Questions about a VFD for Lathe spindle drive

[sharpshooter90]

Hey- that could have been a picture of our spindle! I was taught to always use a press and never hammer on a spindle, but I must admit that at times I have " gone caveman" when I didn't have access to the proper tools. I see the top bearing and race seem to have come out complete- On our machine there was no notch cut into the quill to drive out the lower race. The guys in maintenance had that one figured out though- they just used a welder and welded a few places around the inner diameter of the race and it shrunk up enough to drop right out. Those heavy equipment guys do have some good tricks. Our machine had a saw cut in the back of the casting with 2 tabs and a lock handle, so when you tightened the handle the casting squeezed around the quill to lock it in place. This saw cut would get sand in it, so we just filled it with grease to seal it up. Around the quill, we found a piece of inner tube and used a tin can as a punch and cut a hole in it- then just used scissors to cut around the OD and made a primitive seal. We stretched it over the quill and siliconed it to the casting. It was kind of crude looking, but it kept everything out. I don't think you need a seal for normal work unless you are doing a lot of grinding on cast iron.

[digitalmdj]

First off a press is used when no other method can work. The delrin plastic protected the quill and did not damage anything. It alowed me to tap out the quill slowly and not drop it to the floor . That almost always happens in a press when things dont go right. As for the lower bearing race. I used a torch with a small tip and heated the outer race and as it cooled is it sliped right out. The inner race I heated it until I could tap it off without harming the spindle shaft. If you press off the inner race without heating it it can sometimes gouge the shaft and you will lose some of your bearing press. We always do this when we pull off bearings on our steam turbines. We cant afford to repair a rotor shaft from not being careful . A press can cause more damage than its worth. It is used when other options have failed.

[fastlanecafe]

Speaking of bearings, here is a story that's a bit off topic, but current to today's news. I had an uncle who was a big " buy American" person all his life. He always bought Buicks when most of our family rode in Fords or Chevys. It was always fun to visit my cousin and ride in his dad's car. During the first gas crisis in 73-74 when prices went from 35 cents up to 70 cents per gallon, my uncle got into a panic because it was costing him 15.00 to fill his tank. Like millions of other Americans he put his patriotism aside in favor of his wallet and began looking for economy cars. Japanese cars were out of the question for him, but other " furrin" makes made by white people were OK. He settled on a Fiat sedan that got about 40 MPG, compared to the 15 for his Buick. When he traded in the Buick, I think they paid him by the pound- practically nothing. Anyway, here is the bearing story- within 6 months, he had taken that Fiat back to the dealer so many times that he was spending more in gas going to and from the shop than he was using in the old Buick. They replaced every single wheel bearing on the car in that time, plus a bunch of other problems. The funniest of them were the window winders which were a sort of cable and pulley affair which would come off the tracks with a cartoonish " sproing" and the window would drop out of sight. He struggled along with that thing for 2 or 3 years, always puffing out his chest to everyone and bragging about his great gas mileage. Eventually people got used to the 70 cent gas prices and bigger cars began to come back. Just before he passed away he traded the Fiat in on a new Buick and of course the dealer gave him zip for the Fiat.

[digitalmdj]

Well I own a Jeep JK 4 door. It had to be reworked to make it off road worthy. I have always owned a Toyota. But I wanted a jeep this time. I am happy because everyone makes parts for it even though its new. Everthing is metric on it and so are most cars these days. My point is why is it so hard to find metric nuts and bolts locally. And metric tooling is like a foreign language to most tool places. Yes they have a few items but they are still pushing standard size tooling. Even at work everthing is going metric because we dont make anything in the US anymore. It seems they would get it together and standardize everthing like they tried thirty years ago but failed.

[fastlanecafe]

Not sure where you live, but every auto parts store and Home depot around me carry metric nuts and bolts. Bearings have been built to metric standards for years, of course they still make inch sizes for older products and will continue until there is no more demand. Also, gotta disagree with you on the press issue- I was taught to always use a press as well. A press gives a steady shock free pressure to remove and install parts. If needed you can use a torch in conjunction to aid the process, and of course always put your drop table under the part so it doesn't hit the floor. I cannot imagine you are planning to use a hammer to install your new bearings. It reminds me of that old urban legend of the guy who needed a push to get his car started. He asks a lady to push him and tells her that his car is automatic, so he needs to be going 35 mph before it will start. The lady then backs up and hits him going 35mph.

[smallblock]

Fastlane,
I remember that old story about the 35 mph push start along with the one about the cement truck driver who caught his wife with a guy in a cadillac convertible and filled it with concrete. I also have a true story along the lines of your Fiat/Buick uncle. A friend of mine dreamed for years of owning a new pickup. When he finally got to the point of being able to buy one, he went all out. He got a fully loaded 1 ton dually with crew cab, 4 wheel drive, air, power etc. Every option they could pile on it. I think the thing cost him about 40,000. That was 5 years ago, and he used to beam with pride when he drove around, that truck was his life's dream. In the past couple of years though it has all changed. With gas prices going to over 3.00 per gallon, it now costs him about 150.00 to fill all the tanks. Now he hates his truck- always saying how this POS costs him so much to drive etc. He seems to be blaming the truck for the high gas prices. I guess some of his attitude is natural, since the newness of owning the truck has long ago worn off, but its really strange how his life's dream and his pride and joy have become a constant source of anger over this one thing. I tried to tell him that its the same truck he dreamed of years ago, and now that its all paid for, the cost of the gas is really not that big of an issue, but he seems so focussed on his unhappiness that he doesn't listen.

[digitalmdj]

Well pictures tell the truth and I have alot of them and will post them as needed.

[smallblock]

To Gfull60,
You mentioned you got a good deal on your VFD drives- can you pass the info along? How did the whole thing work out? I'm having a ball with my new machine, but still thinking of going to a variable speed drive out of laziness.