SLA®
Frequently Asked Questions
Q: What material does stereolithography prototyping use?
A: The resins used in our SLA® machines are photosensitive epoxy polymers. Currently, Dinsmore & Associates employs three stereolithography resins in our machines. WaterShed© XC 11122, ProtoGen™ 18420, and NanoTool™. The WaterShed© XC 11122, the newest of our innovative resin lineup, provides the best moisture and humidity resistance of any SLA® resin, in addition to excellent clarity.
Q: What tolerances can the stereolithography process hold?
A: Published tolerances of the models are +/-0.005″ (0.127mm) for the initial inch, plus an additional 0.0015″ for each additional inch. If higher accuracy parts are needed, please contact us; we can accommodate you.
Q: How can I ensure that raised text on my prototype is legible?
A: We have made a graphical guide that should help you. The height of the text should be a minimum of 0.015″high, and the cross section of the text should be 0.015″ or thicker. Text thinner than this cannot be reliably traced with the 0.010″ thick laser beam.
Q: How does Dinsmore & Associates price parts?
A: Projects typically range from $195 to $495. The following factors influence pricing:
- Z-axis height
- Volume
- Complexity
- Number of parts
The per-part price decreases as more parts are ordered until the point where there are too many parts to fit on a single run of one of our SLA® machines.
Q: What size parts can be produced?
A: Dinsmore & Associates largest machine has a build envelope of 20″ x 20″ x 24″; however, multiple SLA® prototypes can be glued together to create larger prototypes.
Q: What is the smallest feature that can be produced?
A: In standard resolution, the minimum feature in the X-Y plane is 0.010″ and the minimum in the Z axis is 0.016″. In high resolution, the 0.003″ laser beam spot enables smaller features. Dinsmore & Associates recommends a minimum wall thickness of 0.020″ for prototype support.
Q: What colors can be produced?
A: Stereolithography prototypes can be dyed, painted or plated in virtually any color.
Q: What kinds of finish options are available on SLA® prototypes?
A:
| Level | Finish | Description |
| Level 1 | Strip and ship | Remove supports No sanding |
| Level 2 | Standard finish | Remove supports Lightly sand to 150 grit Bead blast |
| Level 3 | Foundry pattern | Remove supports Sand to 220 grit Remove ~95% of the build lines |
| Level 4 | Mold ready | Remove supports Sand to 320 grit Remove ~100% of the build lines Prime and putty |
| Level 5 | Presentation | Remove supports Sand to 320 grit Remove ~100% of the build lines Prime, putty, and paint Matte gloss |
| Level 6 | Clear coat | Remove supports Lightly sand support surface to 320 grit Clear coat |
| Level 7 | Water clear | Remove supports Sand to 600 Remove ~100% of the build lines Clear Coat |
Q: What temperatures can SLA prototypes withstand?
A: The standard epoxy resin has a heat deflection temperature of 144°F and high temperature epoxy resin has a heat deflection temperature of 392°F.
Q: Can stereolithography prototypes be machined?
A: Yes, SLA® prototypes can be drilled and tapped, milled, or put on a lathe.
Q: Why should you use SLA® versus another rapid prototyping technology?
A: The accuracy and surface finish of SLA® are unsurpassed by any of the competing technologies, such as selective laser sintering (SLS®).
Q: How long does it take to build a part?
A: A typical order of prototypes is shipped out two days after receipt of order. Most parts build in less than 12 hours.
