# RUG/Pennsylvania/State College/Trouble Shooting Guide

The contents on this page will help calibrate and troubleshoot your printer to help get to the print quality that you desire.

Once you have finished building your printer and can successfully talk to your printer through a host program, I'm sure you will be dying to start printing. Unless you are extremely lucky, your first print will not be perfect. Using the table below, you can correctly calibrate your printer.

Issue Possible Problem Solution
Objects are the wrong size 1. Steps/mm are incorrect in the firm ware

2. You may not be using the 'right units' from STL to GCode to Printer.
To fix Problem 1:
Move the X or Y axis of your printer by 10mm. Measure the distance that the X or Y axis actually travels. Let’s say your Y axis actually moved 5mm. Now divide the 10mm you instructed the printer to move by the 5mm it actually moved. 10/5= 2. You will now need to find the steps/mm vector for the Y axis in the configuration.h file of your firmware. Multiply whatever this value is by the factor that you calculated (in this case 2). Now re-flash your firmware (add link) and try again. Make sure to check your stepper motors if they're anything other than the common 1.8 degrees/step.

To fix Problem 2:
Check the unit size of the STL using ReplicatorG (they have handy buttons for this in their scale tab), or check to be sure that your G-command matches the units you expect.
Circles are not printing
circular
1. Axes are not orthogonal

2. Your x carriage and/or y carriage rattle or their belts have too much slack.
To fix Problem 1:
Carefully check measure your system to determine where the asymmetry lies. Common locations to check in a mendel-based design are in the y-axis bars (make sure they're 90 degrees to the X axis), or in the z-axis (make sure that it's not tilting, but totally normal to the build plane.

To fix Problem 2:
Belt tension is the simpler of the 2 problems to fix. All you need to do is tighten the belts to create more tension, ridding the belt of the problematic slack. Rattle in the carriage may be to flawed design (check our OpenX and OpenY updates) or flawed assembly (do what you can to remove any rattling.
Your object experiences "warping" 1. Printing with too much infill

2. Un-level bed

3. Using wrong temperature on for heated bed
To fix Problem 1:
Reduce infill by 10% and attempt print again.

To fix Problem 2:
There is really no easy way to level the bed but we have found a way that works fairly well. First thing to do is check the X-axis bars. This axis will be adjusted using the Z-axis oddly enough. The Z-axis rods can be individually by hand. This will allow you to either move the right or left side up or down to become even with the opposite side. Move the X-carriage from one side of the board to the other and see if there is any change in the distance between the board and hot tip and adjust the Z height of either side as needed.

Next, we will level the print bed. The bed level is adjusted using the four screws attaching the print bed to the Y carriage. Tightening one of these screws will lower the bed in this corner and loosening the screw will raise it. Move the hot tip to the four corners of the print bed. If the distance between the print bed and hot tip changes, make the necessary adjustments so that the distance is constant across the entire print area.

To fix Problem 3:
Raise bed temp by 5 degrees Celsius and reprint. (Note: Do not go above 75 degrees Celsius)

Your object has gaps in the layers 1. Inconsistent extrusion

2. Layer height is set too high
To fix Problem 1:
See "Inconsistent Extrusion" below and start watching your prints if you haven't been.

To fix Problem 2:
If using Slic3r: Goto "Print setting: tab and click on layers tab. Reduce layer height as needed. A good place to start is 80% of nozzle diameter. (For example if you are using a .5 mm tip, you would want to start at .4 mm layer height ad adjust from there)
Weak Print 1. Temperature too low

2. Inconsistent extrusion
To fix problem 1:
To fix this, raise the temperature in the GCODE for your printed part. The set temperature command is M104 S200 (for a hot tip temp of 200 degrees Celsius)

To fix problem 2:
See "Inconsistent Extrusion" below
Inconsistent Extrusion 1. Overvoltaged motor/low tip temp

2. Idler too Tight/Loose
To fix Problem 1:
It may be that your extruder motor has been driving too hard to get the job done, sometimes a problem due to an overtightened idler. Make sure that the assembly works without filament, with filament, and with a heated nozzle, before attempting to print. Alternatively, the operating temperature of the tip might be too low, also giving the motor a hard time.
To fix Problem 2:
While your printer is extruding, check to see if your idler bearing is rotating. If it is not, tighten the screws attaching the idler to the extruder body.
If your printer is not extruding, reverse your extruder 15mm. Check your filament for damage. If there are deep cuts in the filament from the hobbed bolt, your idler is too tight. Loosen the screws attaching the idler to the extruder body. Here is an example of a filament damage, this was noticed at the Beta printer, it wasn't extruding, partly because the idler was too tight. click here
Your object has lots of beads on the sides 1. Over-extrusion To fix problem 1:
Extrude 10mm of filament while measuring what length of filament is fed into the extruder. Let’s say 5mm if filament was actually fed into your extruder. Now divide the 10mm you instructed the printer to extrude by the 5mm it actually extruded. 10/5= 2. You will now need to find the steps/mm vector for the extruder in the configuration.h file of the firmware. Multiply whatever this value is by the factor that you calculated (in this case 2). Now re-flash your firmware (add link) and try again. For help with flashing visit this link ………..
Your motors are running hot and loud 1. Potentiometers
are turned up too high

2. Belts are too tight
To fix problem 1:
Locate the specific motor connection on the control board (x, y, z1, z2, or extruder). Then locate the potentiometer - it will look like a small metal ring with a phillips head screw shape. Take a screwdriver and turn the potentiometer down far enough to reduce the motor's noise. However, make sure its still high enough to supply the current needed for the motor to actually have enough torque to turn the belt/shaft.

To fix problem 2:
Locate the belt that your motor is turning and add slack if possible. (Not too much or you will run into the 'Circles are not printing circular' problem listed above.)
Your first print layer is thin, squished, or warping immediately. 1. Your z-axis home is set too low

To fix problem 1:
Raise the z-axis opto slightly, if possible on the machine you are using. This will allow the filament to exit the extruder tip properly. However, do not raise the opto too high or else your print will not stick to the board properly. Important: Make sure the piece of aluminum/plastic which breaks the opto connection will still fit nicely through the opto slot after you have adjusted it.

To fix problem 2:
Bring the z-axis up a few clicks then extrude a few mm of filament to ensure it is working. Remove this filament with tweezers and restart the print. (Note: this usually occurs when the print does not have a first perimeter outline. If you can add this outline it should also fix the problem.)
You load your file into pronterface, hit print, and it goes crazy. (A local issue due, largely) 1. You're using a Slicer Gcode on a printer that reads Skeinforge Gcode or vice-versa
To fix problem 1:
Try slicing your .stl file with the other program (opposite of which you originally sliced it) and start the print again.
Your first print layer is not sticking to the bed. 1. Your z-axis home is set too high

2. Tip temperature is not hot enough
To fix problem 1:
Lower the z-axis opto slightly, if possible on the machine you are using. You want to have the tip close to the bed when you home the z-axis, but not too close that it will prevent the filament from being extruded. If you lower it too much, you'll see problems like those in 'Your first print layer is thin, squished, or warping immediately':Problem 1 listed above) Important: Make sure the piece of aluminum/plastic which breaks the opto connection will still fit nicely through the opto slot after you have adjusted it.

To fix problem 2:
Set the temperature a bit higher in your G-code. Try only a few degrees at first (you don't want your tip burning or literally dripping filament.
Extruder Loses Position in X or Y axis. 1. Belts are jumping teeth

2. Worn out drive pulley/Loose set screw.
To fix problem 1:
Increase the tension on the belts by tightening the zip ties that hold the belts together. Do not over tighten and causing the motor to run hard and hot.

To fix problem 2:
Determine if the pulley is slipping on the motor shaft. If pulley is slipping, tighten set screw and test again. If the pulley is tight, dismantle, remove and replace drive pulley with a new one. It is recommend to get a high resolution pulley for best results.
Motor is not working. 1.Motor doesn't drive.

2. Motor fails to respond to gcode properly.
To fix problem 1:
Check that motor is plugged in properly. Test by plugging the motor into another working axis driver and determine if it still won't work. Acquire advise from other before throwing out the motor.

To fix problem 2:
Determine if the pulley is slipping on the motor shaft(see above section). Check the potentiometer setting on the driver board. Do not overheat the driver board by turning up the chip too high). You will burn out the board easily if it gets too hot.
Bed drives to far causing belts to jump or extruder crashes into bed. 1.Ends stops disconnected, not working, or positioned wrong.

2. Motor lead plugged in backwards.
To fix problem 1:
Check that all end stops are plugged in properly. Check that continuity of wires. Reposition and tighten the end stops to the correct position.

To fix problem 2:
Remove motor lead to the problem axis, flip the plug and re-insert and test again. Make sure that the correct motor is plugged into the correct axis driver on the ramps board.