Sometimes I find a part for my project that there isn’t anyone posting about making. So then the dreaded analysis-paralysis syndrome starts to rear it’s ugly head because I think too much about how to make something I haven’t seen made.
I started looking for posts on BPF and the Google Chat history on 2wings.com, and searching the Internet.
Somehow, on my plans, (I must be blind) but I can’t seem to find a darn drawing for the tail wire lugs. Nothing on the horizontal or vertical stab page and nothing on the brace wire page. I did find a drawing on Steen Aero’s website. They are selling stainless steel tail wire lugs, but the exchange rate and the cost for the number I need was more than I was willing to pay.
After seeing the Steen lugs in stainless steel, I thought those would look nice since they’re polished. However, it doesn’t say what stainless they were made from; was it 304 or 316? Analysis paralysis really started to rear its head so I sent Don a message and he kindly obliged to say what he felt but of course, added that it might be a good idea to check the strength of the material substituting.
So I did the calculation and I’m sure someone smarter than I can confirm but using 304, 316, 4130 x 0.125” inch thick sheet I came up with a yield calculation for each. The 304 was about 1030 pounds, the 316 was about I think 1150 pounds, and 4130 was closer to 1800 pounds.
Doing the math and building such an airplane I decided that 4130 was going to be the material. After all, I’m not an engineer and I have no bail out experience experience. 🥹
I didn’t have a drawing from my plans, but using AC41.13, a drawing I received from Kelvin from his ultimate, and the Steen dimensions, I created the following part.
So with my 6 x 12 sheet, I popped into a local welding shop that I know has a nice sheer and they sheared my sheet down to 7/8” strips an 8th wider to have extra material to remove with sanding surfaces to bright metal; with the rolling marks correct direction for bending.
I then sanded with my belt sander the strips down to remove the sheer marks to nice shiny bright surface. Followed by cutting to length with good old-fashioned Armstrong hacksaw.
The holes were drilled in the strips, using a centre drill first and then drilled 15/64”. I didn’t ream them until after the next operation. The mini mill was a good score on the Canadian version of craigslist called Kijiji… best part was it came with some tooling and it was less than purchasing a new drill press. I’ve used it for making all kinds of things for my project.
They still needed to get a pleasing radius on the ends that also complied with hole/edge distance. Back when I did my hinge straps, I made a little block of aluminum that had holes drilled in it certain distance from its edge that I can attach using a screw to hold the material to the aluminum block and then the material can be rotated up against the sander to get the radius sanded in.
Once that was done, the holes were reamed to 0.250 then all surfaces brightened to 400 grit and edges/holes chamfered.
Lastly, I had to get the bend in them so I stuck a piece of masking tape on either side to prevent marring the surface, figured out the bend radius allowance/ sight-line to get the bend in the middle, and then used my homemade nose break bar that I clamp down with my finger break.
I was very fortunate to find my finger break and shear that formerly belonged to a university physics department that was spending their budget on new equipment, selling their old stuff for cheap. Unfortunately, it seems like students tried to bend hardened steel rod with a finger brake so some of the fingers are damaged, but are useable for my shop 😅 since I just sanded out the high spots.
The nosebar is made with a 3/8 piece of drill rod tacked to a 2” strip of middle steel, (I made it when I bent up the aluminum trim tabs for the tail). To securely clamp down the part to be bent, you have to use some material on either side the same thickness of the material being bent for the nose break bar to sit on.
Now for the good part, the pictures.
Hope this helps somebody, and if anybody sees something wrong, let me know!
I have extra material so if you need a set of lugs, let me know, I’m ready to go into production🤣.
Ryan.
I started looking for posts on BPF and the Google Chat history on 2wings.com, and searching the Internet.
Somehow, on my plans, (I must be blind) but I can’t seem to find a darn drawing for the tail wire lugs. Nothing on the horizontal or vertical stab page and nothing on the brace wire page. I did find a drawing on Steen Aero’s website. They are selling stainless steel tail wire lugs, but the exchange rate and the cost for the number I need was more than I was willing to pay.
After seeing the Steen lugs in stainless steel, I thought those would look nice since they’re polished. However, it doesn’t say what stainless they were made from; was it 304 or 316? Analysis paralysis really started to rear its head so I sent Don a message and he kindly obliged to say what he felt but of course, added that it might be a good idea to check the strength of the material substituting.
So I did the calculation and I’m sure someone smarter than I can confirm but using 304, 316, 4130 x 0.125” inch thick sheet I came up with a yield calculation for each. The 304 was about 1030 pounds, the 316 was about I think 1150 pounds, and 4130 was closer to 1800 pounds.
Doing the math and building such an airplane I decided that 4130 was going to be the material. After all, I’m not an engineer and I have no bail out experience experience. 🥹
I didn’t have a drawing from my plans, but using AC41.13, a drawing I received from Kelvin from his ultimate, and the Steen dimensions, I created the following part.
So with my 6 x 12 sheet, I popped into a local welding shop that I know has a nice sheer and they sheared my sheet down to 7/8” strips an 8th wider to have extra material to remove with sanding surfaces to bright metal; with the rolling marks correct direction for bending.
I then sanded with my belt sander the strips down to remove the sheer marks to nice shiny bright surface. Followed by cutting to length with good old-fashioned Armstrong hacksaw.
The holes were drilled in the strips, using a centre drill first and then drilled 15/64”. I didn’t ream them until after the next operation. The mini mill was a good score on the Canadian version of craigslist called Kijiji… best part was it came with some tooling and it was less than purchasing a new drill press. I’ve used it for making all kinds of things for my project.
They still needed to get a pleasing radius on the ends that also complied with hole/edge distance. Back when I did my hinge straps, I made a little block of aluminum that had holes drilled in it certain distance from its edge that I can attach using a screw to hold the material to the aluminum block and then the material can be rotated up against the sander to get the radius sanded in.
Once that was done, the holes were reamed to 0.250 then all surfaces brightened to 400 grit and edges/holes chamfered.
Lastly, I had to get the bend in them so I stuck a piece of masking tape on either side to prevent marring the surface, figured out the bend radius allowance/ sight-line to get the bend in the middle, and then used my homemade nose break bar that I clamp down with my finger break.
I was very fortunate to find my finger break and shear that formerly belonged to a university physics department that was spending their budget on new equipment, selling their old stuff for cheap. Unfortunately, it seems like students tried to bend hardened steel rod with a finger brake so some of the fingers are damaged, but are useable for my shop 😅 since I just sanded out the high spots.
The nosebar is made with a 3/8 piece of drill rod tacked to a 2” strip of middle steel, (I made it when I bent up the aluminum trim tabs for the tail). To securely clamp down the part to be bent, you have to use some material on either side the same thickness of the material being bent for the nose break bar to sit on.
Now for the good part, the pictures.
Hope this helps somebody, and if anybody sees something wrong, let me know!
I have extra material so if you need a set of lugs, let me know, I’m ready to go into production🤣.
Ryan.
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