Delta Homing issues


This is my first printer build and while i'm making good progress I've been stumped by a couple things. Hopefully I can get some hints. My printer is based off the boots biv1 rostock from thingverse. It's running sainsmart mega/ramps1.4 hardware with repetier firmware. I am using repetier host as well. My initial configuration was completed through the online tool.My google foo is weak when it comes to this so I really appreciate the help.

1) The machine homes fine but its LOUD. Do i need to modify the feedrates?  

2) When I sent the machine the command to move the effector 30mm above the bed it crashed hard. I just found that my Z_MAX_LENGTH was incorrect which I just changed, haven't tested that yet though. Should the X, Y, and Z max lengths equal?

3) In the host when i home the X, Y, and Z coordinates in the manual control tab stay red and do not turn black after homing. According to the documentation I've read they should. Now I just re-measured the Z lenght and found it was way out like i mentioned in item 2. Other than that i'm not really sure where to start. 

Thank you again!!


  • Hi all! 

    After getting home I got into the config.h and started playing with the feed rates. Looks (sounds) like the noise issue is solved. I changed the z max feedrate and z homing feed rate from 2 to 8. Also, repetier host looks like it recognizes it's position now so that's looking better.

    I do still have an remaining issue though. When I manually move the z axis down 1.0 through the host it moves the effector more like 15mm. I am using spools and spectra line so no belts. The spools are 24.4 mm in diameter at the smallest portion. so my circumference should be 76.96. 3200 / 76.96 = 41.58 (i set it to 41 just for testing). I would expect 1.0 through the manual arrow controls to move it more like 1 mm. Am i mistaken on the units displayed? I'm assuming i'm not so any help with this remaining issue would be greatly appreciated. 

  • edited March 2016
    Your circumference is actually 76.65mm.  Therefore one full revolution of rotation gives 76.65mm of linear motion.

    You are most likely using 1.8* steppers.  That means there are 200 steps for a 1:1 in rotation.  If you are running 1/16 microstepping, then you have 3200 steps per revolution.

    3200 / 76.65 = 41.75 steps/mm

    If you somehow are only running 1/8 microstepping, then you have 1600 steps in one rotation.

    1600 / 76.65 = 20.87 steps/mm

    That would give you a difference of 20.88mm of larger movement.  I would check to make sure you are at 1/16 microstepping.

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