Community guideTips & tricks / Racking & hanging
How part orientation and fixturing affect results
AMT’s vapor smoothing systems run under vacuum, which, in AMT’s words, allows the vapor “to travel freely, condense on hard-to-reach areas of the part, and smooth them evenly”. That is why complex parts and lattices smooth well. How you hold the part still matters, for a few simple reasons.
Contact points
Wherever a part touches a rack, a hook or another part, the vapor cannot reach that spot in the same way. Plan contact points:
- on faces that are hidden, will be assembled, or are not cosmetic;
- as small as practical, but secure enough that the part cannot move or fall;
- away from sealing faces, if the part needs to be sealed all over.
Spacing
Give the vapor room. Parts that touch each other, or are packed so tightly that they shadow each other, can come out uneven where they meet. Spacing is a trade-off with how many parts fit in a run; your first few runs are the time to find your balance.
Orientation
Think about which faces matter most, and keep them clear of contact points and away from neighboring parts. For parts with internal channels, orient them so the channel openings are not blocked by the rack.
Talk to your application engineer
Rack layout and the process recipe go together. Your AMT application engineer sets the recipe for your parts, and loading is part of the same conversation, especially for large, heavy or flexible parts.