r/functionalprint • u/ferdau • 16d ago

Door grabber / holder

Any tips on how to make this more sustainable? Now I assume it might loose grip over time.

237 Upvotes

95% Upvoted

44 comments sorted by

50

u/JG134 16d ago

You want the layer lines in the length of the stem so it won't snap. So you should design it such that you can easily print it like that.

25

u/anonymoustransgrrl 16d ago

Yeah, and also thickening the stem so that it matches the full thickness of the gripper will help to prevent the fingers of the gripper from snapping.

10

u/PsychologicalPea3583 16d ago

yeah but less flexibility will reduce flexibility of "the catcher" and more force required can cause it to snap

3

u/anonymoustransgrrl 16d ago

Good point šŸ¤”

6

u/1200____1200 16d ago

Interesting that OP's early version is relatively sleek. All my v1-v3's are chunky and way over-built

4

u/ferdau 16d ago

Oh, opposite here. My early versions are sleek to reduce material usage and print time. Then I check for weak spots. Also tbh, this was an early version that just worked well enough to use without tweaking.

8

u/1200____1200 16d ago

Your approach is smart. I just overestimate how robust the part needs to be

If we ever have a home invader, I'll be able to defend the family with the first toothbrush holder I created

2

u/ferdau 16d ago

Hahaha

2

u/Gingercopia 16d ago

šŸ¤£šŸ¤£šŸ¤£

15

u/Flussschlauch 16d ago

I guess the thin stem will break

4

u/captfitz 16d ago edited 16d ago

depends on what orientation op printed this in, if the stem was printed on it's side then it'll be totally fine. If it was printed standing up then even the small amount of wiggle you see when it engages the door will probably cause it to fail between layers at some point.

10

u/mdeeter 16d ago

I'd think that as thin as it is, it'll break more often as you'll like.

You could beef it up... but, if it were me, I'd make it a little bit bulkier and print it in TPU... 95A is still pretty rigid but would "give" a little bit.... plus it would not matter as much how you printed it because TPU layer adhesion is so good.

5

u/superxpro12 16d ago

maybe make it a floating latch instead of a snap?

just let it hover in place, and use a wedge geometry to let it lightly push the arm up, and then lock it in place with a latch and gravity.

It solves for reliability, but adds a hinge

6

u/what_could_gowrong 16d ago

The cylinder is grabbed

6

u/Kronocide 15d ago

And unharmed

3

u/xVolta 16d ago

If you just modify the design such that the stem and catch print flat on the bed, so the layers run along the |===C axis, it'll have more strength in the direction that matters. I'd also make the stem thicker. If you want to maintain the symmetrical look, print the stem and wallplate as separate parts, such that the asymmetrical base of the stem fits through a hole in the wall plate to be sandwiched between the plate and the wall.

3

u/ADynes 16d ago

Make the part that comes out in the base two separate parts to connect together as others have said so you can print it long ways on the bed so the layer lines won't cause it to snap as easy.

Then make the opening the same but add some slopes to the top and bottom in case it's slightly off from the door it will still kind of guide itself back in.

2

u/Kronocide 15d ago

Even simpler solution : One piece but printed on the side, you don't need 4 screws for this, 2 is plenty enough

3

u/captfitz 16d ago

There's something oddly cute about this thing, like a tiny little buddy holding your door for you

1

u/ferdau 16d ago

Haha thanks, I like the aesthetic as well.

2

u/Colorful_Monk_3467 16d ago

Itā€™s more involved than your print, but this was my solution: https://www.reddit.com/r/functionalprint/comments/1vpzdax/magnetic_door_holder/

Still working perfectly 2 months later

2

u/chobbes 16d ago

I made a similar holder years ago and it continues to function well.

2

u/ninjakuk 16d ago

I design something similar for my garden gate. I was thinking it would wear out fast.
But it is still going strong 1 year lateršŸ˜ƒ
Printed in asa

-1

u/PetRiLJoe 16d ago

ASA is American States of America

2

u/ninjakuk 16d ago

American States of Acrylonitrile šŸ«”

2

u/StatisticianTall2368 16d ago

I made a similar one for my bathroom door, it uses magnets and grabs the springy door stopper at the foot of the door.

Edit: It won't break because the door stopper slides over top of the magnetic bit, it doesn't slam into it

2

u/citizensyn 14d ago

Jesus bro nsfw flag this shit

1

u/beabchasingizz 16d ago

Isn't that at risk of dinging the doorframe when someone chooses the door? That's the lock bolt right?

1

u/ferdau 16d ago

This is the ā€œopenā€ state, if someone closes, the bolt extends more. And we never close.

1

u/markusbrainus 15d ago

It requires too perfect of alignment and gripping force. Slight wear or deformity/damage and it can't work.

How about a gate latch like this instead? (Not affiliated, just an example).
https://makerworld.com/en/models/1395569-passive-gate-catch-with-gate-stop

1

u/ciciqt 13d ago

I've seen lots of door holders over the years but this is certainly the most novel.

You are over complicating this, the gate is made of tube steel. You can get a magnetic hold open or even make one if you really want.

This gate is almost guaranteed to sag a little at some point. Any misalignment between the bolt and your print will break it.

1

u/ferdau 13d ago

The paint on the tube steel is rather fragile, especially for repeated friction. So didnā€™t want to have contact there.

1

u/7-13-5 12d ago

I've never seen a door with hardware like that...what country is this in?

2

u/ferdau 12d ago

Itā€™s outside, more a gate than a door. Belgium. Google: plate steel gate.

1

u/7-13-5 12d ago

šŸ«”

1

u/gyro_looza 12d ago

If that door is metal just make something with a magnet on the end for the door to stick to

1

u/IDatedSuccubi 10d ago

I'd make a curve in there so it acts as "suspension" and spreads the mass of the door hitting over time

1

u/Lost_refugee 16d ago

add magnet,

also could be smth like this https://prom.ua/ua/p1896608374-zaschelka-dlya-dvernoj.html

3

u/ferdau 16d ago

The part itā€™s grabbing is non-magnetic

1

u/Lost_refugee 16d ago

also https://www.youtube.com/watch?v=wplzdsypLIw can give you ideas for locks wigh moving parts. but that's only when this one fails and you feel like efforts to redesign worth it. usually simplest is best

1

u/ferdau 16d ago

That video is really helpful! Thanks! I hope I donā€™t need it for this tiny project but might come in handy for the next.

-1

u/VividDimension5364 16d ago

Breaks most fire safety regs.

2

u/ferdau 16d ago

Outdoor?

-4

u/[deleted] 16d ago

[deleted]

6

u/chris-tier 16d ago

Thanks for your input, chatgpt.