glider trailer top opening styles

[shkdriver]

Does anyone have any opinions about the relative benefits of an "alligator"
style opening trailer vs a full opening top?
the Luebke plans trailer I am building will be 31 feet long and 53 inches wide with a 17.5 inch tall lower sides. the top would be 37 inches taller in the front half and taper down in the back half. Steel square tubing frame with aluminum skin. if I build the front half fixed and open only the back 16 feet, I could dramatically reduce the weight of the opening portion, with a small penalty of limited access.
The problem of the top weather seal is more difficult, but not impossible.
Also the ability to control the opening top "shake" while on the road is much easier.
I think the full opening top might easily get to 300 lbs, while the partial top could be as low as 120 lbs.
Last year I saw a online article of a Lak with a partial opening top and it seemed to be a good solution.

Thanks,
Scott

[[email protected]]

On Monday, August 11, 2014 2:46:26 PM UTC-4, shkdriver wrote:
> Does anyone have any opinions about the relative benefits of an
>
> "alligator"
>
> style opening trailer vs a full opening top?
>
> the Luebke plans trailer I am building will be 31 feet long and 53
>
> inches wide with a 17.5 inch tall lower sides. the top would be 37
>
> inches taller in the front half and taper down in the back half. Steel
>
> square tubing frame with aluminum skin. if I build the front half fixed
>
> and open only the back 16 feet, I could dramatically reduce the weight
>
> of the opening portion, with a small penalty of limited access.
>
> The problem of the top weather seal is more difficult, but not
>
> impossible.
>
> Also the ability to control the opening top "shake" while on the road is
>
> much easier.
>
> I think the full opening top might easily get to 300 lbs, while the
>
> partial top could be as low as 120 lbs.
>
> Last year I saw a online article of a Lak with a partial opening top and
>
> it seemed to be a good solution.
>
>
>
> Thanks,
>
> Scott
>
>
> Getting a good sealing of the center joint is a meaningful complication.
It also means that the roots get close to the top of the trailer as the wings go forward which is a problem the full clam shell type does not have. They are easier on the back of the tip carrying person,
UH
>
>
>
>
>
>
> --
>
> shkdriver

[BobW]

On 8/11/2014 6:58 PM, wrote:
> On Monday, August 11, 2014 2:46:26 PM UTC-4, shkdriver wrote:
>> Does anyone have any opinions about the relative benefits of an
>> "alligator" style opening trailer vs a full opening top?
>>
>> The Luebke plans trailer I am building will be 31 feet long and 53
> > inches wide with a 17.5 inch tall lower sides. the top would be 37
>> inches taller in the front half and taper down in the back half. Steel
>> square tubing frame with aluminum skin. if I build the front half fixed
>> and open only the back 16 feet, I could dramatically reduce the weight
>> of the opening portion, with a small penalty of limited access.
>>
>> The problem of the top weather seal is more difficult, but not
>> impossible.
>>
>> Also the ability to control the opening top "shake" while on the road is
>> much easier.
>>
>> I think the full opening top might easily get to 300 lbs, while the
>> partial top could be as low as 120 lbs.
>>
>> Last year I saw a online article of a Lak with a partial opening top and
>> it seemed to be a good solution.
>>
>>
>> Thanks,
>>
>> Scott
>>
>>
> Getting a good sealing of the center joint is a meaningful complication.
> It also means that the roots get close to the top of the trailer as the wings go forward which is a problem the full clam shell type does not have. They are easier on the back of the tip carrying person,
> UH
>>
>>
"What UH said," wrt the center joint seal. That noted, nearly 3 decades-worth
of ownership/use of a George Applebay designed/fabricated "alligator style"
trailer never bothered me leak-wise. The Applebay joint did/does allow a small
amount of (western U.S.) dust to enter along with a minor/slow drip leak
top-dead-center. Perhaps a perfectionist's problem...

And "True," for the smaller root clearance, but gravity is your friend.
Clearance is clearance; never an issue for the aft-end-tapered Applebay trailer.

FWIW, the Applebay "jaw" - aluminum-covered square-steel framework - was
designed to be spring counterbalanced. It definitely helped, but wasn't an
operation-killer when the original cables needed replacement...at least not
for a reasonably functional lower back. Maybe 50-60 pounds at the lift gate? YMMV.

Bob W.

[[email protected]]

The Cobra design WORKS.
Better access to the whole trailer when the top is up.
Easier to get inside to clean.

[Rob Brown[_3_]]

On 2014-08-11, shkdriver > wrote:
>
> Does anyone have any opinions about the relative benefits of an
> "alligator" style opening trailer vs a full opening top?

Please forgive my reopening an old topic, and for that matter, my
general ignorance on the topic for that matter.

When I was last involved in the sport 25 years ago, most of the trailers
at our club were simple long tubes with a big door at the back, and
maybe a small hatch at the front. (Was "Minden Trailer" a brand in those
days?) As a sometimes helper during rig and de-rig, it did not seem
to add much (or any? my memory is hazy) difficulty to the operation.

Yes, you have to bend over to enter the trailer, but I'm not sure how
often you would have to do that. Why is it worth the extra expense, weight
and complexity (especially in a homebuilt) for a top-opening trailer?

[Bill D]

On Wednesday, November 19, 2014 2:45:06 PM UTC-7, Rob Brown wrote:
> On 2014-08-11, shkdriver > wrote:
> >
> > Does anyone have any opinions about the relative benefits of an
> > "alligator" style opening trailer vs a full opening top?
>
> Please forgive my reopening an old topic, and for that matter, my
> general ignorance on the topic for that matter.
>
> When I was last involved in the sport 25 years ago, most of the trailers
> at our club were simple long tubes with a big door at the back, and
> maybe a small hatch at the front. (Was "Minden Trailer" a brand in those
> days?) As a sometimes helper during rig and de-rig, it did not seem
> to add much (or any? my memory is hazy) difficulty to the operation.
>
> Yes, you have to bend over to enter the trailer, but I'm not sure how
> often you would have to do that. Why is it worth the extra expense, weight
> and complexity (especially in a homebuilt) for a top-opening trailer?

To the extent there was a problem with tube trailers, it's that they were too small in cross section. If the builder had added as much as 12 inches to the width and height, it would have been noticeably easier to get gliders in and out of them. Then too, no one ever worked out a really good rear door design.

Tubes are inherently stronger and lighter than cam-shell types and probably cheaper to build. Any additional aerodynamic drag incurred with a wider tube probably costs less in fuel than the extra weight of a cam-shell.

[Dan Marotta]

The Pfeiffer tube trailer that my Mosquito came in had an excellent back
door design. The door was hinged on the right side and, when swung open
had brackets for rigging tools, grease, rear jack crank, etc. There was
a ramp hinged at the middle and bottom which folded up before closing
the door. When swung up, the ramp secured the wingtips with padded
cuffs. I thought it was a great design, much better than the home built
trailers, but you did have to bend over to get inside.

Dan Marotta

On 11/19/2014 3:19 PM, Bill D wrote:
> On Wednesday, November 19, 2014 2:45:06 PM UTC-7, Rob Brown wrote:
>> On 2014-08-11, shkdriver > wrote:
>>> Does anyone have any opinions about the relative benefits of an
>>> "alligator" style opening trailer vs a full opening top?
>> Please forgive my reopening an old topic, and for that matter, my
>> general ignorance on the topic for that matter.
>>
>> When I was last involved in the sport 25 years ago, most of the trailers
>> at our club were simple long tubes with a big door at the back, and
>> maybe a small hatch at the front. (Was "Minden Trailer" a brand in those
>> days?) As a sometimes helper during rig and de-rig, it did not seem
>> to add much (or any? my memory is hazy) difficulty to the operation.
>>
>> Yes, you have to bend over to enter the trailer, but I'm not sure how
>> often you would have to do that. Why is it worth the extra expense, weight
>> and complexity (especially in a homebuilt) for a top-opening trailer?
> To the extent there was a problem with tube trailers, it's that they were too small in cross section. If the builder had added as much as 12 inches to the width and height, it would have been noticeably easier to get gliders in and out of them. Then too, no one ever worked out a really good rear door design.
>
> Tubes are inherently stronger and lighter than cam-shell types and probably cheaper to build. Any additional aerodynamic drag incurred with a wider tube probably costs less in fuel than the extra weight of a cam-shell.

[[email protected]]

On Wednesday, November 19, 2014 7:41:04 PM UTC-5, Dan Marotta wrote:
> The Pfeiffer tube trailer that my
> Mosquito came in had an excellent back door design.* The door was
> hinged on the right side and, when swung open had brackets for
> rigging tools, grease, rear jack crank, etc.* There was a ramp
> hinged at the middle and bottom which folded up before closing the
> door.* When swung up, the ramp secured the wingtips with padded
> cuffs.* I thought it was a great design, much better than the home
> built trailers, but you did have to bend over to get inside.
>
> Dan Marotta
> On 11/19/2014 3:19 PM, Bill D wrote:
>
> Also very good for tripping and shin banging if you are not used to it.

[Bill D]

On Wednesday, November 19, 2014 6:57:37 PM UTC-7, wrote:
> On Wednesday, November 19, 2014 7:41:04 PM UTC-5, Dan Marotta wrote:
> > The Pfeiffer tube trailer that my
> > Mosquito came in had an excellent back door design.* The door was
> > hinged on the right side and, when swung open had brackets for
> > rigging tools, grease, rear jack crank, etc.* There was a ramp
> > hinged at the middle and bottom which folded up before closing the
> > door.* When swung up, the ramp secured the wingtips with padded
> > cuffs.* I thought it was a great design, much better than the home
> > built trailers, but you did have to bend over to get inside.
> >
> > Dan Marotta
> > On 11/19/2014 3:19 PM, Bill D wrote:
> >
> > Also very good for tripping and shin banging if you are not used to it.
> UH
> >
> >

I got a brief look at a small Asian crossover SUV in a shopping center parking lot (too brief to get the brand) whose rear hatch used two arms extending forward ending at hinges on the roof. The hatch neatly lifted up over the roof and completely out of the way. It was obvious the weather seals worked better than traditional hatches where the seals get squeezed at the a hinge. I couldn't help thinking of glider trailers.

Applied to a tube trailer, the door and "doghouse" would lift up and clear of the fin and rudder leaving the opening at the back of the trailer completely clean.

[Papa3[_2_]]

On Wednesday, November 19, 2014 8:57:37 PM UTC-5, wrote:
> On Wednesday, November 19, 2014 7:41:04 PM UTC-5, Dan Marotta wrote:
> > The Pfeiffer tube trailer that my
> > Mosquito came in had an excellent back door design.* The door was
> > hinged on the right side and, when swung open had brackets for
> > rigging tools, grease, rear jack crank, etc.* There was a ramp
> > hinged at the middle and bottom which folded up before closing the
> > door.* When swung up, the ramp secured the wingtips with padded
> > cuffs.* I thought it was a great design, much better than the home
> > built trailers, but you did have to bend over to get inside.
> >
> > Dan Marotta
> > On 11/19/2014 3:19 PM, Bill D wrote:
> >
> > Also very good for tripping and shin banging if you are not used to it.
> UH
> >
> >

One of the biggest problems I've noticed is that the wing spars have to come out past the end of the tube trailer before you can lift them. That involves some combination of ramps, free-floating dollies, or back breaking lifting. The only time I've actually hurt my back assembling/disassembling a glider was helping a friend to stabilize an LS3 wing that was about to tip over.

In a Cobra/Komet, the dolly is captive in the trailer and the root of the spar is easily accessible to lift and start swinging the wing around. I'm sure a good design could be built for the tube trailer, but I haven't seen one yet.

NOTE: I have seen the Shirenewton (I think) trailers where the wings go in tip-first, but that means a lot more maneuvering to get the spar to the fuselage.

So, the bottom line: Clamshell trailers seem to require the least awkward lifting, fewest steps, and provide the most stable platform for assembly/disassembly IMO.

P3

[Dan Marotta]

I didn't mention that, with the Pfeiffer, the fold out ramp included
tracks which allowed the dollies to be rolled out exposing the entire
spar. No bending over required. Of course, some folks could bang their
shins if they weren't used to it...

Dan Marotta

On 11/20/2014 8:03 AM, Papa3 wrote:
> On Wednesday, November 19, 2014 8:57:37 PM UTC-5, wrote:
>> On Wednesday, November 19, 2014 7:41:04 PM UTC-5, Dan Marotta wrote:
>>> The Pfeiffer tube trailer that my
>>> Mosquito came in had an excellent back door design. The door was
>>> hinged on the right side and, when swung open had brackets for
>>> rigging tools, grease, rear jack crank, etc. There was a ramp
>>> hinged at the middle and bottom which folded up before closing the
>>> door. When swung up, the ramp secured the wingtips with padded
>>> cuffs. I thought it was a great design, much better than the home
>>> built trailers, but you did have to bend over to get inside.
>>>
>>> Dan Marotta
>>> On 11/19/2014 3:19 PM, Bill D wrote:
>>>
>>> Also very good for tripping and shin banging if you are not used to it.
>> UH
>>>
>>>
> One of the biggest problems I've noticed is that the wing spars have to come out past the end of the tube trailer before you can lift them. That involves some combination of ramps, free-floating dollies, or back breaking lifting. The only time I've actually hurt my back assembling/disassembling a glider was helping a friend to stabilize an LS3 wing that was about to tip over.
>
> In a Cobra/Komet, the dolly is captive in the trailer and the root of the spar is easily accessible to lift and start swinging the wing around. I'm sure a good design could be built for the tube trailer, but I haven't seen one yet.
>
> NOTE: I have seen the Shirenewton (I think) trailers where the wings go in tip-first, but that means a lot more maneuvering to get the spar to the fuselage.
>
> So, the bottom line: Clamshell trailers seem to require the least awkward lifting, fewest steps, and provide the most stable platform for assembly/disassembly IMO.
>
> P3

[Frank Whiteley]

On Thursday, November 20, 2014 8:04:06 AM UTC-7, Papa3 wrote:
> On Wednesday, November 19, 2014 8:57:37 PM UTC-5, wrote:
> > On Wednesday, November 19, 2014 7:41:04 PM UTC-5, Dan Marotta wrote:
> > > The Pfeiffer tube trailer that my
> > > Mosquito came in had an excellent back door design.* The door was
> > > hinged on the right side and, when swung open had brackets for
> > > rigging tools, grease, rear jack crank, etc.* There was a ramp
> > > hinged at the middle and bottom which folded up before closing the
> > > door.* When swung up, the ramp secured the wingtips with padded
> > > cuffs.* I thought it was a great design, much better than the home
> > > built trailers, but you did have to bend over to get inside.
> > >
> > > Dan Marotta
> > > On 11/19/2014 3:19 PM, Bill D wrote:
> > >
> > > Also very good for tripping and shin banging if you are not used to it.
> > UH
> > >
> > >
>
> One of the biggest problems I've noticed is that the wing spars have to come out past the end of the tube trailer before you can lift them. That involves some combination of ramps, free-floating dollies, or back breaking lifting. The only time I've actually hurt my back assembling/disassembling a glider was helping a friend to stabilize an LS3 wing that was about to tip over.
>
> In a Cobra/Komet, the dolly is captive in the trailer and the root of the spar is easily accessible to lift and start swinging the wing around. I'm sure a good design could be built for the tube trailer, but I haven't seen one yet.
>
> NOTE: I have seen the Shirenewton (I think) trailers where the wings go in tip-first, but that means a lot more maneuvering to get the spar to the fuselage.
>
> So, the bottom line: Clamshell trailers seem to require the least awkward lifting, fewest steps, and provide the most stable platform for assembly/disassembly IMO.
>
> P3

P3, et al,

The following link is to a PDF of BF's tube trailer one man rigging system. I believe the trailer is a Minden Fab. The glider is an LS-3. Bob did not design or build the system, it came with the glider and works wonderfully. The pictures were taken on a day when the wind was gusting to 25kts from front to back of trailer. I originally created this for a LAK12 group, so references to LAK12 are included. I made a similar steel model for my LAK-12 factory trailer. I think Bob still has the LS-3, but is flying a DG-800B presently.

http://www.coloradosoaring.org/rigging/rigging_plan_aluminum_example.pdf

Frank Whiteley

[Frank Whiteley]

"Frank Whiteley" wrote in message
...

On Thursday, November 20, 2014 8:04:06 AM UTC-7, Papa3 wrote:
> On Wednesday, November 19, 2014 8:57:37 PM UTC-5,
> wrote:
> > On Wednesday, November 19, 2014 7:41:04 PM UTC-5, Dan Marotta wrote:
> > > The Pfeiffer tube trailer that my
> > > Mosquito came in had an excellent back door design. The door
> > > was
> > > hinged on the right side and, when swung open had brackets for
> > > rigging tools, grease, rear jack crank, etc. There was a ramp
> > > hinged at the middle and bottom which folded up before closing
> > > the
> > > door. When swung up, the ramp secured the wingtips with padded
> > > cuffs. I thought it was a great design, much better than the
> > > home
> > > built trailers, but you did have to bend over to get inside.
> > >
> > > Dan Marotta
> > > On 11/19/2014 3:19 PM, Bill D wrote:
> > >
> > > Also very good for tripping and shin banging if you are not used
> > > to it.
> > UH
> > >
> > >
>
> One of the biggest problems I've noticed is that the wing spars have to
> come out past the end of the tube trailer before you can lift them. That
> involves some combination of ramps, free-floating dollies, or back
> breaking lifting. The only time I've actually hurt my back
> assembling/disassembling a glider was helping a friend to stabilize an LS3
> wing that was about to tip over.
>
> In a Cobra/Komet, the dolly is captive in the trailer and the root of the
> spar is easily accessible to lift and start swinging the wing around.
> I'm sure a good design could be built for the tube trailer, but I haven't
> seen one yet.
>
> NOTE: I have seen the Shirenewton (I think) trailers where the wings go
> in tip-first, but that means a lot more maneuvering to get the spar to the
> fuselage.
>
> So, the bottom line: Clamshell trailers seem to require the least awkward
> lifting, fewest steps, and provide the most stable platform for
> assembly/disassembly IMO.
>
> P3

P3, et al,

The following link is to a PDF of BF's tube trailer one man rigging system.
I believe the trailer is a Minden Fab. The glider is an LS-3. Bob did not
design or build the system, it came with the glider and works wonderfully.
The pictures were taken on a day when the wind was gusting to 25kts from
front to back of trailer. I originally created this for a LAK12 group, so
references to LAK12 are included. I made a similar steel model for my
LAK-12 factory trailer. I think Bob still has the LS-3, but is flying a
DG-800B presently.

http://www.coloradosoaring.org/rigging/rigging_plan_aluminum_example.pdf

Frank Whiteley

Oops, winds were 12-15kts on the day. Bob said the rig is good to 25kts
unassisted.

Mea culpa,

Frank

[Bill D]

On Thursday, November 20, 2014 8:04:06 AM UTC-7, Papa3 wrote:

One of the biggest problems I've noticed is that the wing spars have to come out past the end of the tube trailer before you can lift them. That involves some combination of ramps, free-floating dollies, or back breaking lifting. The only time I've actually hurt my back assembling/disassembling a glider was helping a friend to stabilize an LS3 wing that was about to tip over.
_______________________________________
True, but unnecessary with a good design. The approach I would take is to use a captive wing root trailer dolly that allows the wing to swing like a gate away from the fuselage after it's been rolled off the trailer. Add a castering wing-tip dolly (think tail-dolly) and you wouldn't have to carry the tip. Add a one-man dolly which is attached to the wing after it's been swung out and you just have to release the root from its dolly and walk it to the fuselage without the sashay out past the rudder. A rig like this allowed me to rig a Twin Lark's massive wings solo in less than 10 minutes with zero lifting.
_____________________________________
> In a Cobra/Komet, the dolly is captive in the trailer and the root of the spar is easily accessible to lift and start swinging the wing around. I'm sure a good design could be built for the tube trailer, but I haven't seen one yet.
________________________________
Yes, they're excellent designs and a joy to use but anything can be improved.

Bill D

[Brian[_1_]]

Aside fromm easier to remove wings from a clam shell as already mentioned the clam shell trailer is a lot smaller (lower profile). since it can close down over the profile of the glider and wings.
I suspect this makes them pull better in general but then my Schreder Style tube trailer pulls great.
Agree the rear door system could still use some improvement.

Brian
HP16T

[John Galloway[_1_]]

At 15:03 20 November 2014, Papa3 wrote:
>On Wednesday, November 19, 2014 8:57:37 PM UTC-5,

>wro=
>te:
>> On Wednesday, November 19, 2014 7:41:04 PM UTC-5, Dan
Marotta wrote:
>> > The Pfeiffer tube trailer that my
>> > Mosquito came in had an excellent back door design.=A0 The
door
>w=
>as
>> > hinged on the right side and, when swung open had brackets
for
>> > rigging tools, grease, rear jack crank, etc.=A0 There was a
ramp
>> > hinged at the middle and bottom which folded up before
closing
>th=
>e
>> > door.=A0 When swung up, the ramp secured the wingtips
with padded
>> > cuffs.=A0 I thought it was a great design, much better than
the
>h=
>ome
>> > built trailers, but you did have to bend over to get inside.
>> >=20
>> > Dan Marotta
>> > On 11/19/2014 3:19 PM, Bill D wrote:
>> >=20
>> > Also very good for tripping and shin banging if you are not
used
>to=
> it.
>> UH
>> > =20
>> >
>
>One of the biggest problems I've noticed is that the wing spars have
to
>com=
>e out past the end of the tube trailer before you can lift them. That
>invo=
>lves some combination of ramps, free-floating dollies, or back
breaking
>lif=
>ting. The only time I've actually hurt my back
assembling/disassembling
>a=
> glider was helping a friend to stabilize an LS3 wing that was about to
>tip=
> over. =20
>
>In a Cobra/Komet, the dolly is captive in the trailer and the root of
the
>=
>spar is easily accessible to lift and start swinging the wing around.
>I'm=
> sure a good design could be built for the tube trailer, but I haven't
>seen=
> one yet. =20
>
>NOTE: I have seen the Shirenewton (I think) trailers where the wings
go
>in=
> tip-first, but that means a lot more maneuvering to get the spar to
the
>fu=
>selage. =20
>
>So, the bottom line: Clamshell trailers seem to require the least
awkward
>=
>lifting, fewest steps, and provide the most stable platform for
>assembly/di=
>sassembly IMO.=20
>
>P3

Someone must have specified their Shirenewton trailer for tip first
loading of the wings because every modern glider one I have seen
(including the one I owned until last year for a D2cT) has had root first
loading. Iain Evans also makes excellent dollies and rigging gear. Mine
had rotating wing root dollies so the wing could be rotated flat for easy
one man rigging - far far easier than with the Cobra trailer + OMRA for
my new glider - although the Cobra looks a lot cooler and is famously
excellent for towing.

John Galloway.