Our high school has a '92 Enco 100-1588 10x54" mill. One of the students called me over, saying is was vibrating a lot. The head was quite warm. After pulling it apart, I found that the top motor pulley was cracked. Inside the cover was coated with belt dust.
The set screw was long gone. I've got a new pulley on the way. I later discovered that the motor shaft is a mess. Look like someone took an angle grinder to it!
The journal at the faceplate has about a thou runout. The low portion of the shaft, where the bottom pulley slides up and down, has about 4 thou runout. I haven't priced out a new motor yet. I'm sure its not cheap, assuming it available. I was surprised when MSC said they had the pulley.
Is the 4 thou runout too excessive?
The keyways are not the best either:
While I have the thing apart, I plan to replace all the bearings except for the spindle bearings. Both belts will be replaced as well.
The spline on the top of the "worm coupling shaft is pretty worn. Not sure it really need replacement though. We almost never use it in low speed.
This is the top shaft,
And the bottom:
Any comments, suggestions etc are greatly appreciated. I'm not a machinist, just a high school robotics mentor who doesn't know not to take stuff apart! My main worry right now is the motor shaft runout.
Oh, one last thing. where is a good source for replacement bearings? They are mostly 6xxxZ. I assume MSC is going to charge me a lot more for them. As you can guess, we don't have an unlimited budget!
Thanks for your help,
Andy
The set screw was long gone. I've got a new pulley on the way. I later discovered that the motor shaft is a mess. Look like someone took an angle grinder to it!
The journal at the faceplate has about a thou runout. The low portion of the shaft, where the bottom pulley slides up and down, has about 4 thou runout. I haven't priced out a new motor yet. I'm sure its not cheap, assuming it available. I was surprised when MSC said they had the pulley.
Is the 4 thou runout too excessive?
The keyways are not the best either:
While I have the thing apart, I plan to replace all the bearings except for the spindle bearings. Both belts will be replaced as well.
The spline on the top of the "worm coupling shaft is pretty worn. Not sure it really need replacement though. We almost never use it in low speed.
This is the top shaft,
And the bottom:
Any comments, suggestions etc are greatly appreciated. I'm not a machinist, just a high school robotics mentor who doesn't know not to take stuff apart! My main worry right now is the motor shaft runout.
Oh, one last thing. where is a good source for replacement bearings? They are mostly 6xxxZ. I assume MSC is going to charge me a lot more for them. As you can guess, we don't have an unlimited budget!
Thanks for your help,
Andy