Shawn_Laughlin
Aluminum
- Joined
- Mar 28, 2019
I’ve read through a lot of different threads on here and other machinist forums and I haven’t seen anything that would answer my question. I don’t want to talk about what machine I have I just want to learn a little about bearing preload and ask a few different questions on this site bc I imagine some the best machinist you can find are right here. My machine which was bought new about a month ago has not produced an acceptable finish one time.No matter how fast or how slow,hss or carbide inserts it doesn’t matter. I’ve used every combo of feed and speed as I think possible and nothing helps. It vibrates and shakes even thoug it’s firmly bolted to concrete.
Well with a shaft that is hanging off the 3 jaw or 4 haw I can lift and get .001 .0015 movement at the chuck and spindle .Is this normal? If I check runout on the flange of the spindle it’s around .0002 to about .0004
It runs very smooth with the chucks removed and had read that it was probably bearing preload so I tightened it a little, took a couple cuts and it really made a difference in she finish and the noise but still unsatisfactory results,with pretty much a spiral groove down the length. And now it Sounds like it’s running a little bound up.
Another thing that I’m not sure about is the carriage rack and pinion. The track looks to be mounted a little high which looks to be causing excess backlash between it and the gear. I’m not sure if this would make a huge difference or not?
Something is up bc I’ve seen beautiful mirror finishes made without a grinder or sandpaper ever touching the material with this same model.
If I have a piece between chuck and live center and turn it down and then take my test indicator and Rotate the part has a runout of .001 at the end of shaft near live center.. That seems piss poor to me and I’m getting sick to my stomach knowing I didn’t have the money to just throw away on a big anchor.
Does anyone think adding extra support to the existing stand would be a good idea? Thanks
Well with a shaft that is hanging off the 3 jaw or 4 haw I can lift and get .001 .0015 movement at the chuck and spindle .Is this normal? If I check runout on the flange of the spindle it’s around .0002 to about .0004
It runs very smooth with the chucks removed and had read that it was probably bearing preload so I tightened it a little, took a couple cuts and it really made a difference in she finish and the noise but still unsatisfactory results,with pretty much a spiral groove down the length. And now it Sounds like it’s running a little bound up.
Another thing that I’m not sure about is the carriage rack and pinion. The track looks to be mounted a little high which looks to be causing excess backlash between it and the gear. I’m not sure if this would make a huge difference or not?
Something is up bc I’ve seen beautiful mirror finishes made without a grinder or sandpaper ever touching the material with this same model.
If I have a piece between chuck and live center and turn it down and then take my test indicator and Rotate the part has a runout of .001 at the end of shaft near live center.. That seems piss poor to me and I’m getting sick to my stomach knowing I didn’t have the money to just throw away on a big anchor.
Does anyone think adding extra support to the existing stand would be a good idea? Thanks