Micro Drive is based on the focusing adjustment of an astronomical telescope. The "course" adjustment is the floor to floor run and the "fine" is the final stop even with the floor.
Simple science really. To get extremely accurate floor levels it helps to be running the machine on a very low gear ratio. This machine runs most of the way driving through the usual worm gear, then for levelling into the floor, a second worm gear is coupled to the back. The second little motor is driving through two worm gears I can’t remember the exact ratio, but it’s certainly extreme. That big round thing under a guard is the clutch that connects the two together for the final level. In 42 years as a lift engineer I’ve only ever seen a couple of them and they’re probably gone now.
What an amazing machine room with the large motor and the smaller motor to do the lift movements. This equipment is from the early 1900's. 1908-1915 period. Absolutely incredible equipment over one century old.
She's a little younger than that. She looks like 1920s machinery to my eye, 1930s at the absolute youngest - no younger than that though. Slate panels for the switchgear, with small(ish) contact assemblies- suggests 1920s to me. But I agree with you - the really smooth and curvaceous profiles on the castings, the svelteness of some of the cast sections and webs, screams "Great War" vintage or earlier. I'd bet she was designed around the 19-teens and was just continued in production much unchanged through the 20s. Probably Otis was running the same patterns in the foundry unchanged for a while.
On the machine tag, the latest legible patent date is 1922. So she's gotta be at least that young. I guess I'm going to have to go patent diving to see what the mechanics behind the large spinning clutch between the two motors is. I guess that's for the automatic floor-leveling system (I think that's what the "micro drive" moniker meant). Haven't seen that before.
There were two of these Otis Micro Drive machines in the building where my elevator company was located in down town Los Angeles. They were originally powered by 600 VDC fro the street car line that came into the basement of the building. In the 1950's they were powered by an AC/DC motor generator in the machine room. Where does the elevator in this video get it's power from?
While these motors are DC and having spotted a DC rectifier in one of the controllers likely a 3 phase circuit either fused or circuit breaker in the electrical panel room (primary disconnect) powers the rectifier board.
One big geared traction machine, 2 DC motors if this machine room was from one of the two earlier videos of the cabs with the 2:1 roping I noted the dead hitch plate and ropes. I noticed it has a DC rectifier on one of the controllers.
What you’re seeing is the smaller motor engaging to level the car with the floor. That large spinning thing is a device that is attached to the driveshaft of the smaller motor, and clamps down onto a drum connected to the driveshaft of the larger motor and drive sheave. When the larger motor stops, this device clamps onto the drum, and in turn connects the driveshaft of the smaller motor to that of the main drive sheave allowing it to turn. However when the main larger motor is running, this device unclamps from the drum allowing the main motor and driveshaft to rotate freely without the resistance of the smaller motor.
@@SPS8elevatorsoflakecounty Thank you very much! I was never in the trade but have always had a fascination with elevators. I've only made my way in to a few mechanical rooms over my career in commercial construction.
A tear came to my eye
Im a Retired Elevator Mechanic
I would love to know the science behind this one. Truly awesome!!!
Micro Drive is based on the focusing adjustment of an astronomical telescope. The "course" adjustment is the floor to floor run and the "fine" is the final stop even with the floor.
Simple science really. To get extremely accurate floor levels it helps to be running the machine on a very low gear ratio.
This machine runs most of the way driving through the usual worm gear, then for levelling into the floor, a second worm gear is coupled to the back. The second little motor is driving through two worm gears I can’t remember the exact ratio, but it’s certainly extreme. That big round thing under a guard is the clutch that connects the two together for the final level.
In 42 years as a lift engineer I’ve only ever seen a couple of them and they’re probably gone now.
What an amazing machine room with the large motor and the smaller motor to do the lift movements. This equipment is from the early 1900's. 1908-1915 period. Absolutely incredible equipment over one century old.
She's a little younger than that. She looks like 1920s machinery to my eye, 1930s at the absolute youngest - no younger than that though. Slate panels for the switchgear, with small(ish) contact assemblies- suggests 1920s to me.
But I agree with you - the really smooth and curvaceous profiles on the castings, the svelteness of some of the cast sections and webs, screams "Great War" vintage or earlier. I'd bet she was designed around the 19-teens and was just continued in production much unchanged through the 20s. Probably Otis was running the same patterns in the foundry unchanged for a while.
On the machine tag, the latest legible patent date is 1922. So she's gotta be at least that young.
I guess I'm going to have to go patent diving to see what the mechanics behind the large spinning clutch between the two motors is. I guess that's for the automatic floor-leveling system (I think that's what the "micro drive" moniker meant). Haven't seen that before.
What a beautiful testament to old school electro-mechanical engineering. A simple design makes for years of service!
BEST VINTAGE MACHINERY EVER!!
Gebaut für die Ewigkeit. Eine wunderbare Maschine.
Now that it PROPER vintage!! :)
There were two of these Otis Micro Drive machines in the building where my elevator company was located in down town Los Angeles. They were originally powered by 600 VDC fro the street car line that came into the basement of the building. In the 1950's they were powered by an AC/DC motor generator in the machine room. Where does the elevator in this video get it's power from?
I’m not completely sure, to be honest with you
While these motors are DC and having spotted a DC rectifier in one of the controllers likely a 3 phase circuit either fused or circuit breaker in the electrical panel room (primary disconnect) powers the rectifier board.
Love that streetcar & interurban 600 Volts!
Very fine piece of machinery!
Built to last
Absolutely incredible!!
I want to try to repair it hopefully...nothing is impossible i have a old otis elevator here in the philippines model 1969 otis also...
It’s like a combo elevator and CT scanner.
I still have you beat though. I’ve seen 3 in action at once 🤪🤪
Really awesome machine
One big geared traction machine, 2 DC motors if this machine room was from one of the two earlier videos of the cabs with the 2:1 roping I noted the dead hitch plate and ropes. I noticed it has a DC rectifier on one of the controllers.
Amazing machine
I think there's a pair of micros at The Speed Building, here.....rototrol position indicators too
Стоп, этому КВШ больше 100 лет, и канаты ровнинькие! А новые шкивы бывает за год згрызает
Whoa epic!
3:55 What is the function of the thing that spins after the motor shuts down?
What you’re seeing is the smaller motor engaging to level the car with the floor. That large spinning thing is a device that is attached to the driveshaft of the smaller motor, and clamps down onto a drum connected to the driveshaft of the larger motor and drive sheave. When the larger motor stops, this device clamps onto the drum, and in turn connects the driveshaft of the smaller motor to that of the main drive sheave allowing it to turn. However when the main larger motor is running, this device unclamps from the drum allowing the main motor and driveshaft to rotate freely without the resistance of the smaller motor.
@@SPS8elevatorsoflakecounty Thank you very much! I was never in the trade but have always had a fascination with elevators. I've only made my way in to a few mechanical rooms over my career in commercial construction.
YOOOOOOOOOOOOOOOOO
OH MY GOD
Made in USA or France?
USA
Foam
Стоп, этому КВШ больше 100 лет, и канаты ровнинькие! А новые шкивы бывает за год згрызает
Стоп, этому КВШ больше 100 лет, и канаты ровнинькие! А новые шкивы бывает за год згрызает