MartyFeehan's Xanga

Sunday, August 30, 2009

Sun, 30 Aug 2009 00:46:25 GMT

So, another long pause in my updates. Well, I spent the summer building ribs, building ribs, and building ribs! Lets see, what else........ I got a good start on my spars and....... AN ENGINE!!!!!

I'll just jump into pictures. Building ribs is a lot of pieces, a lot of repeating steps over and over and a lot of glue. Nice thing was no welding in the 100 degree heat!

I also reserved my FAA registration number: N367PS. So, what is the significance? Well, you will have to grab a Bible, and go to Psalms 36:7 to find out.


First, I used a router to finish cut the plywood "D" for the ribs. Then it was cutting lots of little pieces and lots of cap strips. I decided to buy some cap strips from Aircraft Spruce as I got tired of using the planer.

Finished plywood pieces.

Using the planer to make the cap strips. This took a long time so I wound up buying about half the strips for about $50!

Lots of cutting on the band saw!

Strips ready to glue, top caps bent and ready.

Gluing the first rib, very big step. Lots to repeat, 26 for both wings plus about the same false ribs.
Lots of little parts in the bins, already made.

Lots and lots of clamps. And yes, I made the clamps from PVC pipe and dowel rods. I found the design on another builder's site.

I decided to move into the house, much cooler.

OK, this turned out to be much better than the card table in the middle of the room. Misty seemed to agree with her watchful gaze.

My helper Sandy. Ivy; our older dog; slept most of the time.

Three a day was the rate of production. Each rib took about two hours with 4 hours drying time. Do the math, long days! Ann was with her Mom so I worked very long days.

Family pictures that I placed inside one of the ribs as a kind of time capsule. I've done this on many projects over the years, kind of my signature that no one is likely to see. I know it is there.

Preparing to cover up forever ........ I hope.

Typical shot of gluing on plywood. Some of the ribs are plated with ply of various sizes depending on location in the wing.

More plywood plates.

Next, bending cap strips for the false ribs. I used the same method for the full cap strips. The jig was right out of one of the EAA books. The false ribs are only the "D" plywood with some cap strip material and gussets. They go between the full ribs stopping at the spar. That's why the name, false rib.

Gluing up the false ribs.

After removing from the jig, the gussets had to be glued on the other side. I had to do the same step on each full rib also. Lots of time but I watched a lot of TV as I glued wood together.

I took a day off and took my granddaughter Nayeli to her first air show. What fun.

Nayeli, just three years old, helped me build some false ribs in her dining room the afternoon of the air show. The air show was only an hour from her house. The parts she glued will be included in my wings as is. That kind of freaked out her Mom, Rhiannon just a bit!

And finally, all the ribs for both wings are finished and hung from the wall in the guest room. Guess what the theme of the guest room is?????

Next, the spars. I bought the wood in Washington State in 2005 and have stored it since. I planed down the wood, and needed to glue one of the spars from three pieces. The others are about ready. I should start assembling the wings in a few weeks. Then a side step to get an engine.

I was able to help remove the engine from my friend Eric's Piper Tri Pacer. The engine is a 135hp Lyc. O290 D2. Eric is upgrading to a larger engine for the type of flying he needs to do. He made me a great offer on the engine. He just flew round trip to Oshkosh (40+) hours with no problems. We did a compression test, than pickled the engine for the two or so years until I need it. I can simply bolt it up, hook it up, and start it. This will not only save me $$$ but as important (or more maybe) save me lots of time. I took a bunch of pictures of the removal so installation will be much easier.

Ready to take home. My trash trailer sure has hauled lots of interesting stuff. If only we had left the prop on we could have driven home like a Florida Air boat! OK. well not!

The engine is now safely at home! Next step will be moving the fuselage to my classroom so I can assemble the wings! Stay tuned!

By the way, a hint about my "N" number: it's part of my profile here on xanga.

Thursday, May 07, 2009

Thu, 07 May 2009 03:55:59 GMT

Die springs finished!

I won't go into too much detail but I have included some photos. I have also included the final drawings for the struts. I had a few changes like ........ well I had the slot on the inner tube going the wrong way (pointed out to me very kindly, thank you) and some minor dimension changes along with the actual length for my 2+2.

Below is the first fit of the struts. I raised up the wheels to get them 90 degrees to the floor to establish the strut length. 1/2" was latter subtracted to allow for load on the gear with the finished aircraft.

Next I cut the struts to the correct length and reinstalled. I marked the inner hole location using the outer slot for a guide. Then. driller hole and re assembled. I then marked the inner slot and to took everything apart and cut the slot with a dremel.

Next, compress the spring.....

and then put everything together and it all fit!!!

I know this is a bit brief but their are lots of ways to put this together and if you understand the plans than you will be able to build this using ways you are used to doing things. After drilling a few holes in the tail feathers I forgot than it's on to the wings!

Sunday, March 01, 2009

Sun, 01 Mar 2009 06:21:26 GMT

Die Springs ........ v2.0. I spent some time over the past week or so making parts for my second set of die springs. The first set I made are now cut into pieces to remove the springs. Other than the spring removal issue, I also did not like the bushings as installed. I will be increasing from a 7/16" tube to a 1/2" to give a thicker cross section. I don't know if it matters but I feel better about the greater thickness. Below are some pictures of the parts for the sliding collars. I finished welding them today and am ready to drill the holes for the bolts.

The tubes are all cut and ready to be cleaned prior to welding. All sizes are according to my new drawing.

First couple of tubes welded. The longer tube at the back is to hold everything in alignment for tack welding the washer in place.

Finished collars ready to drill.

Sunday, February 22, 2009

Sun, 22 Feb 2009 07:19:24 GMT

"Don't be afraid to start over when you have a question or concern about a part; only be afraid if you don't!"

My new mantra! I finished my die spring shocks last week ......... and cut them up into pieces today. That's right, I cut them up. I wasn't convinced it was the best design since the spring was non removable as I built it.

Along with not having the spring removable I didn't like the size of the bushings. After getting in touch with other builders and pilots who use this type of shock, I redesigned the shock to allow for disassembly. Tonight after cutting the above finished shock apart, I started building a new set using the redesign below. Stay tuned!

Monday, February 16, 2009

Mon, 16 Feb 2009 04:35:31 GMT

Below is the drawing for the Die Springs I am building. I am having some problems deciding if this design will work as the spring is not removable as shown I drew the drawing below from some other plans posted elsewhere that I simply re drew for clarity. So, I am looking for a solution that will allow me to remove the spring. I have tube one finished with the lower washer welded in place but I am thinking I may need to re do it in some manner to make the spring removable. Any suggestions???

Tuesday, January 13, 2009

Tue, 13 Jan 2009 04:30:53 GMT

The tail is finished! Well, it has been done since Thanksgiving but I haven't gotten around to updating my log; so her we go. As you can see, I finished the elevators and have them installed. The alignment of the two sides came out great and the hinge pins slip right into place. How long did it take me to scratch build? Well, I started back in May figuring out how to make the ribs and finished just after Thanksgiving. There was a lot of tooling to make for the various parts and that did take a bunch of time. All told I think about 200 hours was spent on everything. Cost was much lower than any kit options. I think I spent less than $300 on everything (excluding the jack screw and yoke). I did make my own link assembly (included in the $300) for a considerable saving but very time consuming. So, here we go with pictures............

Bending the trailing edge, very high tech and it worked just fine. Second one came out just as good and a match. This method was shown on one of the EAA tech tip videos.

Trailing edge # two.

Below, the two matching trailing edges. Just take your time, go back and forth from the tree to the table and it won't take long at all; about an hour for both.

Next, fitting the ribs. I am not showing a lot of pictures here as this is the same as the rudder. Just remember, you need two that match.

Here the spar is shown fit onto the trailing edge.

Ready for welding welding.......

Next came the control horns. After trying to hand bend (hammer and heat) I decided to make a "V" block and use a press to make the 90 degree bend. My block is a piece of maple cut with a v down the middle and a piece of angle iron glued in place. I ground the bottom of the angle iron for a deeper v; angle iron is very round at the bottom. The shoe I used is simply a piece of 3/8" mild steel ground with a radius on the edge with the same hand held grinder I use for all my cutting. The press is from Harbor Freight. I had the press but needed a new jack; 6 ton for about $20. The press worked just great and will be very handy for upcoming parts.

The Press from Harbor Freight

The "V" block, shoe, and material rough cut for the horns.

Next, welding the horns in place. I tack welded them in place and finished them after I checked for fit on the completed stab.

Next, the hinges. I again used the hinge jig drawings shown for the rudder. The only difference was I made them out of wood to make them more accurate. Yes, they burned but I only need them once and they were easy to make.

Ready to weld .......

After test fitting and adjusting, the hinges were finish welded and the pins fit in place.

Here is the finished horn and hinge close up.

And the finished tail!

So what's next? I think the over head trim system for the elevator and then the control sticks. i am also thinking about finishing the landing gear ......GOT WHEELS! Stay tuned. I have taken a couple of months off for the holidays and work stuff but hope to be back at it soon.

And yes, it still fits in the garage! With the tail removed I can even get my wife's car in so I don't have to scrape the windows.

Thursday, September 11, 2008

Thu, 11 Sep 2008 03:05:30 GMT

This entry shows the progress over the past three months or so. It may not look like much due to the "learning curve" on some of the parts. Needless to say, things took a lot longer to figure out than expected. As I began the process of building the stabilizer, I realized that I could make all the parts except the leading edge. The plans called for enlarging (swage) the end of the leading edge to fit over the connecting tube (tube between both stabs). Think tent poles. One tent pole is made larger to fit over the second tent pole of the same size. Seeing that there was no way to do this on my own and unable to find a formed leading edge with the swage, I redesigned the stab to use a sleeve rather than the swage. This was nothing new as I found at least one PMA'd part built the same way but no longer available.

This is the design I came up with. I knew it required making my own link assembly and connecting tube but the savings would be worth it. Cost of PMA'd parts was about $ 250, my cost was about $15 plus lots of time. So, I started on the link first.

Most of the work was straight forward. The time came in keeping the inside of the link clean and straight to accept the connecting tube. I knew the connecting tube needed to be turned down and not having a lathe, that took time. I wound up grinding the connecting tube on a belt sander down to the proper diameter. I was able to get the tube + or - .003" along the entire 16" length so I was happy. The inside of the link assembly was sized using a brake cylinder hone going back and forth for a long time! All said and done, the link and connecting tube took me WAY too long but it came out great. By the way, some builders are using a polished or chromed connecting tube but Piper only calls for 4130 "fitted to a sliding fit" so I went with that. If you have a lathe to turn the connecting tube you will save lots of time. If you have a way to align bore the link, even better. Me, a brake hone with sand paper wrapped around it and lots of cutting oil did the trick. Did I mention LOTS of time?

Building the link

Another shot of the link

These little tabs are for the trim indicator wire.

Finished link with connecting tube in place

Next, bending the leading edge tube. I won't show the mangled tubes that represented the learning curve. Lets just say that I spent about two weeks figuring this one out. Finally, another builder sent me a picture of his jig and it all worked out. My jig consisted of two pieces of 3/4" ply cut to the curve with a "generous" amount of curve for spring back. I say generous because I had to adjust it three times to get it correct. I screwed them together and cut and sanded the profile. Then, I took them apart and used a 1/2"cove router bit on each piece, keeping in mind up and dow, then screwed them back together now having a 1" profile to match the tube. I packed the tube very tightly with sand and drove in wood plugs at bottom ends to keep tight. Most important thing about the bend is you MUST have a much longer piece of tube than necessary to make the bend work. 8' is minimum length and 10' would be better. You will wind up cutting of about 4' when finished. This is another reason to use .035 rather than original .028. .035 is about $2.50 a foot and .028 is something like $8.25 a foot. .028 costs a lot more for the learning. With the end of the tube held tight against the end of the jig, slowly start pulling it into shape. You will need to move a bit of tube out past your starting end as you progress to get the curve just right. My first attempt had the sleeve welded in place. Big mistake. I had to redo those sleeves and weld on after the curve was bent. I did use a little bit of heat after I had the curve bent around the form to relieve a little stress. You will se in my pictures how much extra curve was needed to get everything just right. After three weeks and lots of figuring, the first tube was finished. The second one only took about 2 1/2 hours start to finish!

Tube clamped and bending begun. This doesn't show additional block between the end one shown and tube.

Here you can see the generous amount of curve needed on the jig for spring back.

The second tube! Much faster

The two finished tubes with jig removed.

Next, I welded on the sleeves keeping the curve clamped in place.

I used a little heat to relieve any stress and let it cool to control spring back. I did this a few times until the curve was held with out any pressure.

Finish weld of the sleeve

Now it was business as usual. The remainder of construction was the same as the rudder.

The plans did not show this step but it was on the Super Cub drawings so I did the same.

Another view of the end of the stab

Here the end is welded closed

End rib fitted in place. All ribs were made in the same manner as the rudder ribs.

Trailing edge with bushings for tail brace wires

Ribs in place, ready for welding

The finished stab. For the second stab, repeat all the above steps without the learning curve!

Here is everything after fit up. It is very important to keep the leading edge and the trailing edge exactly parallel with each other and the second stab exactly the same dimensions as the first for alignment. Mine were a little off and I had to cut the inside rib loose at one end, pull the tubes closer together and reweld. This was not the end of the world, just normal fitting as I see it. I have started on the elevators and have one of the curves bent but no pictures yet.

Sunday, June 29, 2008

Sun, 29 Jun 2008 01:11:46 GMT

The rudder is hinged in place and it moves! This is one of those moments that keeps a builder going; at least me anyway. I used the rudder hinge jig from www.supercubproject.com and it worked out great. It took me a bit of time to make the jig. After I went out and bought a uni-step bit it went a lot faster. Below are the picture of the hinge process. My next step is to weld on the control horn.

This is the jig in position for the upper hinge. The jig holds everything in alignment. You can download drawings for the jig at www.supercubproject.com The drawings are on Christians link page, down toward the bottom of the page. Take a look at his pictures section and you will find much better pictures of the use of the jig.

Another view of the jig in place. You can see the lower jig at the top edge of the picture.

This is the first fit up of the rudder. I did have to make a few adjustments for fit. The top of my tail post was a bit out of alignment and the rudder spar needed some straightening.

Here is the upper hinge with the pin in place. I will probably shim with a couple of thin washers for final install.

Here is the lower hinge. The small tube above the hinge is the rudder stop. The stop will be trimmed after the rudder horn is welded on to the sleeve just above the hinge on the rudder spar.

Saturday, June 21, 2008

Sat, 21 Jun 2008 23:53:46 GMT

Wow, three months since my last update. In that time, I have made some progress but in the process I had to learn A LOT! After finishing the channel under the front section, I decided to build the rudder bar. This proved to be a lot more challenging than I thought it would be. I built them according to the plans, but had to start over three times to get it right. I started by welding up the pedals, that was ok. I am going to have toe brakes on both sides so I had to change the set up a little. Basically, the copilot side needed removable toe pieces like the pilot side. Also, I added a finger strap to the top of each pedal (not shown on the plans. Then came the trouble. I first welded the “V” that connects the two sides together. My plan was to weld that to the longer of the two rudder bar tubes and cut out the section for the right pilot pedal. The problem arose when final welding, it kept cracking! Finally after some advice from Supercub.org, I got the sequence down and no cracks. Getting everything to fit and turn was a pain; 4130 will not stay straight when welded. I finally got everything turning ok and it was time to make the attachment hardware. I made a set of the “U” shaped connectors but did not like the metal to metal contact. After a bunch of research, I settled on making pillow blocks out of UMHW Polyethylene. As my research made a full circle, I discovered that the RV aircraft have been using this method for a while now so I felt good about the change. One problem, how much friction in the pedals is too much? So, on to build the rudder and tail fin.

To build the rudder, I needed ribs. These were made from 22g mild steel, bend to a taper. So, I needed a bending break. So, I built one. Than, I needed to bend the 15 degree edge on each rib. So, I made a wood bending block for each rib with proper taper and angle. All in all, I spent about a month figuring all this out and getting materials together. Making each rib turned out to be very easy, about a half hour for each.

So, I set up the table and built the tail fin and rudder using the same kind of blocking method used in building the fuselage. With the fin and rudder finished (except for hinge) I now am trying to figure out how to enlarge the ends of the stabilizer leading edge tube to accept the connecting tube. At this writing, I have no idea how to accomplish this task. Stay tuned.

Below are pictures of the rudder bar construction along with rudder and tail fin.



Rudder pedal and cable connector tube and rudder bar with most parts in place.

Ready to weld the V. Gap must be maintained to keep weld from cracking as weld expands and cools.

Using a saw blade to maintain the gap at final welding

Rudder bar clamped in place with wood blocks for pillow block bearings.

Clamped in place with final pillow blocks

Making ribs using home made bender.

First bend followed by bending the 15 degree bevel with wood bending block inside.

Finished rib.

Welding the washers and bushing for tail brace wires.



Ready to weld and welded.

Bending the trailing edge of the rudder. I actually bent this around the tree in my front yard to get the correct bend!

Ready to fit other parts in place.

Support wire welded in place followed by top of spar.

The welding process............. blocked than tack welded on table.


Rudder horn made from .090 4130. Make sure to leave extra metal on the tabs before bending and than trim off extra. I didn't do that ................. this is the second one I made!

Rudder in place ready for hinge and rudder horn.

Below is an idea to redesign the stab tube to eliminate the need to swage the ends of the tube. Any comments?

Saturday, February 23, 2008

Sat, 23 Feb 2008 22:53:52 GMT

The bottom stringers are on! I guess you could say that I am "finished" with the major construction of the fuselage. No, it is not complete by any means. Next step (other than finish welding here) is to start fabricating the control systems. That is the rudder bar, sticks, pulleys, and tail group. I also have many unknown tabs to attach as I decide what kind of interior finish to go with. So I have a lot of "detail" work to do at this stage of the fuselage. I will be able to flip the fuselage back over after the final welding of the lower channel is complete.

Lower stringers looking aft

Front attach fittings for stringers

Stringer side attach fittings tack welded in place

Looking aft from side of fuselage