Tapered pins (again)

[[email protected]]

Helped the new owner beat his 27 together, last Sunday.............he looked shocked when I suggested he "taper" at least one pin. Nothing too severe, just 15 degrees and only on the part that extends out the back side of both spars. Found a 40mm pin in the barn from K-21 and it has 5 degree taper that starts an inch from the end, that sharpens to 15 degrees about 1/2" from the end. Looks professional, did Schleicher ever offer a tapered pin? Anything would be better than their blunt pin that will only start when everything is EXACTLY perfect!
JJ

[Matt Herron Jr.]

On Tuesday, April 24, 2018 at 7:10:49 AM UTC-7, wrote:
> Helped the new owner beat his 27 together, last Sunday.............he looked shocked when I suggested he "taper" at least one pin. Nothing too severe, just 15 degrees and only on the part that extends out the back side of both spars. Found a 40mm pin in the barn from K-21 and it has 5 degree taper that starts an inch from the end, that sharpens to 15 degrees about 1/2" from the end. Looks professional, did Schleicher ever offer a tapered pin? Anything would be better than their blunt pin that will only start when everything is EXACTLY perfect!
> JJ

I checked how much extra pin length protrudes out the back of the spars on the 27. Unfortunately only the radius of the pin sticks out! On the other hand, the previous owner acquired an aluminum pin with lots of taper, a nylon pin with lots of taper, and a Delrin eccentric pin. Obviously this was an issue for him.

At least I will have something to try next time :-) Thanks for your help yesterday.

Matt

[[email protected]]

On Tuesday, April 24, 2018 at 3:10:49 PM UTC+1, wrote:
> Helped the new owner beat his 27 together, last Sunday.............he looked shocked when I suggested he "taper" at least one pin. Nothing too severe, just 15 degrees and only on the part that extends out the back side of both spars. Found a 40mm pin in the barn from K-21 and it has 5 degree taper that starts an inch from the end, that sharpens to 15 degrees about 1/2" from the end. Looks professional, did Schleicher ever offer a tapered pin? Anything would be better than their blunt pin that will only start when everything is EXACTLY perfect!
> JJ

Does the end of the pin definitely stick out beyond the spars? I wanted to do that to JS1 pins but apparently the pins were only long enough to fill the spar stub holes.

[[email protected]]

I was thinking about having my Pegasus pins tapered. I'll have to check how much is protruding from the spar. Who has done this and is it something any good machinist can do? Does the taper JJ mentions seem about right?

[[email protected]]

On Tuesday, April 24, 2018 at 11:13:41 AM UTC-4, wrote:
> I was thinking about having my Pegasus pins tapered. I'll have to check how much is protruding from the spar. Who has done this and is it something any good machinist can do? Does the taper JJ mentions seem about right?

I own a Pegasus - and my pins are tapered - about 1/2 inch on the end - I believe that is the way it came. I do not have an issue assembling quikly.

Only once, I did have residue on the ring that looks like a big washer around the root pins - cleaned that and no more problems. Anything on that creates problems.

WH

[JS[_5_]]

If the water ballast dump valve is open or the airbrakes locked, assembly can be difficult.
If the flaps are in L position it will go together but the stick won't move side to side and the flap handle won't move.
MM Fabrication sells an assembly tool (designed and originally sold by Steve Bralla) that works very well. A more simple approach than tapering the pins. It wasn't on his website last I looked, so call or email Mark.
Jim

[JS[_5_]]

On Tuesday, April 24, 2018 at 9:03:55 AM UTC-7, JS wrote:
> If the water ballast dump valve is open or the airbrakes locked, assembly can be difficult.
> If the flaps are in L position it will go together but the stick won't move side to side and the flap handle won't move.
> MM Fabrication sells an assembly tool (designed and originally sold by Steve Bralla) that works very well. A more simple approach than tapering the pins. It wasn't on his website last I looked, so call or email Mark.
> Jim

Previous post was re: ASW27.
Jim

[[email protected]]

FYI- I am now producing tapered and eccentric wing assembly pins made from Acetal plastic (Delrin). They aren't on my website yet, but I generally have a few of various sizes in stock. Contact information (cell phone number and email) are on the website mmfabrication dot com.

[Bob Kuykendall]

I made the HP-24 pins taper a bit, and it doesn't take much to make a big difference. My pins taper about 15 degrees for about 1/2", and if that doesn't do it the wings are way out of position. In my ship there just isn't much room between the ends of the pins and the autoconnect hardware, since I've crowded that stuff forward in order to reserve a bunch of mid-fuselage volume to allow for BRS.

But I do make eccentric tapered pins out of Delrin where the axis of the tapered portion is inclined from the axis of the cylindrical part. These work great to draw the wings together the last little bit on sticky ships. I can make these in pretty much any diameter.

--Bob K.

[Scott Williams]

Is the original pin hollow?
Is there room aft of the aft spar hole for a delrin tapered "extention"?
Or aluminum or nylon?
Just brainstorming.
Good luck
Scott

[[email protected]]

On Tuesday, April 24, 2018 at 10:10:49 AM UTC-4, wrote:
> Helped the new owner beat his 27 together, last Sunday.............he looked shocked when I suggested he "taper" at least one pin. Nothing too severe, just 15 degrees and only on the part that extends out the back side of both spars. Found a 40mm pin in the barn from K-21 and it has 5 degree taper that starts an inch from the end, that sharpens to 15 degrees about 1/2" from the end. Looks professional, did Schleicher ever offer a tapered pin? Anything would be better than their blunt pin that will only start when everything is EXACTLY perfect!
> JJ

I've made a bunch of assembly pins. Diameter is .010 smaller that wing pin. End tapers to .10 smaller in diameter over 1-1/4 inches with smooth transition. Handle made to not look like a wing pin.
Works great.
UH

[Eric Greenwell[_4_]]

wrote on 4/24/2018 7:10 AM:
> Helped the new owner beat his 27 together, last Sunday.............he looked shocked when I suggested he "taper" at least one pin. Nothing too severe, just 15 degrees and only on the part that extends out the back side of both spars. Found a 40mm pin in the barn from K-21 and it has 5 degree taper that starts an inch from the end, that sharpens to 15 degrees about 1/2" from the end. Looks professional, did Schleicher ever offer a tapered pin? Anything would be better than their blunt pin that will only start when everything is EXACTLY perfect!
> JJ

What, did you lose your broomstick? Works for me on my 26E, and I got the idea
from you!

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/Guide-to-transponders-in-sailplanes-2014A.pdf

[[email protected]]

On Tuesday, April 24, 2018 at 7:10:49 AM UTC-7, wrote:
> Helped the new owner beat his 27 together, last Sunday.............he looked shocked when I suggested he "taper" at least one pin. Nothing too severe, just 15 degrees and only on the part that extends out the back side of both spars. Found a 40mm pin in the barn from K-21 and it has 5 degree taper that starts an inch from the end, that sharpens to 15 degrees about 1/2" from the end. Looks professional, did Schleicher ever offer a tapered pin? Anything would be better than their blunt pin that will only start when everything is EXACTLY perfect!
> JJ

Hmm... the two 15's, two 19's and the 20 I've dealt with all had a moderate but helpful taper on the portion of the pins that extend out aft of the spar. None of them looked like they had been modified. I've helped one 26E owner who was having trouble taking the wings apart (he had previously owned a single pin type glider and at the end of a long day forgot to take the second pin out before derigging - as you can imagine the wings were most reluctant to come out) but I've never helped put one together nor did I take a look at the pins on that ship. Maybe they used to taper them more?

[[email protected]]

Yeah, I tried my broomstick, but the 27 pins are much bigger. ......got to be just under the pin diameter! On my ship I pull the wings together with the broom handle, then shove a tapered pin in the right side. After it's in, I raise or lower the fuselage with the jack as I feel the bushings come together with a finger in the hole. When she's perfect, pop goes the pin................usually!
:>) JJ

[Eric Greenwell[_4_]]

wrote on 4/25/2018 6:48 AM:
> Yeah, I tried my broomstick, but the 27 pins are much bigger. ......got to be just under the pin diameter! On my ship I pull the wings together with the broom handle, then shove a tapered pin in the right side. After it's in, I raise or lower the fuselage with the jack as I feel the bushings come together with a finger in the hole. When she's perfect, pop goes the pin................usually!
> :>) JJ

First thing I do is get the right wing into position, and at very close to the
right angle. I have a bit of wood on the floor of left side spar opening in the
fuselage - when the right wing spar stub touches the wood, the wing is at the
correct angle.

Maybe I'm not using the broomstick the way you do. It's 2/3 the diameter of the
holes. After the left wing is in place, I put stick in half way into the pin
holes on one side, then pull towards the center line. That levers the wing halves
together; then, raise/lower the left wing tip to get the holes lined up (mostly),
insert the pin, then insert the pin on the other side.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/Guide-to-transponders-in-sailplanes-2014A.pdf

[[email protected]]

Mod-1 to the basic broom handle incorporates anti-lateral technology. On days when the wings want to be ****y........broom handle is inserted as far in as possible and therefore prevents left wing in - right wing out, syndrome. Mod-1 broom handle is 12" long and just under real pin diameter, one end is round, but the other end has a gentle taper down to 1/2 diameter. The tapered end is used to get things started after wings are within 1/2" of final destination. Shove it in half way, then apply lateral force (fork right, tongue left). After wings are within 1/4" pull handle out and shove rounded end in...........repeat above persuasive technique!
:>) JJ

[OHM Ω http://aviation.derosaweb.net]

I need to make one of these high-tech broom handles. Is this made out of a hardwood (maple, oak) or a softwood (pine)? Thanks, John

[JS[_5_]]

On Friday, April 27, 2018 at 9:34:38 AM UTC-7, Jonathan St. Cloud wrote:
> On Friday, April 27, 2018 at 8:09:15 AM UTC-7, OHM Ω http://aviation.derosaweb.net wrote:
> > I need to make one of these high-tech broom handles. Is this made out of a hardwood (maple, oak) or a softwood (pine)? Thanks, John
>
> I just purchased a finely made set of alignment and rigging tools so I can get the bushings aligned PERFECT, still takes ten minutes or more. I am wondering where I can get a fine broom handle without having to purchase then destroy a new broom :)

More on alignment:
After the glider is rigged, draw a line with a Sharpie or similar on the end of the fork spar (or front spar if a Schempp, Glasflugel, etc) continuing onto the fuselage.
In a Libelle, you can mark the rear bulkhead and the bottom of the spar "box" at the same time for fore-aft alignment.
This will be your reference for the first wing going on.
When the glider is apart, mark a center line on the front side of the single spar, extending it to the tip of the spar. Easiest to do with the wing on sawhorses/trestles and/or the rigger.
When assembling the first wing, line up the marks on the spar and fuselage.
When inserting the second wing, watch for the center line mark through the pin holes, and adjust before inserting fully.
Then use the broom handle or delrin cam tool of choice.
In S-H gliders, Dave Nadler's triangulation technique really helps with fore-aft alignment of forward-swept wings.
https://www.youtube.com/watch?v=JEUQLSgUpoY&feature=youtu.be
Jim

[Craig Reinholt]

or ;-)
http://www.slugger.com/en-us/baseball/wood

> Go to the hardware store and look for hammer handles.
> UH

[Darryl Ramm]

On Friday, April 27, 2018 at 12:23:56 PM UTC-7, Craig Reinholt wrote:
> or ;-)
> http://www.slugger.com/en-us/baseball/wood
>
> > Go to the hardware store and look for hammer handles.
> > UH

And if they don't fit.... emery tape! :-)

[[email protected]]

I picked up this level for $30 yesterday and have not had an opportunity to test it while rigging, but my thought was to zero the level on fuselage and then determine the appropriate angle for the wings when each was at the correct dihedral for assembly.

https://m.lowes.com/pd/Johnson-Level-Magnetic-Digital-Angle-Locator/1000085673

[bumper[_4_]]

Better than a broom handle, and no need to cut up a wood bat, go on-line and search for <wood tire thumper>.

Note: These may also be useful for thumping other things, both animate (to get their attention) or inanimate (for the same reason).

bumper

[Karl Striedieck[_2_]]

I had a machinist make tapered inserts for the 27 pins. The pin is hollow and was heated before the cooled,tapered insert was inserted.

As noted, as built there is practically no pin protruding beyond the spar when inserted and not much space between the pin end and the fuselage spar box. A small amount of Dremel action on a non load-bearing part of the spar box allows enough room for the lightly longer, tapered pin.

The pin handle is removed (four screws) before the pin is chucked in a lathe and the blunt tip cut away.

As delivered, the relatively blunt end of the original pins require precise alignment for pin insertion, but with the tapered ends they can be shoved in with only casual attention to alignment.

This solution eliminates extra gizmos such as pry bars, shovel handles or nylon tools.

Anyone interested in pics of the pins and spar box grinding can get same from: karls at uplink.net