Eagler's Nest

Airframes => Double Seaters => Topic started by: Richfroh on February 21, 2015, 08:10:57 PM

Title: Top Compression Struts ???
Post by: Richfroh on February 21, 2015, 08:10:57 PM: Do the top compression struts go between the spar caps like the bottoms? Plans page 30 shows the top compression strut below the spar caps. The amendment for the inboard rib explains that it goes between the spar caps.

Also, should the compression struts be installed inboard or outboard of the ribs?
Title: Re: Top Compression Struts ???
Post by: docmatt on February 27, 2015, 10:38:01 PM: Rich,
I can't believe I don't know the answer off the top of my head since I did that about 2 weeks ago. I'm pretty sure they go just beneath the upper spar caps and only the bottom ones get plywood reinforcement on the gusset wedges. I'll check when I get home in the morning and post an answer. Let me know if you'd like any specific pictures. I have a nice naked wing sitting on the work table. Hopefully, I'll get some nose ribs on tomorrow.
Title: Re: Top Compression Struts ???
Post by: Richfroh on February 28, 2015, 01:09:56 AM: Thanks Doc,
If you have any pics of the upper compression struts that would be great. Please let me know what info you used to determine where they attach since I have seen conflicting info. I hope to get the compression struts and diagonals in this weekend.
Title: Re: Top Compression Struts ???
Post by: Tom H on February 28, 2015, 06:58:07 AM: Richfroh, here is a pic of DE Stubby wings before they were covered. Only one I could find right away. But, you may be able to see what you are looking for. I don't know off-hand the source for how this was determined.
Title: Re: Top Compression Struts ???
Post by: docmatt on February 28, 2015, 07:25:57 AM: Rich,
I used page 30 and the inboard compression strut supplement. I think the pictures are a little ambiguous. On the upper struts, I glued the strut to the underside of the upper rear spar cap on one end. And, to the rib station and spar web on the other end. I ran the upper strut parallel to the bottom of the wing. On the first rib strut, I glued it higher because of the fitting block filling the space between spar caps. I felt satisfied with the strength of the joints without using additional gussets because parts of the joints are on the side of the grain of the wood, and there is additional bracing from gluing to the ribs. Also, they are primarily in compression. I used gussets on the lower struts because all of the glue is on the end grain of the strut.

Here are some pictures. I have crummy bolts on the fittings for positioning purposes.
Title: Re: Top Compression Struts ???
Post by: docmatt on February 28, 2015, 07:27:56 AM: Oh, and I arbitrarily chose to put the compression struts outboard of the ribs. I don't think it matters.