How to Build a Part Using a Layered Manufacturing
Technology - StereoLithography (SLA)
CAD MODEL & STL FILE GENERATION
- Generate a three-dimensional computer-aided design model of an object. You can do this by using CAD software, IDEAS.
- Convert this CAD file into a STL file.
* Under File
* Select Export
* Choose Rapid Prototype File, and select the part.
* In this window choose (SLA 190) under - Prototype Device and type (0.02) under - Absolute Facet Deviation. In the output file select (binary).
- Check your directory to make sure that an .stl file has been created.
Figure 1: I-DEAS Screen
TRANSFER STL FILE TO COMPUTER LAB D115
- For students this can be done this way in D115:
* Hit the Start button
* Choose Programs
* Select Windows NT explorer
* Go down to Homedir on "the brain.Rutgers" (Z)
* Select the uo folder
* Open the folder of your username and you should see
all your current files.
* Save the .stl file to the c: drive under the temp folder.
and also save to your zip disk.
Converting STL file into build files using 3dlightyear
Figure 2: Lightyear Screen
- Log in to a computer in D115
- Hit the Start button
- Choose Programs
- Select 3D lightyear 1.00
- Once the window is open, under file menu select Machine Setup Wizard.
- Another window will show. Type anything desirable under Name and select (SLA 190) under Machine type. The other parameters are okay and dont need to be change. Click Next (4 times) until a big window shows. Click Done.
- Open the file you save in the c: drive under the temp folder.
Note: Dont open the file from your zip disk since the software 3D lighthyear will not create the supports for the part if you do it this way.
- Under Edit menu, Select the part.
(Refer to the Graph of the last page)
- ( #1 ) Under Edit, Rotate the part as necessary. Once the rotation is done click button Automatic STL placement on the menu display in the left-hand column of the 3D-lightyear screen. (See Picture).
- ( #2 ) Verify your .stl file with the button located in the menu of the left-hand column. (The red cross button, See picture). Make sure the .stl file is good and the part is successful. If the part or .stl file is not good hit the same button one more time. The part should be ready now, but if the part is not ready still, you must examine your CAD file for any incomplete surfaces, etc. Do not continue if the file is not verified.
- ( #3 , #3a ) Create Supports with another button located in the same menu (See picture). The supports should display in the screen. Edit Supports with the next button if necessary. In the edit support window you can click on Custom Draw and see the different support regions. Click on the different regions and delete the ones that are not needed. Once you delete them go to File and chose region apply this should be in the same Custom Draw window. Close this window and hit Support and Regions under the Edit support window. Finally close this window.
- It is not necessary to Modify your Build Style when using the SLA 190.
- ( #4 ) Modify the Re-Coat styles for the SLA 190. Edit the Z level wait for the recoat styles. Usually the Support recoat should be very fast and the Z level wait time for this recoat is fine. The Part recoat parameters will be very long, and half of the Z level wait time is more than enough. (Check the Recoating Z-wait recommendation table)
- ( #5 ) Finally Prepare your file. By doing this you will create the four build files needed to build the part in the SLA machine: .l, .r, .v, .prm. Once you prepare the part you can see this files by following the next procedures.
* In the E: drive
* Choose Program files
* Select 3D systems
* Click 3D lightyear
* Choose build, and you should see these four files created. Save
the files in your zip disk.
Figure 3: Recoating Z-Wait Recommendation table
Figure 4: Critical Circle Diameter Definition
Build Part Using SLA-190 Machine
- Preparing of the SLA machine.
- From Main Menu, select toolbox
- From Toolbox, select utilities From utilities, select Power Sequencer. The status of the laser, heater, and shutter should be displayed at the bottom of the screen. Turn the laser and heater on. The laser should be on for approximately 20 minutes before building any part. The power level of the laser should reach a power between 26 mW-35mW. You can check the power level of the laser by choosing Beam Analysis under the utilities menu.
- From utilities, choose vat utility. This is basically done to check and adjust the resin level of liquid in the SLA machine.
- From Vat Utility, chose Adjust Resin Level Utility. Add liquid if necessary.
- FTP the four build files to SLA machine.
- The next step is FTP the files created by 3D lightyear into the SLA machine.
- First save the files from your zip disk to the e: drive under the temp folders to the computer in the SLA room.
- From toolbox, choose DOS menu
- From DOS menu, choose DOS
- A new window will show, type the following commands
- C:/work> FTP 188.8.131.52 (Connects to the IP address of the computer in the SLA room)
- Type username and password. Username can be "undergraduate". Password is "effort".
- ftp> pwd (it tells you what directory you are using)
- ftp> cd e:/ (changes directory to the e: drive)
- ftp> cd e:/temp (sees the files save in the temp folder of the e: drive)
- ftp> ls
- ftp> mget (name of file).* (name of file corresponds to the name of the STL files)
- ftp> bye
- c:/work> menu (goes back to menu)
- Under menu select Build.
- Type the name of your part and press Enter to begin building.
- If there is a lot of memory in the SLA machine from previous building parts, you must re-start the computer. (ctrl+alt+del).
- If your building process was interrupted, you can try the following way to continue to build your part. Under Menu Select Build. Then type this in the build window: restart/Build_fileName.
- Post processing of the part
- Remove the support structure.
- Clean the part twice. The 1st time use alcohol. The 2nd time use chemical water. They are all available in SLA lab.
- Put the part in the laser chamber for post curing because the part was only solidified by 80% during building process.