Est. 1998 — 27 years of woodworking knowledge
crank it up
GaryG in MD
When I was a teen, in the 50s, my Dad had a 1922 Model T pickup.
He let me drive it, but he wouldn't let me crank it.
He said it could break my arm. He was probably right.
So now I have a Jet 1236 with a bad starter cap, and I have to hand crank it until the replacement comes. That brought back my memory of the Model T.
BTW, without a starter cap, the Jet 1236 will run backwards! Here's my chance! ;-)
Re: crank it up
John K Jordan BTW, without a starter cap, the Jet 1236 will run backwards! Here's my chance! ;-)
>>>So now I have a Jet 1236 with a bad starter cap, and I have to hand crank it until the replacement comes. That brought back my memory of the Model T.
I noticed exactly the same things when the capacitor quit on my Rikon bandsaw and on my Jet mini lathe. We used the lathe in a class until I could bring my spare the next day.
The reverse made me think of a mini lathe enhancement: wire a switch to take the capacitor out of the circuit when I want to turn in reverse, say for sanding.
JKJ
Re: crank it up
AZ in Colorado Springs
When the capacitor failed in my table saw I was able to give the blade a push with my hand and the motor would start. I did that exactly twice and decided not to play the odds anymore.
Re: crank it up
John Stegall
We did the same thing with a Ford tractor at school. The instructor always warned us to pull up from the bottom because if it kicked back it would jerk it out of your hand. One kid didn’t listen and had a broken arm to prove it. My BIL got hit in the jaw with his tractor but no broken bones or teeth.
you could do that...
GaryG in MD
...but you'd have to hand crank it every time.
Trust me, it gets old quickly.
Yikes!!!
GaryG in MD
No, no, no!!
Not with a saw!
The 1236, on it's slowest speed (around 500 rpm) gets a very slow and safe start.
It kind of grudgingly lurches into rotation.
Otherwise I wouldn't be doing it.
My Dad was right, as always...
GaryG in MD
He came up through the service ranks starting as an IHC truck mechanic, and he really knew his stuff. Later, he taught it.
He welded a drum onto one wheel of the Model T. He jacked up the back end and used a hawser wrapped around it to pull his boat out of the water! Perhaps not wise, but he made it work. My Mom's clothes lines in the back yard were driveshafts set in concrete, with welded braces T'd across the top. Now we have covenants and 3-D printers. I think I prefer the former.
Gary . . . $10 bet . . .
Doc Green
Gary, I've got a shiny $10 bill that says you can't explain in fundamental terms why it is that a simple single-phase induction motor will run if you give it an initial push. 
(No shaded poles, start windings, and stuff like that allowed.)
Aside: Recently I have had two inquiries relating to a PM 3520 that behaved that way - would not start unless you spun it, and it would then run in either direction. In both cases, the problem was the loss of one leg of the three-phase circuit going to the motor. 3-phase minus 1-phase = 1-phase. (new math)
~Doc
Hi Doc,
GaryG in MD
You get to keep your green.
When I got to Northwestern for my Frosh year, I had the opportunity to take "Motors and Generators" or "Circuits". Since I had already been a ham radio operator for 5 years, I think you can guess which I took. Of course, it was vacuum tubes, but, hey...
As a consequence, motors are just big heavy spinny things to me, and they usually work right.
When they don't, I go into a learning mode, as I have now.
I had to learn what a centrifugal switch is!
And I'm happy to have done it.
But phasers? Isn't that Star Trek? ;-)
I'll put my money on the cap. In fact, I already have! Hopefully it will be here in a few days.
Cheers, Gary
Re: Hi Doc,
Doc Green
Gary, I'm a bit disappointed because I was hoping you could explain it to me. I tried to figure it out years ago, but gave up. Have not been able to find an explanation in any textbook - came close once with an old dusty volume in a library, but they stopped short. Neither has Google been any help.
I, too, cut my teeth on vacuum tubes and still find a certain charm about them. Then transistors came on the scene, followed by integrated circuits. Nowadays, when you want to build something, you buy a small computer (microcontroller) and teach it to do what you want. What's the fun in that?
~Doc
electronics
John K Jordan
>>>Nowadays, when you want to build something, you buy a small computer (microcontroller) and teach it to do what you want. What's the fun in that?
Actually, there's a lot of fun in that! (Arduino is great) But you can't teach it to be a sensor or components needed to interface with something it can drive directly! (still need to know the electronics)
JKJ
Re: electronics
mikeee12345
Not using any technical electrical terms an electrical motor works via the F.M. principal.
better start polishing that sawbuck
GaryG in MD
Doc,
I'm as old as dirt.
I have an EE friend whose older than dirt, and he took the M&G course!
He's the kind of guy that spent days studying a photo of an old power station interior that I sent him and figuring out exactly what each piece did.
I have posed your question to him, and I expect an answer that will satisfy you.
Stay tuned.
...GG
Re: better start polishing that sawbuck
Bill Boehme
For a sawbuck I will answer your question and you can pay yourself the five you saved so we will both be five bucks ahead. 
How's that for math?
Re: better start polishing that sawbuck
Bill Boehme
I just noticed that the "official" definition of a sawbuck is a $10 bill. Texas farmers were so poor that most had never seen a $10 bill so they had to substitute a $5 bill as a poor man's sawbuck.