26 Feb 2015 08:58 - 26 Feb 2015 09:00#16438 von der_michel
to prevent you to run into the same questions i had some things i'd changed on my 840 to convert it from ok to wonderful.
1.st i changed the Stepper for X and Y to Stepper with more than 45ncm (cost aprox 40 Euros) and this Euros are well spend.
To mount the bigger Stepper to the X-Axis you need to use some distance screws(Computer Mainboard screws might work)
2nd i did get rid of the original Stepper Controller and use this one (http://goo.gl/ZOtfpS), and with this on half step the hole machine runs
much better, smoother and more powerful.(Need different Power Supply)
3rd. The 2 little 3mmx5mm set screws to mount the rack-wheels to the 2 Y-Axis shafts are not fitting, so buy 2 3mmx10mm set screws and
sanding/cut it to the matching size. Now the set screw are fitting, and have now a flat angle.
The Steppers do 200 Steps for 360° and the shafts doing 3mm by turn, so on full step we have 200/3=66,66 Steps/mm and on half step we have 133.33 Steps/mm. (To convert it to useless inch format - use your favorite calculator )
With the better Stepper & Control i run my Machine with 1700mm/min
Hope this helps to have a proper 840 that makes you have real fun
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