- Joined
- Jan 10, 2019
- Messages
- 1,220
I recently bought an old Webb/Takisawa lathe which weighs about 2500 lbs. I read up on it before it was moved, and the manual said it should be lifted by placinge rods through holes in the bed casting. Come time to move it, and I watched a very experienced heavy machinery mover put one sling under and behind the chuck, with maybe half of it ending up under the casting. Before he lifted it, I mentioned that the mfg said to use the rods, and he gave me a brief but clear glance that conveyed that I didn't know what I was talking about, and how he did it was harmless due to the lifting force being less than what the spindle bearing sees during normal operation.
It arrived safe and appears to be fine, but I still wonder, is he correct, or not? I can see that as-designed, the spindle bearing must resist the large upward force as the chuck tries to climb up over the cutting tool, so up to some amount of force, it's a non-issue. As said above, he didn't place the sling directly under the spindle, it was riding behind it, on both the head casting and the gap between the casting and chuck. I just don't have an idea of how much sideways force is put on the bearing when taking a deep cut—there are a lot of variables to guess at.
It arrived safe and appears to be fine, but I still wonder, is he correct, or not? I can see that as-designed, the spindle bearing must resist the large upward force as the chuck tries to climb up over the cutting tool, so up to some amount of force, it's a non-issue. As said above, he didn't place the sling directly under the spindle, it was riding behind it, on both the head casting and the gap between the casting and chuck. I just don't have an idea of how much sideways force is put on the bearing when taking a deep cut—there are a lot of variables to guess at.