Hatz Biplane Association

Hello all!

It's been quite a while since my last post, not since the old forum, actually. I've been slowly making progress on my Classic, and hope to set up a website soon to post pictures and log my progress. I have been following others' postings and progress, and appreciate all that I have learned from them. Hopefully I can contribute something now.

I am finally finishing up the last of the steel parts and fittings for my wings. Once all of these are primed, all of the "little parts" for the wings will be done. I'll finally then be ready to start planing and drilling my spars and thereafter actually assemble the wing panels.

One part has me stumped, though. Looking through the photo CD that Jeff Shoemake supplies with the plans, I noticed a brace for the bottom wing #2 compression tube that does NOT appear on the plans. Its purpose I would presume is to brace the compression tube to relieve bending loads that would be imposed by the aileron idler.

Question one: Is this part really necessary? I can't quite tell if this is just something a builder added on his/her own, but since it's on Jeff's CD, I would think that this was added later, and perhaps the plans were subsequently changed. If you are a builder of a plane on that picture CD, could you please enlighten me? What has everyone else done?

Question two: If this brace is necessary, what size tubing was used? Wall thickness? It probably attaches to the compression tube using the same AN-4 bolt as the aileron idler, but what bolt should be used on the spar?

Thanks!!!

You're right that the brace is not on the plans. I have amassed a fairly large collection of builder pics scrounged from the web over the years and I have probably seen more wing photos without that piece that with it. From what I can tell, it appears that many of the photos on the Makelan CD are donations from early builders. Yes, many of the photos are from Jeff, but there are also many that are not. These also include the fiberglass turtledeck that Mike Foote put on his classic, internal COMM antennas, and the like. So keep that in mind. My personal opinion is that the brace was something that a builder wanted to add on and a few others have done the same.

I would stick to the plans. You could always contact Jeff to clear it up if you want. I know some folks have had a hard time reaching him, but I've always had good responses from him including one just last month. Just use the correct email address... hatzkit@gvtc.com

My $.02

Mark & Doug,
I just finshed the final wing last week and I like you Mark had at one point mulled over this very issue when I was in the assembly process. I decided to stick with the plans and not add that support because I could only find one picture where it had been added and figured it may had been added in the very early stages of Hatz Classic re-design work and changes from the Hatz.
I feel comfortable having not added that support as the compression tubes are very solid when installed and when the drag/anti drag wires are adjusted during trammeling, I feel provide additional support to the entire structure.

I noticed this too, so I called award winning builder Ron Sieck. When he was building his, he talked to Jeff and for some reason the brace was left off the plans. Ron felt like it really should be there. He used half inch .035 wall tubing at about a 45 degree angle to the spar. AN3 3/16 bolt through the spar. I'm at the point right now where I need to put this in.
George Francis 115HC

Thank you for posting that info George, I left it off as mentioned and now wonder what to do now that it's too late to correct. I'm glad you caught the plans mistake in time.

Darn. I enclosed the ply leading edge D section just last week and didn't think about this brace. I think I'll add it. I guess I have two options; cut the 1/16" ply for a wrench or come in from the front by drilling a small hole through the leading edge bull nose piece to pass a 1/4" socket extension. Minor setback. For pictures check my log at http://www.thehatz.com.

-Scott

I've started a new thread on this under a topic that will be more easily searchable for future builders:
viewtopic.php?f=8&t=364