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Leadscrew

Posted by Bee69 
Re: Leadscrew
September 05, 2017 10:28PM
Ok
I have some working figures now Thank you.
Feed rate is 40
Acceleration 75
I tried figures higher that these, they did not work.

One thing I notice, not sure if it is a problem or not, there is a slight hesitation at the beginning and end of the movement
Re: Leadscrew
September 06, 2017 06:06PM
What value is your jerk?

In this case Jerk is not the kinematic term for change in acceleration, reprap-jerk is the maximum change in speed in mm/sec that can be changed in the interval between two segments, so if its too low you might get a slight hesitation when starting and ending a move, as it needs to be at a lower speed to change the direction. the default is set to 20
Re: Leadscrew
September 07, 2017 07:11PM
So, let me get my head around things so far, the changes I have made will affect all axis, reason for asking is I see a slight hesitation in the X axis.
I have not made any changes to the jerk yet, how would it be if I try 25 first up.
Re: Leadscrew
September 08, 2017 01:07AM
#define DEFAULT_AXIS_STEPS_PER_UNIT {80, 410.6, 410.6, 837.00} // default steps per unit for ***** MakiBox A6 *****
#define DEFAULT_MAX_FEEDRATE {60, 40, 20, 45} // (mm/sec) 
#define DEFAULT_MAX_ACCELERATION {2000,75,30,10000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION 3000 // X, Y, Z and E max acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 3000.

Im guessing the above is how your settings look now. If you are seeing an issue with the x that was not there before then I think you may have changed the default_acceleration, this would affect all the axis
Re: Leadscrew
September 08, 2017 02:59AM
Quote
scottybfg
#define DEFAULT_AXIS_STEPS_PER_UNIT {80, 410.6, 410.6, 837.00} // default steps per unit for ***** MakiBox A6 *****
#define DEFAULT_MAX_FEEDRATE {60, 40, 20, 45} // (mm/sec) 
#define DEFAULT_MAX_ACCELERATION {2000,75,30,10000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION 3000 // X, Y, Z and E max acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 3000.

Im guessing the above is how your settings look now. If you are seeing an issue with the x that was not there before then I think you may have changed the default_acceleration, this would affect all the axis

Ok it does not quite look that way, my original settings were

#define DEFAULT_AXIS_STEPS_PER_UNIT {80, 80, 410.6, 837.00}
Now Y 400
#define DEFAULT_MAX_FEEDRATE {250, 250, 3.3, 25} // (mm/sec)
Now Y 40
#define DEFAULT_MAX_ACCELERATION {3000,3000,100,10000}

#define DEFAULT_ACCELERATION 1000 now 75.

Should I change these to suit yours.

Edited 1 time(s). Last edit at 09/08/2017 03:00AM by erniehatt.
Re: Leadscrew
September 09, 2017 02:41AM
Leadscrews on X and Y don't really make sense for a 3D printer unless one use's high lead ones. These are not cheap.
Yet the biggest issue it that leadscrews must be properly mounted and they must stay that way otherwise, they will bind.


"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)
Re: Leadscrew
September 09, 2017 04:14AM
Thank you for that.
The only reason I went to the leadscrew was because the fittings for the belt drive broke and I had no way to reprint them, going to the leadscrew has allowed me to do so, so I will be going back. the biggest drawback I found with the lead was the extra time it took to print an item, an 8hr item took 13hrs.
Re: Leadscrew
September 09, 2017 08:02AM
I just took the settings you posted early on and changed to what you said you had now.

change your:

DEFAULT_ACCELERATION from 75 back to 1000

and

#define DEFAULT_MAX_ACCELERATION {3000,75,100,10000}

that will cap the Y axis to 75 without affecting the X
Re: Leadscrew
September 11, 2017 03:46AM
I would like to thank everyone for the great help here, it allowed me to be able to print the failed parts, and get back to belt drive.
I was temted to stay with the lead screw except for the extra time added on to the print, the quality was pretty good.
Thanks again Guys.
Re: Leadscrew
June 05, 2021 02:36PM
I am adding 2 new 2mmx2mm start 1 ACME lead screws. It seems to me that I could just take the formula for calculating extrusion amount. Which is basically running the Z Axis up, lets say 50mms And plugging the difference into the formulas for E Extrusion. Can some one tell me if that would work or why it would not work. Because one you find the right formulas it seems simpler to me.
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