has anyone worked up a model to 3d print a mounting bracket?

[curt mayer]

My lucite clear backing plate broke at one of the cruciform cutouts, and I saw a very nice aluminum bracket

that somebody bent.   this to me seems overkill, and I was wondering if anybody 3d printed a workable bracket.

if not, I'll start on one and put it on thingyverse.  

--curt

[John Kennedy]

I don’t have a model but I’d like to see one. How would it work?

[curt mayer]

so, i worked up a not-very-precise pair of brackets, printed them up, and they work.

from the photos, you can see my first cut at the holes.  the model's holes should be right.

these took 3 hours to print, so I wasn't going to turn the crank again.

it's nowhere near perfect.  what it is, is sturdy.  I printed it in PETG.

I'm going to cut the lucite back panel at some point and secure it only using the 4 center screws.  this should protect the board.

I'm hoping a hot knife or a dremel will do the job.

attached is the STL and OBJ files from tinkercad.   I'm having trouble getting it up on thingiverse.

but this might work:  https://www.thingiverse.com/thing:4249793

[TheHighNibble]

Nice work. I might give it a go and print me some too.

[John Kennedy]

I'll give that a go later, assuming my printer can print something that size.

[curt mayer]

I want to emphasize that this bracket I uploaded is workable, but not perfect.  It's a hack, really. 

There is more daylight than i want in the corner, as the top hole is not quite far enough out.  The printer I printed them on isn't dialed in right, so most of my test prints were about diddling with temperature, fill, raft and so on.  I'd be happier if the holes were 100% spot on, but I just ended up poking a hot soldering iron through.

I think that requiring the bracket to be flush with the card isn't a great idea, since the reset switch through hole pins stick out.  I ended up cutting them flush.

Finally, the SD card location is right, so any mods to hole location, bracket shape, etc, need to preserve the eventual card location.

The best is the enemy of the good, so I'll stop here.

--curt

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[Thomas Ganter]

I present to you my solution.
I felt the acrylic was such sleek a design I did not want to go without it.

Printable 8-up on almost all printers.
Attached back and front using superglue.
Also glued in the broken-off pieces from the original backplane.

Advantage is also that you can no longer "push out" the back from the screw since the screw is covered back and front.

FreeCad and STL files also attached.
Feel free to share improvements in case you come up with some.

Greetings,
and stay healthy,
--Thomas

John Kennedy schrieb am 30.03.20 um 16:35:

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[curt mayer]

I like this much better than my hack.  It would be a fine thing to put out in new kits.

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[John Kennedy]

Interesting. I’ve a glowforge and I could laser cut this shape in clear acrylic (or opaque to hide the glue).

I can try this and if it works out maybe send out some if anyone else needs them? 

As as long as my acrylic supply lasts - my local store has shut down to focus on making medical supplies.

[TheHighNibble]

I've just drafted up an acrylic part based on the same concept. I will post it as an SVG file and soon as I figure out exporting it in that format.

[John Kennedy]

PDF works for me too. 

[TheHighNibble]

You can't trust PDF to scale correctly. This is one reason why you can't (reliably?) print to a laser cutter from a Mac because the macOS print system is actually ghostscript and that uses PDF as the internal rendering format even if the target device isn't PDF.

[Martin Reinhardt]

Besten Dank fuer die IMSAI Verstaekung. I printed the reinforcement upgrade you made, it's perfect thanks for sharing.

[Mike Corrigan]

Thanks Thomas.  I printed eight of these from your .stl file and glued them to my back plate (also with the acrylic bits that broke the first time I tightened the mounting bolts.  This works perfectly.

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[briandenley]

Mike:

Do you need 8? Or 4?  Are there two for each corner?

Thanks

Brian

[Gavin Haubelt]

You need 8 total, two for each corner and they work great! 

/Gavin/

Gavin Haubelt

Founder/Lead Developer

iCityWork

(559) 492-6318

gavin....@icitywork.com

www.iCityWork.com

@iCityWork

FaceBook /icitywork

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[briandenley]

Thanks Gavin.  is the STL file posted anywhere here?

Brian

[Brian Denley]

I think I found it.  From Tom Ganter?

Brian

Sent from Mail for Windows 10

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[Gavin Haubelt]

Yes it is somewhere, but here is the file for you.

/Gavin/

Gavin Haubelt

Founder/Lead Developer

iCityWork

(559) 492-6318

gavin....@icitywork.com

www.iCityWork.com

@iCityWork

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[Gavin Haubelt]

this is the one I used and it worked perfectly.

/Gavin/

Gavin Haubelt

Founder/Lead Developer

iCityWork

(559) 492-6318

gavin....@icitywork.com

www.iCityWork.com

@iCityWork

FaceBook /icitywork

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[briandenley]

I printed up 8.  Will attach them tomorrow.

Brian

[Tom Hunter]

The 4 corner cricifix shaped cut-outs are mechanically unsound on a 3 mm acrylic sheet. The reinforcing 3D printer designs from Thomas Gartner should be part of the kit or alternatively the back-panel should be made out of 6 mm acrylic. Despite Dave's video advice about the the 4 screws to "really tighten them up very firmly", I was very gentle but nevertheless the back panel developed fine hairline cracks around the cut-out which hold the nuts. The bits didn't break off, but the cracks were clearly visible and it was just a matter of time for the whole back panel and frame assembly to disintegrate. Rounded edges rather than the hard crucifix shape with 90 degree corners may also make it less fragile even if 6 mm acrylic panels would be used.

Thanks Thomas for sharing your STL file with us. I have printed 8 copies and glued them on. I have attached a few photos.

Cheers

Tom Hunter

[briandenley]

Mounted my 8 brackets on the acrylic today.   I will wait until tomorrow to reassemble.  The acrylic assembly seems much more robust now. Of course those nuts are never coming out again!

Brian