It really takes balls of steel to attempt such a repair.

I worked my way through college in part as a repair technician at Unisys. I once witnessed a FedEx driver loading a shipment of workstation PCBs ($44k each in 1988) by throwing the flat boxes like Frisbees into the truck. When I reported the incident, mgmt was not amused. FedEx had to pay for re-testing and replacement. It cost FedEx several years' salary for that driver, and needless to say, he was no longer employed. We appreciate our delivery drivers, and while accidents do happen, respect and care are a must, and are very much a two-way street!

Beautifully done! I liked how you just took a moment to enjoy its motion after it was clear that it was actually working again! As you worked on it and described the fine details of its operation, I found myself thinking that - once upon a time - there was undoubtedly a workbench somewhere in the Kollsman factory, possibly in Brooklyn NY, or perhaps in California, and a man who worked every day at that workbench, who could have diagnosed the problem in a few seconds and (probably) repaired it in a few minutes. He would have had containers of tiny parts all around him, carefully organized, and would have known (from long experience) exactly which parts needed to be replaced and which only needed to be cleaned and adjusted. That bench, and that man, are probably long gone. Whoever he was, he had a family, and problems and triumphs of his own, and a background, a life story, and a long history of coming to work every day at his bench. After years of toil, he knew everything that it was possible to know about Kollsman altimiters. His knowledge was very valuable in its time, and kept him employed for many years. Blessed are those who work to decrease the entropy of the world.

Heh. An incredibly delicate device, yet built robustly enough to survive in an aircraft while getting the snot knocked out of it in turbulence, microbursts, on landing or takeoff. But one trip on a FedEx truck kills it dead. Fortunately, not beyond repair, but still... Good ol' FedEx. What would we do without you. Lol.

All the pivots in a Kollsman Altimeter are hardened steel shafts. Looks like someone dropped this altimeter and the force broke the pivot off at the tip of the pivot screw. On the sector shaft there is a glass jewel that the pivot goes into. Adding a ball to be the pivot may work but dont expect it to work for long. Also, be carefull changing pressure too quickly or you will damage the instrument. I spent 20 years as an FAA Repairman for Aircraft Instruments and have repaired and calibrated a lot of Kollsman Altimeters.

Watching an altimeter unwind at that impossible rate - even on a bench - makes this pilot's sphincter clinch.

You will need an watchmakers lathe to work on that screw Marc. Another interesting video, thanks! It’s almost midnight here, so I always enjoy when your videos appear!

I absolutely love the look of those vintage aircraft instruments from inside and outside.

This is the perfect opportunity for a collaboration with KZfaqr Clickspring!

Wow! This takes me back lots and lots of decades ago when I worked for Kollsman Instruments testing these very instruments. My job specifically was testing and calibrating the "pressure discs" you talk about. It's been so long that I don't even recall what we called them. In fact, I'm kinda triggered right now by even looking at them because that's when some co-worker stole my girl. Worked out okay though, so I guess I'll watch the rest of the video. 😃😃😃

One of the things I admire about you is that you always maintain a positive altitude! :)

Yes! A lazy Sunday with CuriousMarc and Master Ken! And archaic mechanisms! ❤

I wouldn't mind owning one of these. I spent 9000 hours as a 747 flight engineer and this would make a great souvenir. I already own a cockpit clock. Mechanical altimeters often include a vibrator device which taps on the case at about 15Hz to make the pointer move smoothly. It might be there, possibly in the bezel, powered by the lighting system. That would make it more accurate.

FWIW: Regarding that sea-level pressure adjustment Marc mentions, made to an altimeter when on the ground, in the USA it is calibrated in inches of mercury {i.e., Imperial units}. Example: *_"29.92,"_* which is called 'standard day conditions'. In other parts of the world, millibars are used. I THINK *_"1014"_* is the standard day reference in metric units.

My son and I built a watch at home last year (from parts) and this truly reminded me of it! Nice work.

You can also make a test port using the good old fashioned method, using a glass manometer tube with a mercury fill, and using the good old fashioned u tube manometer as on the ones I used in the instrument trade.

The fiddly bits are no match for your micro engineering skills! Instruments like that are usually shipped in a triple padded container with shock sensors and hand carried with both hands until installed. At least that’s how we did it in the military. Great job and thank you for sharing.

I used to fix this kind of equipment professionally and Heli overhaul service for few years. Those Fancy calibrated units to use for testing its nothing else just a T junction for Atmospheric and Vacum lines that switched over on different pressures, to different barometer .You are good to go with a properly calibrated altimeter. just take into account deviation in between 0-100-300 and every 300m points. if its more than 30m +/- not good if remember correctly. Also You really need that screw to rest on that jewel otherwise deviations will be too great. just because there gears it amplifies everything.

Some of your more hotshot watchmakers can re-pivot a balance in a fraction of the time it takes to turn a new staff. Drill hole, insert carbon steel pin. The pivot screw is big enough that it may be a fairly simple operation to drill an 0.5mm hole in the end of the screw and install a pin in it.

Decades of machining skill really showing here. Marc only needs a couple of seconds to see something is up.

You should invest in a Sherline lathe. Makes working with stuff that size a joy, especially with a DRO. I can't count the number of unavailable parts I've repaired or made replacements for with mine. One of my Fluke meters is only still alive today because of it, after breaking the no longer available range switch shaft. Took about 30 minutes to measure up the old one, make a new one, and install it. I wasted at least twice that long trying to find the part for sale.

I see that the altimeter is labeled ‘CABIN ALTITUDE’. I believe that for the cabin pressurization system.

How great to see a situation where tapping on the instrument actually works 😊

I can remember being told that the VSI was an instrument that's not needed much so in the event of a blocked static port. you would break the VSI glass to let the cockpit air pressure supply the static system. never got to break one to find out if it worked. 🙂

Wow I bought one off ebay last month and had the same fault! I carefully filed a point on the screw and it works well! I used to own some Texas instruments bourdon tube pressure metres years ago! They are well worth a look out of interest!

Well done!! I thought it was a goner but you got it! 👏

I am massively working with avionics. And have seen many such cases when barometric device falls and ruby bearing or shaft brokes. Usually it in unreparable, sometimes possible with a donor

Well done..! A simple homemade Mercury manometer will give you a primary reference standard for pressure calibration. It will be as accurate and precise as your measurement of column height and temperature. Yes, be careful with Mercury. But, you know how to do that...

That's some very tiny things to work on and your hands are so steady... Wow! I've had the awesome delivery from FedEx as they hucked the package out of the truck onto my front porch... SCORE!!! As I'm sure he said as he gleefully drove off... But the dumb dumb probably didn't notice that I have 4, yes FOUR!!!, video cameras covering my front yard and porch from multiple angles?? Well, I caught the whole thing on video so I don't have to guess how the thing I ordered got broken... LOL.

Replacing a worn or broken pivot is a common watchmaker's job. They drill a hole in the shaft (in this case, your screw) and insert a short length of the correct diameter of polished music wire, secured with a tiny bit of Loctite. He or she would need the screw and also the jewel to determine the correct diameter of music wire. Of course, if you still have the old broken pivot, that could simply be measured.

You have amazing skills and endurance Marc. I think this is an awesome repair. In the mean time it is fantastic to see how the diagram I knew for a long time is translated to the real deal and you showed it perfectly up to the nitty gritty parts that matter. Thank you for another great video!

Great Job!!

I'll have to show this video to my flight students. It's the next best thing to taking one apart themselves!

Honestly, I would mark the case as not flight worthy. You never know where something might end up.

I have always wondered how an Altimeter works mechanically. very interesting innards, I imagine that if any adjustments / calibrations were needed when this was in service, they would be extremely Fiddly. thank you for posting 😃

NIce Job Marc!

Nice mechanics, sometimes there is a vibrator for smooth movements. (a automatic finger tapper)

I wish old GE "Selsyn" motors weren't so expensive on the surplus market. They're used a lot in heavy industry to transmit the position of valves or gates.

Amazing

The mechanism is surprisingly simple (although very delicate).

I came for the electronics but stayed for the clockworks.

Someone clearly didn't follow the shipping instructions that are printed on the side of the altimeter itself. Although you got it to work, more or less, I believe for longterm use it's better to get that pivot done correctly. Ball bearing joints are not really used in clock-like mechanisms, even today - it's very difficult to make a ball joint move accurately enough

If it is a pivot screw you may get a clock maker to repair or make one for you... Just a though.

Marc, maybe a watchmaker could source the parts for you. Another very excellent repair.

Hey I've got one of those Geiger counters. Very cool.

Really nice job, with all the required perseverance and even taping on it at the end. The downside is that you made the FedEx gods very angry....

Well more like 'Ace Watch Repair' than vintage electronics but nice example of a true analog instrument. My first guess was a broken pivot so I guess I did learn something from all those hours hanging out with my dad in the hanger where he keep his Cessna. Especially when he scolded me about touching the altimeter because I will break the pivot

Cool. I was wondering how you were going to deal with providing test inputs for air pressure, etc.

This guy is the Michelangelo of the screwdriver

FedEx: Dislodging pivots and botching instruments since I don't know when. Nice fix of a lovely instrument. Those teeny tiny balls... and flying high on a vacuum pump, haha!

amazing

You adjusted the Kollsman window to the correct local pressure but you should have also pre-positioned the hands to the of the elevation of your workshop. If you shop is at exact sea level then you're okay. But other than that it's not going to show the correct elevation altitude.

Marc's tiny balls of steel saved the day. 👍

Good enough for me too

Good to see you using a geiger on those instruments. Better safe than sorry.

Your emco lathe is stamping its feet in the corner....turn a new pivot 0:11 screw out of silver steel....harden and lap the tip...great content..

I will never tire of listening to a French person saying the word "Pitot"

Wow it was expecting electronics and it is an aneroid pressure sensor. Coolest yet.

My dad fixed an Altimeter which was the atmospheric pressure type. He had to fab up a staff on his lathe. He was a very experienced watchmaker but had wanted to work on instruments in the Navy. However there were no positions at that time, and he went to mechanic school. Later watchmaker's school in late 40's. So this was a taste of what he wanted to do.

Russian Post uses similar legendary extra careful methods to deliver things :D

I have the baby sister of that geiger counter the gmc500+ which I moded with an lnd712 tube so it can get alpha beta and gamma works great

👍

That's an amazing rate of climb! Your workshop must be on Starship! 😅

I still don’t get how the linear movement of the aneroid plates expanding gets converted into the rotation though?

I have a broken altimeter with the same exact problem identified at @11:00.

That thumbnail caption = Bob the Builder vibes.

I have an electric artificial horizon off a jet fighter. It works but it drifts. If you want to have a go, ill send it over.

Nice to use a manual shaker...

I have a gyro from a Huey Helicopter that needs some love

Solder... maybe silver solder is more than sufficient to retain your the ball on the end of the screw for your application.

yeah got to watch out for the ones that use radium paint for their dial faces! I have one in my garage. Fun to show people with the old geiger counter. I don't keep them inside even if it's far away. Radium decomposes into radon gas. Typically the radium has burned the paint so badly that it appears very yellow/brown in color and no longer glows on it's own. Sometimes you can make it glow a little if you shine some UV light on it. If it were radium, it would trigger your counter through the glass, and without the glass it's about like having a chest X-ray every hour of direct and close exposure.

Because of course one of you would have a Geiger counter at hand!

Now you just need to put it and the other altimeter in parallel and see if they even slightly agree. 🙂

Pretty sure that cavity in the broken screw isn’t going to be perfectly concentric not surprised it’s not running smoothly.

How do they make those tiny steel balls???

The broken instrument with the TWA property tag on it appears to be a Cabin Differential Pressure Gauge, possibly intended for monitoring the effective elevation above ground pressure equivalent inside an aircraft. Commercial passenger aircraft are typically pressurized to about 6,000 feet in the cabin. I’m not sure such a gauge is intended to indicate all the up to the ~30,000 feet it received on the post-repair trial.

*_"...and the legendary extra careful_** FedEx **_handling..."_* 🤭🤭🤭🤭🤭🤭🤭

Wow...to do that damage someone hit it with a baseball bat or dropped it from a roof. Very surprised the glass wasn't shattered. Someone at FedEx doesn't like altimeters ;)

29.92 inHg is normal Pressure

You may try to put a minuscule drop of cyanoacrylate in between the screw and the ball before tighten it? would it works?

Thats exactly how Fedex would deliver my packages. Drive up the driveway, throw them out the window onto the gravel driveway, and leave. They did that with a new laptop computer one time. It sat in the pouring rain for 4 or 5 hours before I got home. Fedex drivers were too fkng lazy to walk 30 feet to my covered front porch.

Mine has radium in it… comes from a C-119 flying boxcar and no I have no fear from it - been around radiation elements all my life.

Couldn’t you have drilled a little dimple into the “set screw” to cradle the ball better?

I'm sure any watchmaker can repair it with no problems.

probably not good to spin it so fast with the vaccuum application, maybe put a restriction in the vac line

Starting at about 15:20 in this video: Marc _getting high_ for YT views...😉

I went to look for parts one and two and cannot find anything with a similar title…

That pivot screw could probably be duplicated by a watch maker or watch repair person. Who knows.

I would not put my ball in there.😂

Sounded to me like the aneroid popped during the first vacuum pump run - I test altimeter with hand pump only so it was fun watching it done by machine

I thought the shtick from Jim Carrey posing as the delivery guy in Pet Detective was hilarious, and likely over the top, of course. But maybe not.

... that is a concerning rate of climb...

I guess that amount of radium is not dangerous unless you eat it or inhale. smoke alarms emit radiation at much higher levels

You can work on it even if it's radium. Just don't scrape it, don't chew on it like the end of a pen and don't place it inside your glass of water for sudden vigor and vitality.

How would these precision mechanical instruments work in an old jet fighter, which might be subject to significant G loads?

No wonder so many planes have crashed through the years with fragile instruments like this altimeter to read altitude? One good bump and the whole thing is outta wack. I think I will stay off of aircraft and just stick to my trusty old pickup for travelling.

Or if the ball would be temperature stable enough to not change at altitude. Also the circular watch spring could also be a temperature compensation for mechanical growth or shrinkage of metallic pieces moving with the bellows or diaphragms (aneroid capsules).

I would not be surprised if this was a scrap item. Could be crash recovered or might have suffered a 'rapid vacuum loss event' during testing 😂. Thing is on a serious note some cheeky monkies 'fix' these things and sell them on as genuine parts. With forged paper work they can be worth many many times what you got it off Ebay for see 'The problem of bogus parts' by the UK CAA to get an idea of why repairs of a non approved standard are a nightmare for commercial aviation. Anyone minded to fiddle with units that can still be found in operating aircraft please please make sure you never let it loose back into the wild!!! You may be acting on good intentions but the people who say may take it off your hands maybe are not so honourable.

The bearing was not in the enclosure?

A cabin altitude gauge with a 50,000 foot needle? What in the heck? I guess if it was from a *really* high performance test plane intended to go above 100k it would sort of make sense......Airliners (which is what I'm familiar with) tend to not have cabin altitudes above 10,000 - most of the ones I know, alarms will start going off at 10k, and once you hit 14,000 is when the oxygen masks automatically drop.