View Full Version : Accupro ball bearing drill chuck

05-03-2009, 12:31 PM
As mentioned on another thread, my Golden Goose ball bearing drill chuck was recently damaged when a reamer it was turning shattered and seized. The chuck jaws appear to be slightly scuffed. New jaws would probably make it good as new, but parts don't seem to be available.

In fact, the Golden Goose chucks, which were once sold as Enco's house brand, and also sold on ebay by 800Watt, no longer seem to be readily available in the U.S. It's a shame, because they are excellent chucks.

So..... I ordered another Enco "house brand" ball bearing chuck, which nowdays is an "Accupro" brand made in Spain. The finish on the Accupro jaws appeared a little rough compared to the Golden Goose.

I tested the R8-to-JT3 spindle for runout. I believe this is an import spindle that I purchased from Enco years ago. Runout at the JT3 spindle was 0.0005".

Then the Accupro chuck was tested for runout, using a piece of ground HSS. Runout about 3/8" from the chuck was 0.0015". That's acceptable, but nothing to crow about (I had hoped that I would be able to gloat about how my cheap import chuck was better than Neil's expensive German chuck).

The crash-damaged Golden Goose now has 0.0045" runout. When it was brand new, it had 0.001" runout.

I have another Golden Goose ball bearing chuck on my drill press. It's been in service for several years. When it was new, it had 0.001" runout, but today it had 0.003" runout. It has not been abused, but it has slipped on the spindle several times, so it is possible that the spindle needs to be cleaned up.

In conclusion, the Spanish Accupro is a decent chuck, though I would rather have a new Taiwanese Golden Goose.

It appears that even quality chucks will develop some runout over time. Once the jaws have been scuffed even a little, the gilt-edge accuracy is lost.