Collaboration on a 3D printed threading dial for a SouthBend 9C

brino

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I have been slowly learning about 3D printing and have printed a number of useful parts, but have not printed anything that wears against another part.

I have read about printed change gears for a lathe (https://www.hobby-machinist.com/threads/if-you-need-gears-print-them.65634/), and was recently asked about printing a replacement gear for one that was stripped in a friends (2D) printer. So I guess I gotta learn.......

Then I read @RWanke 's post here:
https://www.hobby-machinist.com/threads/quality-of-3d-printed-thread-dial.67790/
It looked like an interesting project.

I looked around and found an existing model here:
Thingiverse: Southbend 9c Thread indicator one piece body

So I PM'ed RWanke to see if he was interested in a "collaboration".
I would print the parts if he would give some honest feedback about how they worked out.
We came to an agreement, and will attempt this "collaboration from a distance".
We will attempt to document the endeavour for the benefit of all.

That model comprises three parts.
The body:
1521165715281.png
1521165757025.png


The dial:
1521165934599.png


...and the gear:
1521165972720.png


Stay tuned for more updates!

-brino
 
I already have the printer and bought a number of spools of filament on sale.
For me the cost to produce it is ridiculously low, and the knowledge is well worth the investment.

I have a spool of black PLA filament loaded. It's about CAD $45 dollars for a 1kg spool.
The three parts for the threading dial are predicted to use 71 grams of plastic.
That's about $3.20 in material. Shipping will cost more than that!
But again, I want the experience and feedback....that is valuable to me.

I printed the parts in PLA and I think it will be okay, but if that doesn't hold up I'd want to try some nylon or ABS.

Printing is not always quick, it does depend on print quality, infill rate and of course object size.
The software says it will take 7.5 hours to print this at the recommended 100% infill (solid object) with a slightly higher detail (lower than recommended layer thickness 0.14mm instead of 0.2mm).

Here's what Cura showed:
1521167272167.jpg


Next up some real photos!

-brino

1521167272167.jpg
 
Here it is early in the print cycle:
early1.jpg


early2.jpg


Closest to the camera is the gear that rides on the lead screw, then the body, then the dial itself.

I use blue painters masking tape from the local hardware store on the heated printer bed. It allows the printed object to adhere really well during printing, but also to release easily form the bed when finished. It only leaves a little tape on the object that can be scraped off with a knife.

The Thingiverse page recommended: Rafts=no, Support=yes, Resolution=0.2mm, and Infill=100%.

I decided to print with: Platform Adhesion=brim, Support=Everywhere, layer height 0.14mm and Fill Density=100%.

The "brim" gives me a thin outline of the part on the bed. That helps the part stay put, and also gives the extrusion nozzle a chance to start passing plastic before it get to the real parts.

The "support" option builds a matrix of plastic support material under any overhangs to stop the melted filament from drooping when the angles or gap is too severe. They are meant as tempoary, disposable parts that break off easily. Some of it was already starting to break away as I removed the parts from the printer bed.

Note also the difference in terms between different software packages.

Since this is a relatively long print I went to bed.

The next morning it looked like this:
print_done1.jpg
print_done2.jpg


All the those "columns" are the support material for the overhangs...they should snap right off.

-brino
 
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Here they are off the print bed with the stripped support material roughly placed where it came off:
stripped1.jpg

stripped2.jpg


....and here are the parts without the support material:
clean1.jpg


clean2.jpg


-brino

clean1.jpgclean2.jpgstripped1.jpgstripped2.jpg
 
I almost forgot......

The model I used here (linked in first post) was based on another model from here:
https://www.thingiverse.com/thing:1306037
This second one give a little more detail about the reamer, rod size and set-screw to use for assembly.

-brino
 
A surprising amount of waste. I didn’t think there would be so much.
 
The support pieces are mostly hollow. They use very little plastic. They just form a bridge for the first horizontal layers that aren't actually on the printer bed.
 
Well done, the parts look good. Finding a model on Thingiverse saves a lot of time.
 
I would have to guess that creating the model of the body took a bit of time and effort.
It's nice to be able to find a model ready to go.
 
I'm really getting fired up about this. The parts look great, at least from this great distance. :grin: I hope I can make my part of this collaboration work as well as your end Brino.

I was thinking of you earlier this morning while reading some info on the very expensive change gears for cutting metric threads on an inch lead screw lathe and was wondering if printed gears would be an economical alternative, even if they only lasted for a few projects. ?? Again I know nothing about 3D printing and am having a hard time wrapping my head around melting globs of plastic on top of each other and it holding together. I guess I'm having flashbacks to my younger days attempting to melt model car plastic together to form "custom" parts. :eek:
 
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