I have a 20+ year old Delta 14″ w/ riser (purchased new). Recently decided on an overhaul. New tires, link belt, upgraded drive pulleys, re-aligned pulley co planarity, new thrust bearings, upper/lower wheel co-planer, etc. Orange tires were carefully stretched so I don’t think that is the problem. This is a home machine, not a production unit, so it’s not very “high mileage”. It has unfortunately, been left with the blade in tension on more than one occasion.
I was disappointed in its post overhaul performance, the machine still seem to vibrate excessively. On closer examination, the lower wheel seems to vibrate (wobble). The same condition exists with or w/o a blade mounted. Measured the following:
Upper Wheel runout .008
Lower Wheel runout .019
Checked the lower wheel (off the saw) and it is out of plane by about .020
Also checked the play in the bottom bearings, at the wheel side: .008-.009
Lower axle measures OK, and is not bent.
My concern is both the lower wheel planarity (or lack of) and the play in the bottom sealed ball bearings seem on the high side. I understand the bearings are an inexpensive but time consuming replacement, the wheel however is $$$. I am sure the vibration is in the lower wheel assembly. What is normal for a bandsaw of this size/ price/quality? Do I need new bearings, a new wheel or do I just live with it?
Barry
Replies
Vibration can come from a number of sources, such as spinning parts being out of balance. Another possibility is that parts can be bent, worn, or poorly machined, making them wobble as they turn.
A final possibility is that the sum total of the various moving wheels, blades, and belts, which are all OK by themselves, can still set up harmonics that can make the whole machine vibrate. This third category is fairly common on band saws in general and in my experience a bit more common on the Delta saws of your machine's vintage, I don't know why.
Sometimes the only way to find the source vibration in a machine is to very methodically check out the individual parts and then the various groupings of parts moving under power. My advice would be to live with the vibration since it rarely affects the quality of the cut. If you want, I can take you through the steps I would take to track down the vibration, but it will take some time and may not, in the end, solve the problem.
Let me know what you want to do, if you do want to try to find the vibration I can take you through the process a few steps at a time.
John
John,
Thank you for the reply. I have already checked the most obvious sources of vibration, running w/o the blade, checked motor, belt tension, replaced OE zinc pulleys, link belt etc. What's involved in the removal and replacement of the lower wheel bearings?
.008 seems like a lot of play to me. While not high milage, I am guessing that high tension and the "warped" lower wheel (although, maybe .019 is still in spec for this class of saw) could lead to early bearing failure.
Barry
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