SLA design guide
1. General
2. Wall thickness
requirement | parameter(mm) |
---|---|
keep strength | >2.0 |
keep the appearance | >0.8 |
the minimum thickness | >0.4 |
There are different thickness walls. After checking the appearance and strength. Designer should make sure the thickness bigger than the above parameter or the model might have risk.
3. Column
We need at least following parameter to keep enough strength:
- The diameter of round column at least 2.5mm;
- The size of square column at least 3mm*3mm
If the parameter less than the above parameter, the model may failure:
- For blue part in the above picture
- Scraper may broke the model before solidify the next layer of model;
- The vibration of ultrasonic cleaning machine may broken the model;
- Some small accident during transport may broken the model;
- For yellow part in the above picture: The model would bend because of outside environment;
4. Hole
- The diameter of round hole should be at least 1.2mm, or the hole may close off;
- The size of square hole should be at least 1mm, or the hole may close off.
In addition, the 3D printing hole would be a little small than design. If designer has requirement in size, engineer and designer can use machine to enlarge it.
5. Text
The laser of SLA machine has minimum laser spot size. So the heigh of model need safety value( the minimum text height )
Limit value(mm) | Safety value(mm) | |
---|---|---|
Embossed text | 3 | 4 |
Engraved text | 2.5 | 4 |
6. Bridge
The safety value should be less than 8mm, or we need support for bridge
7. Overhang angle
Normal ,the overhang angle over 40 in model should add support, but we don't need support in this model because it is short and thick
8. Cone
I need support to measure it9. Circle
In prototype measure, almost every direction would scale for 99%.
10. Groove
Width\Thickness | 0.2 | 0.4 | 0.8 | 1.0 |
---|---|---|---|---|
1.0 | OK | OK | OK | OK |
0.9 | OK | OK | OK | OK |
0.8 | OK | OK | OK | OK |
0.7 | OK | OK | OK | OK |
0.6 | OK | OK | OK | OK |
0.5 | OK | OK | OK | OK |
0.4 | OK | OK | OK | OK |
0.3 | OK | OK | OK | OK |
0.2 | NO | NO | NO | NO |
0.1 | NO | NO | NO | NO |
The conclusion is width bigger than 0.3mm, thickness bigger than0.2mm.