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.

Mounting the Current Limiters and the Shunt

They were to take place of the old voltage regulator, onto the same mounting pads. I needed a backplate...

Pattern

...and a very basic one at that. Basically, a "hole pattern adapter".

Cut

Mounted

I also needed to plug the nearby hole left by the removed mechanical tach cable. That one needed a large plug, and, as before, I decided to use a pipe plug with straight threads. It's nice, light, and aluminum.

Tach cable hole plug

There, the black one. Above the grommet with a couple wires.

That washer took a couple tries to make BTW. First one was functional, but too ugly.

The washers

Plugging the Holes

There were some more holes left after removing some old things. They were for #6 or #8 screws; and I could barely access the other side (fuel tank that's right behind the firewall makes it super hard).

Instead of attempting to maneuver nuts back there, I wanted to try something along a rivnut.. but a bit better. Steel.

Spruce sells these steel "nutserts", which seemed to fit the bill. Got a set, with install tooling.

A nutsert with an installation nut

I had to enlarge the holes on the firewall a bit to fit even the smallest nutserts; and used #4 screws to "plug" them.

Nutsert installed

Nutserts with screws

Fat Wires

The contactors got mounted and torque sealed (of course I forgot to add a diode jumper to the starter contactor, will have to add later). Next, came figuring out the alternator wire and battery contactor -> shunt jumper (main buss feeder from the battery basically).

Initially, I thought I could route the alternator wire on the right side of the motor; keeping the starter on the left (remember, the firewall layout on this plane is reversed of sorts - with battery and oil cooler having their locations swapped and producing all sorts of grief due to that).

While not bad, holding the alternator wire on the firewall would've required more holes, and it'd go straight down, at 90 degrees to the main harness on the firewall (going left to right), kinda "crossing" it under. So I gave that idea up pretty quick, instead deciding to run it along that main harness - neatness and 1 less hole/clamp instead of a shorter by about a foot run.

Initial alternator and starter hookups

Alternator wire is the white one going into the ANL current limiter, and starter wire is the red one joining it after coming off of the starter contactor (black) there.

And then, I needed the battery -> starter jumper. That was the spot to hook up the buss feeder too, with other end on the shunt.

I made this fancy thing...

Contactor jumper and buss feeder

... and of course, a mandatory pile of shame...

The Pile of Shame

Clocking of terminals is critical on these fat wires. If you're doing two wires, relative position of them in the terminal is critical too. You lose concentration for one moment and clock them wrong; and you're redoing the lead.

The first one I didn't like the crimps on.

The second one I messed up the clocking on.

The third one (bottom one) is the good one.

Mr. Max made a comment that it's the music that's distracting me (he was busy building his "water system" out of the old fuel system hoses and fittings I took out at the time).

The initial setup

I did not like this. See how tight that Master <-> Starter contactor jumper is? It was very tight. The rigid alternator wire hooked into the ring on the master contactor side was too tight too (that adel clamp that I needed to hold stuff under the starter contactor had to be there - there will be other wires bundled there later). It was so tight that it bent the ring when I attempted to set it up.

No, that wasn't good at all.... hmmm..

Aha! I did a similar trick with the gascolator! Reverse the flow.

Flow reversed starter contactor

Much better! All I did was swapped the jumper from the Master contactor, and the starter lead on the starter contactor; and, while that made the fat red wire jumper much longer, it made the whole setup much, much cleaner. It made the buss feed wire a bit less pretty, arguably, with that weird "dip", but there's no avoiding it. I'll live with that.

The pile of shame grew.

Growing Pile of Shame

By the way, here's how a crimped end looks up close.

Crimped ring

Even with heatshrink, I had these thoughts of water weeping in between the strands on the ring end, and staying there, and slowly eating up the wire. Probably a non-issue; but it didn't sit well with me. So I used that as an excuse to whip out my small soldering torch, and add "solder caps".

Solder cap

Much better and neater, don't you think? Solder here acts as a filler between the strands and to "tin" the bare copper wire of the welding cable I'm using for those fat red wires. Much; much cleaner and prettier this way.

Ground Strap

This plane didn't have any. The battery was grounded to the motor (good - the biggest current demand is from the starter). The motor wasn't grounded to anything else at all, making the current flow thru probably the control cables and fuel hoses to the rest of the plane. Not good.

So, one was needed. That took more thinking and fiddling. I had a plan initially to ground the battery to the motor and the motor mount (Grummans do something similar - battery to firewall; and motor mount to motor) - but I wasn't sure about how good a connection there is between the motor mount and the firewall. So I decided to jump the motor to the firewall - a very common setup.

Simple braid will suffice.

Braid - one end

Braid done

I used a super flexible Raychem SFTW tubing and heatshrunk it. Doesn't affect the flexibility, but protects the strands a bit.

Braid installed

Random Soldering Picture

Filling the end with solder

Battery Box

Battery leads were easy to make. Had to fiddle a bit with grommets (holes in the box are much larger than wires, and I had to use a "hose section around a wire in the grommet" trick to keep the wire tight and nice.

The battery box was another matter though.

Glenn had replaced the original large ("standard") battery with a small Odyssey - and took out the space with a bunch of chunks of random foam...

Foam

The box had "dimples" for the battery to stand on, lifted off the bottom (the bottom was made into a funnel of sorts that ended in a drain - setup for an old school battery that could leak acid). Those dimples were sized for a full size battery, so Odyssey couldn't stand on them.

So, .. ahem.. the solution was?

Bottom

Yyyyeah. No. Come on now.

Proper bottom

And that chunk of whatever it was? Belongs here:

Right there

Now, the checks...

I hooked up the leads, routed them out of the box, and closed it up, only to realize that the battery was loose in the "up and down" direction. Not good at all, but the solution was simple.

Mock up

I mocked up something quick out of some foam I had around, and closed the lid. Much nicer! No more bouncing. See, I didn't want the battery to hit the top and be bouncing if the airplane all of a sudden went to <0G (in turbulence, trivially possible - and it is aerobatic after all!)

Ordered some foam from McMaster, and padded the top of the box, and the battery sides.

Battery sides padded

Box top padded

Now, the battery was sitting solid. No more bouncing.

And with that, I moved on. The main layout was done - the rest of tightening, tying, and strapping has to be done when all the wires are in, close to the end of this rebuild.

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! ;)