Troubleshooting Colchester Master

[jgimp69]

So I recently got a Colchester Master running. I found that when the lathe is on (motor and pump running, chuck not engaged), the chuck spins until I hit the brakes a few times. The chuck also continues to spin when I hit the carriage lever to neutral after some cuts. One would assume the clutches need to be adjusted as this would indicate that they are set to "tight", but, when doing heavy cuts it bogs down and looses power which I always found to be because they need to be brought in. The sypmtons seem to be contradicting eachother. Before I go "a rippin and a tearin" into this, taking the lid off, and the mechanism apart, has anyone come across this?

 

[TorontoBuilder]

My brother has owned his master 2500 for about a year and never encountered such an issue.

You should post this question to the colchester group because the user base is larger and well informed on the many colchester specific issues

main groups.io Group

This group is mainly for owners of Colchester Lathes, although owners and users of other makes of lathe are of course also very welcome. The Colchester Lathe Company was first established in 1887, with the first geared head machines produced in 1907. Colchester’s production hey-days were from...

colchesterlathe.groups.io

 

[RobinHood]

From your description, you probably need to adjust both the clutches & the brake.

Most of the time, the clutches are run too tight. The manual gives specific “spool-up” times for a chuck when the clutches are engaged. Follow that time precisely; do not make them tighter as the clutches will heat up really fast / overheat when idling thus causing the dragging you see.

The brake needs to be set correctly as well. If it is too loose, the spindle will keep rotating. Also, the brake needs to release immediately upon clutch engagement.

Some Masters have all mechanical brakes activated by a lever & rod / brake pedal, mine has the electro-mechanical one connected to the clutch lever.

Always set your clutches first. Disconnect the brake during that process. Let the chuck coast to a stop. Only once you have the accel times (in both directions) set correctly, set up the brake.

There is a very fine balance in getting this right. Don’t expect to get it right the first time. Once set though, you can run your lathe practically forever without any hassles. Yesterday I did two 3.5h shifts on it, nothing overheated or started grabbing. It reaches operating temp of about 45* C and stays there. Did some heavy cuts too in 4140: 100 thou DoC, 1030 rpm, 6-8 thou / rev feed.

I would still pull the cover to check the lubrication. Remove the two V-belts from the motor but leave the little pump belt. Now you can start the lathe safely and check how the lube system flows oil onto the clutches. In my machine (and I suspect all the other factory setups as well), the left side of the clutch got lots of oil flow while the right side got very little. So I modified the oil ports (tubes) with little delrin orifices to even out the flow. Now both sides of the clutch (fwd & rev) receive equal amounts of oil. This is very important, imho, especially when the clutches are open (free wheeling) because if one gets more lube than the other, the side with less will heat up, expand & start to drag. The oil carries any heat away.