NDM Rapid Tooling Process for Aluminum

and Thermoplastic Parts

Paul ArmstrongJohn 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 of NDM

Core and Cavity

• Process yields excellent tool finish• Captures intricate detail

Core in Universal Base

• 600,000 shots and still running

Cavity

• Ideal for geometrically complex shapes

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.

NDM Process Steps

Step 1 – Engineering Review

•Prep of e-Prep of e-modelmodel– Add shrinkAdd shrink– Add draftAdd draft

Step 2 – Build Pattern

•Create master Create master modelmodel– SLASLA– CAMCAM

Step 3 – Rubber Mold

•Create patternCreate pattern– Negative Negative

impression from impression from mastermaster

– Using RTVUsing RTV

Step 4 – Prepare Mold

•Treat rubber mold Treat rubber mold with mold releasewith mold release

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 10- Run PartsStep 10- Run Parts

•Cavity mounted in mold base

Step 10- Run Parts

•Core with ejector pins out•Note gates and runners

Step 11- Finish part

• Raw casting with runner still attached

Step 11- Finish part

•Casting – both sides•Runner now removed•Part ready for de-flash

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

Injection Molded Plastic

•Plastic- Noryl 873

MIM- Metal Injection Molding

• Nickel/ Steel Alloy

Questions

www.armstrongmold.com

Paul Armstrong - sales@armstrongmold.com

John Mathews - jmathews@armstrongmold.com

To Obtain Information Regarding The Licensing of The NDM Process Contact:

B&D Sales Corporation19 Fifth Avenue

Cranston, RI 02910sales@bdsales.com

401-781-4810Fax: 401-781-5580