Re: Z axis March 12, 2014 12:58AM |
Registered: 13 years ago Posts: 2,947 |
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Re: Z axis March 12, 2014 09:54AM |
Registered: 11 years ago Posts: 112 |
Re: Z axis March 12, 2014 11:56AM |
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Re: Z axis March 15, 2014 05:16PM |
Registered: 11 years ago Posts: 112 |
Re: Z axis March 15, 2014 08:52PM |
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Re: Z axis March 17, 2014 12:00AM |
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Re: Z axis March 17, 2014 10:05AM |
Registered: 11 years ago Posts: 112 |
Re: Z axis March 17, 2014 11:44AM |
Registered: 13 years ago Posts: 2,947 |
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Re: Z axis March 25, 2014 12:19PM |
Registered: 10 years ago Posts: 5 |
Re: Z axis March 25, 2014 05:46PM |
Registered: 10 years ago Posts: 22 |
Re: Z axis July 14, 2014 05:20PM |
Registered: 9 years ago Posts: 156 |
Quote
cns1
I'll take a crack at it...
Guess 1), using sound linear motion design practice, the other side of the shaft should be supported by a bearing in that application, most motors that are readily available to rep-rappers world wide come with too short a shaft, or the shaft has a flat on one or both sides.
Guess 2), the distance that you can move an axis using cable drive is limited by the amount of cable you can spool on and off of your "bobbin". As the diameter of the shaft gets smaller for a given ammount of travel the number of wraps increases, until you reach a point where the wraps become both unmanageable, and they dramatically increase the angle at which the cable is deflected from where it attached to the carriage. If the angle becomes too great then the cable tension increases as you reach the end of both sides of your travel. This can do anything from causing your axis to deflect, to causing the motor to skipp stepps, to snapping the cable.
In looking at the diameter that sublime chose for the spool/bobbin it appears to me that the z-axis upgrade was designed to manage the cable angle for 150-200mm travel.
Anyway that's my best guess.