Top ten glider trailer features?

[shkdriver]

Hello,
I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are;

Tracks and captured wing root dollies with adjustable tension hold down
brackets for the spar root (seen in a cobra containing a ventus)

Captured aluminum ramp with fold over center track, with either hydraulic
or double screw jack height adjustment (cobra again).

Pivoting lower carriage wheels on belly support dolly (cobra).

Drop down tailgate which provides a braced repeatable height of tail end
of trailer for rigging and derigging.

Front access hatch, ventilators, spare tire access when loaded.
Good lights with some lights down the length of the trailer.

Storage space for all the ground handling gear.

So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about.

Thanks,
Scott W.
N-1521

[Mike the Strike]

On Tuesday, November 26, 2013 8:51:59 PM UTC-7, shkdriver wrote:
> Hello,
>
> I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are;
>
>
>
> Tracks and captured wing root dollies with adjustable tension hold down
>
> brackets for the spar root (seen in a cobra containing a ventus)
>
>
>
> Captured aluminum ramp with fold over center track, with either hydraulic
>
> or double screw jack height adjustment (cobra again).
>
>
>
> Pivoting lower carriage wheels on belly support dolly (cobra).
>
>
>
> Drop down tailgate which provides a braced repeatable height of tail end
>
> of trailer for rigging and derigging.
>
>
>
> Front access hatch, ventilators, spare tire access when loaded.
>
> Good lights with some lights down the length of the trailer.
>
>
>
> Storage space for all the ground handling gear.
>
>
>
> So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about.
>
>
>
> Thanks,
>
> Scott W.
>
> N-1521

Hydraulic jacks have a fairly high failure rate. Screw jacks fail rarely and would be my first choice..

Working brakes would also be a nice feature!

Mike

[Tim Taylor]

I prefer screw down feet to using the tailgate. The tailgate hinge tends to wear with time from using it as a support.

Also if you are using the tailgate as the support you can't close the tailgate and have the trailer not at risk of turning while you are gone.

Get a nice set of screw jacks and you will be much happier in the long run.

[JS]

Hard to go wrong copying a Cobra. But leave the awful foam-backed carpet out.

[Tony[_5_]]

Set the height so you minimize dragging the tail of the trailer on the road when going in driveways. That is a constant problem with my driveway with most trailers.

I really liked the internal side storage compartments on Greg Cole's sparrowhawk trailer. He made the trailer as wide as the outside of the tires in the middle and tapered to "normal" width at the nose and tail. This created large storage areas ahead of and behind each wheel. That would require a major departure from Luebke plans though.

Keep good notes, someday I need a few more trailers. I have a set of Luebke 1-26 trailer plans for a future Cherokee II trailer.

[Bob Kuykendall]

On Tuesday, November 26, 2013 8:24:29 PM UTC-8, Tim Taylor wrote:
> ...The tailgate hinge tends to wear with time from
> using it as a support...

Isn't that just another way of saying that most tailgate hinges are too flimsy?

[son_of_flubber]

I sorely miss the shock absorbers that the cheapskate designers of my 1999 Avionic trailer wrote off as decadent western luxury. The road vibration on the first long haul eased the pins out of the tailgate hinges. I don't imagine that that level of jarring vibration is good for a sailplane.

I've seen shock absorbers on some glider trailers.

I would also like some sturdy tie down points on the corners for tieing the trailer down when high winds are a possibility. Presently I loop the ropes around the frame members but that is a hassle to thread them through lying on my back in the wet grass.

[[email protected]]

Mount the stuff that you use every time you rig/de-rig at the rear of the trailer. Saves several trips back and forth to the front of the trailer. I have cleaning supplies, tape, ballast funnels, and the one man rigging dolly mounted in the rear. For me, it is much easier to get the rigging dolly out of the back of the trailer than trying to wrestle it out through the front hatch.

P9

[[email protected]]

On Tuesday, November 26, 2013 7:51:59 PM UTC-8, shkdriver wrote:
I wished we had trailer-wide drawers in front and in back of the axle. One could stow a lot of rigging stuff there.

Heinz

[Jim White[_3_]]

My ten....

Newer cobra trailers have trays attached to the wing dollies that bring the
cleaning materials in them down the back when rigged. Nice touch.

I wouldn't be without my hydraulic jack. Much much easier.

I store my probes inside the clamshell at the back, safe from damage.

Easily swappable number plate. Install mountings at the standard cobra
pitch so crew can easily attach their number plate.

Very strong hinges, fittings, and locks.

Solar panels or wind turbine that can drive a fan or dehumidifier as well
as charge batteries. I wish I could power a small heater to keep the
temperature above freezing.

Screw jacks are a pain. If you do not want to prop with the door (the rear
of my trailer sits on tyres) then fit drop down stands and wind the front
up on the dolly jack to drive them into the ground.

Single axle better than dual but fit Tyrons to ensure tyres cannot come off
when flat.

Double skin or insulation to ward off condensation.

Maintenance free exterior - hate washing and polishing.

[Burt Compton - Marfa]

Build "canopy holder" brackets inside the top of the rear clamshell. Older sailplanes had detachable canopies. If I recall correctly, your SHK canopy, like our Open Cirrus, detaches completely / is not hinged. Placing it on the ground is a recipe for disaster. Our rule was the canopy was either securely on the sailplane cockpit or up in the trailer brackets after the fuselage was rolled out.

As was suggested for clearance, use larger rims than typical for rear clearance into dips, swales, bar-ditches. Especially important for off-road retrieves.

Some trailer history as I recall it: Back in the sixties when the first glass sailplanes were imported from Germany, the enclosed factory trailers were generally an afterthought. Many pilots built trailers from scratch. Cobra type trailers today are a vast improvement - just pick your options and write a check (I have two plus a Swan copy.) At the national contest at Marfa in 1967 Dad (Fritz Compton) and I took many photos of the innovative devices in the all-wooden trailers that the legendary Ben Greene built for his SHK, SH-1 and others. Those trailers were works of art. (Do any survive to this day?)

In 1968 Dad welded up his trailer before the 17.7 meter Open Cirrus arrived at the dock, based on the dimensions of the sailplane. Some adjustment was built-in for the dollies and it worked very well. The ratchet tooth bar tilting system in front allowed precise tilting in 2 seconds. Time and motion efficiency was a priority. The wingstand (none available commercially) was a cut down step ladder which I still use. Dad and I could assemble the big Cirrus in ten minutes / de-rig in five especially when a t-storm was approaching! I still have that trailer and the Open Cirrus is assembled in my hangar at Marfa, Texas. One of prettiest sailplane profiles in the air. Dad lets me fly it occasionally . . .

[JJ Sinclair[_2_]]

On Tuesday, November 26, 2013 7:51:59 PM UTC-8, shkdriver wrote:
> Hello,
>
> I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are;
>
>
>
> Tracks and captured wing root dollies with adjustable tension hold down
>
> brackets for the spar root (seen in a cobra containing a ventus)
>
>
>
> Captured aluminum ramp with fold over center track, with either hydraulic
>
> or double screw jack height adjustment (cobra again).
>
>
>
> Pivoting lower carriage wheels on belly support dolly (cobra).
>
>
>
> Drop down tailgate which provides a braced repeatable height of tail end
>
> of trailer for rigging and derigging.
>
>
>
> Front access hatch, ventilators, spare tire access when loaded.
>
> Good lights with some lights down the length of the trailer.
>
>
>
> Storage space for all the ground handling gear.
>
>
>
> So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about.
>
>
>
> Thanks,
>
> Scott W.
>
> N-1521

Make the forward storage compartment big enough to store your one- man-rigger mostly assembled (3 wheels on the lift post). Lift the 3-wheels out, slide the saddle on and she's ready to go. I set my fuselage height a tad low, slide both wings in, shove my 12" broom handle into the far spar holes, then pump the hydraulic jack with my foot as I watch the near spar holes come into alignment. When the two spar holes come together, I shove in the first spar pin, then remove the broom handle and make any indicated height adjustment with foot jack as I watch the other holes.
I would make the final axle placement with everything in place, adjusting axle location to give about 100 pounds of tongue weight. Electric brakes are probably the best.
JJ

[rlovinggood]

Scott,
Provide method of securing empty fuselage and wing dollies so they won't roll around in an empty trailer during a retrieve.

Someone else mentioned spare tire, but make it easy to get the spare tire out and the flat tire back into the trailer. My spare is located under the trailer behind the axle. It's "okay" to remove, but a real tough chore to remount. The 15" steel rim and tire are HEAVY. I've thought about making the "hoist" type of arrangement that some pickup trucks have for their spares.

Don't skimp on the size of the front cargo door. The newer Cobras have large doors. Older trailers have smaller doors. Go big!

Ray

[John Galloway[_1_]]

I would never tow a trailer with the spare wheel stowed under
the trailer by the axle again -or if I had to I would take a set of
axle stands. I had that arrangement on a trailer that had a flat
tyre when I was towing it solo. It sank down so that there was
insufficient vertical room to access and drop the spare wheel
down. I had to jack the trailer up and go under it to undo the
rusted securing nut by the side of the road with the trailer
above me swaying about as trucks etc went by. It was not
particularly enjoyable.

John Galloway


At 17:30 27 November 2013, rlovinggood wrote:
>Scott,
>Provide method of securing empty fuselage and wing dollies
so they won't
>ro=
>ll around in an empty trailer during a retrieve.
>
>Someone else mentioned spare tire, but make it easy to get
the spare tire
>o=
>ut and the flat tire back into the trailer. My spare is located
under the
>=
>trailer behind the axle. It's "okay" to remove, but a real tough
chore to
>=
>remount. The 15" steel rim and tire are HEAVY. I've thought
about making
>=
>the "hoist" type of arrangement that some pickup trucks have
for their
>spar=
>es.
>
>Don't skimp on the size of the front cargo door. The newer
Cobras have
>lar=
>ge doors. Older trailers have smaller doors. Go big!
>
>Ray
>
>

[Steve Leonard[_2_]]

And when you go big on the front door, put a two latches, towards each bottom corner, not just one in the center of the door. I have a wide Cobra trailer (use to hold an ASH-25) that now has THREE latches for the front door! Think it can be easily done with 2, each about a quarter or so of the way in from the edge along the bottom.

Steve

[Tom Kelley #711]

On Wednesday, November 27, 2013 12:35:59 PM UTC-7, John Galloway wrote:
> I would never tow a trailer with the spare wheel stowed under
>
> the trailer by the axle again -or if I had to I would take a set of
>
> axle stands. I had that arrangement on a trailer that had a flat
>
> tyre when I was towing it solo. It sank down so that there was
>
> insufficient vertical room to access and drop the spare wheel
>
> down. I had to jack the trailer up and go under it to undo the
>
> rusted securing nut by the side of the road with the trailer
>
> above me swaying about as trucks etc went by. It was not
>
> particularly enjoyable.
>
>
>
> John Galloway
>
>
>
>
>
> At 17:30 27 November 2013, rlovinggood wrote:
>
> >Scott,
>
> >Provide method of securing empty fuselage and wing dollies
>
> so they won't
>
> >ro=
>
> >ll around in an empty trailer during a retrieve.
>
> >
>
> >Someone else mentioned spare tire, but make it easy to get
>
> the spare tire
>
> >o=
>
> >ut and the flat tire back into the trailer. My spare is located
>
> under the
>
> >=
>
> >trailer behind the axle. It's "okay" to remove, but a real tough
>
> chore to
>
> >=
>
> >remount. The 15" steel rim and tire are HEAVY. I've thought
>
> about making
>
> >=
>
> >the "hoist" type of arrangement that some pickup trucks have
>
> for their
>
> >spar=
>
> >es.
>
> >
>
> >Don't skimp on the size of the front cargo door. The newer
>
> Cobras have
>
> >lar=
>
> >ge doors. Older trailers have smaller doors. Go big!
>
> >
>
> >Ray
>
> >
>
> >
Yes, what John and Ray said to watch out for is important. With the tire under the trailer and behind the axe it's really a pain getting it back up. I use my small jack and after lifting the tire up, side the jack under it, then jack it up to hold it in position while securing it again. If you can make room inside the trailer for the tire, might be the best way to carry that spare.
My ASW 27 trailer held the spare in front of the nose cone hold and came that way from Cobra.

[Dan Marotta]

I've got two of these on the back of my LAK T-4 trailer and love them:
http://www.pplmotorhomes.com/parts/rv-jacks/light-trailer-jacks.htm

Build in a storage box in front of the fuselage which occupies the full
width of the trailer at the front (under the spars) and is narrower further
aft to allow the wings to slide in. Make it go all the way back to the nose
cone of the glider.

"Tim Taylor" > wrote in message
...
>I prefer screw down feet to using the tailgate. The tailgate hinge tends
>to wear with time from using it as a support.
>
> Also if you are using the tailgate as the support you can't close the
> tailgate and have the trailer not at risk of turning while you are gone.
>
> Get a nice set of screw jacks and you will be much happier in the long
> run.

[Dan Marotta]

Using the stabilizer jacks in back and the front wheel jack on the tongue of
the trailer, I don't tie mine down any more. It's weathered 60 mph winds at
Moriarty without moving.


"son_of_flubber" > wrote in message
...
I sorely miss the shock absorbers that the cheapskate designers of my 1999
Avionic trailer wrote off as decadent western luxury. The road vibration on
the first long haul eased the pins out of the tailgate hinges. I don't
imagine that that level of jarring vibration is good for a sailplane.

I've seen shock absorbers on some glider trailers.

I would also like some sturdy tie down points on the corners for tieing the
trailer down when high winds are a possibility. Presently I loop the ropes
around the frame members but that is a hassle to thread them through lying
on my back in the wet grass.

[Dave Martin[_3_]]

Don't think it has been mentioned.
A couple of good jacking points for the main wheel(s) and a
decent jack to raise the wheel(s).

The best towing trailer I have ever towed have had twin axle
with four wheels but they are awful to ground handle.





At 23:20 27 November 2013, Dan Marotta wrote:
>Using the stabilizer jacks in back and the front wheel jack on
the tongue
>of
>the trailer, I don't tie mine down any more. It's weathered 60
mph winds
>at
>Moriarty without moving.
>
>
>"son_of_flubber" wrote in message
>news:39bc5acd-5db0-40be-8bf9-
...
>I sorely miss the shock absorbers that the cheapskate
designers of my 1999
>Avionic trailer wrote off as decadent western luxury. The road
vibration
>on
>the first long haul eased the pins out of the tailgate hinges. I
don't
>imagine that that level of jarring vibration is good for a
sailplane.
>
>I've seen shock absorbers on some glider trailers.
>
>I would also like some sturdy tie down points on the corners
for tieing the
>
>trailer down when high winds are a possibility. Presently I loop
the ropes
>
>around the frame members but that is a hassle to thread them
through lying
>on my back in the wet grass.
>
>

[[email protected]]

Screw-down stabilizer jacks like the ones used on Cobra trailers now are great. When I bought my Avionic in '04 they only had one at the back. If there had been an option to get one on each corner I would have taken it. As it is I crank down the rear one and set the front of the trailer on a pair of jackstands when it's parked in its usual location at my airfield. Nice and stable even when the trailer is closed. I prefer that to putting strain on the tailgate.

As Bert Compton mentioned a place to put the canopy would be GREAT! I have an ASW-15 and the canopy is kind of awkward to deal with when rigging.

The over-center mechanism for raising and lowering the fuselage dolly ramp is good if you can assemble the glider easily without the ability to make fine changes in the height of the fuselage. In my case the only thing I would need to raise and lower the fuselage for would be to raise and lower the gear so the over center lever approach would work fine.

A third rail and ramp for the tailwheel would be nice, especially if the glider has a heavy tail. The 15 isn't heavy but being able to get the fuselage in and out without lifting the tail would have been worth the extra cost.

Contrary to what Bill White says my preference would be for a number plate holder which makes it difficult to remove the plate because where I live the trailer has its own VIN, title, insurance and number plate. I assume he lives somewhere where the trailer plate must be the same as the vehicle towing it.

Electrical connections for the lights should be whatever is most common with your fellow pilots. Either that, or make sure you keep an adapter or two on hand in case you need a retrieve!

For a similar reason, despite the advantages of electric brakes I would still go with a mechanical surge brake. It might not work as well, but at least it will work with any vehicle they're hooked up to.

A bit more ground clearance than is common with newer trailers would be good too as long as you don't get too carried away. The one thing my old trailer had over the Avionic that replaced it was the ease with which it could get in and out of driveways without bottoming out. Some sort of skid plates at the rear should be installed anyways, just in case.

The slide out under floor storage drawers seen on newer trailers are a fantastic idea.

Don't make it "just wide enough" for the glider to fit. Give yourself a few extra inches space. It makes getting things in and out MUCH easier. My old trailer was a non-clamshell type but because the builder resisted the temptation to make it small it was actually very useable. You could actually make your way from one end of the trailer to the other inside the trailer when the glider was in it. Too bad the wood it was made from had rotted so much.

I have yet to make up my mind when it comes to how the fuselage is held in the dolly. A single strap attaches easily but it only works to prevent the fuselage moving rearward in the dolly. Two metal arms swinging up from the dolly and attaching to points on the fuselage (e.g. with bushings in the ends of the arms slipping over the pins sticking out of the fuselage and held there with a spring clip) seems more secure but you would have to get the fuselage in exactly the right place on the dolly before they would line up.

Looking back at trailer history it still amazes me how long it took for some people to figure out the "fuselage in nose first, wings in root first, right wing on the right, left wing on the left and tailplane in a bracket above" arrangement.

[AJM]

Having recently spent a large number of hours (along with my sailplane partner) replacing rotting wood flooring at the front of a Minden style trailer, a couple suggestions to save maintenance time down the road:

1: A very well sealed/waterproof front access hatch. We added a piece of aluminum angle as a rain gutter above the front door. The Cobra solution for this is nice.

2: Assuming you are using wood for the flooring, a layer of fiberglass on top and bottom to repel moisture. If you can avoid using wood in the floor at all, it could be a plus. The aluminum/foam sandwich floors on Cobra trailers are really quite nice. Cobras going on 30 years old have floors in very nice shape.

3: A design that allows replacing any one panel of flooring independently. On this trailer, the floor panels slide in from the back of the trailer. To replace a full sheet of flooring at the front of the trailer would require removing all of the flooring.

Other items:

4. Safety chains anchored to the frame of the trailer (not just to the tongue) in case of a tongue failure.

-Andy

On Tuesday, November 26, 2013 9:51:59 PM UTC-6, shkdriver wrote:
> Hello,
>
> I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are;
>
>
>
> Tracks and captured wing root dollies with adjustable tension hold down
>
> brackets for the spar root (seen in a cobra containing a ventus)
>
>
>
> Captured aluminum ramp with fold over center track, with either hydraulic
>
> or double screw jack height adjustment (cobra again).
>
>
>
> Pivoting lower carriage wheels on belly support dolly (cobra).
>
>
>
> Drop down tailgate which provides a braced repeatable height of tail end
>
> of trailer for rigging and derigging.
>
>
>
> Front access hatch, ventilators, spare tire access when loaded.
>
> Good lights with some lights down the length of the trailer.
>
>
>
> Storage space for all the ground handling gear.
>
>
>
> So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about.
>
>
>
> Thanks,
>
> Scott W.
>
> N-1521

[Dave Nadler]

Lots of good ideas already posted !
My two cents:

Keep rigging aids up front or at least
in storage bin underneath near axle.
Any extra weight at rear reduces stability;
even though it saves a few steps I wouldn't
do that.

No leaf springs! Get a good quality axle
with shocks and brakes.

Mechanical brakes if done well are hassle-free
and work with any car. I've got Cobra mechanical
(excellent if adjusted properly every year or to),
and hydraulic (also excellent).

If you put jack stands under rear, protect them
from catching on the ground somehow, just now
adding such to my Cobra after they got bent again
(much bigger problem with long trailers).

Have fun, post pictures when you're done,
Happy Thanksgiving, Dave "YO electric"

[JJ Sinclair[_2_]]

On Tuesday, November 26, 2013 7:51:59 PM UTC-8, shkdriver wrote:
> Hello,
>
> I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are;
>
>
>
> Tracks and captured wing root dollies with adjustable tension hold down
>
> brackets for the spar root (seen in a cobra containing a ventus)
>
>
>
> Captured aluminum ramp with fold over center track, with either hydraulic
>
> or double screw jack height adjustment (cobra again).
>
>
>
> Pivoting lower carriage wheels on belly support dolly (cobra).
>
>
>
> Drop down tailgate which provides a braced repeatable height of tail end
>
> of trailer for rigging and derigging.
>
>
>
> Front access hatch, ventilators, spare tire access when loaded.
>
> Good lights with some lights down the length of the trailer.
>
>
>
> Storage space for all the ground handling gear.
>
>
>
> So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about.
>
>
>
> Thanks,
>
> Scott W.
>
> N-1521

I would second the advice to not put anything under the trailer. Off field landings often involve crossing streams or ditches that will rip and tear at those storage boxes and rear jack devices. I remember seeing a detached storage box along side the road, followed by all the stuff that had been stored in there. A clean rear underside may scrape as one crosses the farmers ditch, but will survive the experience in tact.
JJ

[[email protected]]

I make it a habit of looking at trailers at contests, looking for tips and tricks. A few things I've seen that haven't been mentioned.

- John Good mounted adhesive rubber feet about halfway back on the wing dolly tracks on both sides so the wing dolly side wheels had to go over them. this had the effect of preventing the dollies from rolling all the way to the front when the trailer was empty. I have also seen slide-bolt retainers for this purpose, but the rubber bumpers seem to work pretty well.

- I always prepare my trailer for a retrieve after each assembly by securing the wing dollies,fuselage cradle and wing stand with the tail boom tie-down strap. This requires that the tie-down strap NOT be cut down from the Cobra default length. So, you might want to consider how you want the trailer contents to be set up/secured during a retrieve.

- I think the under-trailer storage is a BAD idea, as it makes the effective ground clearance much lower. When I see these trailers at a contest, I always think "I'm glad I don't have that trailer!" ;-).

- Most Cobra trailers with any mileage on them have a big hole in the inside surface of the tailgate where the retention bolt of the ramp has rattled around and eaten away at the thin aluminum. My solution to this has been to pop-rivet a big (2" diameter) steel auto washer over the hole, so the retention bolt bears against steel rather than aluminum. So, you might consider doing something like that at the start, rather than wait for that ugly hole to develop.

Frank (TA)

[Dan Marotta]

I forgot to mention - install rear stabilizer jacks (if you decide to use
them) a foot or so in front of the end of the trailer. That way, the end of
the trailer will drag before the jacks contact the ground. You should have
some sort of skid plates at the rear corners of the trailer.

I don't see a problem with under body storage drawers except that water
could fill them up on stream crossings or even driving in heavy rain.
Mounted close to the axle, they should always have ground clearance unless
you're towing over curbs or boulders.


> wrote in message
...
I make it a habit of looking at trailers at contests, looking for tips and
tricks. A few things I've seen that haven't been mentioned.

- John Good mounted adhesive rubber feet about halfway back on the wing
dolly tracks on both sides so the wing dolly side wheels had to go over
them. this had the effect of preventing the dollies from rolling all the way
to the front when the trailer was empty. I have also seen slide-bolt
retainers for this purpose, but the rubber bumpers seem to work pretty well.

- I always prepare my trailer for a retrieve after each assembly by
securing the wing dollies,fuselage cradle and wing stand with the tail boom
tie-down strap. This requires that the tie-down strap NOT be cut down from
the Cobra default length. So, you might want to consider how you want the
trailer contents to be set up/secured during a retrieve.

- I think the under-trailer storage is a BAD idea, as it makes the
effective ground clearance much lower. When I see these trailers at a
contest, I always think "I'm glad I don't have that trailer!" ;-).

- Most Cobra trailers with any mileage on them have a big hole in the
inside surface of the tailgate where the retention bolt of the ramp has
rattled around and eaten away at the thin aluminum. My solution to this has
been to pop-rivet a big (2" diameter) steel auto washer over the hole, so
the retention bolt bears against steel rather than aluminum. So, you might
consider doing something like that at the start, rather than wait for that
ugly hole to develop.

Frank (TA)

[[email protected]]

Front/Rear weight balance on Cobra's does not create enough tongue weight for stable towing unless I pack every single (heavy) accessory and tool boxes in the front storage box. From this lesson I suggest to avoid adding any weight to the rear that is not required, such as underneath storage. Max out the front storage as suggested earlier, and skip the rear underneath boxes. When balanced Cobra's tow like a dream even at 85MPH, when front is empty is gets "interesting" when towing at highway speeds downhill.

[j gilbert OY]

On Tuesday, November 26, 2013 10:51:59 PM UTC-5, shkdriver wrote: > Hello, I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are; Tracks and captured wing root dollies with adjustable tension hold down brackets for the spar root (seen in a cobra containing a ventus) Captured aluminum ramp with fold over center track, with either hydraulic or double screw jack height adjustment (cobra again). Pivoting lower carriage wheels on belly support dolly (cobra). Drop down tailgate which provides a braced repeatable height of tail end of trailer for rigging and derigging. Front access hatch, ventilators, spare tire access when loaded. Good lights with some lights down the length of the trailer. Storage space for all the ground handling gear. So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about. Thanks, Scott W. N-1521



Being able to plug in 110 volt house current is frequently helpful for:
Vaccumiing, lighting, electric tools, winter heater light, summer fan, etc.

[Dave Martin[_3_]]

Best feature that can ever be fastened to a trailer

A decent tow car but that is another discussion.

2litre minimum, 4x4 also helps or similar.

Best ever Bentley Turbo, but that is another story

[[email protected]]

On Thursday, November 28, 2013 4:51:19 PM UTC+1, wrote:
> Front/Rear weight balance on Cobra's does not create enough tongue weight for stable towing unless I pack every single (heavy) accessory and tool boxes in the front storage box. From this lesson I suggest to avoid adding any weight to the rear that is not required, such as underneath storage. Max out the front storage as suggested earlier, and skip the rear underneath boxes. When balanced Cobra's tow like a dream even at 85MPH, when front is empty is gets "interesting" when towing at highway speeds downhill.

Not generally true, when ordering the client can tell Cobra his requirements concerning weight and front weight. Our clubs trailers all have between 40 and 100kg in front, which tows perfectly stable with a car which is a "lunchbox" for US means.

[[email protected]]

Ah...the perfect trailer...one that someone else built.

[Chad[_3_]]

On Tuesday, November 26, 2013 9:51:59 PM UTC-6, shkdriver wrote:
> Hello,
>
> I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are;
>
>
>
> Tracks and captured wing root dollies with adjustable tension hold down
>
> brackets for the spar root (seen in a cobra containing a ventus)
>
>
>
> Captured aluminum ramp with fold over center track, with either hydraulic
>
> or double screw jack height adjustment (cobra again).
>
>
>
> Pivoting lower carriage wheels on belly support dolly (cobra).
>
>
>
> Drop down tailgate which provides a braced repeatable height of tail end
>
> of trailer for rigging and derigging.
>
>
>
> Front access hatch, ventilators, spare tire access when loaded.
>
> Good lights with some lights down the length of the trailer.
>
>
>
> Storage space for all the ground handling gear.
>
>
>
> So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about.
>
>
>
> Thanks,
>
> Scott W.
>
> N-1521

My factory PIK trailer was excellent but still spent a lot of time eliminating every slowdown. I installed various quick release pins with lanyards so "in and out" are instantaneous. Using tools, or thumb screws or wingnuts is too slow. The back door ramp is good but building a 3rd rail for the tailwheel even better. A screw jack helped solo assembly. The main disadvantage to a back door ramp is the nose of the glider may end up too close to the trailer so you can't walk around the nose, and must walk all the way around wings and tail to get to the other side.
Where I had to kneel in the back, dense foam was permanently applied. A soft covering glued to a sharp edge helps everywhere. Once those details were done the psychological aversion to assembly and disassembly disappeared.

[shkdriver]

On Tuesday, November 26, 2013 9:51:59 PM UTC-6, shkdriver wrote:
> Hello,
>
> I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are;
>
>
>
> Tracks and captured wing root dollies with adjustable tension hold down
>
> brackets for the spar root (seen in a cobra containing a ventus)
>
>
>
> Captured aluminum ramp with fold over center track, with either hydraulic
>
> or double screw jack height adjustment (cobra again).
>
>
>
> Pivoting lower carriage wheels on belly support dolly (cobra).
>
>
>
> Drop down tailgate which provides a braced repeatable height of tail end
>
> of trailer for rigging and derigging.
>
>
>
> Front access hatch, ventilators, spare tire access when loaded.
>
> Good lights with some lights down the length of the trailer.
>
>
>
> Storage space for all the ground handling gear.
>
>
>
> So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about.
>
>
>
> Thanks,
>
> Scott W.
>
> N-1521

I want to Thank everyone who took the time to contribute Their thoughts and ideas. I look forward to implementing many of them.

Thanks Again,
Scott W.
N-1521

[Soartech]

One more thought. The most common problem with any trailer is the lights. They get a little corrosion on their contacts and don't work. Then you have to unscrew the lens and clean them up with steel wool or something. Someone already mentioned using LEDs. I suggest soldering in bright LEDs (with appropriate limiting resistor) instead of bulbs. This will last for many years!

[Casey Cox]

Torsion axel mounted on rails so the axel can be moved forward or aft. Later you may have more weight forward or aft and moving the axel and inch or two will balance it out having proper weight forward. Also you may move to a location that has a higher driveway and moving the axel back will help eliminate bottoming out. New torsion axels also have the EZ lube. I have switched over every and all trailers I have to synthetic grease. I have a boat so it makes it easier to have one type grease for all trailers, however I also think it is superior and less messy. A shot a grease every year and never will need to replace the bearings.

Sealed lights used on boat trailers with only one connection point that connects lights from front/back and sides with di-electric grease.

Don't reinvent - just make a current model better.