Author Topic: A little 3D project  (Read 1387 times)

Offline AdeV

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A little 3D project
« on: July 22, 2019, 06:03:55 PM »
In my master bedroom, I have a built-in wardrobe with four mahoosive sliding mirror doors. They are phenomenally expensive, yet they are the cheapest nastiest construction I could imagine; basically, some bent metal to make the frames, relying on some weird clips and a folded metal piece to tie everything together. Really nasty....

The wheels at the bottom, although rudimentary and not pretty, do function:



The holder simply has a nylon "pulley" (which runs on an aluminium inverted "V", much like a lathe way). The holder slides (rather stiffly) into the other part, which is screwed and clipped to the frame. The long bolt sticking out the top allows one to adjust the wheel height. Gravity keeps the whole shebang in place. As I said, at the moment these run on an aluminum V-shaped track; but they do have a tendancy to fall off at the slightest provocation (e.g. if you open or close the doors...  :scratch:), so I'm going to change the track for a simple slot routed into some plywood, which the wheels will run inside. This should reduce their tendency to go wonky.

The topside of the doors currently has a dreadful "blade" arrangement, glued on with what I can only describe as "hard snot", which run inside a slot in some more V-track aluminium. Unfortunately, because the slots aren't quite completely straight in at least 2 dimensions (and possibly all four), the "blades" have a tendency to bind, jamming the door and lifting one of the wheels off its track...  Here's where my 3D-printer comes to the rescue!

I'd already designed this up with the idea of making it in folded metal; but the 3D printer allows me to play around a bit, and this is what I came up with:



From left-to-right: The wheel's pretty self explanatory. I am not yet sure if I'll use printed plastic, or nylon around a bearing. I guess we'll see how it works out with the printed versions, although I do actually have the nylon already! Then the simple shaft (I'll use metal if I use a bearing, for a nice press fit), then the equivalent of the wheel holder. Unseen in the photo, this has a ~6mm hole up its back end. Not shown ('cos I don't have one!) is a fairly strong spring that'll be in there; this will be trying to push the wheel out of the next part, the "box" for want of a better name. This is the bit that screws to the frame. Atop that is a "handle", and the bolt which goes into the wheel carrier & stops the whole thing from flying out.This could be replaced by a wood screw if a better "bite" in the plastic carrier is required to hold the spring back.

The next two photos show how it's supposed to work:



Imagine it upside down, the wheel is in the upper track, the spring holds it up. To fit the door, or to remove it for any reason, simply pull down on the handle, which pulls the wheel into the holder, out of the track, and away we go!



The height can be adjusted by simply screwing/unscrewing the bolt somewhat. So long as there's enough thread in the hole to keep the spring in check, it should be good; and why the complicated spring/handle arrangement? Well... apart from a) it's cool, and b) ease of installation; it also means I don't need to worry too much about height variations in the upper track. So long as the wheel is sufficiently engaged not to drop out of the track at it's highest point, it should automagically adjust at the low points without binding or other unpleasantness... At least... that's the theory  :lol:

There's a couple of tweaks I need to make to the design to overcome a couple of minor issues I've found; and I need to find some suitable length bolts with a smooth shank at the top (I reckon a cap-head bolt will be better than a hex nut), find some suitable springs, and I'm good to go!

Cheers!
Ade.
--
Location: Wallasey, Merseyside. A long way from anywhere.
Or: Zhengzhou, China. An even longer way from anywhere...
Skype: adev73

Offline awemawson

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Re: A little 3D project
« Reply #1 on: July 23, 2019, 03:03:31 AM »
Nice work Ade, another practical application for 3D printing  :thumbup:

This worries me though:

"Unfortunately, because the slots aren't quite completely straight in at least 2 dimensions (and possibly all four), the "blades" have a tendency to bind, jamming the door and lifting one of the wheels off its track...  Here's where my 3D-printer comes to the rescue!"

. . . are you going in for time travel perhaps  :lol:
Andrew Mawson
East Sussex

Offline russ57

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Re: A little 3D project
« Reply #2 on: July 23, 2019, 11:09:55 PM »
I think you have hit it awemawson.

Its most obvious manifestation is when it wasn't derailed when your s.o. left it, but it is now. The only explanation is that the problem occurred in the future but due to the misalignment in the fourth dimension it appears to have happened in the past.



Russ