Download - NDM Rapid Tooling Process for Aluminum and Thermoplastic Parts Paul Armstrong John Mathews
NDM Process
• Patented program
– Owned & licensed by B&D Sales Corporation
• Under development for several years
– Continuing R&D for improvement
• Armstrong Mold and B&D Sales working jointly to:
– Increase the number of applications– Expand industries that can utilize this
procedure
Topics
• Benefits of NDM• Design considerations• Process steps• Case study• Where do we go from here??
Benefits
• Versatility– Die casting
– Thermoplastic injection molding
– MIM (metal injection molding)
• Fast turnaround, low cost– 2 weeks from CAD file to part
• Mold hardness– Extended tool life
• Quick cavity duplication – Ideal for multi-cavity molds
Design Considerations
• Cavity/Core insert size
– 1” x 1” x 1” to 4” x 6” x 2”
• Complex angular/curvaceous shapes
• Part materials
– Aluminum
– Most thermoplastics
– Most MIM materials
• Draft angles
– Industry standards with radii and fillets
Design Considerations
• Wall thickness– Die casting industry standards
– Injection molding industry standards
• Tool life– Prototype quantities to 100,000+
Process Comparison :Injection Molded Plastics
Lead Time (Wks)
Tool Life
Cost Heat Transfer
Cavity Finish
M/C AL 4-5 Fair Low Excel. Good
M/C Pre-hard
5-6 Good Med Good Good
M/CHardened
6-7 Excel. High Good Excel.
Cast AL 3-4 Fair Low Excel. Good
Cast Kirksite
3-4 Fair Low Excel. Good
NDM 2-3 Excel. Low Excel. Excel.
Process Comparison:Metal Die Casting
Lead Time (wks)
Tool Life
Cost Heat Transfer
Cavity Finish
M/C Pre-hard
5-6 Good Med Excel. Good
M/C Hardened
6-7 Excel. High Excel. Excel.
NDM 2-3 Excel. ? Low Excel. Excel.
Step 1 – Engineering Review
•Prep of e-Prep of e-modelmodel– Add shrinkAdd shrink– Add draftAdd draft
Step 3 – Rubber Mold
•Create patternCreate pattern– Negative Negative
impression from impression from mastermaster
– Using RTVUsing RTV
Step 5- Fill Mold
•RTV molds filledRTV molds filled•Stainless steel Stainless steel
powder powder •Proprietary binderProprietary binder
Step 6 - Baking
•Green work piece is baked Green work piece is baked •Removes liquid binderRemoves liquid binder
Step 7 – Furnace Cycle
•Work piece is heated in vacuum Work piece is heated in vacuum furnacefurnace•Burns off binderBurns off binder
Step 8 - Infiltration
• Infiltrate with bronze to full Infiltrate with bronze to full densitydensity
Step 9 – Prep Inserts
• Finish inserts and prep for mold baseFinish inserts and prep for mold base• Rig moldRig mold• Load into die cast machineLoad into die cast machine
Step 12- Finished Part
•Finished part–Machined in tight tolerance features–Satin Nickel Chrome Plating
• < .001” thick
Case Study - Camera Housing
• Initial prototyping – SLA – CNC hogouts
• DFM analysis– Improved casting design
• RPM casting– Initial 20 prototypes– Aluminum (functional)
Case Study - Camera Housing
• Product development refinement cycle– 3 revisions– Samples via RPM
• Bridge to production– RPM for 4000 parts
• RPM cost– Tooling: $5,000– Casting: $19.85 each
Case Study- Camera Housing
• CAD to usable die-cast parts– NDM in only 4 weeks
• NDM cost– Die: $12,000– Casting: $3.30 each
• Tool payback/breakeven– 725 pieces
• Ramp up– RPM: 100 per week per tool set– NDM: 1,000’s per week
Where do we go from here?
• Larger parts• Faster turnaround • Compete with off shore and others
for production applications
Where do we go from here
–Apply to other processes•MIM-Metal Injection Molds• Thermoplastic Injection Molds•Investment wax tools
To Obtain Information Regarding The Licensing of The NDM Process Contact:
B&D Sales Corporation19 Fifth Avenue
Cranston, RI [email protected]
401-781-4810Fax: 401-781-5580