Printing thin wall flexible tubing

[AnotherBiAl]

Hi all, 3D printing is a new world to me and this is my first post here. Is it possible to print a flexible 1.3mm thick thin wall tube of 17mm diameter and 18mm high? I have a set of four compression springs that have to have a external flexible sleeves. The 1.3mm thick sleeves need to be flexible to accommodate the 3 – 4 mm that the springs periodically compress. The wall thickness is important as the assembly will be in a confined space. Additionally the sleeves must have a washer like 2mm thick top and bottom. It seems a lot to ask. Unfortunately the original manufacturer cannot help with replacement parts which were cast and has suggested that I might try to get them 3D printed. I do not know if this is possible. Can anyone offer any advice please?

[fred_dot_u]

If the wall is 1.3 mm thick, you'd be looking at an optimized 1.2 mm thick wall if using a 0.4 mm nozzle. Having the outside diameter of 17 mm is not a concern either, in my opinion. I would not describe the top and bottom as washer-like so much as having a flange and the 2.0 mm thickness also fits well with a 0.2 mm layer thickness. You could get away with a cylindrical cross section on the bottom of the print, but I suggest that you create your design with a taper outward for the top of the print.

3D printers do poorly when printing horizontally in empty space, so the taper would gradually increase the 1.2 mm thickness to your required diameter. What diameter do you require on the washer-like flange?

If you'll be using a 3D printing service rather than doing it yourself, you should consider to specify different hardness values for the plastic, which should be TPU. I've printed only a few parts in TPU and they are astonishingly flexible and also quite durable.

[AnotherBiAl]

Hi fred_dot_u,

So it will be possible to print the little , I’ll call them bonnets. Excellent news. Thank you. As I said, this is the first time I have looked at 3D printing; it is something that has just been in the background before. Other than pictures I have never seen 3D printer or, as far as I am aware, anything printed with one.

I hear what you say about horizontal printing. Unfortunately there will not be room to taper the walls of the tube and in any case the disk has to cover all of the top with just a small hole, 6 mm or so in the centre. The other end is essentially an infill of the tube, again with a matching 6 mm hole.
I have been reading up on techniques and following on from what you have advised it seems that it would be best to print the larger ‘disk’ first then build the tube up onto it. At the smaller end, the top, would be more like a flat cap with the walls of the tube as the maximum diameter again with a central hole. Although smaller, it would be unsupported apart from the edges. As that would be the case should I get it printed as a separate item then attach it, glue it on, after?

Now for the technical stuff. Looked up TPU and it seems that you are referring to Thermoplastic polyurethane. Is that correct? Please excuse my ignorance but I always feel it is best to clarify acronyms if I am unsure. You also refer to different hardness values. I had no idea that hardness values would be involved so that came as a surprise to me. The internet has advised – I cannot say helped though. A sea of information more or less all of which is way, way over my head. I know a couple of people who have printers but like me, they are hobbyists. None of them know anything about hardness. I am beginning if I am a hiding to nothing and should give up. How on earth do other newcomers to this word of printing manage?

[Bikeracer2020]

Perhaps if you know someone with a lathe who can turn a mould with a central core and split outer shell you could then use a pourable rubber or silicone component to make the parts.

Polypropylene would be a suitable material for the mould, that's what I used when I wanted to make some model tyres a few years ago, hardly anything sticks to it.

Or you could 3D print the mould parts and use a release agent to mould the sleeves.

[airscapes]

TPU for printers typically comes in a couple different harnesses.. Take a look that the Ninja Teck website. I use Ninjaflex and Cheetah.. first is softer and stretchier than the other..
https://ninjatek.com/learn/3d-printing-materials/tpu/
If you can give me an image with the dimensions and you are located in the US I can give it a try for you.

[AnotherBiAl]

That is such a kind offer airscapes but unfortunately I am in the UK (Wales). Thank you for the thought though. I was very kind. I’ll go and take some pictures. I haven't got any good ones and they will be needed no matter how I proceed. Can they be posted on the forum?

[airscapes]

Shipping to the UK really is not a big deal so I am game! What is the exact purpose of this part and why is it 1.3mm thick is that just what the original was due to the material or is there a actual reason for this thickness. What is the temperature range during operation? You said the top has to be like a washer 2mm thick. What do you mean by thick. if the walls are 1.3mm between the ID and OD to you mean there is a 2mm flange on top.. or you mean the first 2 mm of the walls and top 2mm need to be solid? This does not seem all that complicated.. and yes pictures can be posted but they need to be a small file size.. it tells you when you try and attach.
If you want send me a private message and I will send you my email address