Hey Cutloose,
I am NOT having any "real" problem with the unit after they changed out the ballnut mounts. My X axis ballscrew is really quite silky and the Z is great but the Y is gritty. I wonder if the mount for that is just a little off still. It works so I leave it. I was doing some tests yesterday to see if I could get good repeatability out of the machine but my measuring tools kept moving. I will try again today and report back soon on backlash etc (something Cbass asked about months ago.)
As for the extra rails and such that is just personal preference...nothing else. I don't really know if it would help either. Jason has one of these also and runs it 8 hours cutting guitars and I don’t think he has anything other then upgraded ballscrews and the servo motors.
Me I just thought the frame looked a little “light” and wanted 2 extra cross braces (this really was for the 2525 machine I returned but they fit the 3925 also). I REALLY like them there. More places for me to put clamps on when holding wood if you don’t have a top fitted. I think they charged me $25 for the braces with screws etc. Not bad at all.
I did not mean the linear rails on the Y axis (I think the rails and linear bearings they use are awesome) but that 80/20 type aluminum extursion. It would be really cool to have 2 stacked side by side. Again just me.
THE ITEMS I MENTION THAT I WOULD GET ARE JUST PERSONAL PREFERENCE. I don't mean to say the K2 3925 needs them at all or turn this thread into a K2 needs to get this stuff done to there machines to make them better. Its just little stuff I noted but don't know if it is needed
The only MAJOR thing I think you would benefit from are upgraded ballscrews/ballnuts. I would do that hands down. All else could stay the same.
I think the other thing that would REALLY help is what do you want to make. Is it for hobby use or for production?
As for the Shelrine, they are smaller machines. I have used mine for years and love it. I made new NEMA 34 mount for the K2 off of it. I will post some pics soon. I have pics and stuff on my website with heli, airplane, etc parts.
Finally, I have no "real" education in mechanical engineering, metal working, electroincs, etc. Everything I have done/learned in the past years is self taught with many hours and many mistakes, etc. I burned through my first endmill in about 2 min as I had no clue what feedrate to use for aluminum. Its been a fun road and I would do it all over again. My bro was/is into electroincs and helped me out quite a bit...other then that its guys like you that I learn from. Many internet hours and "touching a wire here and touching a wire there"
See here is a perfect example of make sure you know who your asking the question to before you believe any answers
Also, I had my machine sent apart because I did not trust shipping after my 2525. It was really easy to put together.
For the price and what I need it for I am happy with the 3925 (hobby and general "fun" use).
later
taus
www.cuttingedgecnc.com