Hatz Biplane Association

Don't have the plans in front of me, but I'd prefer .049 wall longerons. Lots of stress there.

Interesting point. I assumed that the 3/4 x .049 dimension applied to all four longerons.

I was thinking like John. The note definitely says 3/4 X .035 unless noted. The two lower longerons say .049, and the upper longerons are not noted. This led me to think the uppers should be .035. Has anyone clarified this with Jeff? What have others used?

JD

I'm looking to see how I arrived at 31 feet for 3/4 x .049 and what I see is that the bottom longhorns are labeled as 3/4 x .049 but the top ones aren't labeled (or I missed it), so I was going to use 3/4 x .035 for the top (per the note bottom right page 12). I went with the 3/4 x .035 on everything unless the part was specifically labeled some other dimension. I'll measure everything again when I get closer to ordering and I'll review all the pages again. Ordering the wrong size/quantity is bad enough, but I sure don't want to use the wrong dimension anywhere.

Thank you Doug. I sure appreciate the info and help.

OK, here's my steel list:
Feet...Dimensions (Round unless noted otherwise)
8.......1/4 x .035
41......5/16 x .035
8.......5/16 x .065
9.......3/8 x .035
8.......3/8 x .065
68......1/2 x .035
8.......7/16 x .065
55......5/8 x .035
8.......5/8 x .049
8.......5/8 x .065
199....3/4 x .035
171....3/4 x .049
8.......3/4 x .058
6.......3/4 x .095
18......7/8 x .049
8.......7/8 x .058
8.......1 x .049
8.......1 1/2 x .035
8.......1 1/2 x .065
8.......1 1/2 x 3/4 x .049 (Rectangle)
8.......3/4 x .035 (Square)
8.......3/4 x .049 (Square)
6.......1/2 x 1/2 x .035 (Square)

In addition to the list I also ordered my streamline tubing, but can't find the receipt at the moment. I'll go measure them later on. The list represents everything I could determine from the plans except for the engine mount. I still need to order for that.

I over ordered a bit on the 3/4 x .049 ( I probably needed more like 120 feet), but your list looks short on that one. Don't forget you have four longerons @ roughly 15.5 feet (you'll want them a bit long until you trim to final size) so that's ~62 feet right there.

A couple of comments on ordering the steel:
1. Plan for mistakes and order some extra. I've done pretty good so far until I got to the seats where I wasted a couple pieces. Fortunately, I can still cut them up for smaller pieces and make use of the tubing.
2. When you order you can get "full length" tubing which usually runs 18-20 feet. This is often easier because then you can decide how you want to cut it. It also give you some extra length to work with if there are any dents or scratches in the tubing. I had one arrive with a slight dent, but was able to plan around it and use most of the tube anyway.
3. Check on cutting charges and/or minimum sizes when you order. I bought all my tubing (except the streamline) from Dillsburg Aero (now out of business). He preferred to deal in longer lengths and would charge a cutting fee on anything shorter than 6 feet. This is why even for tubing where I may only need a foot or two I still ordered 6 or 8 feet. The savings on everything else more than made up for the extra couple feet.

FYI, I added your site to the Builder's Page.

Hope this helps.

I forgot to type in the horizontal stab & elevator material. I know I'm going to make other orders and that I'll need to re-do some work. I did send in my first order; just wood for ribs. I won't order spars until I'm ready for that. When I make that order, I'll also order all the tubing I can think of.

I used tracing paper in order to reach the amount of material (to make sure I counted each piece and did not miss any or count any more than once). I had a sheet of paper with the various dimensions. As I drew over each piece on the tracing paper, I noted the dimension and wrote the inches I measured in the appropriate place. If I measured from a page with a different scale, that was noted. I then added it all up and converted it into inches and feet. I'm sure I messed up somewhere, but I think I'm in the neighborhood.

If you haven't seen my webpage, check it out; I think you'll like the size and clarity of my images. http://imageevent.com/hatz

I'll rummage through my receipts this weekend and see how mine compare.

Is your steel tubing list supposed to represent all the tubing for the plane or just some portion? At first glance it doesn't look like it represents enough for the entire plane.

Here's what my (minimum) 4130 shopping list looks like so far (see anything weird?):

5/8 X .035...33 feet
3/4 X .049...31 feet
3/8 X .035...6 feet
5/8 X .049...2 feet
5/16 X .035...13 feet
1/4 X .035...3 feet
7/8 X .049...4 feet
1/2 X .035...35 feet
3/4 X .035...121 feet
1/2 X 1/2 X .063 squares...10 feet
3/4 X 3/4 X .032 formed angle...12 feet
1/2 X 1/2 square...2 feet

As far as wood (enough to get started):

Mahogany 1/16" plywood for gussets...2 sheets of 4X8
Spruce capstrip 1/4" for ribs...600 feet
Birch plywood 1/4" for nose block, trailing tip, center section bottom, center ribs...1 sheet 4X8
Birch plywood 1/8 for false nose...1 sheet 4X4
Spars for front...5" X 11'
Spars for rear...4" X 11'
Spars center section...4 1/2" X 5' and 5 1/2" X 5'
Spars (aileron)...4" X 5'
Spruce capstrip for the wing gussets...1/2" X 28'
Spruce capstrip for the wing gussets...3/8" X 12'
Mahogany plywood 1/4" for plywood rib #1 and center section ribs...1 sheet of 4X8

Still thinking about the leading edge components.

My plan is to build ribs then, if I have space (and I don't quit), build wings. Then I'll pursue the fuselage.

Thank you Jeff. Thank you Nick. I've been looking at the plans for almost a month and I'm ready to get my first order in for material. While I wait on that, I'll make the rib jig and various templates.