Another Drill Press Repair Question

[Will Leavitt]

I've got a Dayton 12" bench top drill press Model 3z993b. The chuck is horribly crooked on it (guess that's why I got it free ) How in the world do I repair it? Everything else looks straight except the chuck which you can hand turn to see it's off.

I did do a search and after 15 pages I gave up.

 

[Jack O'Neill]

is it a tapered chuck? Mounts with a tapered shaft . Take it off and check its mounting . Could be a worn bearing the chuck mounts up thru .

 

[scottickes]

Three possibilities come to mind right away.

1. A damaged bearing. This requires tear down and replacement of the bearing and possibly repair of the shaft and housing.
2. A damaged shaft or housing (such as a bent shaft, etc.). Requires tear down and repair or replacement of the bearings, shaft or housing.
3. Incorrect bearing precision. Many times, a machine is repaired with a bearing that has the correct basic part number, but not the correct amount of precision. Some bearings are designed to run extremely true, with a minimum of total indicator runout. Other bearings do not run as accurately as far as runout, but then again that application might not require it. Drills and mills require that the total indicator runout of the bearing be quite accurate, or the hole being drilled or slot being machined will be too large and very much not uniform. The main reason that a person might repair or rebuild a machine with the less precise bearing is the cost of the proper bearing seems to be way too expensive for them. Then they find out that the same bearing part number is 1/10th the cost with a different number on the end. They have no idea what that number means, but the guy at the bearing distributor only gave them the expensive bearing option. Then they went to the auto parts store and found the "same" bearing at $5, instead of $50. Since they need two of them, they can spend $10 or $100. They opt to spend $10, as the front part of the part number is the same, so they purchase the less expensive bearings, and get a bearing that won't run true. They decide the bearing is crap and blame it on the bearing manufacturer or the auto parts store that they purchased it from, when in reality, they didn't realize they were cutting a cost savings corner that they shouldn't be cutting. A general rule of thumb is that for every step up in bearing precision, the costs is multiplied by a factor of 10, give or take. Sometimes only a factor of 5, but sometimes much more. Don't cut corners on bearings. Buy from a major bearing distributor and buy major brands. "You get what you pay for" is especially true with bearings.