nTopology Masking Plugs for Drill Press Casting

Last crawled date: 1 year, 12 months ago

A. Company Name and Industry:
I work at ATI metals, where we 3D print parts for aerospace applications.

B. Job Title and Responsibilities:
My name is Austin Brittain, and I am a process engineer at a metal additive manufacturing facility in Connecticut. I help find ways to make the metal 3D printers run more reliably and produce high quality parts for our customers.

C. Application Information:
When I first saw the nTopology fixture generator, its utility was immediately clear to me. From time to time at work we find it necessary to bead blast or grit blast a surface on a part after it has returned from machining. Usually we mask off the machined surfaces with tape and very carefully blast the surfaces that need retouching. The tape application process is very time consuming though, and it would be nice to have reusable plugs that could be moved from part to part quickly.

I cannot post pictures of customer parts on the internet though, so at first I was stumped on what to enter into the competition. As I thought about it, my mind drifted to one of my many side projects. I am restoring an old drill press that I bought at a junk shop, and its castings are covered in rust and grime. The makerspace I belong to just got a blasting cabinet, which would quickly remove the rust, but I was worried about damaging the delicate machined surfaces on the inside of the part. The Statasys nTopology fixture generator was the perfect solution! In an afternoon, I was able to design a part that was representative of the casting, make plugs for all the holes, and quickly export them. Now I can print these plugs and get to blasting.

D. Project Challenges and Goals:
My goal for this project was to finish my first nTopology project. I saw a demo at work a few months ago, and I have wanted to try the software ever since. I had no trouble making plugs for the holes in the castings, but I was not able to get the surface enclosure tool to work. I substituted the surface masking tool with an overhang, and I think that will work for me. Making a whole model of the casting just to make hole plugs was definitely overkill, but It gave me design practice. If this were a work project, we would already have the model from the customer, so the modeling work would be almost eliminated. I look forward to using the remaining days on my trial to further explore this powerful software.

E. Alternate Manufacturing Technology:
All of these plugs could be produced on a lathe if necessary.

F. Additive Advantages:
Setting up a lathe for a run of custom plugs would be a less efficient use of resources than letting a small 3D printer run overnight. 3D Printing would allow the plugs to be made with elastomeric materials which would otherwise be difficult to machine.

G. N/A

H. Use of nTopology
nTopology provided a very streamlined workflow to get from model to fixture. If I had already had a model of the part, I could have had masking plugs designed in minutes. This would be a huge timesaver if I had a situation that required a lot of surfaces to be protected from blasting.

I. Company Printers:
We have several Laser Powder Bed Fusion and Electron Powder Bed Fusion machines at work. We also have access to a Stratasys FDM 3D Printer at one of our other locations. We also have a cantankerous xerox color laser printer. At the makerspace where I will be working on my drill press project, there are a number of Prusa printers.

J. Future Printers:
I do not think I am in a position to discuss this. I think it would be awesome if we got more though.

4. Material:
I will be printing these parts out of PLA on my personal 3D printer, because that is the material that is available to me. The layer thickness will be .1825 mm (calculated from my leadscrew) and I will uses a standard .4mm tip. Ideally I would print these parts on a Stratasys Fortus series machine, in black TPU 92 A. The elastomer would conform to the rough surfaces of the casting, and It would have the abrasion resistance to survive the blasting cabinet.

5. Impact Statement:
This drill press may be a box of parts right now, but those parts go together into a beautiful, antique too. Since the drill press is so old, if I make a mess of a critical surface I cannot go get another. I have one shot at this, and the masks I created using nTopology will help me get this right the first time. A cutting edge tool from this century will make it possible to restore a cutting edge tool from the last. I think that is pretty cool.