Roto-Tiller Delays Project

 I haven't been getting much done on my airplane projects for the past couple months because I've been busy rebuilding my wife's roto-tiller.  It's a nice heavy duty 8 HP machine built about 1978.  She got it for free and I've been promising for a couple years to rebuild it.  Between the rust and dried grease nothing moved except the engine which turned over with rather weak compression.  The wheels were rusted onto the shafts and had to be cut off and welded back together in order to get the transmission apart.  Other than the tines, tires, hardware, a couple chains and the gas tank which all had to be replace, the rest of the parts just needed cleaning and painting.  A little Marvel Mystery Oil got the rings loose, and with a rebuild on the carburetor the engine runs great.

 The good news is the tiller works great.  I still need to print a couple vinyl labels I couldn't save and make a cover for the pulleys.  The bad news is I spent $900.  Fortunately You can't buy a new one this nice for that price and it was a lot of fun.

Time to plant the garden or we won't have any peas this year.

EAA Gas Welding Class

I've spent this weekend in Virginia Beach practicing welding at the EAA SportAir Workshop.  It was good fun and I learned plenty even though I had to learn to weld to get my A & P back in the 70s.  I don't weld often so I've been practicing on lots of scrap and some tubing from Lowes.  I had lots of questions which I couldn't find answers to on line, in books, or in the EAA welding video.  It really was money and time well spent and good fun.  Now I'm ready to weld up the Tail Surfaces and the Wing Fittings.

Cable Splicing Clamp - Complete

This piece is the adjustable part of the clamp to hold the cable secure while the splice is formed.  On Rich's clamp this piece is made from 1/2" round stock.  Rather than buy another 36" piece of steel for a 3/4" long piece I decided to make this from some of the 1" x 1/2" bar stock. The other advantage to this is it will be self aligning while clamping the cable.  The first step was to drill the center hole for the 3/8" bolt and 2 end holes for the 1/4" bolts.  I used the center drill to start the holes then drilled through with a 1/8" drill for a pilot hole.

The 3/8" bolt hole was drilled with a size Q drill for tapping the 3/8-24 threads.  For convenience I used the same size drill for the other 2 holes.  They just need to clear the bolts so the piece slides easily without turning.

The idea was to notch the ends with the band saw to make assembly easier.  What I hadn't thought enough about was that the three holes are not on a line.  That's why I like making drawings before I start cutting metal.  The solution was to cut to the end holes from 2 sides leaving a tab to keep the bar from turning.  In the end it's how I would make another one.  I'd just move the hole over a little so the tab is closer to the bolt.

The next step was to cut the Vee at the top center for the cable loop to set in.  I then removed some of the metal to give the bar a pleasing shape.  OK you could live without that but come on Craftmen take pride in their work.  The shaping was finished with files and the belt sander.

The adjustment bolt was threaded into the bar with the thumb wheel o
installed.  Some Locktite was use as well as tightening the bolt so it bottomed out.

The head of the bolt was cut off.  A thin washer was added as a bearing.

The end of the bushing was flared with the pointy end of a body hammer.  The hole in the base was chamfered  to allow the peened end of the bushing to flare out and lock the base to the block but still pivot.  I found, in use, this didn't hold well and fixed it with a 1/32" deep counter bore in the bar with a 9/16" drill instead of the chamfer.  Then peended the bushing as shown, rotating the pointy (not round) hammer to peen it in multiple spots.  Much better.

When I went to install the holding plate I found I had not tapped the holes squarely.  I didn't want to make another one so I clamped each end in the vise and bent it slightly to get the bolt aligned.  It may be crude but it worked perfect after lots of thinking to make sure I bent the ends the right direction.

Before assembly all the fabricated parts were  grit blasted for a nice finish.  Keep it lightly oiled with Corrosion-X and it should last for years.  The 2 slider bolts were cut to leave no threads sticking out of the plate, and installed with locktite.

I like it!  Thanks for the loan Rich.

The Fun is in the Doin'

If you've read my postings for a while you've probably noticed I'm not very orderly in working through the project from start to finish.   I tend to work on what ever I have parts, materials, tools ,or ideas for at the time.   When I helped my dad build the Fly Baby back in the 60s we were very methodical.  Pete Bowers wrote the plans/manual as a set of step by step instructions.  You start on page one of a chapter and just check off each task as you go.  When every item is checked off you have an airplane, actually a very cool airplane.

As much fun as it was working with my dad on the magic of building that plane you would think I would be more orderly in my current projects.  I'm not because what I learned from that process was that each little item was a project in and of it's self.  Each had it's own knowledge required, it's own materials, tools and methods.  To some extent it didn't matter so much the order things were done as it did that each was done.

By focusing on each small task, enjoying it, and taking pride and satisfaction in it's completion building an airplane is very easy, a lot of fun, and rewarding.  Finishing and flying the airplane was great but just one more little task or adventure just as each flight in it has been since.

By enjoying each saw cut, each hole drilled, each tool made, each little assembly, each flight for all the joy it contains, the Fun really is in the Doin' Not Just in Being Done.

Merry Christmas and a Fun New Year!

Cable Splicing Clamp - Holding Plate

 The presser bar pushes the cable loop and thimble securely into this plate, which does the actual holding while the loose end of the cable is secured.  It is made from a piece of 1/4" x 1" x 3" mild steel bar stock.

 The hole Locations are transferred from the base plate with duplicating punches to assure the bolts will align well.  The center hole is not drilled it is just a reference point.  The 2 bolt holes are drilled with a #3 drill and tapped with a 1/4" - 28 UNF thread to accept the 1/4" bolts.

 The opening in the center is to hold the loop of cable and the thimble so the hole is tapered to match the thimble.  From the AN100 drawing the sides slope 1:3 so rather than move my nice square table, and have to realign it, I made a hardwood block 1" x 3".  The plate is set on top of it and  held with the wrench while drilling.  The bolt is just there as a stop to keep the block of wood from sliding.  Think of it as a bench dog.  The holes are drilled through with a #2 (3/16) center drill.  Before drilling at the angle I drilled with just the tip about 1/32" deep 5/16" apart.  I chose the 3/16" drill because I plan to use this with 1/8" and 5/32" cable but this would allow up to 3/16" cable to set nicely in the round groove.

 All of the cutting and drilling is done with the bottom side of the plate up (visible).  The edge of all the cuts are more sharply visible on this side and the saw work is all being done by eye.

 The entrance slot and the relief for the thimble are cut next without ant taper.  This is just to get the shape.  From the top side you can see the angle of the drilled holes better.

 The band saw was used with the same 1:3 block to taper the thimble relief by placing the block next to the blade for good support.  The saw is being used more like a powered file than as a saw.  You just gently saw into the plate until the blade just kissed the cut edge.

I also tapered the entrance hole by turning the block 90 degrees to the blade and sawing along the edge of the cut.  Again you could tilt the table but that would have taken longer then making the cuts.  This came out really good and the cable fits perfectly.

The two 1/4" bolts were threaded down to 2-5/8" from the head.  It doesn't show here but they were cut off to leave 1/4" of good threads to screw into the plate.  The center bolt was threaded to give 1-1/2" of threads.  The head will get cut off from it later.

Cable Splicing Clamp - Clamp Base

 This part is made from a piece of 1/2" x 1" x 3" mild steel bar stock from Tractor Supply.  The 1/2" pivot hole is centered 3/8" from the edge.  The two 1/4" holes for the slider bolts are 7/32" from the ends and 1/4" from the same side as the pivot hole.

 To make sure the bolt heads don't catch on the vise in use the bolt heads are recessed into the base.  An easy job with a milling machine.  I created the same result with the band saw.  You need a sharp blade and a guide to control the location of the cut and the keep the bar parallel to the blade.  Just put on a noise cancelling head set and a good book because this needs to be done slowly.  Forcing the bandsaw will cause the blade to wander.  A careful cross cut and the ends are done.

  The ends have a 1/4" radius and the big curve is just tangent to both ends and the middle of the bar.  The shape was rough cut with the band saw.  The final shaping was done with the belt sander and and a mill file.  All the corners were softened.  I think I'll grit blast all the parts when I'm done just to even up the finish.  I don't think it will make sense to paint such a tool. I'll just need to keep it lightly oiled.

Splice Clamp Support Block

 When I grind with the belt sander I am careful to set the table and miter fence as square as I can get them.  Then to minimize uneven grinding I make a couple passes and then rotate the part 180 degrees and make a couple passes.  If you use light pressure you can do a very good job of it.  The center for the pivot hole was then located on one end of the blocks.

 Before drilling the hole down the split between the blocks I used the bandsaw to create a guide hole to help the drill go straight down the center.  The saw cut was made about 1/32" deep.

 The centers for the screw holes were laid out 1/4" from the ends and 3/16" from the sides.  The blocks were then clamped together and the screw holes drilled with a #26 drill (tap drill size for 10-24 UNC threads).  To control the drill better I like to mark the hole with a spring loaded prick punch and then improve the mark with a center punch (fits the drill better), and start the hole with a center drill.  In this case I used a #2 (3/16) center drill.  Once the holes were drilled through I drilled a clearance hole from the screw head side 9/16" into the block, a little past the center split.

 The holes were tapped for 10-24 threads.  By working in the same direction that the screws go, the clearance hole helps keep the tap going straight in.  With the holes tapped the blocks were separated and the screw holes countersunk for the flat head set screws.  I used stainless Allen head screws so I could torque them easier than Phillips or slotted screws.  The screws are arranged so 2 install in opposite corners on each side.

 With the blocks screwed together, the pivot hole was drilled.  The hole was started with a #3 center drill ( 1/4") until it the hole edge was about 1/32" deep.  It was then drilled through with a 1/4" drill following the saw cuts.  Unless you own a drill vise or finger wrestle regularly with Superman, the wrench lets you get a good grip on the part being drilled.

 The hole was then increased at the start with a #4 1/2 center drill (3/8") about 1/16" deep at the hole edge.  The shape and short length of center drills minimize how much they can wander. The hole was then finished with a 25/64" drill to give clearance for the 3/8" bolt.  The steel bushing from Lowe's is 3/8" ID x 1/2" OD x 1-1/2" long.I need 9/16" sticking out the end for the 1/2" support piece and washer between the parts.

 The 1/2" hole for the bushing was drilled 15/16" deep after opening the start of the hole a little more with a #5 center drill (7/16").

 To get this block to clamp the bushing the mating faces of the blocks were ground down until there was about .002" gap with the bushing installed in clean parts.

 The screw holes and the busing interfere so a notch was filed in each side of the bushing the allow the screws to clear it.

The parts were then cleaned in MEK to get rid of cutting oil, etc. A little Krazy Glue was used on the bushing to secure it to the blocks.  The screws were secured with Threadlocker and tightened to squeeze out the gap between the blocks.  The edges of the block were then ground to remove the little bit of the screw heads sticking out past the edges.