Kirk Wallace wrote: > On Wed, 2008-07-02 at 19:44 -0500, Chris Radek wrote: >> >>One thing that jumps out at me is that it seems your accelerations on >>X/Z are extremely low. It looks like it takes an inch or more to get >>up to your rapid speed. > > > That's correct. I seem to recall that I had to balance between > acceleration and tripping the following error alarm. I should probably > go back and optimize my tuning sometime (after I start making money). > > >>If accel really needs to be so low you should try starting the tapping >>move way outside the part (an inch) or tapping at very low rpm and see >>if that helps. It's possible it hasn't settled into sync with the >>spindle quite yet, when it's cutting the first couple threads. >> OK, I think I see a problem. Giving more approach in air will help as the tap enters the workpiece, but then you have the problem the Z axis has to reverse in sync with the spindle. If the spindle reverses too fast, the Z can't keep up, and the approach in air can't help that at all.
The only way to help this is to increase Z acceleration or slow down spindle acceleration. >> >>Kirk and I talked about the importance of cranking up the SERVO and >>TRAJ rates and I think he is running both at at least 1kHz now. Any >>slower just isn't enough to get a nice synchronized reversal. >> >>Chris > > > Oops, by the time I got out to the shop, I forgot about the rate > corrections. Still, I think g33.1 is working well as is with a .1" > to .2" lead-in. I think the problem is inherent with the tap or fluid I > am using. The more I think about it, the more I think running a second > g33.1 to chase the thread is the way to go. To be honest, I really can't > tell the difference between the double g33.1 parts and the hand chased > parts. I suppose I should tap a part on my manual lathe for comparison. > If you haven't upped the traj_period rate, I think it will do more than ANYTHING else to fix the problem. I spent hours fooling with every other parameter with little benefit, then at the CNC Workshop Jeff told me about this and it made an immense improvement. Jon ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
