Laminated Object Laminated Object Manufacturing Manufacturing (LOM)(LOM)

DevelopersDevelopers Helisys Corporation located in Torrance, Helisys Corporation located in Torrance,

CACA Michael Feygin in 1985 as president of Michael Feygin in 1985 as president of

Hydronetics, Inc., which at that time was Hydronetics, Inc., which at that time was located in Chicago, IL. In 1989, the located in Chicago, IL. In 1989, the company changed its name to Helisys, company changed its name to Helisys, Inc., and relocated to Torrance, CA.Inc., and relocated to Torrance, CA.

Principal commercial provider of LOM Principal commercial provider of LOM systems, Helisys, ceased operation in systems, Helisys, ceased operation in 2000. However, several other companies 2000. However, several other companies have similar LOM technology.have similar LOM technology.

SizesSizes

There are currently two sizes of There are currently two sizes of LOM’s availableLOM’s available

LOM 1015 – 10”x15”x14” (build LOM 1015 – 10”x15”x14” (build area) cost of $95,000 area) cost of $95,000

LOM 2030 – 20”x30”x24”LOM 2030 – 20”x30”x24”

cost of $180,000 cost of $180,000

LOM 2030LOM 2030

Click here to view a picture of a Laminated Object Manufacture machine from Helisys.

Materials InvolvedMaterials Involved 1. Paper (most common)1. Paper (most common) 2. Plastics2. Plastics 3. Composites3. Composites 4. Metals4. Metals 5. Ceramics5. Ceramics

ProcessProcess Hybrid process which involves adding Hybrid process which involves adding

and subtracting material to create a and subtracting material to create a partpart

Feed spindle supplies the material and Feed spindle supplies the material and a Take-up spindle controls the excess. a Take-up spindle controls the excess.

Layers the material with thickness Layers the material with thickness ranges from 0.001 – 0.005 inchesranges from 0.001 – 0.005 inches

Each layer is cut with a CO2 laserEach layer is cut with a CO2 laser

ProcessProcess The laser is on a carriage which The laser is on a carriage which

controls the x direction and the lens controls the x direction and the lens moves to control the y direction.moves to control the y direction.

The material is mounted to a plate The material is mounted to a plate which moves along the z axis.which moves along the z axis.

De-cubing (removing material from De-cubing (removing material from the formed cube which houses the the formed cube which houses the part)part)

ProcessProcessMaterial is usually a paper sheet laminated with adhesive Material is usually a paper sheet laminated with adhesive

on on one side, but plastic and metal laminates are one side, but plastic and metal laminates are appearing. appearing.

1. Layer fabrication starts with sheet being adhered to 1. Layer fabrication starts with sheet being adhered to substrate with the heated roller.substrate with the heated roller.

2. The laser then traces out the outline of the layer.2. The laser then traces out the outline of the layer. 3. Non-part areas are cross-hatched to facilitate 3. Non-part areas are cross-hatched to facilitate

removal of removal of waste material.waste material. 4. Once the laser cutting is complete, the platform 4. Once the laser cutting is complete, the platform

moves moves down and out of the way so that fresh down and out of the way so that fresh sheet material sheet material can be rolled into position.can be rolled into position.

5. Once new material is in position, the platform moves 5. Once new material is in position, the platform moves back back up to one layer below its previous position.up to one layer below its previous position.

6. The process can now be repeated.6. The process can now be repeated.

ProcessProcess LOM differs from the systems LOM differs from the systems

previously reviewed in that, rather previously reviewed in that, rather than building up a part by adding than building up a part by adding materials to a stack through a materials to a stack through a forming process, layers of sheet forming process, layers of sheet materials such as paper, plastics, or materials such as paper, plastics, or composites are attached to a stack, composites are attached to a stack, and the laser cuts away the unused and the laser cuts away the unused portions.portions.

LOM ProcessLOM Process

Click here to view a diagram of the LOM machine and more information from efunda.com.

ResultsResults The excess material supports overhangs and other The excess material supports overhangs and other

weak areas of the part during fabrication. The cross-weak areas of the part during fabrication. The cross-hatching facilitates removal of the excess material. hatching facilitates removal of the excess material. Once completed, the part has a wood-like texture Once completed, the part has a wood-like texture composed of the paper layers. Moisture can be composed of the paper layers. Moisture can be absorbed by the paper, which tends to expand and absorbed by the paper, which tends to expand and compromise the dimensional stability. Therefore, compromise the dimensional stability. Therefore, most models are sealed with a paint or lacquer to most models are sealed with a paint or lacquer to block moisture ingress. block moisture ingress.

The LOM™ developer continues to improve the The LOM™ developer continues to improve the process with sheets of stronger materials such as process with sheets of stronger materials such as plastic and metal. Now available are sheets of plastic and metal. Now available are sheets of powder metal (bound with adhesive) that can powder metal (bound with adhesive) that can produce a "green" part. The part is then heat produce a "green" part. The part is then heat treated to sinter the material to its final state. treated to sinter the material to its final state.

De-cubingDe-cubing

Click here to view an example of de-cubing.

SoftwareSoftware It comes with LOMSlice™ software It comes with LOMSlice™ software

which controls the operation. which controls the operation. Uses STL files which are Uses STL files which are

downloaded into the LOMSlice™downloaded into the LOMSlice™

Typical UsesTypical Uses Investment casting patternsInvestment casting patterns Concept verificationConcept verification Masters for silicone-rubber Masters for silicone-rubber

injection toolsinjection tools Fit-checkFit-check Direct useDirect use

Example PartsExample Parts

Example 3Example 3

Example 1Example 1

Example 2Example 2

Click on the links below to see examples of parts.

AdvantagesAdvantages Ability to produce larger-scaled Ability to produce larger-scaled

modelsmodels Uses very inexpensive paperUses very inexpensive paper Fast and accurateFast and accurate Good handling strengthGood handling strength Environmentally friendlyEnvironmentally friendly Not health threateningNot health threatening Precision claimed to be Precision claimed to be ±±0.005 in. 0.005 in.

DisadvantagesDisadvantages Need for decubing, which requires a Need for decubing, which requires a

lot of laborlot of labor Emission of smoke or fumesEmission of smoke or fumes Can be a fire hazardCan be a fire hazard finish, accuracy and stability of finish, accuracy and stability of

paper objects not as good as paper objects not as good as materials used with other RP materials used with other RP methods methods

ReferencesReferences Rapid Prototyping TechnologyRapid Prototyping Technology http://home.att.net/~castleisland/http://home.att.net/~castleisland/

lom_int.htmlom_int.htm http://www.designinsite.dk/htmsider/http://www.designinsite.dk/htmsider/

p0055.htmp0055.htm http://mtiac.alionscience.com/pubs/rp/rphttp://mtiac.alionscience.com/pubs/rp/rp

36.htm36.htm http://www.efunda.com/processes/http://www.efunda.com/processes/

rapid_prototyping/lom.cfmrapid_prototyping/lom.cfm