Feb 14, 2024     Groundhog day - Part Duh! - (15.5 hours)       Category: Rigging

Okay, finished up the remake of the ten flying and landing wire attach tabs that I screwed up on the first go-round. Once the new parts were cut out, fabrication involved the welding, heating forming, drilling, reaming and powdercoating. Once complete, I installed same, replacing the aforementioned problematic tabs.

The first pic below shows the lower left wing landing wires attach tab in position. On the black pad are the first tabs that I drilled the holes too close together resulting in the terminal ends interfering with one another. D'Oh!

The middle pic shows the new rear flying wire tab installation. All four were remade, the first ones were too short by 1/4", pictured beside it on the black pad.

The third pic below shows the forward flying wire attach tab. All four of these were too short and remade about 3/8" longer each. An original is pictured beside it on the black pad.

  Feb 02, 2024     Groundhog Day - (22.5 hours)       Category: Rigging

So it is Groundhog day today, but it's felt like it all week. Got the Forward flying wires attach tabs re-made to a longer dimension. After a careful re-measuring, I discovered the aft flying wires (all four) were long enough, but only about one and a half threads were past the witness holes in the terminals. Not comfortably enough to allow any future adjustments. Better to build longer attach tabs for these too.

Lastly, the lower landing wire attach tabs on each side where both wires attach are the proper length, but I drilled the holes too close together. The end terminals interfere with one another. I contemplated welding them shut and then re-drilling. Abandoned that idea since I wasn't confident it would be as strong as a re-made new one. Are you keeping count? Yeah, it comes to re-making another ten attach tabs. The parts are pictured below in the first picture, less the bushing stock which I needed to order more of.

The second picture below shows the terminal ends coming up a bit short. The top one is the forward flying wire, the check nut is located where it was against the terminal when installed. The witness holes in the terminals are also visible just beyond the threaded ends of the rods. The lower wire is an aft flying wire, where the threads made it to the witness holes, but only just.
The powdercoated tabs pictured also displays my sloppy drilling on the right one. Thought I'd just drill it full size (5/16") in one step, but it wandered off before I noticed it was happening. Had I drilled a smaller pilot hole first, likely wouldn't have had the problem.

I've got four more tabs to go in the welding process. After that,. Drilling, fitting, reaming and powdercoating to go to finish things up and get back to where I was.

  Jan 20, 2024     Forward flying wire issues - (1.5 hours) Category: Rigging

It's been miserably cold and windy around here the last week or so and not so fun to go warm up the hangar as it takes forever.
Did however remove the forward flying wires which are coming up a bit short. Yup, I need to make new attach tabs a bit longer. The threads were just short of the witness holes in the end terminals. Comparing the bolt-to-bolt dimensions of the tab attach bolts to the pin-to-pin dimensions of the forward flying wires (103.75" vs. 100.5") leaves a difference of 3.25". Divided in half for each end means each tab should require 1.625" or 1-5/8" from the C/L of the attach bolt to the C/L of the terminal attach pin hole. Further working that out, the center insert tab needs to be 1-15/16" long and the outer wrapper length is calculated from Murray's analysis (2 X Tab length + 1.33" to wrap around a 7/16" tube) comes out to be just a smidge over 5.2".
So, I'll re-make the attach tabs to the new lengths, but I don't think they'll be noticeably longer to the eye. Unless compared side by side with the originals.
These should result in a pin-to-pin dimension of the installed wire at 100.5" which leaves plenty of length for adjustments in either direction.

  Jan 11, 2024     Hanging the Flying/Landing wires - (2.5 hours) Category: Rigging

Installed all the wire attach "rolls" today in preparation for rigging all of the Landing and Flying wires. Installed the Landing "Tie-Rods" and tightened them until the weight came off the support horses. Kicked out the lower wing support horses and everything stayed put! (good) The landing tie-rods are not yet tensioned completely. It will ultimately require the Flying wires in place to get both sets properly up to tension against one another.

Using the construction laser mounted to the hangar door to ensure wing stations at the interplane strut mounts remain level at the established dihedral. So far, so good.

Installed the Flying tie-rods last, loosely tensioned in place. Somehow, the larger, forward flying wire on both sides is coming up a bit short. Pin-to-pin dimensions on the plans call for 100.5", but measuring them installed the pin-to pin dimension is 101.25". The 3/4" difference is enough that I can slip a wire into the witness holes on the terminals... which means no-go. (bad) All the rest of the wires fit so far and their witness holes are covered by threads (good). I don't anticipate loosening any during the tensioning up process and so don't anticipate developing any more wire fitment issues going forward. (also good)

Next build session I'll get the forward flying wires on the bench to do some careful dimensioning and develop a fix. I had a similar issue with the roll wires for the center section. Although installed I couldn't fit a wire into the witness holes, they were at the very last thread at the hole. That's a pass, but it wouldn't allow any adjustment from that initial-install position as one of the wires would then come up short. Wound up making longer attach tabs, solved the issue.

I'll know for sure when I sort out the dimensioning on these wires, but the fix is likely to be the same as the center section: make up a new set of attach tabs that are a little longer. Sometimes you have to back up to go forward.

  Jan 07, 2024     Finished up the Landing/Flying wire attach tas - (24.5 hours)       Category: Rigging

Got all the remaining Flying wire attach tabs fabricated, drilled, reamed and powdercoated. Now ready to fit them to the airframe and rig the wires.

In the process, I was informed Waco called these attach tabs "Rolls". Noted.

  Dec 29, 2023     Landing Wire Attach Tabs - (16.0 hours) Category: Rigging

Finished up the fabrication and fitting of the landing wire attach tabs today. They will need to be blued and powdercoated, but will get that done as a batch with some other stuff later.
Surprisingly, the plans dimensions worked with these, allowing the wire pin-to-pin dimensions to fit within 1/4" or less.

Edit 12/30/23: I was a little over generous about the plans dimensions working out. Another Hatz builder, Murray Marien had discovered quite some time ago that the wrapper lengths on some of these tabs were too short. They needed to be lengthened some to wrap around their bushings to meet properly at their ends to be edge-welded.

This is the kind of insidious errors in the plans that can lead to frustrations if you've cut all the steel bits, welded and tacked them together only to discover after bending them in place they're too short! At that point it's time to start all over again. Sheesh!
I don't know how he discovered it, (maybe analytically - he does a lot of that) but I know I would have just blundered into it flat-footed if he hadn't noted it.

When I read his build log months ago, I noted it on the plans and drew the templates to accommodate. Later, when I began these tabs, I blithely picked up my (adjusted) tab templates that had been sitting around for months and went to work, having forgotten all about Murray's insightful corrections.
Thanks Murray!

Next up, the flying wire attach tabs are ready to start forming and welding. See pictures from previous below.

  Dec 06, 2023     Wire Attach Tabs - (3.0 hours)       Category: Rigging

Got the rest of the tab inserts cut out out today, then proceeded to sand and grind the edges smooth and to final dimensions.
Results are pictured below.

Spent a couple of hours outdoors (should have dressed better) grinding and sanding everything smooth so as not to blow all the sanding grit around the hangar. Think I got borderline hypothermic standing in front of the sander for too long, spent the rest of the day trying to warm back up. After finishing up, came in and left early.

Next up, should be welding up these bits. I've demo'd that process before doing the roll wire tabs holding up the center section. (See Roll Wire Attach Tabs, in "Rigging" 7/10 2022)

  Dec 05, 2023     Wire Attach Tab Inserts - (3.5 hours) Category: Rigging

Spent this afternoon cutting the thicker insert tabs from .063" stock. They're rough-cut so far and need some more smoothing out before they're ready to start assembling. Minor delay: Bandsaw blade in the metal-cutting bandsaw gave it all... had to replace it before I had to leave this afternoon. Just a bit more cleanup on these parts with the new blade will be necessary tomorrow.
Once cleaned up it'll be time to prep for welding these bits up. More tacking and heat-forming. (Read: Blacksmithing)

  Dec 02, 2023     Flying/Landing wire attach tabs - (3.0 hours)       Category: Rigging

Saturday. Started in on the landing wire attach tabs today. I had glued tracings of the tab templates to scrap posterboard (old soda can boxes), and so cut those out and transferred same to the .050" 4130 sheet. After I shooed all the visitors out of the hangar, I spent the afternoon cutting said parts on the metal cutting bandsaw. Kind of a brain-dead monotony takes over, but I'll have to go back and check my work. Because, per the plans, there are at last count fourteen (14) tabs required in all. I think I counted having cut out thirteen pieces (each forming a tab) when I ran out of the first sheet of steel I had. I then proceeded to layout the last three required pieces on the next steel sheet I had at the ready. Wait, that makes 16?

Update: I mis-counted before I left for the day. I have the correct parts count. But more to go.

The above pieces will form the "wrapper" portions of the tabs, next I will need cut the thicker inner core parts of each tab from .063" 4130. These bits get welded to bushing stock and then sandwiched between both ends of the "wrapper" parts followed by edge welding them together.

  Dec 01, 2023     Starting the flying/landing wire setup process - (2.5 hours) Category: Rigging

Began the process of hanging and rigging the flying and landing wires.
I've had the wings trussed up and braced in order to build the interplane struts explained in the "Wings" category entries. Since those struts are now complete, it's time to start rigging the wires. The first step in that process is to produce the attach tabs into which the terminal ends of the wires pin. Those tabs are in turn, bolted to the wing structure at the strut attach plates and elsewhere on the fuselage, centersection and wing roots.

The plans include full-scale templates for these tabs which is not necessarily the way to bet, although I haven't heard widespread reports of trouble with them.
Trusting, I made copied cardboard templates of same, but verifying before I do any cutting on steel.

To verify, I measured the pin to pin dimensions of the opposing bolts locations for these attach tabs for each wire in the assembly as built. Next, I compared that with each associated wire pin-to-pin dimension. The difference between those dimensions was divided between the opposite attach points and that resulting figure was compared to the plans dimension for each respective attach tab.

After measuring all of the aforementioned, it turns out the plans dimensions for the tabs should work out ok. I had purchased the wires through Steen in the dimensions noted in the plans, but there's no guarantee the as-built dimensions will work out. Hopefully, I'll avoid any rude surprises having checked.

  Jul 10, 2022     Roll wires attach tabs - (10.0 hours)       Category: Rigging

Okay, so I created a new category for my build, "Rigging". I figured as this is a biplane build, rigging encompasses an important and comprehensive portion of it.
This is the first entry in that category.
Photos below show the build sequence for the welded tabs which will attach the roll wires to the top wing center section. I needed to rig these wires at this point to figure out where they poke through the top skin ahead of the passenger just aft of the firewall.
Sequence includes cutting the required thicknesses of steel from sheet and bushing tube. The thicker center insert tabs were welded first to both ends of a length of bushing. Welding these tabs to either end of a longer piece of bushing stock makes for easier handling and clamping while monkeying around heating, forming and welding the sheet steel to the assembly. Way easier than trying to work with just the right length of tube.
Next, the longer and thinner sheets were heated and formed over a 7/16" rod and then aligned and tacked in place to the bushing stock over the previously welded center inserts.
The tacked sheet strips were heated once again and formed around the bushing to lie flat against the center insert. Having them tacked in place makes this an easy and straightforward process with a torch and a few simple blacksmithing tools.
A clamp was placed on the tabs to squeeze the three pieces tightly together for welding. Tacked, then fully edge-welded around the tabs and onto the bushing to complete the welding step.
Next steps will include cutting the welded tabs free of the length of bushing stock, trimming to proper length and drilling/reaming both the bushing and the hole in the tab to accept the roll wire pins.
Wound up with two sets of tabs... The first, shorter set was built to plans and installed. Roll wires just fit, the threads reached right to the witness holes of the forked ends. Just to the ends. Any adjustment even a half turn would allow a safety wire to pass through the witness holes. Fortunately everything was squared up but wasn't comfortable with no adjustment capability. So I made a second set 1/2" longer to allow for deeper thread engagement and adjustment later of the threaded clevis ends.