned with a reference
> point on your wing. Wing should then be positioned close enough to align
> dead on within the adjustable travel of the rigger base if needed.

Hi Marshall - Perhaps I don't understand? A sight-gauge on the fuselage
won't help if my eye (at the root) is in the right location, but the
center of the wing (in the dolly) is not.

> KISS rocks.

Absolutely. I'm going to try a string-gauge that places a target for
the wing-dolly column on the ground. Maneuver the wing dolly til the
support column is over the target, then swing root to fuselage and
rotate.

> More important suggestion: the thought of lifting any wing tip and
> carrying its load to full extension while stepping over a mid-way
> pivot rigger is inviting a probable trip/fall/damaged wing and
> SCREAMS oh my aching back.

Its not that bad! IIRC wing-tip is 40kg.

> ...pilots need a dual purpose rigging aid.
> First it would serve as a “wingout” device...

Spindelberger makes a wing-tip roll-out device for the ASH-30
inner wing panel. The Arcus wing shape makes this harder.
And, a wing-tip device adds more parts and complexity...

Thanks Marshall,
See ya, Dave

[Muttley]

Hi all

rather than walking the rigger in an Arch to the fuselage i used to walk it quite far out with right angles which gives you a long last leg to line it up better with the fuselage, also putting the wing flat for the last leg gives you a better feel and sight of what you are at. (Duo Discus)

[JS]

On Friday, August 26, 2016 at 5:29:26 AM UTC-7, Muttley wrote:
> Hi all
>
> rather than walking the rigger in an Arch to the fuselage i used to walk it quite far out with right angles which gives you a long last leg to line it up better with the fuselage, also putting the wing flat for the last leg gives you a better feel and sight of what you are at. (Duo Discus)

When the glider is rigged, mark the position of the spars on the fuselage with a sharpie. This works great on Libelle, and a Schempp wing root is just the same.
Jim

[David Salmon[_3_]]

At 12:29 26 August 2016, Muttley wrote:
>Hi all
>
>rather than walking the rigger in an Arch to the fuselage i used to walk
>it=
> quite far out with right angles which gives you a long last leg to line
>it=
> up better with the fuselage, also putting the wing flat for the last leg
>g=
>ives you a better feel and sight of what you are at. (Duo Discus)
>

I am using an IMI device on my Discus, and find it quite good, but years
ago I used to rig my 19m Jantar single handed, using a simple, home made
system. 19m 2 piece pre-carbon wings were quite heavy. I think this could
be refined, and it gets round some of the problems mentioned.
2 tip stands and a shorter one same height as the fuselage opening for
inserting the wing. One simple root trolley and a castoring tip trolley.
Pull out the tip a short distance and put on tip trolley, then pull the
wing out fully. A quick lift to put the root on the root trolley. Wing is
now supported on wheels at both ends. Pull out at a small angle to the
fuselage until the root end is in the correct place, from tip castor the
tip round until the wing is perpendicular to the fuselage. Lift spar onto
short stand, lift tip onto tip stand, then go flat rotating on spar. Lift
spar and insert in fuselage, push into place, finally positioning from tip.
Repeat with 2nd wing.
There are several short lifts, no carrying apart from the initial tip onto
its trolley. No stepping over anything, easy to sight the position of the
root end, in any case easy to make adjustments sliding on the stands, no
more walking around than with the IMI.
If I can get round to it, I would like to try making a tip trolley as
above, and use the IMI as the root trolley.

Dave

[[email protected]]

On Friday, August 26, 2016 at 7:32:30 AM UTC-4, Dave Nadler wrote:
> On Friday, August 26, 2016 at 2:32:43 AM UTC-4, wrote:
> > Alignment suggestion: how about a simple sight gauge?
> > A removable fixture sitting on top of the fuselage (maybe 1” pvc pipe
> > attached to a FG saddle) which "fixes" two vertical “whiskers” aligning
> > perpendicular to the fuselage center-line. These “whiskers” would be spaced
> > as far apart as possible without interfering with walking out the wing. With > the fixture on the fuselage top “sweet spot", just "gun sight" the
> > whiskers while out at the tip until properly aligned with a reference
> > point on your wing. Wing should then be positioned close enough to align
> > dead on within the adjustable travel of the rigger base if needed.
>
> Hi Marshall - Perhaps I don't understand? A sight-gauge on the fuselage
> won't help if my eye (at the root) is in the right location, but the
> center of the wing (in the dolly) is not.

Sorry Dave...laughing at myself because I left out the most important piece of the rigger locating concept. Pull the fuselage out and ready it to put the wings on. Place the "whisker saddle" on the top of the fuselage. You know the rigger vertical post will always be "X" paces out from the fuselage when you are ready to slide the spar into the fuselage. So before you pull the wing out, walk out from the fuselage those same "X" paces, "gun sight" the whiskers to create an imaginary alignment plane and position a marker on the ground at intersection of X paces and alignment plane. Now just jockey the rigger vertical post until it is over the marker you placed on the ground and you should be aligned within the travel adjustment of the rigger base. With both wings on, remove whisker saddle and pick up ground markers. Very simple and very few pieces.


I think you could also fashion a simple battery powered "fan line laser" rig to create the alignment plane. Position the laser rig (dollar bill footprint) in the fuselage spar box, shoot the fan line, and place the ground marker. Remove laser rig before inserting wing. Laser would have to be bright enough to see in the daytime. Watch this video for concept of fan laser rig. https://www.youtube.com/watch?v=Yxf7_bRIIWw . Here is one of many laser parts house http://www.greenlasermodules.com/index.html .

Beauty is this would work for any sailplane and any rigger.

Bests.




>

[[email protected]]

Hahaha! I was using the "take 8 paces from the fuselage and plant the wingstand", then "pull the wingtip out and carry it around to the wingstand, then sight through the fuselage carry-through to get the fore-aft alignment" since I built my first WingMate solo rigging aid in 1982. The only difference is that my LS-3 trailer was rigged so you could pivot the wing spar on the dolly. For my ASW 24, I set the wingtip into the stand by the rudder, walk back up to the trailer and transfer the spar from the spar pin hole closest to the root rib to the hole at the tip of the spar, then walk back to the wingtip and carry the stand--with tip installed--around pivoting on the spar dolly until I can sight through the fuselage carry-through.

Any adjustments for height I can make by rolling the fuselage for the first wing and, for the second wing, by adjusting one or both wingtip supports and/or cranking the fuselage dolly up or down. Sounds complicated but as you all are saying, it works very well in practice. I've been solo rigging/derigging for almost 35 years and the only time I need help is when the wind picks up pretty strongly.

I haven't built any WingMates for a while but I may get back to it. The number of solo-rigging pilots at the contests these days is pretty impressive.

Chip Bearden

[[email protected]]

Here is an article that might be worth reading on using lasers as alignment tools for sailplane assembly.

http://www.soaridaho.com/Schreder/Construction/LaserAlign.htm