Rapman v3.1 building and getting started overview
- This initial version was written by a beginner.
- DO NOT BLAME BitsfromBytes FOR ANY MISTAKES! I am 4 week-old rapman baby !!
- DKS 12 March 2010.
RapMan is a commercial kit of the RepRap 3D printer. “RepRap is short for Replicating Rapid-prototyper since it was developed in a research project on self-replicating machines.
This 3D printer builds the parts up in layers of plastic with the help of a custom-made Thermoplast Extruder. The machine takes a 3mm diameter filament of a polymer, forces it down a heated barrel, and then extrudes it as a melt out of a fine nozzle. The resulting thin stream is laid down in layers to form the parts that RepRap makes. The extruder should work up to a temperature of 260 degrees Celsius. It works with various polymers like ABS (Lego-like plastic) and polylactic acid. The extruder can move left/right (X axis) and forward/backward (Y axis) The printed object sits on a platform that will move down (Z axis)
Printing instructions are written in a language called G-code. A user will copy a g-code file to an SD card. This card is then inserted into a slot of the RapMan board for printing.
This article has two functions:
- It's a meta manual for building Rapman version 3.1: We will try to explain how RapMan works in order to help the reader understanding stages of assembly and we will point out the most important manuals and other information sources you should read
- We also cover first steps with respect to printing.
Parts, manuals and workspace
When we ordered a RepRap it came in a fairly small plastic-wrapped cardboard box. In addition, we got some boxes with polymer filaments (10 ABS rolls and 4 PLA). To the left is a picture.
You may check the insides of the boxes. E.g. compare contents to the list that you can find in each of the three following manuals, i.e. in the "included" section in the beginning.
- Build manual (for the "cartesian robot")
- Extruder manual
- Hot End manual (pink/grey hot end cables were missing from both the 3.1 version manual and in our case in the delivered kit)
Finally, there may be faulty pieces. In our case the holes in the base bed (page 51 of the build manual) were not straight. Other folks in the forum reported this problem. IMHO ours were sort of straight enough. The setup, i.e. a bolt with a spring that ties down the print bed is used to micro-adjust the level of the print bed in 3 dimensions (see the operations manual).
Assembly is easier if you can reserve a lot of space for assembly. At TECFA, we used our seminar room and took about 2 x 6 meters :). See picture to the right.
Keep the following picture from the build manual in mind. This is what you are going to build. The most important parts are labeled (we added the hot end, i.e. part of the extruder that will heat the plastic filament).
You also should look a real picture, below is ours:
Overview of the manuals
All manuals are available at Bits from Bytes. At the time of writing (feb 2010) they could be found in the downloads section. The "build info" section includes outdated version. So, in any case, always make sure that you get the manuals for the version you ordered, e.g. RapMan 3.1. Here is a list of the manuals:
- Build Manual - Printed: This manual explains how to assemble the so-called cartesian robot. This refers to the printer (including the motors and the belts that will move the extruder in the X/Y axis and the plate up/down (Z-axis). In other words, it's all that's mechanical, except the extruder.
- 3D Build Manual part 1: As above but include 3D models that you can view in PDF. Click on a "picture" to enter 3D mode. Make sure to install the latest PDF version and to use a PC with a decent graphics card. Also, explore the Acrobat menu to the left. You can add-remove parts for better visibility.
- 3D Build Manual Part 2: As above, part 2. Also includes writing of the motors and the controller.
- Animated Build Manual: As above, but includes animations. We didn't use this manual.
- Build Manual Videos: This manual includes three videos that show how to build some of the more difficult parts.
- Extruder Manual: Explains how to assemble the extruder, i.e. the print head that will be moved around in X/Y directions by the "cartesian robot". It will pull in the plastic filament and feed it into the so-called attached hot end which you somewhere during the assembly process. Finally it also explains how to wire the extruder to the controller.
- Hot End Manual: Explains how to assemble the hot end. The hot end will heat the plastic. It's a bit tricky to assemble, since you have to wrap a heating wire around, attach a temperature probe and cover with fire cement in several stages.
- Operations Manual: Explains how to calibrate and use the printer. In particular: calibrate the print head, update the firmware, use the controller interface and print files.
Notice: In some case, the newer manual versions did not have enough information to understand the process. We had to look at some 3.0 version manuals where procedures are explained in more detail. However, this information needed to be adapted, because some parts are not the same and generally speaking 3.1 is easier, in particular assembling the hot end !
As of Feb 2010, the build manual is quite superb (with little mistakes), the Extruder manual is ok enough, since at this stage you can build without reading .... The Hot end manual is not good enough (yet).
You will need tools. All except two can be easily found in a do-it-yourself store. Read: V3Info.pdf (this file may not sit next to the build manual). Dictionary (terms are in UK English):
- A spanner is called Wrench in US English, "clef à écrous" en français
- Allen key is also known as "hex key", "inbus" or "hex head wrench"
- A Needle file is a small abrasive file, the kind modeling hobbyists would use.
(1) Easy to find tools:
- 4mm Spanner 1
- 5.5mm Spanner 1
- 8mm Spanner 1
- 13mm Spanner 2
- 1.5mm Ball End Allen Key 1 (it's important to get ball ended keys, since sometimes you will "come in diagonally". We suggest to buy quality tools, because of easier fit).
- 2.5mm Ball End Allen Key 1
- 4mm Ball End Allen Key 1
- 2mm Flat Blade Screw Driver 1 (get a good one, this is need for attaching wires to the board)
- Tape Measure 1
- Soldering Iron 1
- 1/2 Round Needle File 1 (we actually suggest to buy several ones including a square-shaped one. Since these are used by modeling fans you can get handful of various shapes for about 5 to 15 Euros (depending on quality). We got the cheap ones.
- Wire Cutters 1 (maybe not needed, since a stripper also can cut)
- Wire Strippers
(2) Difficult to find tools:
- A good multimeter that can measure small resistance. Not difficult to find actually, but may not be found in a supermarket. We didn't test resistances as we should have ... ;)
- A 1/16'' Allen key. We found it w/o problem in a hardware store that sells to professionals.
(3) Extra tools (not mentioned in the bills of tools)
- You might acquire a key that can measure a small torque pressure (the typical thing you get in a do-it-yourself shop is just good for the nuts on car wheels). This is an expensive professional tool. We didn't get one. (see practice run)
- At least two Pliers. One should be long and flat. Useful for holding nuts in place before you use the keys. Cheap ones will do.
- A small (!) tube of super glue. I broke the extruder wheel (the only thing we broke) and fixed it with super glue :)
- A hammer. You are allowed to use it only once though :(
- Various meters, i.e. a long flat 2 meters one for measuring cables and a small metal one (preferably one whose end starts at zero, else a plastic office-type one can also do). The latter one is to measure distances in the assembly and for selecting bolts.
- A (no bigger than 2GB) standard SD card. It will be inserted into the board to print files.
The assembly procedure
Practice run and parts terminology
The practice run has three important functions:
(1) You will learn how much you can tighten the screws. The golden rule is simple: really finger tight then add 1/2 turn with a key.
(2) Terminology: Although we do understand English, we didn't know about these:
- A washer is a "flat disk" (rondelle in french)
Also remember to look at the "big picture" on top for terminology of the rapman parts.
(3) Learn how to read the manual. You quickly will learn about the names of nuts and bolts:
The cartesian robot
The cartesian robot is fairly easy to build if you understand English and are used to reading computer manuals for example. It takes about 2-3 full days (2 persons working on it).
Things that will go wrong:
- Some pieces may be assembled in a wrong way. Make sure to pay attention to "asymmetric" pieces.
- Again: Do not over-tighten. Plexiglass can shatter quickly.
- Geometry. If you do it right, most everything should be "cubic", i.e. same distances and 90 degree angles. If you get that wrong, the printer will not work properly. Make sure to do the calibration right (as explained in the build manuals).
Sometimes you need to inserts bolts in the plexiglass parts. If you can't insert these, don't force too much, but use a needle file to clean the aperture or even to enlarge it. This is why we recommend to get a whole set of small needle files in various shapes.
The extruder and hot end
Tip: If you read this before you ordered a Rapman, consider buying the pre-assambled hot-end which is now available and hidden in some option (March 2010). It costs some extra pounds, but may be worth it :)
The extruder and the hot end are described in different manuals plus in the videos PDF.
The Extruder manual explains how to assemble the mechanical parts of the Extruder. This part is fairly easy.
The hot end manual is not clear enough:
- The manual includes instructions for two different versions of the kit, i.e. insulated vs. non-insulated nichrome. Nichrome is a resistance wire that will heat. It's the kind of wire you may find in a toaster.
- The parts you get are not the same as the ones described in the manual. E.g. the kit already included a non-isolated nichrome wire with the bootlace ferrules attached (i.e. step 9 on page 5 already was completed in the kit I got).
The nozzle assembly (part one) is easy. The tricky part is wrapping the nichrome, fire cementing it, adding the thermistor and fire cementing again.
Here is what we did:
- Attach the nichrome to cables (as explained). You have to attach wires with the ferrules and squeeze these with a plier, then slide the yellow head-proof sleeves over it (in the manual, explained before nozzle assemble)
- Put a small layer of fire cement around the aluminum nozzle
- Make sure that the wires will be on the side of the hole of the MDF !
- Wrap the nichrome around (make sure they don't touch)
- Add fire cement (be careful not to smear anything inside the nozzle hole or the thermistor hole), then wait 12h
- Add the thermistor (this is a bit tricky since you'll have to add fire cement.
- Then cook with the ventilator outlets (as explained in the manual)
- Then add more fire cement to make it look pretty. But don't make it too "fat", else you won't be able to slip the insulation around and printing will be slower since the hot end will cool faster.
- Cook again (actually much longer than they say)
Since we didn't have a good enough multimeter, we didn't test anything after it. If we made it wrong, we'd have to order a new hot end kit anyhow ...
Below is picture of the hot end (without insulation), printing a giant duck:
Test printing and tuning
There are three levels of tuning at beginner stage:
- Make sure that the assembly is compliant with the instructions in the Manual
- Get the temperature, flow rate, and head movement speed combinations right
- Micro ajustments (geometry, belts, etc. and item 2)
Last minute checks and trouble shooting
Check the following (we had all of these wrong in some ways)
(1) Alignment of the X and Y axis
- Alignment of the X and Y axis is crucial. If badly aligned then a circle may print as ugly sort of square. This happened to us, because we took the Y belts away to check the motor.
(2) Belt tensions
- Make sure all three are tight
(3) Z belt tension and alignment, wobbling Z rods:
- Make sure that the end of the rods, i.e. the ball bearings, sit in their casings (rebates). Clean these with a needle file again if necessary. If you don't, the Z axis will be misaligned, rods may wobble, or you hear noisy clicks, because the belt will not be aligned properly.
- That was my huge mistake: I attached the pressure wheels in the wrong way. The side where the wheels stick out should be toward the extruder. Else, the big fat bolt can't move the plastic filament. Big frustration after you try to print the first test pattern :(
- Make sure that the extruder is nicely attached. At some point I removed the extruder to check the nozzle and forgot to tighten 2 screws. Result was a skewed print, i.e. the yellow cup you can see in a picture.
(5) Attached wires
- Even if you did attach the wires to the board and the 25 way pin as told, they may become loose. E.g. in our case, the red wire for the Y motor became loose on the board and the motor would just crank a little bit forward and backward. We thought that it would be a too tight Y Drive shaft, disassembled this one and then wound up with misaligned Y belts, i.e. the the X carriage wasn't aligned anymore with the Y(0) end...
(6) Search for loose nuts and bolts (also after printing a few test objects)
(7) SD card memory errors: Format the card before you use it. You may have to repeat this if errors pop up again.
(8) Filament wheel: Make sure that it turns smoothly. The bolts in the inside must be loose else the extruder won't be able to pull in the filament (or you'd have to turn the wheel manually ....)
Rough alignment of the print bed:
- Align the bed horizontally with respect to the Z axis. I.e. remove the Z belt and turn the rods
- Keep the print head at a safe distance, e.g. 0.5 cm and move it around manually. Then go closer until you are more or less satisfied.
Copy the Control Interface page of the operation manual and over-line the important manual move mode commands, i.e. you should keep this page near the control until you know commands by heart.
Then, power up, and move the print head around in all three axis. If a motor won't work, check wiring. If you hear strange noises, check alignments and belt tension.
Fine tuning of the print bed alignment
Adjust the print bed with bolts. This is a bit tricky and needs several iterations. In each position, the nozzle should be about 0.5 mm away from the print bed. We used five sheets of 70mg paper (500 sheets = 5cm) to do this.
Go slowly when you move the print head. Don't damage the board !
The coordinate system:
The 0/0 coordinates are in the center.
- X goes from -135 to 140
- Y goes from -100 to 105
- Z goes from 0 to 230
How does Rapman know where the print head is ?
- Look at the coordinates in the manual setup. If the print head is in the center and the X/Y coordinates are different, then something is wrong.
- home print head' with the menu in the board and switch it off again. This is particularly important if you make a change the Z axis, e.g. move the board up or down by a 1/10 of a millimetre. Running it home will press the three little switches on the gray boxes (make sure you can see it click ...)
Inserting the filament and manual extruding
Make sure that you rough up the print bed with sand paper. Remove the dust, e.g. you can easily remove the print bed, sand it, then wash it. The principle is that the filament has to stick.
The nozzle, when cold, takes some time to heat. Don't worry if nothing happens during a few minutes. At some point you will see the temperature going up. Also you should know, that temperature drops pretty fast which is a problem with the test files. E.g. if you print without manually extruding some plastic beforehand, things go wrong.
Use manual mode, i.e. Tool setup
- Put the print head in position over the hole (front side, right)
- Up the temperature to 245-250 degrees: Press +/- Y
- Up the extrusion rate to 5mm/s(econd) = 10 RPM: Press +/- X
Then, as soon as the bolt in the extruder starts turning (temperature reached):
- Push in the filament (really down)
- Tighten the two screws (red caps)
- Paint a dot on the filament to check if it goes down ... If it does not, then tighten. If the motor blocks or if it jumps, loosen
- Print at least half a meter
Then, as quickly as you can, run a print file (see below)
Changing the filament
Before you can insert new plastic:
- Heat up the nozzle
- Pull out the old filament
- Push in the new one
- Extrude manually until the color changes ...
Insert the filament as explained above
Printing the test pattern
(1) Upgrade the firmware as explained in the operations manual. To do so you need:
- A small to normal USB cable
- The HIDBootLoader.exe application
- The firmware, e.g. file RapMan2_0_8.hex (as of Feb 2010)
(2) Then print the test raft pattern.
- Copy file 'TestRa.bfb to the SD card
- Insert in the board and print ...
(3) Repair the TestRa.bfb file to make it fit your situation. Most likely temperatures are too low (see G-code below). Your first print will go miserably wrong, unless you are either very good or very lucky.
You also may adjust the belts and other geometry. Our very first cup (see aside) went horrible wrong since we took off a Y belt and the forget to re-adjust as we already explained.
Then print the cup (it may take several attempts to get it right). In the pictures are our second (white) and fourth (yellow) attempts. You also can see the raft made for the yellow version. Somewhere below, you can find attempt #6 (a red cup).
If needed, adapt the print temperature in the M_Mug.bfb file. E.g. if you can get about 0.5 cm/second using a temperature of 247 degrees with the manual extruder test above, change the value to this.
For the raft use the strict minimum, e.g. start with 235 degrees. Search for all M104 (except the one on line 457). The raft should not stick too much to the print board but it should stick. It doesn't matter if it is a bit faulty.
For the cup, around line 457 adjust for color ABS, e.g. to set temperature to 240 degrees (for white plastic), change the first line below.
M104 S240.0 G1 X22.76 Y-18.7 Z1.95 F960.0 G1 X22.89 Y-18.64 Z2.0 F960.0
For the color ABS cup we got a decent result with:
We found that we had to raise the temperature and slow down printing a bit (even for the default white plastic). Also it's a good idea to modify all files to extrude some plastic before it starts printing the raft (did not manage this so far).
Both cups are not yet satisfactory. Some tuning ahead - 15:12, 28 February 2010 (UTC).
Note: The Extruder-Fan doesn't run all the time, so don't worry if it doesn't run with the test files. It is not needed for ABS.
- In G-code, it can be turned on/off: M106 - fan on, M107 - fan off.
Printing - first steps
If you use ABS plastic (by default you likely do) then you must understand the following:
- You should first print a raft at a somewhat lower temperature (else it will stick to the print bed)
- Then, the object will be printed on top.
The three print parameters
It is important to understand that printing will be affected by three parameters:
- Extrusion speed (how fast the bolt turns in the extruder)
- Head movement speed
- Pressure on the extruder's pressure wheels. They have to be fairly tight.
These all interact somewhat and that makes calibration difficult.
To learn more about printing, read the Skeinforge article and follow up links. Since the information is not up-to-date with respect to the latest beta version at the time of writing (22:30, 12 March 2010 (UTC)), you also should read this for an overview.
Temperatures for ABS
- Raft temperature: 235 (or a bit more)
- Print temperature: 240-245 (or a bit more)
- Raft temperature: 235 (or a bit more, since there is the danger that it will not stick enough)
- Print temperature 243-248 (or a bit more). In our machine, we set it to 247 or 248.
If the raft temperature is too low, then there is the danger that the raft and the resulting object will warp. If it is too hot, then you will have trouble getting it off the raft (I use a knife). Notice: later you will learn how to print fatter rafts at the same temperature which will also do the trick. Let's stick to simple stuff for the moment, i.e. getting your cups and poneys printed.
It is likely that you may need to adjust temperatures to your setting. We think that it may be because the thermistor may not be exactly where it should be (how could you check under the cement ...), wiring may be different (length of resistances), etc.
You can manually adjust temperatures during printing, but you may have to react quite quickly. You should only vary in small steps, no more than 2 degrees when you experiment. We found that 2 degrees make a difference. Also remember that white and color ABS polymer do not have the same ideal melting temperature. Other polymers print at much lower temperature !
Also, there may be a problem with transport of the filament (e.g. temperature is hot enough, but plastic is not coming in because you didn't adjust the pressure wheels well enough)
Extrusion speed and pressure wheels on the extruder
- To see if the plastic moves down I painted small dots on the wire.
- Tighten quite a lot (without forcing of course). If the filament does not move, add pressure.
- Until you got it all sorted out, I recommend putting the print head in position (x max and y min, e.g. over the hole that is diagonally opposite from home). Then manually extrude about half a meter of filament at the temperature you set in the G-code file. See if the plastic flows as planned, i.e. 5mm/second ...
It is now time to understand some of the g-codes or to have a table ready (there is also one in the Operations manual).
According to Wikipedia, “G-Code, or preparatory code or function, are functions in the Numerical control programming language. The G-codes are the codes that position the tool and do the actual work, as opposed to M-codes, that manages the machine; T for tool-related codes. S and F are tool-Speed and tool-Feed, and finally D-codes for tool compensation.”
List of RapMan G-code (thanks to Bits from Bytes blog: RapMan special codes
|G0||Rapid Motion in X, Y, and Z axes.||G0 X10.0 Y20.0 Z1.15|
|G1||Coordinated Motion in X, Y, and Z axes with speed F mm/minute.||G1 X10.0 Y20.0 Z1.15 F960.0|
|G2||Arc – Clockwise (Not used by Skienforge)|
|G3||Arc - Counter (Clockwise Not used by Skienforge)|
|G4||Dwell Time||G4 S20|
|G20||Inches as units used||G20|
|G21||Millimetres as units used||G21|
|G28||Go Home (far left)||G28|
|G92||Set current as home||G92|
|M101||Turn extruder on (forward/filament in).||M101|
|M102||Turn extruder on Reverse (Still to add)|
|M103||Turn extruder off.||M103|
|M104||Set target temperature to 245.0 C.||M104 S245|
|M105||Custom code for temperature reading. Not used|
|M106||Turn fan on.||M106|
|M107||Turn fan off.||M107|
|M108||Set Extruder speed to S value/10 = 40rpm.||M108 S400|
|M220||Turn off AUX V1.0.5||M220|
|M221||Turn on AUX V1.0.5||M221|
|M222||Set speed of fast XY moves||M222|
|M223||Set speed of fast Z moves||M223|
|M224||Enable extruder during fast moves||M224|
|M225||Enable extruder during fast moves||M225|
|M226||Pause RapMan as if pause button pressed||M226|
G-code examples for the raft
This applies to our Rapman V 3.1 machine. Yours may be different.
The problems you may get with the raft can be of two sorts:
- It will not stick to the print bed and warp or worse: move
- It will stick too much, i.e. you need to take the print bed off and then remove the print with a knife or something.
The first two parameters to play with are: temperate and extrusion flow speed (RPM * 10). Both are too low in most RapMap test files if you plan to print color ABS
Here is a good setting for our machine to print the raft for the heart (HeatBase.bfb and HeartLit.bfb)
- More heat for the first layer of the raft: S239
- Fatter lines: S550 (don't use the default which I don't what it is, probably around 400). Set/Change the extrusion rate after setting the temperature (as below).
- You may lower temperature again for the second layer (as shown below). Else the raft may stick too much to the object.
In the beginning of G-code file, change both parameters <source lang="gnuplot">
M104 S239.0 M108 S550.0 ...... G code for the first layer M104 S235.0 M108 S400.0 ...... G code for the second layer
</source> Of course, an alternative to raising the extrusion rate would be to slow down the head movement speed.
The object itself was then printed with these (maybe a bit too hot).
The following temperature for the raft was too hot and too fat (had trouble to rip it off)
M104 S242.0 M108 S600.0
- Always extrude at least 30 cm of plastic at high temperature (e.g. 248 for color ABS) before running the file.
- When we started printing from a "cold" situation without extruding some plastic before hand, no plastic came out at start and then the nozzle would get stuck in some mess...
- If you plan to print a larger object, e.g. 12cm long, then make the raft temperature higher than 235 or 238 (my standard setting). The plastic will warp more and therefor attempt to rip it off. I don't have any setting yet, but I'd go for a temperature of 240 or higher and a yet fatter raft, e.g. set M108 to S600.0. But don't blame me if you can't get it off the print bed. Play it incrementally :)
Below are two red cups that are sort of acceptable.
IMHO, the result can still be improved in two ways:
- Readjust the geometry down to fractions of millimeters and tighten/align the belts
- Play more with temperature/speed/extrusion rate settings.
In any case, if yours look much worse, then there is probably something wrong in the geometry. Make sure that distances and angles of your reprap is cubic and there are no loose bolts, rods and belts.
Using the skeinforge tool to generate g-code
As we explained above, the CAM code used for RepRap is g-code and it can be created with several tools (including hand editing).
Currently, most people use either a 3D modeling or a CAD tool (see below), then export to the .STL format and then finally translate to g-code with Skeinforge. Skeinforge is a tool chain composed of Python scripts that converts your 3d model into G-Code instructions for Rapman and other fab lab tools. A more recent tool is a commercial plugin for Netfabb.
- Download and install
- Download: Skeinforge
- Download: Python (if needed)
- Unzip skeinforge.zip in some simple directory, e.g. c:\soft\
Skeinforge is moving target. As of March 2010 all the information we found is for older versions (so you need to adapt information you can find). In this wiki, read:
- Do not trust my settings below. Check your G-code file manually !!
- Example used: parametric lego duplo by Domonoky
Here are the basic steps:
(0) Run skeinforge
- Go to the directory and click on skeinforge.py
(1) Fix profile: In the pull-down menus, select
- "Profile Type" = Extrusion
- "Profile Selection" = ABS
(2) Fix parameters:
- Click on the "Craft" button. A new window will pop up.
- Fix temperatures (much too low !), e.g. for plastic color ABS:
- Base temperature (raft base temperature): 238
- Interface temperature (raft temperature): 238
- All the rest (for now): 247
- Fix flow. Click on "Speed" and set to 200 or higher, e.g. we often use 350 or 400 and sometimes even 600. Note that thickness is also affected by head speed (the feed rate), leave it 16.
- Verify the parameters defining your printer. Click on "Carve" and read Skeinforge Carve. I didn't change anything I believe. But just in case: Make sure that layer thickness is about 0.4.
- Define the "fill". By default an object will not be filled.
If you fill an object, then you can choose from three patterns and also define the thickness of the surface layers, etc.
- Click on "Chamber"
Untick "Activate Chamber".
- same for "Cool". Turn if off.
(3) Generating the G-code, fixing it and printing
- Then click on the "Craft" button in this craft settings window and select your STL file. This also can be done by clicking on "Skeinforge" in the main panel.
... then wait... this can be quite long, e.g. 60 seconds for a simple Lego brick.
- Look at the generated pictures that will pop up. If they look ok, continue.
- Examine and fix G-code. (update: If you configure skeinforge right, you don't need to do this!) I had to remove superfluous g-code from the beginning of the file and that turned on/off the temperature instead of heating it up: got rid of all M-codes I didn't understand. (M105,M115,116,117,....).
- Then print :)
Here are some pictures of the process: The generated g-code was not very smart for this kind of object. E.g. I tried cooling and that may create lot's of temperature settings that will slow down printing. Each time, there is a change, the print head will move, cool down, heat backup and go back to printing. This is why one can see this extra filaments sticking out (easy to remove).
A bad picture of the raw result. Anyhow, I was happy to learn that the printer can easily create "roofs", i.e. print over some empty space with ABS plastic.
The duplo clone has a similar dimensions, but does not fully fit. A bit too loose on bottom and slightly wrong positioning of elements on top.
Then you will have to adjust other parameters like head spead, extrusion rate and layer thinkness. After that you should learn how to calibrate printing for different kinds of parts (e.g. insides and outsides).
Choosing the Filament
According to the RepRap manuals and websites there seems to be a consensus that starting with ABS is easiest.
Filament used by RapMan's extruder is a plastic rod with 3mm diameter. You will most likely found it in specialised shops under name "welding rod" as these are generally used for welding plastic. Note that "welding filament's" come in few different shapes .. triangle cross section, circular cross section and stripes (cubical cross section). You need ones that are circular cross section 3mm diameter. Read more in Polymers.
This wiki has extra information (click on the links)
- Start with this
- Warps and needs slow printing
- needs a special print bed made out of PP/HDPE. E.g. use a kitchen plastic chopping board
- Warps a lot and needs very slow printing
- Printing in a very warm room helps (35 degrees)
- Ecological, so pretty ...
- Does not warp, must have for very large structures...
Post processing (cleanup) of prints
Prints will have imperfections.
- Remove these with a sharp cutting plyer or a knife
- Use the abrasive files you bought for assembly
As alternative or in addition get yourself a cheap multi-tool (see below). After some processing, the object will be ugly (plastic is white instead of colorful)
I found that holding it over the kitchen gas will bring back color. Take a glove or hold it with a plyer and move it quickly back and forth fairly close to the flame. Now be careful: ABS will start bending and becoming soft very fast, i.e. it will bend towards the heat source and alter its form. To prevent this for 2D objects like a paper clip, flip the object over (180 degrees to the other side).
Using a small torch
Using your kitchen stove is not really practical since the flames are too wide, i.e. when heating up a part you likely will burn another. You can get little mini-torch for about 50 Euros and in addition you also may consider buying a "multi tool" for carving, grinding, cleaning, sanding, etc. for another 50 Euros.
Disclaimer: Tested with ABS, don't blame me if you burn your office down.
Quickly pass over all the "white" areas, don't go too close or the plastic will inflame. Flip over 2D objects. I did not try to meld plastic or to smooth out a whole surface. Purpose was to (a) burn the "white away" and (b) other little things that stick out.
Open the windows or do it outside. I don't think that fumes are so healthy.
Note: You see here the bottom of the object (you can see the front side in a piece that explains how to create it). There are other imperfections, but they are rather due to bad calibration (should have made somewhat fatter lines which I did in other paperclips)
Marcus Wolschon suggested to use Acetone (retrieved 21:34, 11 March 2010 (UTC)): “As someone on HAR2001 suggested I tried out acetone to clean a printed object and get rid of the obvious self-printed look. I´m quite surprised. The surface melts from identifiable, connected strands into a single smooth and glossy surface. When I press down on the un-etched version I hear slight creaks as the infill gives way. Nothing of that in the etched version. Of cause, safety precautions are required. Use a well ventilated room and a mask rated for vapours and gas.”
Software tools and tool chain
There are three situations:
- You just want to print existing models with a minimum of hassle
- You may take existing models and adapt (or even merge parts)
- You'd like to model printable 3D objects
To model, there are several options:
- Use a difficult to use multi-purpose 3D modeling software
- Use some special purpose easy-to-use modeling software
- Use a difficult to use Computer-aided design and manufacturing software
- Scan a real object, e.g. with the low cost David Laserscanner
- Create a mashup (take several objects and combine them)
(2) Fixing the mesh
- A mesh should be printable. Use a tool like Netfabb to fix .STL files
- Meshes (different objects) may be combined / merged
(3) Create and fix the .STL
In most cases your 3D general purpose modeling or CAD program can't directly produce g-code. You first should export the model to .STL (or another format like *.PlY).
You then may need to fix your .STL model, i.e. first make sure it has the right size and the right position. But there may be more tricky issues, like repairing (use Netfabb for this)
The coordinate system of the RapMan puts the origin in the middle. To manipulate size and coordinates, there are some options:
- Use skeinforge: turn on multiply plugin in skeinforge, setting the matrix to 1x1 or another value
- Use Netfabb for more operations (that's what I use)
(4) Create G-code
Lists of tools
Selecting appropriate tools depend on several factors:
- The kind of object you want to create
- Your 3D modeling / CAD skills and/or willingness to learn sometimes (very) difficult tools
- Your budget: You can go far with free tools, but some (e.g. Blender) are really hard to learn
In this wiki you should explore software listed under CAD Software. There are many other good resources. The original author of this piece made a small compilation of 3D modeling tools and Computer-aided design and manufacturing tools.
Typical tool chain scenarios
... for beginners !
Reusing ready to print objects
- Get a model from Thingyverse (or another repository for 3D printable objects. Make sure to select one that has a "rapman" or "reprap" tag on it. A fun thing to do would be printing all the Beco blocks. Since they are all similar, you can vary printing parameters and learn about calibration of small simple object printing without having to look at the same object...
- You likely will find almost directly usable .STL files, but you may have to align them to x/y/z = 0. You also may find various source formats produced with various 3D modelers.
- Import to skeinforge or netfabb and generate g-code. In both cases, make sure that it sits in the right position.
- Then verify the g-code manually
Build an easy model with an easy 3D modeler
- Build a model with Google sketchup
- Export to Collada .DAE
- Import to Meshlab and save as .STL
- Import to NetFabb and repair, then save as .STL again
- Import to skeinforge and produce g-code
- See Sketchup 3D printable objects tutorial for an example
- Do as above, i.e. either build 2 or more models or grab them
- Import all to Meshlab as "layers", flatten the layers and export as .STL
- Then as above
A last word of advice
- At some point you really must understand the interaction of relationship between Head speed (how fast the extruder moves on the X/Y axis) and extrusion Rate (RPM, how much plastic comes out) and how they impact Layer thickness.
- Also play with temperatures. E.g. 247 for ABS may be too much.
- Make sure that your .STL files have the x/y/z values set right. Minimal z value = 0. The middle of the object should roughly sit on x=0 and y=0. Get the free Netfabb Studio to achieve this. Also use this software to clean up bad .STL files.
- Then move on and try to figure out how to calibrate for different parts of objects and different kinds of objects. As we mentioned before, Skeinforge documentation is not easy to understand (in the absence of better you can wade through the forums or read this or buy the for RapMan Basic software.
- Home print head with the menu in the board and switch it off/on after each printing (in particular if you print high objects or if you manually moved the extruder).
- Do not leave your printer unattended ! Make sure that filament wheel turns smoothly and that the pressure wheels are tight: Tighten quite a lot (without forcing), then untighten when the motor stops, i.e. you hear a loud clicking.
- Once you figured out how to print good quality ABS prints, consider printing some Spare Parts
- Bits from Bytes. Sells RepRap kits (£750 / CHF 1270).... i.e. the one we describe here.
- The forum is the place to look for advice and help.
Research Reprap 3D printer
- RepRap, a British project, is short for Replicating Rapid-prototyper. This 3D printer builds the parts up in layers of plastics. It can be assembled from parts bought in various places.
- RepRap Project (Wikipedia)
Google sketchup is probably the easiest tool for beginners.
For 3D printing you then need specific tools to repair STL files and to generate the g-code:
- Skeinforge (a tool chain for producing g-code)
- The skeinforge announcement and troubleshooting blog
- download of the software
- netfabb (an integrated software tailored for additive fabrication, rapid prototyping and 3D printing)
- Official netfabb website
- can resize, position and repair STL.
- A base version (netfabb Studio) is free, Netfabb professional is 700 Euros (plus VAT), educational pricing is available on demand.
- A commercial reprap plugin can generate g-code. I.e. this is an alternative to skeinforge.
- SolidView light (not needed)
- SolidView light is a free program with support for SFX, STL, SolidWorks, VRML, and OBJ CAD files. I.e. it can be used to look at STL files.
- Pleasant3D (not needed)
- Pleasant3D Visualization of STL plus minor editing in order to be printable on MakerBots/Rapmans: Move, rotate, resize.
- Meshlab (not needed, to convert files to .STL and to merge .STL files)
- See Meshlab for RapMan tutorial. Meshlab is the open source, portable, and extensible system for the processing and editing of unstructured 3D triangular meshes.
- BCC Video / early 2010)