Thursday, May 19, 2022

Templates For the Aileron Control Horn and Ribs

 

I decided to be more careful this time.  I've been using small blue tick marks to help me find my pencil marks on the galvanized steel, which I like for templates.  Depending on the light the pencil mark can be hard to see.  I confused myself on the last try by where I had made the blue marks.

I still think it makes drawing the actual lines much easier.

I used the optical center punch to mark all my holes and compass centers.

For holes I draw a small circle around the punch mark.  

For compass centers I put 4 tick marks, kind of like center lines.

I have this cheap plastic compass I like for most big curves. The pattern of holes and markings are set up based on the circle diameter, in 0.025" increments, so I rarely use my conventional compass.  It really works very well with my 0.5 mm lead pencil.




I drew the outline and 3 bolt holes first then added all the rivet holes.

After cutting and filing the outline I punched all the holes.

There are 3 pieces which all rivet together so the holes were transferred from the horn template to the other 2 templates.  The horn gets riveted between the 1/4" spruce rib on one side and a piece of 3/4" spruce, stiffener on the other side.  The rivets are Copper Rivets used for saddle and harness making.

The rib template can be used for the full length root rib as well as the 2 piece rib at the control horn.  I'm also using it to make a small rib jig for all the aileron Light Ribs, stick and gussets.

The control horn template can also be used to make the doubler which gets welded on to the forward end of the control horn.

Making Progress!


Sunday, May 8, 2022

Finally Back to Making Things - Well Almost

 The storm of January 3rd has kept me busy cutting up fallen/damaged trees for months.  I'm finally done with trees for this year.

I like to think I'm a good draftsman, but I've drawn this template on steel 3 times to get it right.

When I got it finished I decided to lay it on the drawing just as a final quality check.  I'm glad I did.  Some how I've located 2 holes incorrectly.  Pretty sad given I'm laying it out from my own drawing.

The good news is I'm having fun, even if I get to do this one more time.  Still, better than wrecking some expensive 4130 steel.

Back to the workshop.


Thursday, January 20, 2022

Aileron CAD Drawings Finished

 Before building the ailerons, and the last 2 wings, I decided to finish modeling the ailerons in CAD.  I felt it was the only way to reconcile inconsistencies in the drawings.  I now have about 20 drawings to use building the ailerons.  I believe a good CAD model, and working drawings, help assure I only make things once.


This is the assembly drawing for the aileron.  My redraw is very close to the factory drawing.  There were no factory drawings of the detailed parts, etc.

The big change from the factory drawing is the location of the hinges.  The inboard hinge is in the factory location, but the spacing between the other hinges each change 1/16".  I think the hinge spacing on the factory aileron drawing makes more sense than the factory wing spar drawing, but I've already made my wing spars so I moved the hinges to agree with the wing spar drawing.

The shape of the aileron control horn changed slightly from the factory drawing to agree with the plane in the WACO Museum.  There were some other little issues with how the ailerons were actually assembled. The factory drawing didn't show the gussets on the ribs, or things like where blocks were needed to attach the ribs, etc.

 I now have a plan that I think will work so I'm excited to get to back to making parts.

Friday, December 10, 2021

Aileron Spars Ready to Drill

 The layout work is done on the 2 new rear wing spars.



The ailerons have 2 spars, like the wings.  The WACO NINE has ailerons on the upper wing panels only. They must Not have worked well on the 1925 version, because in 1926, with the Improved NINE, they made them longer with an Elephant Ear balance tab.  The longer ailerons would have had more power and the balance tabs would lightened the stick forces.

On the 1927 Model TEN they got rid of the Elephant Ears ears and added ailerons on the lower wings.

On the NINE the ailerons are operated by cable routed through the lower wings to pulleys hidden in the structure below the aileron control horn. You can see one in front of the aft strut and one behind it.

On the TEN they used push rods to operate the lower ailerons with the upper ailerons slaved to them by a strut between the Ailerons.

The aileron starts about 1/3 of the way along the spar and extends about 18" beyond the tip.
Each aileron is hinged with 4 hinges using an Eye  Bolt and Fork Bolt arrangement.  The fork bolt part bolts through the aft wing spar.  The eye bolt part bolts through the forward aileron spar.  I have 4 drawings showing the location of the aileron hinges, the wing assembly drawing, the aft spar drawing, the aileron drawing, and an older aileron drawing from 1926.  They all have slightly different dimensions.  There are more of these anomalies.  The aileron drawing shows the length of the forward spar is 120" but the Bill of Materials on the same drawing shows 120 1/4".

To resolve these things I've modeled the aileron in TurboCAD.  I'm using the dimensions from the drawings which work in the model.

I have all the ribs and hole locations drawn out on both sides of each spar.  I also write on the spars the size of any drilled holes.

I'll match drill the hinge bolt holes in each aileron spar by using it's wing spar as the master for the holes in the aileron spar.  Even if I measure slightly wrong the hinges won't bind.
The tip of the forward spar has a tapered tip with a gentle Ogee type curve connection the taper to the main straight section.  To layout the curves in this 8" section I clamped 2 blocks to the spar.

The one on the left is clamped flush with the straight edge, with the corner at the start of the curve.  The other block is clamped so it's edge follows the taper, with its corner at the start of the curve. 

I clamped my Starrett meter scale to the edges of these 2 blocks and drew the curve between them.  The clamps should be at the end of each block so the curve is tangent to the 2 blocks.  It was easier to do than explain.


The drawing doesn't show the taper on the aft spar so I made it such that where each rib crosses the 2 spars are the same height.  At the inboard rib the spars are 1 13/32" tall and at the outboard rib they are 1" tall.

I'm ready to start drilling, routing, etc.  We're making parts again!


Thursday, December 9, 2021

Improvement to Shopsmith Planer Knife Adjustment Gauge 513414

 The instructions for the new Knife Gauge involved scribing some lines on both sides of the gauge.  I'm good but I don't think I can scribe lines on both sides, 7/16" from the corner and then 1/32" either side of that line.  Instead I decided to print a label using vinyl vehicle wrap material.  The idea was to print a label which can be wrapped around the gauge so both sides are really aligned.

The label is 3/4" wide by 1 1/16" long before folding around the gauge.  I printed these on 30" wide vinyl so I have a lot of stickers.  I'll give the leftovers to Shopsmith to tryout.

My brand new planer knife touches the gauge at the 1/32" mark before the (7/16") Zero Line.  I like it.
I had to clean the gauge with alcohol to get the label to stick.  A craft knife or razor blade is needed to trim the label after installation, keep reading.

The label is stuck to a transparent transfer film, the long end is pointing left.  The edge of the gauge is aligned with the left line near the center of the label.

I rubbed the first half of the label down tight with the back of my finger nail, then gently peeled up the transfer tape as I worked the label around the gauge.

The 2 lines align with the edges of the gauge.


I used the razor blade to trim off this edge of the label where the planer knife must touch the gauge for accuracy.

This leaves labels on each side perfectly aligned with each other.

The right and left sides of the gauge with the label applied.

If the gauge is heated to about 250°F then cooled the label will adhere even better.


Tuesday, December 7, 2021

Planing the Wing and Aileron Spars

 

I decided to install new knives in the planer before planing the spars.  There are 3 knives in the Shopsmith planer.  Each blade is held in by 2 wedges, with 4 screws each.  Below each knife there are 3 screws for adjusting the height of each knife and for leveling it end to end.

It takes about an hour to replace and/or adjust the knives.  They can be lightly sharpened (honed) without removing them.  The new knives are sharp, I cut myself on one.
When I packed everything a couple years ago to build the wall between the 2 rooms in the attic, I packed up the adjustment gauge and can't find it.  I ordered a new gauge and found they had changed the design.  The original had a curved edge (7) that the knife needed to just clear.  The new one has a straight edge.  They didn't send any instructions and they were closed so I winged it.

It turns out I came pretty close to how they wanted you to use this gauge.  I put a piece of tape on the gauge and marked where a knife touched it, then made sure all knives touched at the same point.  The correct instructions are to put this mark 7/16" from the bottom corner.

I have an idea to make a label to do this more accurately, more on it another day.

The attic is 44 feet long but the wall limits how long a board you can plane without working through the outside door.  The 17 foot and 18 foot boards just fit.  The 20 foot boards will probably need the door open.  I wanted to plane the full length of the board so I could cut out the best section for each spar.

I put 2 rollers on each side of the planer.  It worked out well except that the 1/2" thick aileron spar boards drooped enough that I could have used an assistant to lift the end onto the rollers.

It actually worked quite well even without an assistant.

You really need the vacuum.  This make a lot of chips and sawdust.

The board on the right is the aileron spar from the second board.  You can see where the high spot, caused by the bandsaw blade curve, has started planing first.

The picture below is the wing spar from the other side of the cut.  You can see where the low spot hasn't planed down.

You can't plane 2 boards at once, but if you do multiple boards between each thickness adjustment they will come out the same thickness.

I found I could keep it straight if before each change in height I put an X on the start of each board so I knew which ones had not been planed yet.

I set the board, waiting it's turn, to the left side where it couldn't accidently get into the planer.


The boards tended to slowly rotate as they went through the planer.  I found it only took the slightest touch with my thumb nail to hold them so they feed straight through.
I checked the thickness of each board after each pass using my Vernier calipers.  The planer adjustment wheel has markings for every 1/128" (0.008").  You can easily plane to whatever thickness you want within a couple thousandths of an inch.
All the wing and aileron spars are cut to width and planed to thickness.  The task now is to layout all the bolt holes, rib locations, routing, etc.  I've been waiting almost 2 years to get back to this point.  It took a bit to remember what I was doing with this layout process.

I've call Aircraft Spruce and cancelled my spar order.  

It's great to be back to making wings and ailerons, YEA!

Monday, December 6, 2021

Sawing Spruce Boards Into Spars

 I've finally started sawing spars from my stack of spruce.  I started by inspecting all the boards and picking out the shortest ones with good sections long enough for the 2 wing spars.

The first step was to saw 2 boards to 4" wide.  The spars are 3 5/16" tall.

The boards are 17 feet long and I was able to saw them by myself with 2 sets of rollers on each side of the saw.

The next step was to re-saw them with the bandsaw.  Shopsmith makes a 5/8" blade specifically for re-sawing boards.

I split the board to have a 1 1/4" wide Aft Wing Spar and a 1/2" wide Forward Aileron Spar, plus an extra 1/8" available to plane off each.

I made a fence for the bandsaw with a piece of 3" angle iron clamped to the table.  


I used the featherboard to hold the wood tight at the bottom.  Shopsmith makes a feather board that you can stack up to 4 high just for this type work ($90).

The instructions for the 5/8" blade were to run it at 500 RPM to prevent overheating.

When sawing long boards a wedge can be useful to keep the saw cut from closing and binding the blade.  It wasn't needed with the bandsaw.


The kerf is very clean and narrow.

It measured 0.030" wide, about 1/3 the width of the 10" circular Rip blade I used for the first cut.

I went real slow and the first board came out perfect, straight down the board, and straight and square top to bottom.

The second board I must have pushed too hard and the blade curved into the wing spar, leaving extra wood to plane off the aileron spar.  In the end the wing spar would be less than 1 1/4" after planing in order to clean both sides.  

I'll plane it down for another project.  I bought enough wood to rebuild the monoplane wings for our Fly Baby.  The old ones were lost in a hangar fire.  It's licensed to use either the monoplane or biplane wings.  The monoplane wings work better for trailering to events because they fold in about 10 minutes.  This board will make a nice rear spar.

On the 3rd board I decided to try a different approach.  I've never had luck lining up 2 deep table saw cuts to meet in the middle of the board, so I tried a 3 cut approach.  I made a 1 1/2" deep cut, took the board outside and flipped it end for end, then made a second cut on the other edge.

I used the bandsaw to connect the two assuming the blade wouldn't wander so far off the cut line.

It worked perfect, 2 nice boards ready to plane down.

You can see below how the blade wandered but never cut into either spar.  They'll both plane down perfect.

I had bought a couple 10' boards to use for the aileron Aft Spars.  The rings were at slightly more of an angle than I wanted.  I got the idea to cut the board in half at about the angle of the rings.  Then I used this surface to re-saw the boards.  My first cut was along the line running almost corner to corner of the original board.

It worked perfect.  I used the wedges to cut, quarter sawn, 1 1/8" x 3/16" laminations for the wing tip bows.  I ended up with only a small bundle of tiny wedges for scrap.  I needed 8 laminations and ended up with 9.

Time to do some thickness planing.