Vernier Scale

My buddy Brian taught me to read vernier calipers today. The vernier scale was originally developed by Pierre Vernier in 1631 to allow precise angular measurement for navigation and astronomy. You read the main scale for inches, tenths and ten thousands, and then the vernier scale for thousands. The trick in reading the vernier scale is to see where the tic on the vernier scale most closely aligns with the tic on the main scale – which can be as much as art as a science. Especially is you don’t use a magnifying glass or take a photo with your phone and zoom in.

So there is a bit of a learning curve, but worth figuring out because vernier calipers do not need batteries and you can get a nice set from the age of precision engineering for $25 on ebay. The calipers I bought pre-dated the reunification of Germany in 1990 and were manufactured in West Germany.

Side Quests

I spent the last 5 days crewing and pacing for Trey and Tim at the Mountain Lakes 100 in Mt Hood National Forest, Oregon. The race itself was much harder than anticipated due to long exposed distances through areas that had recently burned. Approximately half the field DNF’d, which carried through to our team with Tim finishing in 26 hours and Trey tapping at mile 40. The most fun/rewarding part of the trip was helping out a stranded runner (Joel) whose minivan had fallen off the jack sans front right wheel while he was trying to change the tire after DNFing at mile 55. Luckily for him we had a low profile floor jack, cinder blocks, a shovel and impact wrench in the back of the truck. Its remarkable in life how we spend so much attention on the main event – the run – when all the magic happens on the side quests.

Scope

I picked up a cheap endoscope on Amazon and used it to delve into the Honda CB 500’s gas tank. The scope worked great, however, unfortunately it revealed remnant lining hidden on the top of the tank. I guess I did not let it soak upside down in the acetone for long enough. I plan to let it sit for a week this time. Hopefully that will get the job done. Otherwise we will need to look at building a scrubber robot to drop into the tank. Maybe some sort of Dremel drone.

A Little Help

Darrow helped me dump out the evaporust, rinse the tank with water and 91% isopropyl alcohol, then coat it with a layer of Marvel Mystery Oil to keep it from re-rusting. We then removed the old petcock and finished cleaning out the petcock holes with a Q-tip. A little more finishing sanding and we should be ready for the clear coat.

New Carbs

New carbs for the 1972 CB500 arrived today. Given the notorious difficulty of properly jetting and turning factory carbs to aftermarket air pods (as opposed to the factory airbox), I opted to purchase new carbs from Murray’s, a family owned business in North Carolina. Now I need to finish the gas tank so I can put everything together.

Evaporust

After completing my side quest to refurbish the typewriter I am back to working on the motorcycle. In re-examining the gas tank I noticed that there were remnants of the polymer lining around the fill hole. So I made the trip to Blick, had an interesting conversation with the clerk regarding pinstriping paint brushes and returned with a bottle of acetone. I put it in the tank with a length of chain and a hand full of bolts and let it soak for 2 days while shaking and rotating. Today I drained the acetone, rinsed it out with the hose and then filled it back up with evaporust.

The plan is to let it soak for the next couple of weeks while I replace the throttle, right control, throttle cable and carburetors.

While the evaporust started to do its job, I wet sanded the damaged clear coat and started to prep it for either a new clear coat or a ceramic coat. Need to do a little more research to determine the best alternative.

The Quick Brown Fox

“The quick brown fox jumps over the lazy dog” is a pangram which uses all 26 letters of the English alphabet and is commonly employed to test the functionality of keyboards.  While everything is still lowercase because the shift key has unresolved gremlins, just getting to this point is a big milestone that reflects 3 weeks of learning and grit. And hey – who needs uppercase in the era of all lowercase  text messaging. Unless, that is, you need to SCREAM. Which here I do, in frustration…

UGGHHHH After fixing the escapement and mainspring  I thought the hard work was over.  I ordered a set of new ribbons from Amazon and upon receipt and unpackaging was ready to start typing. This was not to be the case. My dreams of easy typing were dashed on the boulders first of LC Smith’s proprietary metal ribbon spools and second on a frozen ribbon spool shaft gear on the right side.

Not to be deterred, I rewrapped the new ribbon on the old metal spools (a process called respooling – latex gloves highly recommended) then applied a liberal amount of penetrating oil on the seized spool and worked it free with needle nose pliers.

Now all I need to do is fix the shift key, but that is going to have to wait until I can examine a similar functional typewriter to diagnose why mine is malfunctioning. That brings us to the conclusion of this side quest for now and a return to working on the restoration of the 1972 CB500.

Its Alive!

After 2 weeks of deep cleaning with mineral spirits, PB Blaster, Deep Creep and Evaporust things are starting to come together. I realized that the ribbon lifter was not working after I put the body panels back on and suddenly understood why hot rods often do not have hoods or side panels – so you can get to the engine easier. Then I figured out that the ribbon selector was on “stencil”, which disables the ribbon lifter – easy solve, and everything is functioning as it should. More to follow once I get a ribbon to test it out. After that, I am thinking a hot rod paint job and pulling some of the panels.

Meetup

The Atlanta Typewriter Club meetup today was a great time. Jeffrey and Tom helped me tighten the mainspring to create more lateral force along the draw band and keep the carriage moving so the escapement would not get tangled up with the tripping dog gear. It became apparent to me that I had not been turning the mainspring hard enough because I was afraid to break it, and it really needed to be cranked after years of sitting. Tom told us stories of his time with Bell Labs working on guidance systems for the Titan I missile. Weaponized math!! I think geometry books would probably be more interesting if they focused on ballistics.

Escapement (1940 Super Speed)

The typewriter was completely frozen when we took it home from the antique store. I removed the body panels (10 screws) and used an air compressor to blow out the dust, which revealed a non-trivial amount of rust. I was tempted to just dunk the entire thing in a vat of evaporust but before doing that I emailed Tom Rehkopf (aka “Typewriter Tom”) who told me that dunking is a “last resort”. He was kind enough to invite me to an Atlanta Typewriter Club meetup this Saturday where he would take a look.

In the meantime, I washed the body panels with simple green and flushed the internals with mineral spirits (not to be confused with mineral oil – I learned that the hard way). In doing so, I figured out that the margin lock key was misaligned in the wrong slot, and when i re-slotted it and pressed it the bell rang like a choir of angels. When I then tested the keys, the carriage moved – although intermittently. Progress.

After reading the War Department’s manual on typewriter maintenance I decided to adjust the space bar trigger point and tighten the mainspring. The spacebar adjustment helped a little but I was unable to get the mainspring to turn. I determined that the loose dog (aka the tripping dog) is catching on the escapement (star) wheel, and this binding is resulting in the intermittent carriage movement. I am going to flush with more mineral spirits then apply more lubricant. More to follow.