Upfront

Finish mounting the starter was no problem: clean up the threads, clean up the studs, torque, done. Then, the alternator.

Belt tensioning... too annoying by hand, but it took me a while to stop trying and become sensible.

Belt Tensioning

You gotta safety two bolts over there, and I decided to make it nice: for the bottom (pivot) bolt, drilled a tiny hole in the bracket lower than where the alternator would be, and for the top bolt attaching the bracket to the motor... hmmm...

Somewhere on VansAirforce someone used a cherry rivet as a "hookup" point for the safety wire. I thought to one-up that, and use a short #8 screw - drilling it's head.

Frankly, I didn't think it'd work out.

Drilled cap head

...but as you can see, it did.

So then, to the hole in the bracket. I needed a #8-32 tap.

Side, fun, story: quite a while ago I ended up bidding in a machine shop liquidation auction. Got quite a few nice things, including a very heavy duty bandsaw - and, accidentally, a massive cabinet full of tooling. Anything you could imagine: inserts, drills, taps, slitting saws, you name it. In all shapes and sizes. When we moved the cabinet, we emptied it into about 10 boxes, so ... I did have a #8-32 tap. In fact, probably about 20 of them. Question was, which one of the boxes were they in.

... apparently, in the one on the top. Hmm. This kind of luck is unusual.

Tap

Look at it carefully. Does it look like a regular tap we are all used to?

Didn't to me either.

So to researching we went.

Aha! "Threadforming" tap. AKA "Cold Rolling". So that's how they're done. Rolled threads are formed into the metal rather than cut; giving them superior strength. Basically, the tap shapes the metal, displacing it in the valleys and raising peaks.

Company that made these taps was advertising them for CNC milling. Well, what's a human if not a bio-CNC machine?!

Okay, problem number 2. I was pretty sure normal tap and drill chart values for hole diameters won't work; making too small a hole. Hmm...

The Bible

Aha! "Ideal Theoretical Hole", and closest drill available charts are just what's needed.

The Word

And with that, the affair was a non-event.

The Hole

Actually safetying was annoying - I had to try twice, because I had to use a hand-twister and you had to get the length just right.

Hand Twister

Safetied!

Airbox

That thing needed to be put back on, and carb final torqued with a new gasket. Cleaned it all up inside as much as I could, and had to cut a couple of special gaskets that I can't for the love of me figure out where to get (carb's base is different size from the top - and this is an "airframe" problem - read, "no standard part from Marvel or Lycoming I could find reasonably"). No problem. Used the same material Lycoming used for their gaskets, ordered from McMaster, and made me a couple.

Cutting gaskets

Where they go

Perceptive will see the "airflow straightener". Glenn had it on when he put on the Rotec TBI, and in the times of my research of TBIs, I have discovered that some folks claimed they helped on carbureted motors as well. Well, it definitely won't hurt - aside from my having to do two gaskets instead of one. No biggie.

Carb

One interesting thing that happened. I had to drain the carb bowl of all the preservative oil, and flush it, so I took off the plug, drained it, and started putting it back in. Plug's an NPT thread with torque listed by Lycoming in SSP-1776 at 144 inch pounds.

Hmmm.. I noticed it was going in way deeper than it was in before, and way "harder" than when I took it out.

Hmmm.. Well, it's Lycoming, they know what the hell they're talking about. So in it went, at 144 inch/lbs.

But this bugged me. I think some other day I pulled out the Marvel's manual. 25-30 inch/lbs?! WHAT?!

Back to Lycoming. 144. Marvel (the makers of the carb)? 25-30. Damn it. Forums? Nothing interesting.

I finally figured it out. In SSP-1776, in the table for special torques, Lycoming lists the plug to have 3/4 pipe threads. Mine were 1/8 NPT. Lycoming's torque for those is 40-44 inch/lbs. Still higher than Marvel, but much closer now.

So, I undid the plug, that cut a bit of the tapered thread "deeper", of course. And put it back in, with the right torque this time.

Other Stuff

And then, minor stuff here and there. Cleaned and prepped spark plugs. Put the exhaust back on. Tightened things that had to be tightened. Charged batteries. Tied up everything hanging loose. Gave the plane a good look all over.

We were ready for the final day. There were a number of things I needed two sets of hands for, and I had just the man lined up.

Day X - or, September 19, to be Precise.

My buddy Mr. N. agreed to help, and be my observer and fireman (just in case). Mr. M. was extremely inquisitive about how we're gonna be putting out a burning airplane, and I had to explain a number of times that the goal of an exercise of starting a motor that's been idle for a year is not to have it go ablaze, and having a fire watch nearby is a part of prudence, not expectations. He seemed to have been disappointed. I would be too, if I was 5.

So, on a nice Saturday, we went to the airport.

First, drained all the pickling oil. Took off the prop (because we'd have to spin the motor to pressurize the oil lines). Put the fuel pump back on. Tightened all new fuel lines, and leak checked them. Mr. M. used my fancy "button with alligator clips" to turn it on. Put new oil in, primed the oil cooler and pump (and this is fun in this airplane, because there's no oil filler neck on the motor). Checked control cable travel, and final cotter pinned them. Checked brakes again (though we bled them when I finished fixing them up).

Then, came the pressurization, and purging of oil lines, time. Mr. M insisted that he wants to "press the button" - which would put +12V onto the starter contactor; bypassing my normal starting circuit (latter would make the left mag hot, and I didn't want that).

I told him to press the button and hold it and not let go till I told him to.

Now, starters with a motor with removed spark plugs are fast, loud, and annoyingly sounding. Mr. M. pressed the button. Jumped a bit. Grimaced a bit. He clearly didn't expect it. I didn't see it, Nick told me afterwards - I was watching the oil line. I yelled "Stop" when I saw the oil come out, and looked at Mr. M - who, at that point, was shaking and at the point of breaking down in tears. But! He didn't let go of the damn button. Man.

Mr. M

And that was that. Plugs went in, and we were ready, but broke for lunch, first. Mr M deserved his hot dog.

... back from lunch. Plane out. Wheels chocked. Brakes tested. Fire watch ready and instructed.

Final prep

... damn, that old Concord battery removed from the Cheetah years ago is weak and barely pulling thru.

... second try: no primer, so I have to pump the throttle a bit.

... she's alive!!!!!

I let the temps go up just a bit, and called N. He confirmed everything seemed to have been fine. We shut down, and went over every fluid fitting. All good.

Started her back up - I wanted to warm the oil to a reasonable temp and let her circulate for a bit, maybe 30 minutes - to get the juice flowing again.

On the second run, I revved her harder, and smelled something. Smelled like... burnt wiring? N. went around the engine, all wires, and everything he could see or think was close to being to a hot surface, or an electrical doodad. No signs of trouble.

We decided to proceed.

She ran just fine. I think we ran for about a total of 30 minutes. Shut her down, dragged her in. Went over the wires again - all of them. Nothing, all clean. There were no bad indications on any of the electrical instrumentation, either. So at that time, we left that as a mystery to be solved.

... and with that, we went home. We were tired.

The Problem

... was that the default B&C's pivot arm did interfere with the front baffle hookup brackets.

Interference!

That did actually make me pay attention to the very unusual old pivot arm.

Old one

Nice dogleg, isn't it?

Well, this bracket did not involve any bending, just needed to make the correct one to fit around all the other stuff there on the nose.

Hmm... so how do we do that? Well, first, we need...

The Template

This is not the real template, because (.. read on ;) ). It's the template for the Template.

Start with a piece of heavy paper

Cut around the alternator

All we need to do with this template is show the location of the hookup hole (top hole, the one that attaches the bracket to the motor); the location of the slot for the alternator to hook up to, and the general outline of the alternator

Alternator bolt location is being marked

Bolt imprints along the "pivot arc"

..and finally, some more "no go" zones to prevent interference with other brackets there:

Done!

Notice I also added some "imprints" of the B&C-supplied pivot arm in there, just in case I'd need them.

Okay. I'm lying to you. This template is not the one I used. It was done with the long belt that ended up not working out, so I had to redo the template (thanks God, just the template). The new one was done in the same manner as the one I described above.

Here it is:

The *actual* template used

Okay. So now, we know critical locations of things and where not to go - so, cue in...

Solidworks!

It's magic, I keep telling people.

So, we take our template, and scan it on a scanner, along with a little metal ruler to give us physical dimensions. Then, we go to Solidworks, start a sketch, and insert the scan as "sketch picture". Using the image of the ruler that was scanned in, we tell Solidworks what "one inch" on this picture is. Boom! The image is now dimensionally accurate.

Then, we start drawing around it.

Initial sketch

Above, I positioned the top hole, and the four 5/16" holes around bolt imprints. I then sketched a large circle and made it tangent to three out of four of those holes - it defines the "pivot arc". Then, offsetting it 5/16th gives me the other "side" of the slot; and offsetting it more gives me the "sides" of the bracket in the "pivot arc" area.

I also started sketching the "no go" lines around the top portion of the bracket.

More circles

More circles and lines are added, and off-set. They are not positioned or dimensioned - just made tangent to "no go" lines. You can almost see the outline of the pivot arm, yes? ;)

Now, we take this master sketch; and add arc elements with real lines that we care about.

The arm!

Tada! We got the Solidworks Part.

By the way. How do you "measure" the round over of the B&C arm? Radius gauge? Calipers? Hmmm.. Or...

Measuring with Solidworks

Nice, isn't it?

Next, we print the drawing of our new part; making sure our holes' centers are marked (we'll use that later to drill them)

Done!

And, we got ourselves the actual template!

Now, the final test (Many thanks to USPS for providing material for this test)

Spray glue and cardboard

I wish I could cut 1/8" steel with X-Acto...

The mockup

Tadaa!!

Okay, we have the real template now, and we know it'll work. And now, comes...

The Grind

1/8" steel is no joke

Nice little sheet of 1/8" 4130 showed up from Spruce some time earlier... I used spray glue to put the print out of the bracket on top of it.

Template on steel

First, all the holes had to be drilled. The drill press I have at the moment is severely underpowered, so I had to step-drill them in four steps.

Curlies!

I got to admit, I am starting to become very fond of pretty steel curlies made by nice drill bits.

Also, lesson number one learned: drilling oil (I used TapMagic) gets under the template, and messes up the glue (and unglues it). I need to figure out a better glue.

I drilled the slot's "start" and "end" holes slightly undersized, and reamed the main attachment hole to 5/16ths exactly.

Reamer!

Next, the slot... I rough-drilled small holes around it's perimeter, thinking that a 1/8" shank carbide burr in an air die grinder (basically, Dremel) would work... Ha! It did... for a second ;)

Slot in the making

Boo!

Okay, time to go old school... where's that...

Hacksaw!

I cut it out, and cleaned it out with a bastard file.

Cut out

.. and cleaned up

And then, more and more hacksaw...

.. my right arm

.. is beginning to feel...

.. it ..

Yeah. The last few inches, I gave up, and used the jig saw. It did cost me 3 blades, but I was too ... done with the hacksaw. I figure, about a blade per 1 inch of cut in 1/8" 4130 with a jigsaw...

.. gave up.

Cutting done.

Looks very ugly, right? Well.... to the grinder!

Grind...

.. grind ..

.. grind away ..

Three belts I believe is what it took.

Well, now, the final cleanup on the slot. Yes, Dima, I used the rotary file here :).

Cleaning up the slot

..and, test fit

Tadaa!

That was two evenings, folks; but I wasn't done.

The Three Brackets

Next, I had to prep the edges and sand out all the scratches, and paint. A deburring wheel on a bench grinder helped; and the most nasty marks were filed out and then polished out with the deburring wheel.

Clean edge

It has to be done because every scratch is a stress riser - on fittings, every edge needs to be rounded over, and polished.

Finally, to....

Paint

Every airplane "paintjob" I've done so far was in my makeshift "paintboots". Like this one.

Paintbooth!

I sprayed both the pivot arm, and the baffle support bracket I made earlier, with self-etching primer, and some Rustoleum paint. White will make cracks more visible, if they show up.

Painted!

So there we go. With this done, I can now install the alternator. Just measly 30 hours to get ready to install the damn alternator! ;)