- Joined
- Jan 22, 2012
- Messages
- 655
Rio,
This is the same vibration I am seeing. I have run many many tests trying to isolate the source of the vibration, it is in the motor/pulley or input shaft. Some of this is in my other thread http://www.hobby-machinist.com/threads/question-on-aligning-the-lathe-spindle-and-bed-twist.41864/ . As rotating mass is removed the magnitude of the felt vibration goes down but the vibration is still present. The motor by itself runs smooth, either with or without the motor pulley. It is not normal, my Chinese Enco 12x36 lathe does not have a felt vibration at any speed. This is with either the 3 jaw or 4 jaw chuck. It is still running the belts that came from the factory 3 years ago. It is a single phase 2hp motor running a dual belt setup.
Matt,
The upper pulley is as cast, the only machined surface is the bore and keyway. I am pretty sure it is die cast as runout is pretty good, max I measured was .004" and that was on the surface the belt runs on. I haven't tried truing the pulley as I have to machine a mandrel first to keep it concentric with the bore and my other lathe is down. I was focused on improving the stand rather than bolting to the floor , seeing that bolting might not fix the issue I could go back to working on the pulley.
Mark,
You made a comment about the cup of water in the video being on the headstock and maybe not feeling it on the carriage. Other than doing the break in procedure, the first time I ran the lathe was to machine the test bar as part of the headstock alignment and that's when I first felt the vibration. I had my hands resting on the carriage cranks and felt the shake. That led me to looking closer and seeing that it was worse on the headstock. I have run my other lathe enough that I immediately the difference. The carriage has less felt vibration than the headstock but it is very noticeable non the less as you are feeling it through your hands. It is hard to show something like this on a video thus the cup of liquid.
This is the same vibration I am seeing. I have run many many tests trying to isolate the source of the vibration, it is in the motor/pulley or input shaft. Some of this is in my other thread http://www.hobby-machinist.com/threads/question-on-aligning-the-lathe-spindle-and-bed-twist.41864/ . As rotating mass is removed the magnitude of the felt vibration goes down but the vibration is still present. The motor by itself runs smooth, either with or without the motor pulley. It is not normal, my Chinese Enco 12x36 lathe does not have a felt vibration at any speed. This is with either the 3 jaw or 4 jaw chuck. It is still running the belts that came from the factory 3 years ago. It is a single phase 2hp motor running a dual belt setup.
Matt,
The upper pulley is as cast, the only machined surface is the bore and keyway. I am pretty sure it is die cast as runout is pretty good, max I measured was .004" and that was on the surface the belt runs on. I haven't tried truing the pulley as I have to machine a mandrel first to keep it concentric with the bore and my other lathe is down. I was focused on improving the stand rather than bolting to the floor , seeing that bolting might not fix the issue I could go back to working on the pulley.
Mark,
You made a comment about the cup of water in the video being on the headstock and maybe not feeling it on the carriage. Other than doing the break in procedure, the first time I ran the lathe was to machine the test bar as part of the headstock alignment and that's when I first felt the vibration. I had my hands resting on the carriage cranks and felt the shake. That led me to looking closer and seeing that it was worse on the headstock. I have run my other lathe enough that I immediately the difference. The carriage has less felt vibration than the headstock but it is very noticeable non the less as you are feeling it through your hands. It is hard to show something like this on a video thus the cup of liquid.