z axis loosing steps

[ptjw7uk]

As Irving said I did change for a more powerful stepper and also changed to parallel drive.
I did try all the options for lower acceleration but they all made no difference that I could detect.
I may in the future try and balance the head but at the moment I am thinking more in the way off removing some of the flex in the column, I am also trying to work out the options of changeing the way the Y-axis works by siting the stepper to the rear and fixing in place instead of moving with the Y-axis. aka KX1.
My biggest headache with the rear siting is the head tilting mechanism I may get rid if it altogether and make a new support for the Z-axis arm, just need a great lump of metal!

Peter

[Robin Hewitt]

No real substitute for a great lump of metal :naughty:

...but I am seriously considering filling my round column with concrete.

Rather a lot of concrete reinforcement bars have mysteriously appeared on my steel racks, probably enough to fill it. Hey, it was cheap :heehee:

Wonder what the optimum concrete to iron ratio would be for stiffening a round colum :whistling:

[ptjw7uk]

I have also been pondering on adding threaded rod to add tension to the column but I have not seen this done anywhere or at least not reported on the web.
I really must test this to see if it has any effect, I know it has effects upon brick walls and concrete makes them stiffer!

Peter

[der_fisherman]

I helped a friend about a year ago with a similar problem, we installed some constant force springs to counterbalance the Z-Axis, we did it very "empirically" and weighed the Z Axis and installed two springs, but only connected one for 2 Kg. as that is what it weighed, but as he wants to eventually change to a bigger router, we just left the other one unconnected for the moment!!
Now his Z-Axis is just about neutral we believe, or fairly close.....
The springs were wound onto ball bearings with "side cheeks", sorry I do not have fotos and he has since sold the machgine, but it worked just fine after that.....
The constant force springs (I am told) always exert the same force, they do not increase as they get longer as normal springs do, which is a big advantage,,,,,
You can see them and read a good explanation here:-
http://www.leespring.com/int_learn_c...ce_springs.asp
originally I wanted to use a counterbalance, but the springs were simpler and added far less mass......