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.

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!

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.

Spruce For Wing Spars

 In January 2020, pre-Covid, I found one of my rear spar blanks was defective.  I also drilled a hole in the wrong place on another rear spar,  I ordered 2 new spars from Aircraft Spruce, not realizing 1 1/2 years later they wouldn't even be able to give me an expected date for them to have spar quality spruce.  While I was at the Antique Fly-in, Blakesburg 2021, a fellow Fly Baby builder, Kurt Gubert told me about an old lumber yard in Detroit who had some spruce that might work for my spars.  

Our Fly Baby is currently a Biplane, but it's licensed to switch to Monoplane wings, or back, with a log book entry.  Unfortunately the wings were ruined in a hangar fire years ago.  One of my projects is to rebuild the wings, but I need more spruce.  I want the monoplane wings because it's easier to trailer to events.  The monoplane wings fold or unfold in about 5 minutes.  That was the reason Fly Baby won the EAA design contest back in 1960.  The biplane wings take at least an hour each way.

Before you get crazy, Sitka Spruce is a small part of the several woods they stock and it has not been Certified as spar quality wood, that's up to you to resolve.  A good reference is ANC-19, Wood Aircraft Inspection and Fabrication.

That lumber yard is Public Lumber.  They've been there since 1927.

They're at 7 mile and I-75.  I took the picture of their store form the other side of 7 Mile Rd.  Look to the left 90 degrees and there is the entrance ramp to I-75 northbound.  It is in Detroit, in a residential neighborhood.  I met Craig and Tom, both super to work with.

It's a real lumberyard and full-service millwork facility, the smell of fresh wood, and the sounds of cutting and milling.  They even make their own custom cutters for their millwork.  People after my own heart

The spruce is in the lower bay of the rack at the left of this picture.  The boards are rough saw, 2" thick, 6" - 12" wide and mostly 16' - 20' long.  

They left me to sort out what I wanted.  The aisle is about 12' wide so it takes some thought to pull boards all the way out.  I had a great time examining and restacking boards.  I believe I found enough wood to make my WACO Spars and rebuild the Monoplane wings for our Fly Baby.  It was very fairly priced and I was dancing happy when I left.

It was cool when I got there.  As I worked and warmed up I took off my sweater, Christmas present from my wife.  I left it setting in the bay above the spruce with a tape measure I found laying under the rack.

I went on from there to visit my parents up by Flint.  The next morning I realized I'd forgotten the sweater.  Tom boxed it up and shipped it to me.  Thanks Tom for saving me from some serious dog house time.

I borrowed my son's Transit van to pull the Fly Baby trailer.  It's much nicer than my 24 year old Chevy van with 355,000 miles.

The weather was sunny and dry so I didn't worry about protecting the wood from the weather.  It all stayed strapped down and towed very well.

The round trip was almost 1,700 miles, well worth it.

The wood is safely home in my attic workshop.  

The next step is to pick out boards for the WACO spars.  Then the scary part, cutting them up.