Multi-Color 3D Printer

[Kean]

For the bumpers, you might want to try using TPU filament.  I've read up on the options, but not yet tried it myself.

With something like the designs shown, I think you may need to adjust the model to bulk up any thinner sections as it will likely be too flexible.  You could also possibly do a part part print, with the TPU being  design as an "overmold" to get the best properties of both filaments.  If going into mass production, you can then get the overmold made in silicone.

When selecting a TPU filament, you will probably want to get one with a higher hardness rating like 95A.  The softer ones are great when you want flexible parts, but are notoriously difficult to use in some 3D printers.  Printing TPU requires a direct drive extruder.  Do a bit of a search for other users experience with your specific printer and TPU.

[xrunner]

For the bumpers, you might want to try using TPU filament.  I've read up on the options, but not yet tried it myself.

Haven't tried it yet myself because I haven't had a reason to, but I need to get a roll now and experiment with it.

OK so here's my final take on the bumper design. I wanted the edges to fit more like the bumpers shown on the Rigol function generator shown.

The white panel is only for testing and doesn't have any other purpose yet. I ended up recessing the tabs that the screws go through 1.5 mm. This so the tabs won't be seen and at the same time the front panel will have a clean fit with the edge of the "bumpers". Then I added a 1.5 mm rib on each inside edge of the panel to take up the space at each edge of the case created by recessing. These parts were printed with a 0.6 mm nozzle at a layer height of 0.2 mm for a faster print, but for the final versions I'll do 0.15 mm.

I think I'll make a post in the thread below later with the Fusion 360 files if anyone is interested.

https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/

[mawyatt]

That looks good!! Is the extrusion painted on outside, and what size?

The one we posted is a 110mm by 50mm extrusion that is in two parts, top and bottom that slide together.

Best,

After I re-sized the "bumpers" I think the looks are good. Question for you: you don't show any front or back panels attached yet. In your design, does the panel go under the screw tabs or over them? This has to do with another design idea I am thinking about.

Were you planning on using any slip-proof material on the bottom bumpers? The plastic is not a great material for feet, so I plan on using some thin adhesive rubber on the bottom of the plastic bumpers which would sit on the table. Or you could stick-on rubber feet to the case, as long as they were higher than the bumper height.

Thanks.

The front panel will reside under the "bumpers" as shown, this hides the cover plate seams. The cover plate will be aluminum with a label, or screened printed aluminum, or plastic (multi-color 3D print for prototypes), or even an aluminum or FR4 PCB type, we haven't decided yet for either prototypes or production, and will hold a push button switch, a pair of pots, and some LEDs.

These 3D prints are intended for the 1st few prototypes of a production product. The production product will use a more "rubbery" and "flexible" bumper of silicone or similar material, as it will experience very rugged handling in use, not lab use!!

Edit: This "Bumper" concept may carry over to another project and having an aluminum cover that is in electrical contact with the extrusion provides a Faraday shield which is necessary for this other project. Seems like an ideal means for a simple, low cost, rugged enclosure for electronics & PCBs. 

Best,

[mawyatt]

For the bumpers, you might want to try using TPU filament.  I've read up on the options, but not yet tried it myself.

With something like the designs shown, I think you may need to adjust the model to bulk up any thinner sections as it will likely be too flexible.  You could also possibly do a part part print, with the TPU being  design as an "overmold" to get the best properties of both filaments.  If going into mass production, you can then get the overmold made in silicone.

When selecting a TPU filament, you will probably want to get one with a higher hardness rating like 95A.  The softer ones are great when you want flexible parts, but are notoriously difficult to use in some 3D printers.  Printing TPU requires a direct drive extruder.  Do a bit of a search for other users experience with your specific printer and TPU.

Thanks, will take a look at this TPU filament type.

We aren't that comfortable with 3D printing and only used PLA so far, so may take awhile as we gain more experience.

Best,

[mawyatt]

OK so here's my final take on the bumper design. I wanted the edges to fit more like the bumpers shown on the Rigol function generator shown.

Siglent like Rigol have a similar type front "bumper" design.

Best,

[mawyatt]

Pulled the trigger on the Bambu X1 per some recommendations, we'll see how this works out. We have a few things to create for an ongoing and starting project, so having a more "refined" 3D printer without a lot of additional effort was an important decision point. Also understand that having a fully enclosed printer is important, we were just using a kludge styrofoam taped together cover for our present 3D printer, so this also helped with the decision.

We'll also give the TPU filament a try later, need to order a reel.

Anyway, thanks for the help and recommendations.

Best,