The incomplete RepRap Prusa Mendel beginner's guide

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The incomplete REPRAP beginner's guide is an attempt to gather in one document all the information about REPAP MENDEL PRUSA, that is available in the internet.

The reason of doing it, is that it is sometimes more practical to have some basic information gathered in one place, than trying to get fast and accurate answers in IRC or anywere else in the internet, for issues that a newbie cannot even understand and express.

Mostly this work is a ‘copy&paste’ of sites' critical info, links with usefull material, and some of my experience.

Although it is focused on the Mendel Prusa model, I hope it may be useful for builders of other models.

Under no circumstances this document can be considered as complete.

By COS_ (Konstantinos Tziampazis). You can download this document (but rather old)here:https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B6agwEC__Vy7MDFiMjEwNDktMzM3NS00N2ZmLTg3NDUtM2JlZTc4OGE1Y2U3&hl=el


CHAPTER 1, INTRODUCTION

What is 3D printing?

…“3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable and easier to use than other additive manufacturing technologies. 3D printers offer product developers the ability to print parts and assemblies made of several materials with different mechanical and physical properties in a single build process. Advanced 3D printing technologies yield models that can serve as product prototypes.” (https://secure.wikimedia.org/wikipedia/en/wiki/3D_printing)

…“A large number of competing technologies are available to do 3D printing. Their main differences are found in the way layers are built to create parts. Some methods use melting or softening material to produce the layers, e.g. selective laser sintering (SLS) and fused deposition modeling (FDM), while others lay liquid materials that are cured with different technologies. In the case of lamination systems, thin layers are cut to shape and joined together.” (https://secure.wikimedia.org/wikipedia/en/wiki/3D_printing)

Reprap Mendel prusa is an FDM 3d printer. Here are some videos on how FDM works. You can find many more on youtube.

…“Industrial 3D printers are made by companies such as Objet Geometries, Stratasys, 3DSystems and Z-corp. The average price of such a printer is €10,000 or more.” (https://secure.wikimedia.org/wikipedia/en/wiki/3D_printing)

I found these videos of commercial 3d printers:

Object260 connex

Zcorp 3D Printer 650

Stratasys

What is reprap? … “RepRap is a free desktop 3D printer capable of printing plastic objects. Since many parts of RepRap are made from plastic and RepRap can print those parts, RepRap is a self-replicating machine - one that anyone can build given time and materials. It also means that - if you've got a RepRap - you can print lots of useful stuff, and you can print another RepRap for a friend... …RepRap is about making self-replicating machines, and making them freely available for the benefit of everyone……RepRap was the first of the low-cost 3D printers, and the RepRap Project started the open-source 3D printer revolution. It is described in the video on the right.” (http://reprap.org/wiki/Main_Page)

… “RepRap is short for Replicating Rapid-prototyper. It is the practical self-copying 3D printer introduced in the video on the left - a self-replicating machine. This 3D printer builds the parts up in layers of plastic. This technology already exists, but the cheapest commercial machine would cost you about €30,000. And it isn't even designed so that it can make itself. So what the RepRap team are doing is to develop and to give away the designs for a much cheaper machine with the novel capability of being able to self-copy (material costs are about €350). That way it's accessible to small communities in the developing world as well as individuals in the developed world. Following the principles of the Free Software Movement we are distributing the RepRap machine at no cost to everyone under an open source license (the GNU General Public Licence). So, if you have a RepRap machine, you can use it to make another and give that one to a friend... …The RepRap project became widely known after a large press coverage in March 2005, though the idea goes back to a paper on the web written by Adrian Bowyer on 2 February 2004.” (http://reprap.org/wiki/RepRapWiki:About)

Adrian Bowyer explains his 3D printer RepRap:

There are various reprap models such as:

  • Darwin (the father, where it all begun)
  • Mendel (by Ed Sells, the successor)
  • Huxley (by ErikDeBruijn, the smaller)
  • Prusa (by Josef Prusa http://josefprusa.cz/pages/english, the faster&easier to build&print Mendel)
  • Prusa V2 (by Josef Prusa, newer, better, with new RP parts, and many old but optimised)
  • Makergear Prusa (By Rick Pollack, a modded prusa with some RP parts modded for best performance http://www.makergear.com/ )
  • Axis, Glider (Mendel-like from botmill http://botmill.com/ )
  • Orca (mendel-like from mendel parts http://www.mendel-parts.com/ )
  • Insert here if I miss any model

NOTE: you must have in mind that choosing a mendel-like model, may be hard to find specific parts when these will/may brake.

The RepRap Family Tree shows the development and variations of the reprap project


Ok, I want one

Well done! Before you make up your mind you need to make some research on the subject. After all you are a newbie …..( since you are reading this).

Before reading further, you must understand that reprap is an open source project that is under development, and requires some technical skills (from soldering to crafting). If you are excited with 3D printing only and NOT with building, I suggest you buy a pre-assembled, commercially sold machine and don’t bother reading the rest of the document concerning building and fine-tuning.

Remember …“it's generally suggested not to buy a full kit because you will have a hard time finding someone to repair the machine once it does break. All 3d printers eventually break. If you INSIST on buying an assembled machine, try:...."(http://ietherpad.com/UaMN2zn4sn)


For assembled-ready machines please read chapter 2.

It is a good idea to read this document BEFORE you even start searching in the internet. This can save you time from unnecessary or misleading information. After reading, you may be more focused on what you want and how you are going to find it.

1st stop is the website of reprap.org. Here, you will find almost anything, although some info may be obsolete, other may be up-to-date.

http://reprap.org/wiki/Main_Page

I suggest you read A LOT. You can use the glossary to familiarise yourself with new terms (http://reprap.org/wiki/Glossary), select one of the ‘how to build’ pages (http://reprap.org/wiki/RepRap_Options) just to get the taste of what awaits you…. Also there is a search engine within the website that you will find very useful, since the tons of info cannot be easily found through page browsing. For example type in the search field: object, extruder etc. I found it quite useful as a dictionary for unknown technical words (i.e. heated bed)

All the necessary information about building can be found here: http://reprap.org/wiki/Prusa_Mendel_Assembly


2nd stop is irc://irc.freenode.net/#RepRap (for chatzilla) or http://webchat.freenode.net/?channels=reprap a simple browser-based chat interface.

Those with IRC clients, simply select the freenode server, then the #reprap channel.

In irc you will get help right away, by very experienced users. Just introduce yourself and ask your question. In irc, information is up-to-date, although sometimes you may find difficult to explain exactly what is the issue that you are experiencing. This can happen because of language barrier and lack of technical experience. But don’t worry, almost everybody is willing to help.

3rd stop is the reprap forum at http://forums.reprap.org/ Here, your question may have been already answered. Check this thoroughly.



CHAPTER 2, ACQUIRING

You have 3 options:

  1. build one (buy all the parts from different dealers)
  2. buy one complete Mendel (or Mendel-like) kit
  3. buy a fully assembled Mendel

Category 3 usually applies to models of category 2 but the models are sold already assembled. However, I wouldn’t recommend it since they are delicate and heavy for shipping:

check the http://reprap.org/wiki/Prusa_Buyers_Guide. More information you can find in the IRC channel.

Category 2 is the playfield for the average amateur who does not know much about electronics, crafting, soldering, engineering, programming, or does not have easy access to all the parts needed to build a machine. It is for those who have fun building plastic kit models, or for those who have some experience with tools such as screwdrivers, multimeters, dremel, solders, etc. It is for the majority (like me) who want to build a printer fast and easy.

The recipe is easy: the kit comes in a big and heavy box, you spend some time building it (lot of fun for model kit builders), you spend some time calibrating it, you spend the rest of your time printing and sharing our knowledge in #reprap.

check the http://reprap.org/wiki/Prusa_Buyers_Guide. More information you can find in the IRC channel.

Category 1 is for the more experienced builders (ex-builders of category 2). Machines build that way cost considerably lower, about 50% less than category 2, but there is always the risk of finding parts with lower quality (like smooth rods that must be straight and very smooth). Nevertheless you have the overall quality control over each part, so you make your choices.

A reprap consists of several different types of parts:

  1. RP parts (repraped parts, that are used to mound the rods that make the frame, mound motors and x-y carriages). These are printed from another reprap
  2. Mechanical parts. Are the smooth rods (to slide the carriages) and threaded rods (to make the frame), nuts, washers, belts, bearings, springs etc.
  3. Electronics parts. The controllers of the motors. All these are connected to a main “controller” that reads the gcode from the computer and translates to motor moves. Today, the most popular electronics are Arduino with pololu shield (or RAMPS, http://reprap.org/wiki/Ramps ), Arduino with Sanguilolou shield (http://reprap.org/wiki/Sanguinololu )
  4. Electrical parts. Like cables, power supply, stepper motors, endstops, etc
  5. Hot-end parts. This is the most tricky part to find/make. More info at http://reprap.org/wiki/DIY_Direct_hot_end
  6. The printer firmware. Sprinter by Kliment is the suggested FW for Ramps machines. It uploads to Adruino via the arduino control software
  7. The software. This includes: A) the HOST software that connects the PC with the printer (repsnapper, or preferably Kliment’s pronterface), and B) the application to convert the solid model into a series of gcode instructions that your printer understands (slic3r by Sound or skeinforge/SFACT-by Action68)
Spacexula, is trying to make a Step-by-Step cost-related guide
Since most of us cannot make our own hotend, here are some of the most well known suppliers:

* Arcol
* Budaschnozzle
* J-Head
* MakerGear
* MakerBot
* Mendel-parts
* ParCan

Check out this video comparison of the ParCan Hot end and the Reifsnyderb J-Head hot end by Rotorit.

If you wonder how the hotend can fail, check this video

SUMMARISING

To make a reprap print an object you need to:

  1. build the hardware
  2. build the electronics (Category:Electronics; RAMPS, Sanguinololu, etc)
  3. wire the motors, fans, endstops, thermistors, hotend to electronics
  4. upload firmware to electronics
  5. load Host to PC and connect printer
  6. use a slicer program on PC(skeinforge/sfact , slic3r) to slice an stl file (the object you want to print)and generate gcode
  7. load to your Host the generated gcode from the slicing program
  8. execute the 'print' command on Host



CHAPTER 3, BUILDING

Assuming that you have all the needed parts, it is time to start building…. The BOM (bill of materials) is a list of all the necessary parts that you will need to build a prusa. This can be found in the prusa visual build manual mentioned below.

Manuals

  • The REPRAP book. This is your first stop. A very comprehensive guide on building your own reprap.
  • Optionally, if you are making the WADE’s extruder, you will need this manual

Below, there is a series of instructions for Makergear Prusas. They are prusas with some parts modified for better. Makergear is also known for its good quality of hotends

  1. stepper plastruder instructions
  2. ceramic heater core instructions
  3. superpack instructions

After you have finished building, you need to calibrate the printer.

Here is Triffid Hunter's Calibration Guide

Video Guides

Building

Soldering-Electronics

Hotend building

  • If you are experienced, you can make your own hotend. Wildseyed decribes how, in a series of tutorials

Software/firmware

Calibration

Electronics

  • Some info from reprapwiki on Gen7

Note: When you ask kthx or someone for the cable color order for motors connection on electronics, you usually get 4 colors in particular order. It is presumed that you hold the electronics board at the right orientation, that is the orientation that allows you to read the letters or words that are printed on the board - not read the letters upsidedown!

Arduino

Arduino drivers, control application, and install instructions (you need those to connect arduino with your computer and upload the firmware) Download page

Installation: Step-by-step instructions for setting up the Arduino software and connecting it to an Arduino Uno, Mega2560, Duemilanove, Mega, or Diecimila.

Software

You need: 
#the HOST software (Pronterface, Repsnapper, RepRap)
#the application to convert an object file into Gcode (Skeinforge/SFACT, Slic3r, Reprap, Repsnapper)
#additional software (to create 3d objects for printing and then adjusting them on printing plate.
Note: for printing one object only, it is automatically set to center of print surface)

Here, is a Comparison_of_RepRap_Toolchains (a toolchain consists of all the software elements needed to create printed 3d models from CAD models to firmware)


Host Software


Pronterface

Repsnapper application, the host+slicer, manual and code for all available OSes

RepRap host software latest release , the original host+slicer by Adrian Bowyer's team. For installation instructions see:

and for user instructions see:

ReplicatorG Host+gcode application and manual


Slicing Applications


Skeinforge gcode application and manual. Windows self-extracting here.Enrique's blog contains all the announcement and troubleshooting info about new versions of SF.

Slic3r a promising gcode application by Sound, and read me

SFACT is already merged into Pronterface distr., you can also download SFACT. Since it is always in developement, you may need to test the experimental versionthat needs python to run or the daily update version. Also, there is a SFACT FAQ.


Additional software


Art of illusion , the software that helps you to design your objects

OpenScad, which is more focused on the design of non-artistic objects.Read the manual carefully, also check

A Tutorial roundup is available from makerbot.

Blender can be used to arrange many objects in one print batch, like the platter found in pronterface. Also you can use it to rotate objects on the plate to meet your needs. A quick guide can be found here.

Here is a page on Useful_Software_Packages with more description details and more links.

Firmware

  • Sprinter firmware by Kliment and Caru, download it, unzip it, load it to arduino connection software, and then upload it. Remember to specify what arduino you have, from the ‘tools’ menu.Please consult spacexula's video guide mentioned earlier.
Note: before uploading your FW to arduino, you must make some changes in order to make it work properly..
Just load appropriate *name*.h file on a text editor, or use Arduino's editor and make appropriate changes as suggested below:
*changes in "cofiguration.h" (these changes are compatible with sprinter. In Marlin, expressions may be slight differ but can be
easily located. I have not tested other FWs)
-set your motherboard (i.e.for RAMPS #define MOTHERBOARD 33)
-set thermistors (i.e.for 100k #define THERMISTORHEATER 1 #define THERMISTORBED 1 )
-set your microsteps (consult josef prusa calculator, Triffid Hunter's Calibration Guide)(i.e. for mendel with wade 
 extruder:  float axis_steps_per_unit[] = {80, 80, 3200/1.25,700}; )
-verify resistors at endstops (i.e.#define ENDSTOPPULLUPS) 
 also verify endstop flag (true or false depends on NC or NO connection, more for this chapter 4&5)
*changes in "pins.h" (ONLY FOR RAMPS OWNERS, for sprinter & marlin)
-verify your RAMPS motherboard version
(i.e.  // uncomment one of the following lines for RAMPS v1.3 or v1.0, comment both for v1.2 or 1.1
         //#define RAMPS_V_1_3
         // #define RAMPS_V_1_0)


  • Teacup firmware, by Triffid_hunter, Traumflug, jakepoz, "...claimed to be faster than Sprinter, more elaborate configuration options Teacup is a decent alternative for Sprinter. However, because of its easier configuration we advise you to get started with Sprinter."(https://reprapbook.appspot.com/#d0e982)
  • Marlin firmware by Edvz, is a mashup between Sprinter, grbl and many original parts.It is available for all hardware types (read the read.me file). Marlin is configurable the same way as Sprinter. So, if you have already sprinter on your electronics you can paste most of your settings to Marlin. Main improvement over sprinter is the look-ahead function. The changes that need to do in marlin are about the same those given earlier for sprinter. Read the config.h carefully nad make appropriate changes.
  • Sjfwis another firware by Scribblej, instruction can be found here.

Here, is a List of all Firmwares available, with more descriptions.

Here, you can find a comparison between Sprinter and Marlin.

Miscellaneous

  • WWW
Flickr account. You need one in order to show your prints and printing problems
Thingiverse, is the repository for 3d objects ready to print. You need it to download test pieces for your machine calibration. Also your main source for objects to print.
Dropbox.
Pastebin.com, you need this to paste your problematic gcode instead inserting to irc reprap channel


  • Articles
Choosing Filament
A nice article on cooling fans mounted on extruders


  • IRC

Log in to irc #reprap and start logging (simple browser interface) (firefox chatzilla plugin) IRC Server: irc.freenode.net.You may not know, but your query may already have been answered in there just minutes before you ask. Always check the log thoroughly. IRC #Reprap’s bot, kthx: http://bot.kthx.nl/bot/factoid


  • Blogs
Josef Prusa's blog, and his ideas on the heatbed.
Richard's blog on developments.
Reprap Blog
More in-depth info about your mendel at the hydraraptor blog


  • If you choose to power your printer using an ATX power supply, like those that use the PCs, you will need to go to "How to jumpstart atx psu". The wiki page explains more about psus.
  • Create a folder in your hard disk named REPRAP or whatever you like, in order to keep there everything related to reprap; from software to tutorial videos and docs for future reference. Subfolders named software, objects, videotutorials, manuals, irclogs, etc keep everything organised.
  • The Essential Calibration Set is what you need after building. It is advisable to regularly print some after major or minor changes to hardware or software. Also advisable when you have printing problems. Get it here
  • Prusa V2 files.
Check the blog, the RP differences and download the files.
  • Material Safety Data Sheet for PLA [1]or [2] and ABS [3] or [4]
  • You may want to scan objects for printing... check this site. You can make a 3d scanner on your own!

CHAPTER 4, TIPS

After getting enough info on what you are about to do, it is time to actual start building.... I will try to describe the steps i followed to build and finally do my first print.

Building tips

  • I recommend you should first read the Reprap book to familiarise yourself. Then, read the visual guide while watching the video guides of spacexula. In this way you will understand fully the visual guide.I found some supplemental build details here and here.

Note:Don't be afraid of mistakes!Excluding exceptional cases, REPRAP is VERY FORGIVING if you make any mistake.Bolts and screws make any joint temporary, so a mistaken placed part can easily be fixed.The same applies to soldering:always have the desolder with you..

exceptional cases in my point of view can be considered:

  1. Heatcore overheating due to faulty/disconnected thermistor
  2. Liquid or loose bolt&nut drop on electronics (you need to find some cover after finishing everything)>The sane applies for loose cables near electronics
  3. Connecting/disconnecting motors or any other cable from electronics without turning it off first
  4. RP part break due to overtightening (like rod clamps), but this can be replaced with another.
  5. Motor overheating due to poor cooling or if there is an obstacle on one of the carriages path, forcing it to stop while the motor is trying to move it
Of course, if such a mistake happen, the broken/burned part can always easily be replaced.

So the bottom line is that even you make the worst mistake, it will cost you some extra money & time..

  • Machine orientation

decide what is your front side for the machine.Original design assumes that Front is the side that y motor is mount.Before building further, understand the positions of the y,x motors and the corresponding positions of x,y endstops.

  • The jig

Make sure you have a jig."Use spacer bars to calibrate common distances. A good arrangement for the y-axis jig is to tape a longer bar over the top of the spacer bar (see pic) to achieve a perpendicular alignment. The top bar only has to be longer by ~10 mm at each end. This arrangement is not necessary for the other two frame jigs. Another good method is to use threaded rod with nuts at the right distance. If you twist the nuts in opposite directions you will lock them."(http://reprap.org/wiki/Mendel_assembly_notes). Note:when tightening your frame you want that the jig can be inserted easily into the measured gap.This means that you must not apply force to insert or extract it.

  • Measure, tighten, measure again

This is self-explanatory, but sometimes underappreciated. Your machine must not be loose, but not overtight either...

  • Inserting the x-y carriages

When inserting the x-y carriages you need to pay attention to the following:

  1. first assemble but not tighten.
  2. make sure the carriage move freely.Try to give it a push, it should move little more before it stops.You must not apply much force to move it.If you do, then you need to realign your smooth rods and bushings.
  3. move y carriage to the far end (away from you). Tighten the 2 bar clamps of that side.
  4. repeat step 2.The carriage must behave the same.
  5. move y carriage to your side. Tighten the 2 bar clamps of that side.
  6. repeat step 2.The carriage must behave the same.
  7. Repeat all the procedure again for x carriage.


  • Tightening the x,y motor belts

When tightening the x,y motor belts, you need to make sure that it is optimum tight.This means that the belt is virbating like a tightened string when hit lightly. Note: DO NOT OVERTIGHT.In order to assure this, just observe how the y motor's shaft is moving off center when applying force on the the belt that is attached on the pulley.Very important is that the pulley is vertical to the belt and not off-center due to tension.You can understand this by moving the y carriage manual;if you notice that the belt is trying to move out of the pulley's teeth or it is traveling along the idler's width, then you must either:

  1. realign the idlers (one or both of them)
  2. realign belt clamps
  3. realign motor
  4. release or apply tension to the belt

The same goes for the x carriage. I call optimum belt tighness when you rotate a little the pulley by hand and you see that the carriage moves as well.If there is a chance that you turn the pulley but the carriage does not follow right away -watch cerfully if there is a small raise of the belt at the teeth of the pulley while doing this- then you have to tighten the belt.Also when you press the belt vertically with your finger, you need to feel some resistance from it.

  • Cable wiring

Before make any wiring, decide where your electronics will be, how the motor and endstop cables will run along vertices, how heatbed cables will allow the y carriage move freely, without obstructing its move.You need to know your electric/electronic arrangement in order to calculate the right cable length.

  • Y carriage holes

Before assembling the y carriage on rods, you need to make the holes that the screws of the print bed will mount.Also you need to make corresponding holes on the print bed. Moreover you need to make holes for the heatbed (if you choose to use one). Lastly, you need to take measurings in order to make the glass or aluminum print surface (if you choose to have one)

  • Endstops

They usually have 3 pins under the names:NO,NC,C.Sprinter firmware assumes that you have connected the NC and C cables to "S" and "-" accordingly. If you haven't done so, then either you change the firmware (inside the FW code, you will find what to change in what since there is detailed explanation), or change the wiring of the endstop side.(NC or NO go to "S" C go to "-")

  • Preliminary Tests

After assembling the x and y carriages, before mounting the e-motor with heatcore, it is wise to make some motor tests. You will need to have all motors and endstops wired to electronics (preferable mount also the thermistors), upload the firmware to electronics, do all the firmware adjustments mentioned in previous chapter, load the host, connect the printer to host and finally give some "move" instructions, "home" instructions, "extrude" instructions.

IMPORTANT:Before turning the machine on, have the x,y,z axis centered. 
This means that your carriages are in the middle of their paths, not at the ends.
Also be ready to turn the OFF switch if something is going wrong.

You dont have to have filament or have mount the heat core. Observe if the carriage moves at the correct direction.Correct direction is moving away from the endstop when you give a "+ X 10" instruction.If it does not move or if it does move but when you have pressed the endstop, consult previous bullet point or troubleshooting guide.Check all the axis same way:"+X 10". Then give the "home: instruction to home the carriages.If all 3 axis home ok, then it is time to check extremities.Just tell it to move to +200 for the x,y carriages (of course it is at home first). Then try to extreme z axis.Give repetitively the +z 10 command to reach 10 cm in hight.Be careful not to hit any part at vertices while raising x carriage, also be aware of the x carriage timing belt....If everything is ok, perform a virtual print. Simply load a file to skeinforge or what ever you have for slicing, slice it, load it to host and press the print button.During print, you will notice the x carriage move, the z axis move, the y carriage move.Also you will notice the e-motor rotate as well.If you don't notice any strange noises, or whatever suspicious, you continue mounting remaining parts.

Note:for virtual prints you must not have connected the heatbed and heatcore power cables..

  • How to insert/extract filament

Inserting

  1. Loose the filament idler springs.
  2. Insert filament by hand gently, until it cannot move more.
  3. Set heatcore at extracting temp, that is 185C for PLA and 230C for ABS.
  4. When temp is reached, push gently by hand filament down until it oozes from the nozzle.
  5. Tighten idler springs.
  6. Test extrude from host program.

Extracting

  1. Loose the filament idler springs.
  2. Set heatcore at 150C for ABS, 130C for PLA.
  3. When temp is reached, pull up the filament with your hand.
  4. Turn of heatcore immediately
  • Alternative to printed parts (RP)
  1. z axis couplers. After some printing you may have problems with z axis RP couplers; they loose their grip on the thread rod causing loosing steps.Usually people replace these if they see that the problem is persistent. I have found these couplers but you may also search and find more of these types.
There are also some RP new coupler designs for prusa such as 
http://www.thingiverse.com/thing:7757
http://www.thingiverse.com/thing:12582
http://www.thingiverse.com/thing:10906
http://www.thingiverse.com/thing:11187
  1. bushings. It is known that the original prusa plastic bushings wear off after some use.The trend now is LM8UU linear bearings.There are many reprap shops that sell them now.However just type 'lm8uu' in ebay search bar to see what will come out.Remember, that these bearings require PR parts that are modified to grip these bearings.All the modified parts can be found in thinkiverse.
  • Mounting Glass and the Heated Buid Platform

Check this video

Calibrating - Fine tuning tips

  • X&Y carriges Endstops calibration

Supposely you have mounted the heatbed or the print surface in general, you need to adjust exactly your endstops in order not to print outside this area.The print surface of your prusa or mendel is 20x20 cm.

  1. Move y carriage to home.
  2. Move x carriage to far left, then right and make sure that the nozzle has equal distance from each edge.
  3. Then move y carriage to +200.
  4. repeat step 2
  • Fine tuning exact distance between nozzle-surface

When you set the nozzle to a certain distance from the print surface when homing the z axis, you must be sure that this distance will be the same for all the print surface, wherever the nozzle will be, when z=0.

  1. Move y carriage to +100.
  2. Move x carriage to +100.
  3. Home z axis.
  4. Set z endstop to required nozzle-surface distance.
  5. Move x carriage to far left.Home y cariage
  6. If the distance is not what you have set, then readjust it by screwing/unscrewing the adjacent screw that holds teh print surface (the one that has the springs under the print surface)
  7. Move x carriage far right.
  8. Repeat step 6.
  9. Move y carriage +200.
  10. Move x carriage far left.
  11. Repeat step 6.
  12. Move x carriage far right.

Verify settings with steps 1,2,3.After this, try print this to verify your settings. Nozzle must have same distance from surfac<e everywhere. In order to define the right nozzle-surface distance, see troubleshooting guide, printing.

  • Fine tuning Z endstop

There is a possibility to loose z endstop exact location.. Just move nozzle to center of surface (x,y =100) and calibrate z endstop.

Printing tips

  • Printed parts detaching tools

In my experience detaching ABS from Kapton may prove a little bit hard. A set of blades like these can be very useful for detaching and cleaning the part.

  • Rough print surface

After some use, your kapton may become rough due to peeling.It is not time to replace it, at least not yet. Try in skeinforge/sfact the raft plug in, setting 1 interface and 1 base layers. Leave rest of values untouched. It prints 2 intercrossed layers before printing the part, helps smoothen all surface problems (including slight inclination), allowing your piece to have a nice first layer. But you may experience some trouble removing it from piece, or for ABS, need to have high bed temp since first layer is not touching the bed anymore.

  • Rotating objects in openscad

The following is an extract from a dialogue i had with Triffid_Hunter in #reprap

"openscad: rotate([0, 0, 0]) import_stl("blah.stl");

<Triffid_Hunter>COS_: the 3 numbers for rotate are rotation about the X, Y and Z axes in degrees.change by 90 to test output. The stl must be in opencscad folder. Then select design->reload&compile. Then if satisfied, select compli&render then export as *.stl file."

  • Rotating objects in Blender
  1. open blender
  2. file->import stl (load the stl you want to rotate)
  3. right click on object, press "r", then the axis to rotate(x,y,or z)
  4. type the angle to rotate (90,180 etc ) object will rotate instantly
  5. press enter when satisfied
  6. file->exprot stl, save object

Note: be careful that the object must touch the grid (z axis=0) otherwise object will not start print at layer 0 but higher..



CHAPTER 5, TROUBLESHOOTING GUIDE

Building

MOVING AXIS

  • Carriage moves only to one direction, but moves reversed only when i keep press the endstop

Verify your endstop wiring.Cables should be at NC and C. The "NC" goes to "S" on RAMPS and the "C" goes to "-".

OR

Change the logic of the firmware.Sprinter&Marlin allow this.I have not tried any other FW. If anyone has, please write it here.

Sprinter&Marlin firmware, configuration.h
//If your axes are only moving in one direction, make sure the endstops are connected properly.
//If your axes move in one direction ONLY when the endstops are triggered, set [XYZ]_ENDSTOP_INVERT to true here:
const bool X_ENDSTOP_INVERT = true;
const bool Y_ENDSTOP_INVERT = true;
const bool Z_ENDSTOP_INVERT = true;


  • I am getting a reading off my thermistors, but ALL of my axises will not move at all.

Confirm that you did attach the 12V leg of your power supply to the electronics. If you attached 5V by accident none of the Axises will work (http://titanpad.com/qJEQDJxQs6 , the live REPRAP FAQ guide)

  • In which direction should the Axis move?

Z goes up when going positive, down when going negative X goes left when going negative and right when going positive Y goes forward when going positive and back on the negative You can reverse stepper direction by flipping the stepper plug, or changing settings in firmware. ALWAYS REMOVE POWER BEFORE UNPLUGGING A STEPPER (http://titanpad.com/4MdGMrV192 , the live REPRAP FAQ guide)

  • 1 axis will not move at all, what is wrong?

If only 1 Axis will not move -1st swap the stepper motor to a different driver, If the problem is likely that you do not have proper electrical connection to the motor, insure that both coils are connected AABB A connected to A B connected to B electrically -If the problem stays on the Axis it's an issue with the board, if your electronics have removeable stepper controllers move the stepper controller to an axis that works. If the problem moves then you either have a stepper that is turned all the way down, or a dead stepper controller -If the problem STILL does not move you might have an issue with your electronics themselves, turn your board over and make sure that the sockets for the stepper controlers and the related capacitors/reistors for the axis are all properly soldered. Any questions with a joint just touch up the solder.(http://titanpad.com/qJEQDJxQs6 , the live REPRAP FAQ guide)

Heatbed

  • I cannot apply my 70mm Kapton on glass surface without bubbles!The tape is too large and i cannot control it

Have you tried the wet method? Check this video

Electronics

  • What order do the wires in my stepper motors get connected to my Stepper Driver?

Ramps and Sanguinololu Electronics both have motors attached in an AABB pattern meaning 2 sets of wires that are "Closed" or give you a resistance in the 1st 2 pins, and the second coil, which again gives a resistance in the Second 2 sets of wire. The color is different for each manufacturer.(http://titanpad.com/4MdGMrV192 , the live REPRAP FAQ guide)

Electrical

MOTORS

  • When I send a move command to an axis the motor makes a buzz sound without moving.

You need to adjust the trimpot.It can be found on the stepper driver, it is the little round thing that looks like a screwhead.Turn the power off, and turn it a little bit clockwise.Rotating the tripot gives more power to motor, but you need only as much as it can move it, as more power can lead to motor burn.This rotation can be done without turning off the electronics but you must be carefull not to touch anything with your screwdriver.

  • My motor is being strange. It makes a grinding noise whenever I tell it to step 10mm and adjusting the pot doesn't fix it. The wiring seems to be fine as well. In addition, it will sometimes move, but then reverse direction a bit. This is also happening with my extruder, it will move in one direction then back off

Your connector to your motor is very likely lose, swap the axis and the behavior should follow the motor. recrimp or replace the motor connector. If the problem is on the motor side of the conneciton you might have to replace the motor if you can't take it apart.(http://titanpad.com/qJEQDJxQs6 , the live REPRAP FAQ guide)

  • One of my motors just stops turning partway through an otherwise perfect print.

Most likely, the motor is overheating, and losing torque. You need to turn down (counter-clockwise) the adjustment pot for the motor.(http://titanpad.com/4MdGMrV192 , the live REPRAP FAQ guide)

  • I can't get my motor into the sweet spot between enough current and too much. If I turn it down enough to stop from overheating, I get skipped steps.

Add a fan, heat-sink or both to the motor driver.(http://titanpad.com/4MdGMrV192 , the live REPRAP FAQ guide)

  • I need more info about stepper motors, i.e. wiring, motor types etc..

check the wiki http://reprap.org/wiki/Stepper_Motors also you can check http://www.sapiensman.com/step_motor/

Firmware

  • My printer cannot communicate with Host

There are several things to see:

  1. check usb cable, both ends
  2. check host speed setting to mach that of your FW
  3. check COM port
  4. sometimes high speed is not tolerable by Os&computer
  5. FW speed setting:
marlin for baudrate 250000:
// This determines the communication speed of the printer
#define BAUDRATE 250000
//#define BAUDRATE 115200
//#define BAUDRATE 230400
*Note: Marlin requires pyserial version 2.6 on linux bots to get to 250000 ( Marlin FAQ, at http://titanpad.com/zKInCaYQb0)
sprinter for baudrate 115200
// This determines the communication speed of the printer
#define BAUDRATE 115200
  • X,Y,Z carriages go beyond limit (200mm for X,Y and 100mm for Z)

check FW setting:

marlin prusa settings
#define min_software_endstops false //If true, axis won't move to coordinates less than zero.
#define max_software_endstops true  //If true, axis won't move to coordinates greater than the defined lengths below.
#define X_MAX_LENGTH 200
#define Y_MAX_LENGTH 200
#define Z_MAX_LENGTH 100
sprinter prusa settings
const bool min_software_endstops = false; //If true, axis won't move to coordinates less than zero.
const bool max_software_endstops = true;  //If true, axis won't move to coordinates greater than the defined lengths below.
const int X_MAX_LENGTH = 200;
const int Y_MAX_LENGTH = 200;
const int Z_MAX_LENGTH = 100;
  • My print suddenly gets shifted over by Xmm, partway through the print.

There is a good chance that your acceleration is too high than your hardware can manage. You have to reduce acceleration through firmware:

Marlin firmware (original value is 3000.Try 1000 or 1500):
#define DEFAULT_ACCELERATION          1500    //   X, Y, Z and E max acceleration in mm/s^2 for printing moves 
Sprinter firmware (these valus normally work):
float max_start_speed_units_per_second[] = {25.0,25.0,0.2,10.0};
long max_acceleration_units_per_sq_second[] = {1000,1000,50,10000}; // X, Y, Z and E max acceleration in mm/s^2 for printing moves 
long max_travel_acceleration_units_per_sq_second[] = {500,500,50,500}; // X, Y, Z max acceleration in mm/s^2 for travel moves
#endif

Software

TO BE CONTINUED....

Printing

  • What is the right distance between nozzle and surface?

It should be equal or less your print layer.If you print at 0.25 layer height then this is your distance.Measuring this distance is easy with a feeler gauge;just set distance using the z endstop and measure the gap in betwen by inserting the feeler gauge thin steel blade.If it gets through roughly, it is ok, but if it gets through very easily, you need to reduce the gap and measure again. Be carefull while measuring, the feeler gauge blade must fit in the gap without having to push the print surface down in a manner to compress the 4 surface support springs

  • My print suddenly gets shifted over by Xmm, partway through the print.

This could be caused by a number of problems. The most likley is you need to adjust the current for your stepper motor - find the adjustment pot for the motor, and carefully turn it up (clockwise) a tiny bit. If you still lose steps, turn it up a bit more. It could also be do to your belt tension being too low (and too high of tension can lead to current probelms as above). Belt or bearing binding is another common cause of these problems. Make sure your axes all move smoothly, if you feel any sticky spots that could be the cause.(http://titanpad.com/4MdGMrV192 , the live REPRAP FAQ guide).Check also the firmware troubleshooting

Note:if you have such a problem on x carriage, after several hours of printing with the heatbed on, then you must know that the heat from the heatbed affects the belt tension.If your belt is somewhat loose, then the heat decrease the tension a lot.Usually you miss steps when carriage acelerates to move to next print point

  • Why does my extruder skips steps whenever I am trying to print?

Issues to check

-Is your stepper controller getting hot? If it overheats you will get skips durring extrusion

-If using a geared stepper, does the 2 gears mesh exactly the same across the full rotation of your larger gear? If you have a part that has higher resistance you gear might not be perfectly round / have a defect. Try to use a hand file to clean up the gear meshing, or move the stepper motor gear further from the driven gear to allow more room for the defects.

-Is your thermal barrier getting hot? If your thermal barrier gets to hot it can cause increased resistance to motion by your cold end. You might need to put a fan on your thermal barrier.

-Your nozzle might have trash in it. If all else fails remove your hot end and clean out all the plastic. Most hot ends this can be done with a blow torch, but some are too fragile for this and you must use a long acetone dip.(http://titanpad.com/NKIQnvwEtd , the live REPRAP FAQ guide)

  • My prints will not stick to the HBP (Heated Build Plate).

Many things can cause a print not to stick, check these things:

-Is your HBP hot enough? 70C for PLA 110-120C for ABS

-Have you got skin oil or lube from the axises on the plate? It will cause prints not to stick (you can clean them with alcohol, acetone, or ammonia (Windex, tested on glass) )

-Are you pressing the 1st layer into the HBP enough? The extrusion should take on a slightly flat appearance without actually squishing it (you should not see the nozzle dragging thought he middle of the print.

-Are you printing the 1st layer slow enough? All materials like the travel speed to be 15-20mm/s for the 1st layer.(http://titanpad.com/4MdGMrV192 , the live REPRAP FAQ guide)


CHAPTER 6, ADVANCED LESSONS

TO BE CONTINUED....