NLA: DeWalt DW708 Mitre Saw "Dust Extactor"

In which the awesome power of 3D printing resurrects an obsolete part

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My father-in-law is a very talented artist and maker, building elaborate stage sets for his local community and school theaters, among other projects. He has a lovely, enviable workspace a few steps outside his door, stocked with a full wood shop.

He recently contacted me and asked if I could reproduce the Dust Extractor nozzle for his beloved DeWalt DW708. The part is somewhat fragile, and having been knocked a few times, repaired a few times, he discovered, to his irritation, that DeWalt had discontinued the part, classifying it as "obsolete". There is no replacement option.

He lives a ways away, and I couldn't 'pop round' to examine the saw, so we used the mail to send the parts back and forth. I made detailed measurements of the original and then replicated the general shape in Tinkercad.

Tinkercad is NOT the best tool for industrial design, but I am very familiar with its capabilities (and the price is right). I increased the dimensions of the mounting flange, requiring mounting bolts that are 5 mm longer than the original. Not realizing that the overall length is a critical dimension, my first iteration was too long to fit without binding. After some feedback on how version 1 fit, I also made some subtle changes to the the mounting face.

Version 2 reportedly mates to the saw "better than the original"

Print Settings

Printer Brand:









0.20 mm layer height


50% for strength


The overall form factor lends itself well to 3D printing without support. I stuck a brim on the bottom to keep it stuck on the bed. I also designed some integral support for overhangs at the mounting face. Lastly, there are removable support vanes inside the bolt slots and under a curved overhang.


The part needs a little clean-up before use. Remove the brim: Snap it off with a pliers and file smooth as desired. Pluck the supports from inside the bolt slots, trim remnants with Xacto blade Other supports: There are three vanes that support a convex overhang where one of the mounting bolts must go. A deft swipe with an Xacto blade removes these easily enough.

Good enough is good enough, but I lavished a bit of obsessive trim work on the clean-up, just to make it look nice.

How I Designed This

As mentioned, I used Tinkercad to design this. I made a detailed sketch of the pat and then measured critical dimensions with a digital caliper. I took liberty with the dimensions of the mounting tabs and the length of the part. The mounting tab was a win, but the greater length caused clearance issues for the first iteration.

There are a lot of "union" and "difference" operations in building out this part. I find that constructing subassemblies, saving them as discreet STLs and then putting them all together at the end avoids a lot of manifold error problems. Finally, I used Microsoft's Netfabb STL repair tool, and converted the fixed file from 3mf format back to STL's in MeshLab.

The part printed in about 3 hours.


Dust Extractor nozzle for DeWalt DW708

Standard Tesselated Geometry - 1.10 MB - 01/30/2018 at 21:49


  • 2 × 5 mm longer bolts, M5

  • Hack Life

    theschlem01/30/2018 at 22:32 0 comments

    One of the lessons I took from this project was to check your assumptions / know the context in which a part functions.  I didn't understand how the part fit into the entire saw assembly and assumed that I could make it longer for the sake of my design convenience.  A longer part allowed me to smoosh two assemblies together, optimizing air (and sawdust) flow through the part.  The first version of the part was - surprise, surprise - too long.  It hit the motor on top of the saw, effectively negating all the nice work I'd gone to, to make it fit well.  

    I only revised the part once, but when given the opportunity, I decided to tune up a few minor details that bugged me, making me happier with the final product. 

    Lesson: Look not just at the part you need to make, but how it fits into the entire assembly. Expect iteration, but don't sabotage yourself!  

    Corollary: If you think it's perfect in V1.0, it probably ain't.

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  • 1
    Print, trim, use

    No tricks.  Nothing to see here.

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