3D Printing Group

why My partner insist to make auotomotive parts by &FDM 3D printing and vacuum casting instead of MJF or SLS 3D printing? 

Backgroup:

1. The autotive parts is large. At first, the partner donot permit slipt. Finally he accept.
2. The quantity is just 1 pcs.
3. The material:At first, the partner donot tell us material requirement. According to our experience, usually, PA 11 Or PA12 Nylon is commonly adopted in MJF or SLS for auotmotive parts. While in Vacuum casting, the common material is ABS Like, PP Like, soft rubber, Nylon like, sometimes Carbon fiber material.etc. FDM common material is ABS filament for this kind of auotmotive parts. SLA material is Resin.

At first sigtht, when we participate this project, we suggested the right material and right solution is MJF or SLS with Nylon material.

But the partner insist to produce it by FDM 3D printing or vacuum casting.

A. First choice: FDM 3D printing cost is USD3800, Material ABS. we use 1m printing size FMD 3D printer to print it.

B. Second choice: Vacuum casting : we should make prototype by SLA 3D printing or CNC and then make it.

Its cost is obvious higher.

C. Third choice: SLA 3D printing: With the best industrial resin, its cost is USD1250

D. Forth Choice: HP MJF or EOS SLS: Its cost is USD890,Nylon material, slipt and assemble acceptable.

I feel doubts about this.

And this partner usually perfer to adopt FDM instead of SLS or MJF to print industrial parts.

Why?