Three-piece upper wing... stronger than Babe the OX.
December 29, 2016 Laying the foundation...
I'm not sure what's up with the upper-wing center section. I keep leaving it for other things to do. May be a good thing... since the CAD's aren't the same as the original drawings done by Curtis.
Well, I didn't do any actual work on the upper-wing center section... what I did do was set up the table in the spare room upstairs and looked over the orginal blue prints along with reading the thread in the biplane forum about it.
I think I'm ready to start laying out the pieces... getting the upper wing tank welded up and finishing up and moving onto the rest of the upper wing.
January 9 - 13, 2016 Wrapping my head around it all...
Wow... WOW ! It all started on Monday. I wanted to start diving into the wing center section... start figuring out what needed to be done. A thread on the biplane forum pointed out the CAD for the 3-piece wing was incorrect (lets say that it was pointed out that the sway wires are being shown on the front of the center section instead of the back like all other aerobatic biplanes).
So... I broke out the plans and tried to wrap my head around them. Kinda makes it tough when you need to shuffle a few different plans together. After looking over the plans for a while I had the urgency to see the CADs for the individual parts and pieces (maybe for a more in-depth look?). Thing was... I couldn't find them... for two days. okay... so I find them, make sure that I had them all, then started comparing the smaller CADs to the larger CADs. Found all that I needed to find... Then, looked through that thread on the fourm to see what was wrong and what was right.
After a few nights of what seems like aimlessly wandering around... I still couldn't figure it out (I'm no aerospace engineer and I'm not going to forge ahead into unknown stress territory). Today, Friday, I just about threw in the towel two or three times. The CADs weren't right, I wasn't wrapping my head around what was said on the forum, my Pitts Model 12 plans didn't help any... None of it was helping. Started writing on the forum two times about my decision to revert back to the original one-piece design of the Skybolt. But... I didn't want to give up on it. There was an answer somewhere in that pile of drawings on my card table... I just wasn't seeing it yet.
I dove back into it deciding that all the CADs were wrong (not that they were) and focused on the original plans that Curtis drew up. Looking at it... drawing some sketches on a blank sheet of paper. A little more looking... a little more sketching. It was starting to make sense. After about a half hour I thought I, make that, I had it figured out. Checked the pieces that I had made and the only thing that I need to do is make (4) -36 SL Wire Lugs and (4) -37 SL Wire Lugs.
The problem all along was trying to make the CADs work with the blue prints... and that my good man, ain't gonna work. Thank you annonomous guy (he doesn't want to be known) on the biplane forum that pointed me, and everyeone else, in the right direction with this.
Thinking back over the past week... something inside me wants to just break-out and start doing something with my hands... anything. I've learned a little restraint with the build. Sometimes you just need to sit back... think it through... and then move on. And believe me, some of those "think it through's" miss the spot and you need to re-think it through. All the while... you're not building a DAMN ! thing, thinking you're not getting it done. Ya just gotta accept moments, sometimes days, weeks or months, like these and push through...
I saw this video on Facebook the other day; a speech by Charlie Day, Creator of "It's Always Sunny in Philadelphia". Kinda sums up this struggle, the build... and of course life. The below quote is not verbatim... kind of condensed. You should listen to the entire video for yourself.
"My lesson is this... you cannot let the fear of failure stop you from doing what is going to make you great. You cannot succeed without the risk of failure. Be willing to fail. Let yourself fail. Fail in the way and place where you would want to fail. Fail, pick yourself up and fail again. Because without this struggle, what is your success anyway?" - Charlie Day
January 14 - 19, 2016 Trials and tribulations...
Wrapping my head around it all.
Been basically waisting my time playing with the idea of figuring out the sway wires and how they'll effect the upper former at station. Went about it half-ass at first (the playing part). Not quite sure why...
A day or two of half-ass and then on the third day I decided that maybe it'd be a better idea to located the actual spar, with the two brackets on it, in place and then string the line to see what hits what. It'll also tell me how far into the front pit the sway wires will come. So... on the forth day I jig the spar in place strike my lines and low and behold... the rear sway wire barely misses the former's outside, vertical support. DAMN ! We'll the fishing string that I used barely misses it. The actual wire would be hitting it. The forward line misses everything by a long shot.
Found out that the sway wires will be front and center 4.5inches inside the front pit... and the further you go up the wire... the further it's in the pit. Not so sure if anyone will be very keen on having sway wires that close to them.
From my mock-up I've learned two things; 1. I'll need to cut off and re-locate the outer upper former supports and 2. I just may be constructing a single-seat biplane?.
Here are a few photos...
Time to move the two outer upper former supports.
April 19, 2016 A few parts...
to keep me busy.
WOW ! I never did get very far with the upper wing center section. I was focused on the formers for supporting the sheet metal skin all this time.
I'm still working on that project but have a break waiting on some material. Decided that I would begin making a few pieces that I need for this section.
After a little looking I found the patterns that I had printed out so long ago... glued them onto the piece of metal and began drilling holes. Did NOTHING but drill holes tonight; 1/4inch, 3/8inch, and 1/2inch. Two hours of drilling holes. Now all I need to do is cut the parts out, grind them to size, file and sand smooth... oh yeah, and ream the holes out to size.
April 20, 2016 A few parts...
to keep me busy.
Another step towards completing the lugs... spent the night rough-cutting all eight out of the .190 metal blank. Ground down two to size.
April 21, 2016 A few parts...
still keeping me busy.
Another step towards completing the lugs... spent the night grinding all eight to size. Started filing and sanding three of them... each of those close to being finished. Just a few more scratches to file/sand out.
again... That's it. And, "That's it." took a little over two hours.
In the image below... Three right have been filed and sanded up to 180 grit. Need to file a few more of the scratches out and sand up to 220 or maybe 400. The other five still have the marks from the grinder on them.
Click on image for larger photo.
July 12 - 15, 2016 Way too many lugs...
nineteen and counting.
Not sure what it is about these lugs... tried reaming out the 1/4inch and 3/8inch holes and I'm not doing it... Locking the lug in the vice and using a hand reamer to do the job. The initial bites into the smaller hole (must be because the hole is too small ???) aren't straight and it ends up making the hole over-sized.
Decided to re-make them drilling the hole with the correct size drill bit. No problem... or so I thought. When rough cutting the lugs (before grinding and sanding them to size) I cut a little too close to the line and when I did a test on filing it smooth... the filing took it well within/past the line, so I decided to re-make that one again. Glued the pattern to the .190 material, picked up the 1/2inch drill bit that I had been using. Double-checked the size... WAIT ! this AIN'T 1/2inch. It's slightly smaller ! DAMN ! Picked up the 1/2inch bit and drilled the hole, along with the 1/4inch hole.
okay... I'll try to re-drill all these other ones to 1/2inch. and... it AIN'T workin' ! okay... I have enough material to make a few more and then I'll need to buy more material. First of the third batch... drilled the 1/2inch and the 1/4inch holes. Cut, then grind and file to size. Second of the third batch... it's taking FOREVER for the 1/2inch bit to drill the hole. It's dull... but being the person I am, I am bound and determined to drill this hole. What should have taken ten minutes probably took a good 45 minutes. The rest of the piece was easy-peasy.
Before making the third one, I went out and purchased a new 1/2inch drill bit. The 1/2inch hole for the third of the third batch of lugs took a total of 12 minutes. Yeah... just what I thought. Both holes and cut, grind/file to size took less than 45 minutes. ThankYouVeryMuch...
July 17 - 22, 2016 I've said more...
How much more can I say about making the SL lugs ??? Eeeeeeeeeeeeeeeesh !
All I can state is... I drilled the holes to size. Period.
UPS initially directed the shipment wrong somehow and it took a day longer to get the metal for the newest lugs. $27.00 to ship a piece of 9inch x 9inch x .190 material. Somethings wrong there. I'll need to call Aircraft Spruce about it.
Anyways... I've been drilling, cutting and filing my way through the remaining lugs. All I need to do now is sand them smooooooth.
NOTE: There are nine SL lugs shown below. I only need eight; four large and four small. Had the extra large one already glued on the sheet of metal with the holes cut before I realized I didn't need to make it... figured I'd finish it... just for shits and giggles.
wait wait wait wait... I do have something to say. It's not about the lugs, but it has something to do with the two sets of plans for the upper wing center section.
I spent two hours trying to shuffle the original Curtis plans with the new Steen Aero plans. It wasn't working. I finally decided that I would just go with the orginal Curtis plans.
July 23 - August 2, 2016 It's ready...
but am I ?
How much more can I say about making the upper wing center section ???
More questions than answers...
This shuffling stuff (again) is for the birds... Standard plans ? Radial plans ? They're overall pretty much the same... except the sway wires and landing wires. oh.. the Radial plans have a tube for a compression "rib".
It was stressed to me (and you need to make your own call on this) that the sway wires need to be on the back spar in order to transfer the stresses correctly (or something like that). Over the past few weeks I've been fiddling with all of this.
The table is set up. The fittings on the back spar are locked into postion. All I need to do is rise about my fear of making a mistake when drilling those two 3/4inch holes into the back spar.
Images below: Landing wire connect to the back spar only. Table ready for production... back spar locked in upside down with front spar just laying on table. Last image shows the spars locked in the correct postion and a note reminding me that it is being built upside down.
August 4, 6 and 7, 2016 A rollercoaster...
I'm slowly creeping towards having to drill the first hole. It's inevitable... but it seems like I'm just making excuses not to get around to doing it.
Took one entire work session to re-ream the 1/4inch bolt holes that hole that fittings into place on the rear spar for the UWCS. Didn't see that one coming... but I guess I was happy, since it did push back the inevitable.
Needed to make that jig too. The one that I will use to keep the hole going straight through the spar. Worked better on the test piece. A little off center when doing the first "real" hole. Damn... First started to enlarge the smaller hole with stepping up the drill bits.
My initial plan was to end up drilling the final hole with a 3/4inch bit. It wasn't working out that way... After messing around with trying to use even a 1/2inch bit in the hole (without success). I had to think of a plan "C". Had a large set of adjustable reamers that I got way back when. Figure... what the hell.
The hole was off-center so I first enlarged the hole by filing a larger opening while at the same time making the hole more centered in the match-drilling process. I slowly worked my way up from 3/8 to 3/4inch using three of the adjustable reams... slowly meaning s-l-o-w-l-y. It took me three hours total from initial drilled hole to final "match-drilled" hole. What I at first thought a disaster turned spot on.
Second and final hole... I'll drill up to the smallest I need to begin using those adjustable reamers.
August 8 - 11, 2016 Not good, or...
Received the 3/4inch reamer and... More work on the 3/4inch holes for the upper wing center section. Not sure how I did it but I'm not happy with either hole.
I will be ordering a few lengths of tubing so that I can make sure that the 3/4inch reamer aligns perfectly with the opposite 3/4inch hole. This is a set-back that I didn't want to see happen.
I'll be plugging both holes with sitka spruce and starting the entire process over again. WOW... didn't see this coming... The learning that we need to go through at times. In a week or two I'll be happy I went through this learning.
August 20, 2016 Same size...
or next larger ?
Made a few plugs for the two holes. Got to thinking after I made them that maybe I'll open them up to 7/8inch, from the 3/4inch, and insert larger tubes with correct size hole for bolt? Or, try and re-do the 3/4inch and if I'm not happy with it go up to the 3/4inch?