"Project Bantam" - brass ring gear reproduction

Bob Weaver in Shelby, Ohio had a batch of reproduction brass ring gears made.  During Bob's own restoration he needed one as well, and I was fortunate enough to obtain the second-to-the-last one he had made.  The Weaver family were very pleasant folks and I enjoyed doing business with them.  The gear looks like good quality American workmanship.  That kind of workmanship is worth it, and it didn't come cheap.

"Project Bantam" - magnamatic ignition

I came across this article in Gas Engine Magazine, and I'm certainly glad I did.
http://www.gasenginemagazine.com/gas-engines/cheap-fix.aspx
The author showed how to fit a common B&S coil to the Magnamatic Ignition on this model FB engine. The concept is simple. Remove enough material from the core to make it fit under the flywheel. And it is tight.

Original Coil

After some careful hacksaw work and filing, and I think it turned out rather well. I did not use a hoseclamp like the fellow in the article. I fashioned two spring clips to emulate the original ones. I made them VERY tight, and also put a screw on one side to positively locate the coil along the shaft axis, as an added measure to make sure it doesn't wander around due to vibrations.

Modified Coil

Modified Coil and Core assembly

"Project Bantam" - gearbox teardown

The axle shafts on the gearbox were flopping around in their bushings, so I knew there was going to be some parts replacement inside.  I just didn't think it would be this bad.  I was told that the brass ring gear had been repaired once before.  That didn't console me much either, since I knew it was probably bodged back together.  My father didn't have a lathe at the time, so the previous repair would have been dodgy.

 

Opening the cover on the gearbox revealed a lot of sludge, but no broken parts.  It all came apart easily by following the overhaul instructions.  The back of the shift shaft was a little rusty, so that had to be addressed before the shift fork would come off.  Otherwise the bearings look relatively good, and I took note of the part number on the input shaft seal.  "Victor 62012", which is supposed to cross over to "Federal Mogul 470954".  The axle shaft seals were so bad, I couldn't even read them, they're supposed to cross over to "Federal Mogul 254287".

The gearbox wasn't a problem, it came apart easily from the differential.  The worm gear pulled out without any problem and showed some wear.  Opening the differential showed the horror of the main failure.

It seems a lot of the teeth had dissolved into sludge.

The spider gears look ok.  They don't seem to have any significant wear.

Cleaning everything out was a several hour process.

 

The axle bushing is obviously broken off causing the excessive wear of the teeth.

I doubt this gear salvageable, I supposed I must obtain a new (different) one...

"Project Bantam" - slow work in the cold weather

There's been limited progress the last few weeks.  The weather has been cold, so parts passing through the electrolysis tank haven't had the opportunity to be cleaned outside as quickly as I would like.  The workshop is nice and clean, but I need to take the parts outside to wash them, and there has been snow.

The seat and spring came out rust free and have a nice coat of black paint.  They will require new bolts and some washers since I cut the originals off with the angle grinder.  The mounting bolt to the body that snapped off still needs drilled out and re-tapped.

 

The tin-worm ate the fan shroud rather severely.  It will require some intensive reconstructive surgery.  More on this later.

I just set the carburetor aside for attention at a later time.

Removing the flywheel is providing a bit of a challenge.  The 1-1/4" nut came of relatively easily.  The flywheel was blocked up and I simply hit the 3/4" ratchet handle with a big mallet, and the nut came loose.  Pulling the flywheel is another story.  Its really stuck.  PB Blaster and some patience will be required on this one.  The flywheel is cast iron and I can't afford to damage it.  Another larger puller may be required.

  

"Project Bantam" - Missing Parts arrive

A big Thank You shout out to Mr. Daryel Shaffer who supplied the missing parts for "Project Bantam".  It would have been difficult without having a few reproduction parts available.

The brief status update is that the electrolysis tank is still cooking away.  I've got the seat and spring in the tank now.  The rear wheels just came out and got a coat of primer.

Project "Bantam" - easy rust removal through chemistry and electricity

I was going to media blast the rust off, but I recalled an electrolysis process which might work well.  Since I just lent out my media blaster, I figured this was an easy enough thing to try on a sunny afternoon.  I rigged up a variable power supply with ground fault protection, and overcurrent / short circuit protection.  Its not fancy but it works.  The autotransformer (variac) feeds an isolation transformer which has a huge 24vac secondary.  I put a 5 amp breaker in series with the variac output to protect it.  The limiting factor is the rectifier which is protected by a 10 amp fuse.  I also put a ammeter in series to watch the action and adjust the variac as needed.

I got a plastic tub, which I estimate to hold 12 gallons, and filled it with the appropriate mixture of water and soda ash (sodium carbonate).  The grocery store had a nice box of Arm&Hammer Washing Soda in the detergent isle.  I applied power, and watched for smoke!  It was eventful enough to get some nice bubbles form on the electrodes as the variac was dialed up to 3 amps DC current drain from the tank.  Now I just watch and wait while chemistry takes the labor out of rust removal.

Process Started 

Witches brew of ions and oxides

Unfortunately, its going to be too hard to get the whole tractor frame in a tank big enough.

The results were rather good.  The old paint and rust just came right off after about 24 hours of electrolysis.  The anodes needed scraped clean every so often as the current dropped off due to the increased resistance.  After removing the grill from the tank, the smallest pits of the original casting were free from rust.  I was pleasantly surprised.  The wire brush took care of the rest of the residue with a minimal amount of scrubbing.  The resulting "black rust" magnetite conversion scrubs right off.  I shot the grill with a quick coat of primer to avoid any more red iron oxide rust.  The whole surface will need to be glazed and sanded with a fine grit to eliminate the appearance of any pits once the top coat is applied.

Project "Bantam" - a protective layer of filth

With every oily rag machine there is some aspect of "filthy protective layers".  This is where one layer of filth is covered by a subsequent one and preserves the original paint where no rust forms.  I took the frame out and power-washed it this morning to discover original paint peeking out under where the engine mounts, and inside the transmission tunnel.

Also the worst of the rusty spots were uncovered.  These will require cutting, patching, and welding.

The transmission and diff were so covered in filth that the power washer didn't even touch it.  I got out the high strength (non water based) parts cleaning solution and scrubbed the affected areas.  I'll have to let it sit, and come back and do it again.

A concerning issue is that the input shaft diameter has been affected by a locked up pulley bearing.  I'll have to figure out how to deal with that.  The U-joint seems to be awfully dry, but still operational.  The zerk fitting is rusted beyond all hope.  Not quite enough protective filthy layer there.

The serial number plate is fairly well preserved.  The model number and serial can still be read.  There was some corrosion behind the plate.  I ground off the rivets from the back and punched them through.  The plate came off without any problem.  I did the same with the Poyter dog plate.  Its not quite so good condition.  Its faded, and has got some Rustoleum primer on it from +20 years ago.

Finley was out helping a little bit this morning.  He quickly tired of the tedious operation of scrubbing off the filth.  He insists that the tractor be painted red, instead of the original orange.  The decision is yet to be made.

Next operation will be to continue to scrub the filth off before administering the sand blasting.