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Topic: Printing Thread features

I've been experimenting with printing threaded features to thread onto a typical 2L soda bottle.

I've noticed that at .3, even .1mm, that this thread tends to have too much overhang when printed with the threads pitch going vertical:

http://i.imgur.com/MQtZd.png

  I've tried printing parts normal to the pitch, then assembling, but this is painful and laborious:

http://i.imgur.com/rWcSK.png

Anyone have any advice here?  Being as I am stuck with a not standard thread (as far as I know there aren't any taps for 2L bottle threads) I'll have to print.

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Re: Printing Thread features

Might want to try a couple of the 2L threaded objects on thingiverse and see if any of their thread designs print for you.

Threaded watering can cap

2L Bottle Threads

2L Threaded Watering Spike

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Re: Printing Thread features

You will have to increase the diameter of internal holes to have them come out good.  Try .015" diameter increase to start with for that size. 

I successfully printed threads about that size for a custom spool guide, so it can be done. 
http://www.soliforum.com/topic/350/new- … e-for-sd2/

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Re: Printing Thread features

Ian's post on Undersized Holes is relevant to your project.

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Re: Printing Thread features

nickythegreek, cmetzel,

thanks for the posts.  I did actually use thingiverse for the male portion and created the female parts above from them.

I may have not been clear, the parts I have been making do actually fit onto the bottles.  But because of the direction of printing, and the overhang, the threads are stringy.  When I torque the print, it cracks in the overhang areas until it strips.

http://dl.dropbox.com/u/11885748/2012-12-14%2017.15.12.jpg

I have been able to use more coarse threads with good results, however these are specialized threads that won't work with the 2L bottles.

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Re: Printing Thread features

Okay so the issue isn't really the threads it's the overhang and stringing.  Have you tried turning down the speed, increasing the infill, adding a fan to cool the previous layer?  Can you turn on infill and pick it out once you're done?  You can also modify the geometry to have a taper on the bottom side of the thread so it's not a complete shelf that it's trying to print in air.  The threads on a 2L bottle should be pretty forgiving in that respect. 

What is the end use of this if you can say?

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Re: Printing Thread features

You might want to try rotating the part on edge. You would have to use support but the treads should be stronger.

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Re: Printing Thread features

timp610 wrote:

You might want to try rotating the part on edge. You would have to use support but the treads should be stronger.

I would do this. If you have the extruder fan mod I would try it without support first...should print fine.

SD2 with E3D, SD Press, Form 1+
Filastruder
NYLON (taulman): http://www.soliforum.com/topic/466/nylon/

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Re: Printing Thread features

DePartedPrinter wrote:
timp610 wrote:

You might want to try rotating the part on edge. You would have to use support but the treads should be stronger.

I would do this. If you have the extruder fan mod I would try it without support first...should print fine.


Thanks guys.  I didn't think it would work, which is why I never even tried.  But putting the full part on side, with the fan mod, without support worked:

http://dl.dropbox.com/u/11885748/2012-12-16%2013.57.30.jpg

There were a few splotches at the top due to lack of support, but these didn't hinder the results in anyway.  Smooth to thread on, and strong!

http://dl.dropbox.com/u/11885748/2012-12-16%2013.58.19.jpg

10 (edited by DePartedPrinter 2012-12-17 06:50:48)

Re: Printing Thread features

if you want to try for even more perfect threads you could try separating the cap into two parts. This way the printer never has to print an overhang. Connect the parts once they are printed...

I need to play with printing threads again. I did a bunch of thread tests when I used to print on a dimension printer and I was getting amazing results with that (although we were using support material). I wish the support material was better with single extruder type printers.

SD2 with E3D, SD Press, Form 1+
Filastruder
NYLON (taulman): http://www.soliforum.com/topic/466/nylon/