Last 2 Spars Routed

 The process for routing the spars worked very well.  It's worth going back and looking at the other posts.

The First One covers the guides and basic method used.

The Second One is about the much needed dust collector.

The Third One is about planing and sanding the routed surfaces.

By the time I did these last 2 spars I had forgotten what I did.  Fortunately I had these old posts to remind me how I did it.

I used the ShopSmith as my work table with roller stands to hold the spar flat.  Fortunately my attic is 44 feet long so I have room to slide the long (15') spars in either direction.

On the first spar I forgot to lightly cross clamp the guides to the spar.  The spar started sliding with the force of pushing the router.  The cross clamps also assure the guides don't move away from the spar, so you get a very straight edge.

The vacuum hose for collecting saw dust has to be positioned so it doesn't stop the router because the hose snags on everything.  I hung it from a nail by one of my skylights.

The routing itself goes pretty easy with slow steady motion, not across the grain.  Across the grain makes a deeper cut than with the grain.  WEAR EAR PROTECTION, it's noisy.  I use my Bose headset which I wear all day in the embroidery shop.

I used 2 drill bits, 1/64" smaller than the desired cut depth, with a straight edge to set how far the router bit protrudes beyond the base.  There's a picture in the first post.

The piece of 2x4 with the corners routed to 3/8" worked very well for sanding the rear spars.

Along with the 150 grit Sandblaster I bought some 80 grit.  It worked very well for the first pass on the rear spars, where I couldn't use the block plane or my rubber sanding blocks.

The last 2 spars are done.  How cool is that?

Finished Drilling 2 Rear Spars

 

The attic is a bit crowded with the fuselage in there.  I should have turned the ShopSmith so the working side was on the left, where I had more room.  Hey it worked the holes are drilled and I'm ready to route the spars.

I only use the template to locate the drill, clamp the spar to the table, recheck the location, then move the template aside while drilling.  It's slow but the holes line up perfect.

Back To Drilling The Last 2 Wing Rear Spars

 Ok I've only drilled 2 holes, but I'm back working on the spars. The holes are the 5/16" holes which go vertically through the spars for attaching the wings.  Here are the links to go back and look at the details of how I did this for the first spars.

Aligning the ShopSmith to get accurate holes.

Positioning the drill.

Drilling the holes

After rechecking the alignment of the drill to the table and the fence we're ready to drill.  The spar is supported on 2 roller stands.  I moved the spar so the first 2 feet could be used to align it parallel to the fence.  The actual hole is 1-1/4" from the end of spar, therefore I wanted a longer edge to get it parallel.

The first pass is with a 1/4" drill.  The rear spars are 1-1/14" thick so I used a 1/2" gauge block between the drill and the table so the hole is centered on the spar width.  I center punched the holes with the optical centerpunch.

I clamped the spar to hold it flat and drilled just over 1/2 way through the spar.  Then the spar was flipped over and drilled from the other face of the spar.

The 2 halves of the hole aligned so well that a 1/4" bolt went easily through the hole.

I sort of repeated this process to drill out the hole to 5/16".  I used the 1/4" drill bit to align with the drill centerline, clamped the spar to the table, then switched the bit to a 5/16" bit and again drilled over 1/2 way through the spar, flipped the spar over and repeated.  After drilling the second side I used a letter P drill to open the hole slightly and in this case drilled all the way through, into my backing board.

Again a 5/16" bolt goes easily through the hole.

Now I need to drill all the holes for the fittings, etc.

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!

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.

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.