Plastic Bag Stand

My wife found this bag holder online some years ago. Its features were: clips at the end to hold the bag; extendable arms for different size bags; foldable arms for storage; suction cup to hold it in place. Well... it actually didn't do any of those thing well. 

The first modification she wanted was a bigger base as the suction didn't work at all and the base was so small it wouldn't stay up on its own during use. So I drilled a hole in it and made a screw-on base.

Finally, she told me the clips didn't really hold anything either - she resorted to binder clips.

I decided I could do better.

AND it had to be printable with no support.

I already had a base. I needed to figure out how to make extendable arms and a really good clip. Lots of research and trial and error later...

I looked at all kinds of clips and boiled it down to 3 contenders: 

• a one-piece coiled alligator style (ruled out for not enough tension in the near-closed position); 
• a clothespin style (ruled out for requiring a metal spring and needing support)
• a printed spring (the winner: credit to Blake Haas for Spring Clip Stronger)

The tricky thing with the arms was getting the tension correct so they would not slide down under a light load. I settled on a saw tooth on the upper arm and snap clip on the lower (broke a few getting this right!). In order to print this part with no support, they need to be vertical - a little brim might be a good thing. I also ultimately went with ABS for this part for extra strength on the little clip.

It turned out it also took a few trials to get the fold-down and stay-up mechanism right.

This works with sandwich, quart, and gallon size bags.

Printing is straight forward. I used PLA, 0.20, 20% for all parts except the outer arms.

Assembly

• You may need to smooth the pins to get rid of any elephant foot.
• You will likely need to clean up the inside of the pin holes to get the pin in.
• The clip:
  • snap one end of the spring into one clip half,
  • slide the clip halves together on the pivot,
  • bend the spring slightly and snap it into the other clip half.
• The upper arm has a small bump at the bottom end to help prevent it from sliding free on routine extension. Align it with the small notch on the lower arm. Slide the parts together. You may lift the snap clip on the lower arm SLIGHTLY to allow the bump to pass. If it doesn't go easily - STOP - and consider trimming down or removing the bump. You may use more force to push the arms together without serious consequence, but lifting the clip too much will break it off.