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What about the Hinge Spar..??

PostPosted: Mon Apr 25, 2005 1:34 pm
by Larwyn
This past weekend I got all the spars glued in place to the sidewalls and ceiling. Even cut out the ceiling and framed in the Fantastic vent. But when I got to the final spar I came to a stop. I'm sure I've read about how people have beefed up the "hinge spar", but as my hinge is not expected to arrive until this Tuesday, I did not have it on hand to help in the decision making. What do you experts recommend for a hinge spar? As I used oak 1x2's for all the other spars I was thinking of doubling them up in an "L" or "T" fashion, giving both horizontal and vertical strength, but am totally open to suggestion. I'll have to wait till the hinge get's here from Grant before I know if my original plan will work. I'm building a Curved Weekender so the hatch will not be all that heavy as it does not go all the way to the floor in the back but it does get rather windy at the lakes where I usually camp... :)

Re: What about the Hinge Spar..??

PostPosted: Mon Apr 25, 2005 1:50 pm
by DanD
Larwyn wrote: What do you experts recommend for a hinge spar?


I used oak 2 x 2 spars on the body as well as the hatch to support the hinge.

PostPosted: Mon Apr 25, 2005 2:37 pm
by toypusher
Larwyn

Just glue (Gorilla) two of the 1x2 spars together to make a 2x2 spar. If you check the grain very closely, you should be able to alternate the grain for the best strength.

Kerry

PostPosted: Mon Apr 25, 2005 3:29 pm
by SteveH
Larwyn,

I'm certainly no expert, but I designed my tear for the hatch hinge to go at the top of the galley cabinet bulkhead, and doubled it with a spar. I felt the bulkhead would add lots of strength to the hinge spar.

PostPosted: Mon Apr 25, 2005 3:45 pm
by mikeschn
In my first benroy I used two of the 1x2 spars glued together... Oak at that!

In my second benroy I used two of the 1x2 spars glued together... but this time poplar, and that was plenty strong.

If I were to go it again, I would probably use poplar, but definitely glue two of the 1x2s together.

Mike...

PostPosted: Mon Apr 25, 2005 4:27 pm
by davel
I did mine like this out of oak and it seems pretty well anchored.

Image

I'm happy with my hinge spar but not my hatch yet.

PostPosted: Mon Apr 25, 2005 4:41 pm
by Geron
double 1x2 oak for the henge spar is what I did. On both hatch and roof.

Geron

PostPosted: Mon Apr 25, 2005 7:13 pm
by Denny Unfried
Geron wrote:double 1x2 oak for the henge spar is what I did. On both hatch and roof.

Geron


Good thinking. On the original Kit trailers the hinge spar was considered the weakest part of the trailer and almost certainly the first part to fail. 2 X 3 clear oak for me.

Denny

Re: What about the Hinge Spar..??

PostPosted: Mon Apr 25, 2005 11:16 pm
by bdosborn
DanD wrote:I used oak 2 x 2 spars on the body as well as the hatch to support the hinge.


Same here except the body spars are poplar.
Bruce

PostPosted: Tue Apr 26, 2005 7:01 am
by Larwyn
Thanks guys, it looks like double 1x2's is the way to go for the hinge spar as I suspected.

Davel, your pic of the "L" configuration is one that I had in mind. Our walls are constructed differently but that is probably the way I will go with mine too.

Thanks again, this forum is the bestest... :)

hinge spars

PostPosted: Sun Nov 12, 2006 9:34 pm
by eamarquardt
I haven't built a teardrop yet but I've built lots of other things including a two ton dump trailer that uses a High-Lift mechanical jack without any problems. When I build a teardrop (materials are being ordered now) I plan on using a gear hinge that goes on top of the roof and the hatch. I'll use two pieces of 3/4 poplar for the spars and on the bottom of the spar will be a 1/8 x 1" piece of aluminum bar stock. The hinge will be through bolted through the spar and through the aluminum bar stock. The hinge will be in compression and the 1/8 bar stock will be in tension, kind of like a mini "I" beam. The stiffness will come from the aluminum, not the wood which is pretty much serving as a spacer. I'm a big believer of through bolting rather than screws when possible and I'd bet that fewer designs are stronger. The trailer will weigh a few ounces more, but everything in life is a compromise.
Eric "Gus" Marquardt

PostPosted: Sun Nov 12, 2006 10:05 pm
by madjack
SteveH wrote:Larwyn,

I'm certainly no expert, but I designed my tear for the hatch hinge to go at the top of the galley cabinet bulkhead, and doubled it with a spar. I felt the bulkhead would add lots of strength to the hinge spar.


...we basically did the same thing...the whole bulkhead would haveta rip out for a wood failure to occur!!!!!
madjack 8)

PostPosted: Mon Nov 13, 2006 1:16 am
by asianflava
Me too, the hinge is on top of the bulkhead. I used poplar for my spar to make it harder for the screws to pull out. Initially I was just going to use it there but changed my mind and made all my spars out of poplar.

PostPosted: Mon Nov 13, 2006 8:03 am
by bledsoe3
You guys worry too much. I drove from Portland, OR to Eureka, CA with two screws holding my hatch on. I think the only time to be concerned is when the hatch is up and it's windy. I used Grant's hinge and a poplar spar. Someday maybe I'll finish it.

PostPosted: Mon Nov 13, 2006 10:06 am
by madjack
Jim, surely you jest...no one around here worries about such things or obsesses over the frames or over builds or......
madjack 8)