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3D Printing a useful DEC bracket

Vince,

It is really impressive : http://www.vcfed.org/forum/album.php?albumid=51&attachmentid=32897 !!!

I was able to do this myself without my son's help tonight. We are still getting the hang of this machine. The major snag last night was that the horizontal axes would only move 4". Evidently we had never printed anything longer than 4" in a horizontal dimension before. The controller needed the g-codes sent to store the full extents of the horizontal axis positioners (6"). Now I just have to get it off the bed without breaking it!

I watched it as it printed, and it is somewhat hollow inside. There are hollow square-wall honeycomb cells inside. I need to figure out how/if to print a solid piece.

The uses are limitless. Maybe I can print replacement key plungers for the dec keyboards!

Lou

PS. I realize now that I should not have rotated it onto its back to print it. The way the model loaded originally would have put the layers in the strongest orientation. We'll do another as you originally had it.
 
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Look for a infill setting ... for models and whatnot low infill is good to save time and plastic, 100% is good for strong parts

And yes if you get the printer all tuned in you can make some good quality parts with low amounts of finish work, with is good for fiddly small items
 
Lou - N2MIY said:
Vince,
It is really impressive : http://www.vcfed.org/forum/album.php?albumid=51&attachmentid=32897 !!!
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Thanks! When I first did it, I was new to Sketchup and those spheres were a bear. Now that it's done, though, they are relatively easy prints. (I've not seen one in clear before.)

I watched it as it printed, and it is somewhat hollow inside. There are hollow square-wall honeycomb cells inside. I need to figure out how/if to print a solid piece.
Click to expand...
It is probably not necessary for it to be completely solid. Mostly it has to bear the screws and not tear up when you pry the filler panel off.

PS. I realize now that I should not have rotated it onto its back to print it. The way the model loaded originally would have put the layers in the strongest orientation. We'll do another as you originally had it.
Click to expand...

Yeah, though there will still be weakness where the posts join the bar. That's not so terrible though, once it becomes easy to crank out another. (As Al mentioned, it is important that the filler panel come straight off, not at an angle. Best to loosen both sides a bit before pulling.)

Vince
 
Lou,

I'll have to try this with a friend that has a 3D printer because I trash those brackets on my Pdp-8a. Maybe my final solution is to cast or mill a few in aluminum or brass.

I'd also lobby for someone doing the circuit board handles, if they have need. Some boards are missing them and for new boards, haven't' found a source...

-Crawford
 
So make an on-axis partial cut through the diameter of the ball with a jeweler's frame saw. There's your give. If you do the bracket in brass, the brass will work-harden a bit with every insertion.
 
Chuck(G) said:
So make an on-axis partial cut through the diameter of the ball with a jeweler's frame saw. There's your give. If you do the bracket in brass, the brass will work-harden a bit with every insertion.
Click to expand...

Might be worth trying to reuse the rest of the plastic with a threaded insert and fabbing brass pieces with threaded ends to mate, though
I don't know how brittle the rest of the part is now and how it would handle being drilled into.
 
I'm also thinking that it probably wouldn't hurt to lube the ball ends with a bit of silicone grease before applying the panel. It might just prevent any further hang-ups when pulling the panel off.
 
RL01/2 Unit Select Plugs

RL01/2 Unit Select Plugs

I have 3-D printed a couple more useful items with Vince's help. He has .STL files of RL01/2 drive select plugs on his website. Somehow there seem to be more drives in the world than there are 0 and 1 select plugs. I wanted to solve that issue, in my world anyway.

I learned a good bit about how to really dial in my printer in order to print the prongs of the plug sufficiently accurately and with sufficient strength. I had never printed something with fine details so important before, but it can be done! (But I did have to print a lot of crappy parts first.)

The plug in the left of this picture http://www.vcfed.org/forum/album.php?albumid=63&attachmentid=36227 is a proper DEC plug. The plug on the right was 3-D printed in PLA plastic on a Printrtbot Simple Metal. It took a little over an hour. Print speed and layer thickness were the critical parameters. For my machine with a 0.4mm print nozzle, layer thickness of 0.1mm and print speed of 15mm/sec made decent, strong parts.

Thank you again Vince!

Lou

PS. Here is a picture of a plug in the process of being printed : http://www.vcfed.org/forum/album.php?albumid=63&attachmentid=36226
PPS. Here is a progression of my learning, with a first try at the far right, and a useable part one in from the left (leftmost being a real plug) : http://www.vcfed.org/forum/album.php?albumid=63&attachmentid=36228
 
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Lou - N2MIY said:
I have 3-D printed a couple more useful items with Vince's help. He has .STL files of RL01/2 drive select plugs on his website. Somehow there seem to be more drives in the world than there are 0 and 1 select plugs. I wanted to solve that issue, in my world anyway.
Click to expand...

I would have just ordered it from Shapeways, but I am glad the files were useful, and impressed that you were able to print one.
The required accuracy is quite challenging with hobby printers!

Can you infill the numeral with ink, or was that level of detail too fine for your print?

Vince
 
Vince,

No, the outline of the number did not come out. I am printing the plugs with the number side facing down. That side always gets a little squashed as the machine deposits the initial layers of material. So I just freehanded some numbers on the front with a paint marker. It is good enough for my needs!

This Printrbot Simple Metal seems pretty good to me for a low-end hobby printer. I need to find some cheap/free 3-D CAD software so I can draw my own parts. My interest is first in making brackets/bezels/buttons for project enclosures.

Lou
 
Lou - N2MIY said:
No, the outline of the number did not come out. I am printing the plugs with the number side facing down. That side always gets a little squashed as the machine deposits the initial layers of material. So I just freehanded some numbers on the front with a paint marker. It is good enough for my needs!
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No surprise there, as the recess is pushing even what Shapeways can print reliably. (I think what actually happens is that it prints on their process, but then the rim is rounded off by their polishing step.)

This Printrbot Simple Metal seems pretty good to me for a low-end hobby printer. I need to find some cheap/free 3-D CAD software so I can draw my own parts. My interest is first in making brackets/bezels/buttons for project enclosures.
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The version of Sketchup and associated tools that I use is archived here:
http://svn.so-much-stuff.com/svn/trunk/3D/Sketchup Tools/
They don't always work with the newer plugins and such, though.

Purists view Sketchup with scorn, but it has worked for me. 3D tools do have a sizeable learning curve. The solid inspector has been a
big win, as it is quite easy to draw stuff that doesn't represent a possible 3D object!

It's important, regardless of what tool you chose, that every line or point be referenced to another, and/or to an axis. Otherwise,
vertices aren't really vertices, planes aren't planar, etc. Don't be afraid to enter an angle, length or endpoint, rather than try to
click on it. (If you are trying to click on it, make sure it is highlighted as the alignment target before actually clicking.)

Oh, and another tip -- if you've made a mistake, erase it and try again. Trying to fix something that has gone out of square or whatever
is very difficult, and the tool will keep trying to line up your rework with the mangled existing stuff.

Vince
 
Vince,

Thanks for posting the link to the version of Sketchup that you use. I installed it and the add-ins and have been learning for about two weeks now. I can now draw and print my own parts.

I can strongly recommend a book I bought entitled "3D Printing and CNC Fabrication with Sketchup" by Lydia Cline. I learn by examples and this book has plenty. The author is a drafting instructor at a junior college. Although it has been 25 years since I had drafting in school, it's clicking with me. I also like her use of imperial units (I'm old school.)

Lou
 
Lou - N2MIY said:
Thanks for posting the link to the version of Sketchup that you use. I installed it and the add-ins and have been learning for about two weeks now. I can now draw and print my own parts.
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You're welcome! I'm always glad to see stuff I make available is useful to someone.
I can strongly recommend a book I bought entitled "3D Printing and CNC Fabrication with Sketchup" by Lydia Cline. I learn by examples and this book has plenty. The author is a drafting instructor at a junior college. Although it has been 25 years since I had drafting in school, it's clicking with me. I also like her use of imperial units (I'm old school.)
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Cool! You're probably better at it than I am, then :).

I use the imperial units too, as I think it is more "correct" to design in the same units
as the originals were done in. This puts me in conflict with the conventions of the 3D
printing community, however, so I've started exporting STL files in metric units as well
as the ones in imperial units. (The Sketchup files are imperial, though.)

Vince
 
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