ETLB Squawk Forums — Archive

Building 1650 EROS.

1) At the spar drawing at the lower part of the page (for aft spar), there's a note to only tack the root gussets and glue those after the ribs are in place. The note is not up higher on the page with the forward spar. Does the note apply only to the aft spar?

2) There's a hole drilled into the root fitting at 2 3/16" from the spar edge. The edge is sloping. Is the 2 3/16" dimension from the center area?

Thanks!

John

The two gussets at the root end of the rear spar, indicated in the image attached, are to be glued to the spar when you assemble the wing.  When you fabricate the spar you can staple them temporarily, so you can drill the holes, but they will need to come off in order to slide the ribs into the spar.
The 2 3/16" dimension is taken perpendicularly to the sloping end of the spar.  Probably the best way is to use a square block of wood, drill a hole at 2 3/16" from one edge of the block, then use the block as a spacer, with the RS-100 brackets bolted to it to to position the brackets as per drawing. Then mark and drill the holes in the spar to match the holes in the brackets.  Dennis Tyson shows this system on the second episode of his Youtube Buil Vlog at 'https://www.youtube.com/watch?v=BSrId2v3oU0&t=19s'

. A question rather than an answer.Cant the front of the two intercostals of each rib which sandwich the rear spar with a 1/32" gap be left off when building the rib.That way it can be glued on later along with its gussets  after the rear intercostal has been glued first to rear spar with no clearence issues.

Great! That makes sense. Thank you! I saw in the directions about the block idea for the 2 3/16"; cool idea.

Thanks again! And I appreciate the image. I'll check that link.

John C

John, I now realize that by attaching an image of the complete wing I may have create some confusion. The correct sequence is to build the spar without gluing on the two RS-561 gusset at the root of the rear spar. Then when you assemble the wing you slide from the root end the ribs 2 to 5, and you slide from the tip end the ribs 6 to 10.  After that you glue the two gussets to the rear spar, then you need to modify rib 1 and tip rib to slide those in over the gussets, see photo attached. The two RS-1 doublers shown in the photo are not in the plans, but I think it is a good idea.

Thanks! I like the idea of the doubler in your photo. I'll keep that in mind when I reach that point.

John C