Need either a thread or “3D Chassis for PCBs” category

Thought I was send a message, this seems to have created a new thread, hope the moderators can make sure this ends up in the right place.

At any rate, thoughts about 3D printed chassis and the effects it has on PCBs. Also interesting in seeing what styles people are using for their chassis.

I’ve got a very different style for chassis than most, frankly a bit more primitive but also very beefy. Everything can be screwed to a large board or plywood for trying things out. All walls 4mm thick, and different way to notch/hold things together. I also have screws all the way through, either M2.5 or 4-40 (M3 if you prefer…). Nut at the bottom encased, head at top buried. Once screwed down, you can remove the top and put it back on without having to remove the chassis from the board.
Some side analysis views for you, and a “pretty pix” of a bunch of chassis in this style for the bigger project I’m working on. Note the holder for a USB dongle so the PI can go mobile and not have the dongle fall out, and taking a commercial WiFi board and putting it in a chassis with a fan and small PCB to work as a thermostat.
Had to do a bunch of “test bricks” to fine tune the sizes for the hex nuts and head cut-out. Very printer dependent to get the ridges right, on the Prusa a layer is .15mm and the width of a pass is .45 mm.
I have a spreadsheet with the sizes for shaft clearance, head clearance, nut dimensions and depth for just a nut and for a nylon nut. And a document with all the things to do for ridge and troughs, edge smoothing, feet, text sizes that work and other notes. It would be interesting to know how many people that use KiCad for PCBs make their own printed chassis, and what 3D printer they use.


trouthAndRidge

Cut this down from the original 11 MB, but you get the picture:

I started off with an Ender 3 and am thinking about purchasing a Prusa i3 MKS3S+ as soon as my hobby budget fills up to some €900.
Recently I tried JLCPCB’s new 3D printing service. It is cheap (as can be expected). There are disadvantages (as can be expected as well), though. The cheap process is SLA, white only. Shipping is a expensive as the part and it takes 14 days to Austria.
But for proof of concept and prototypes it is ok.

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those look Fantastic ! I had not though about a “panel per side” chassis approach, even though I’ve done that with metal chassis. How do you attach the panels to each other?
I very much like my Prusa i3 MKS3+. Worked out of the box (I ordered it assembled, too many problems when I looked at the forums). Takes a bit to get the height right. I use the 49 point (7x7) level instead of the 9 (3x3), it seems to work better. Only handle the print sheet when I have medical gloves on. Discovered this when after many prints I kept having adhesion problems. I just use their filament, shipping does add to the cost but when something works you don’t tweak it.

When I have time this week I’ll put something more detailed together on the approach I’m taking for simple chassis.

I recommend the Prusa i3 MKS3S+. See other comment for what worked for me. Have been using PLA only so far since it’s so easy, but will be printing some chassis in PETG soon.I’ve got 22 boxes of filament in many colors, PLA and PETG so I should be good to go. A purchase decision based on shipping cost, not wanting to run out, and as a regrettable sign of the times concern about the situation in Europe. Initial, It took me 3 to 5 passes to get a given chassis “good” but now am down to 2 or 3.
I found Fusion 360 to be hard to learn. I suspect this is a mix of the software, moving from PCBs in 2D land to 3D land, and terminology common to machining that was new to me. I have a milling machine, drill press, and brake in the basement for chassis work, but never made chassis for a living. I still have to Google for how do things sometimes. The video on how to make a chassis for a PI was the breakthrough moment when just enough made sense that it served as a basis for learning more.

How do you attach the two chassis pieces together? Did you add support to the many small vent holes, or did it just print OK ?

Well in yesterday’s discussion I posted a section drawing. Should make it clear.

No. I just sent the model to China (.stl). Any required supports would be added (and removed) by them. I was surprised myself how clean the venting holes turned out. But then: ist’s SLA, not FDM.

[EDIT] I printed one myself on the Ender. As the holes are app. 1.5mm wide and 2.5mm high, no supports were needed with PLA. But then there was a fair amount of stringing.

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A remote control type board mostly for internal engineering use at my work. Designed in solidworks I should also credit that it was designed by my coworker. I’ve hacked on his design a little to improve a few things though (latest version has an expoxy LED window etc…).

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OK on drawing, looks like a flat head screw that screws into the plastic then.

Yeah, M2.5x16. I do not like those insets.

We are similarly using button head screws right into plastic… I have to ream them a little to get the screws in but production quantity is very low so not an issue in my case.

Also I saw someone did a review of heatinserts vs direct in plastic etc… I linked straight to the section with the good info here : Threaded Inserts for 3D Prints - Cheap VS Expensive 💰 - YouTube

We are thinking of switching to heat inserts for the battery compartment due to it being removed more often.

That’s the only application where I used insets despite my dislike.

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I don’t know if you know of this trick when ordering Filament from Prusa to the US (I don’t know if it also works for other countries, I’ve only shipped to my house in northern Delaware):
Always order two at at time and use DHL shipping. If you need 4 spools, split it up into two orders. This is because Prusa has some sort of deal with DHL that gives us the customer the same shipping cost for 2 spools as for 1 spool. But if you order a 3rd (or more) spool the shipping will be roughly the same as the shipping for 1 spool times the number of spools you order… It only takes me 2-3 days to get spools from Prusa. For me this may change if Printed Solid starts carrying Prusament now that they are owned by Prusa since I can drive to Printed Solid (again, northern Delaware…) and pick up directly from them without any shipping costs.

EDIT: Note, the last time I ordered from Prusa was before the pandemic. The “buy spools in pairs using DHL” trick might or might not work now, I haven’t checked recently.

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CNC Kitchen is a good channel for testing materials out. If you are into 3D printing at all a browse through his back catalog is a must.

Tnx for the ordering tip. I’ve done two orders so far, a 6 spool and and a 12 spool. It would be great if Prusa had stock in the US to reduce shipping a bit.
In the mean time, when I run low I’ll just get 2 spools as needed.

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