On Friday, February 14, 2020 at 9:06:00 AM UTC-8, Ray Lovinggood wrote:
On Thursday, January 30, 2020 at 6:33:47 PM UTC-5, wrote:

I guessed at my trailer's loaded weight and I was WAY wrong. To find out, I drove to a truck stop along the interstate that had truck scales and weighed the loaded trailer there. "Swan" trailer with fiberglass top and LS1-c plus a few sundry items in the trailer (tow-out equipment, a few wrenches/screwdrivers, etc). The trailer weighed 2,040 lbs with a 180 lb tongue weight...

[OT screed on trailer design follows. Ya beens warneded]

This is kind of endemic to glider trailer design. The length gives them a lot of floor area for the volume, and it takes a lot of structural mass to make the floor support someone walking around on it without distress. You either need thick plywood, or a lot of cross-bracing, and either adds a bunch of mass.

And if you really want to protect your glider from rollovers and minor collisions, that takes more mass besides. So it's no surprise that the total mass kind of gets out of hand.

Built to plans, the Schreder semi-monocoque trailer comes in at around 600lbs. But the 0.032" sides, .060" aluminum floor sparsely supported by aluminum angles and whatever guide rails the builder installs, does not offer much protection and does not exactly inspire confidence when you walk around in it. Similar trailers such as Minden Fab with their longitudinal skinning, more closely-spaced frames, and plywood floors tend to come in at around 900 lbs.

Years ago I bought a trailer for my HP-11 that was built by aero engineer Steve Smith. It had a welded steel space frame lower half and a fiberglass monocoque upper half, with 0.040" prefab fiberglass sheeting for the floor and sides of the space frame portion. It clocked in at 350 lbs and towed with a 1.5 liter car, but you had to step only on the frame members when inside it.

--Bob K.