Printing long thin cylinder  

RE:

You could split the tool into two long halves and glue them together. If you want to print standing up you will need to give it multiple tree supports branching at various points on its way up. (Or design a support in). Printing a thin column and to a point is tricky as the plastic doesn’t get a chance to go hard before the next layer. Slowing as the print and more as it gets near the top is a way around this.

The first option will be the strongest. Both options are awkward  

It might be easiest to buy one. 

RE: Printing long thin cylinder

Yeah,  while possible its going to be problematic whatever the orientation on something that thin.  Especially the thing point on the end  if thats 3d printed its going to snap as soon as you look at it wrong.   3d Printed is really the wrong technology for something like that. You will probably get a fair few print fails and I would expect the ok ones to fail easily.

Make a master and than mould and cast them out of something stronger if you want multiples.

RE: Printing long thin cylinder

Printing the main part upright isn't the issue, I think. I'd model in some breakaway supports, and 6 inches isn't too bad. The tip will kill you though. You can print multiple copies simultaneously to address the cooling issue John mentioned but as Neophyl said, but it'll break off as soon as you look at it. Even splitting the part in half and printing it sideways isn't going to add much stability to something so thin, plus is a hell of a lot of work if you want to make many copies.

Effectively you are emulating an over-sharpened pencil.

Does it have to be cylindrical? Would a hexagonal section be OK if you rotated it in your fingers?

If so: print the main body laying flat on the print sheet; a hexagon does not need supports.  Don't print an integral end, instead build a socket into the design and either print separate hexagonal tips or even insert a suitable size nail.

Cheerio,

RE: Printing long thin cylinder

I have been successful at printing things like this. Put the large part on the bottom, stand it up, and use a 5.0mm brim.

If all is good on your printer give a shot. 6" is not too tall.

Tom

RE: Printing long thin cylinder

This is why I come here and ask questions when I look at something and think, "Well, it's obvious. Use a brim." But then I ask and find out what problems to expect and get ideas that I had not thought of.

Maybe some more detail about the tool's purpose will help. Clay shrinks as it dries. Generally, you build a piece, put it in the kiln for a bisque, which dries it out, but doesn't heat it up all the way. Then you glaze it and put it in the kiln again for the glazing. (If you just glazed it, with all the moisture still in it, it'd explode.) The different bodies I use will shrink from 8-15% from when I finish with a piece until it comes out from the final trip through the kiln with the glaze.

This tool is for making holes in pieces for various uses. The tip on the end is to prevent the wider hole from going all the way through to the bottom. (Sometimes that's an issue, sometimes it isn't.) While the tip would make a very tiny hole through to the bottom, it would be too small for anything other than a liquid like water to go through. Since it's likely a hole this small is not going to have glaze in it, it's unlikely water would be going through that hole. The hole itself could be used as a stand for a dried flower, a stick incense, or other decorations. The intent is to be able to make such holes without whatever is set in the hole sticking down through the bottom.

That's why the shape at the end - come to a point (or as close to one as I can print) so when the tool hits the surface under the piece it only leaves a tiny hold at the bottom. Above it is also a very small hole, until a bit higher up, where the hole is the full width.

Bear in mind that when the tool is used on the clay, the clay is soft, so it's not going to meet a lot of resistance until it reaches the surface the clay is resting on.

Also, I mentioned shrinkage. If I want a 3/16" hole, I can't just go to the store and get a 3/16" dowel and stick a point on the end. The finished size will be smaller than whatever size I make it when throwing it. One reason I considered printing for this tool is I can make versions for every percentage size from 8% shrinkage up to 15% shrinkage.

One thought for a design change does occur to me. Maybe, instead of a round part at the end, tapering to a tip (and, yes, I know printing the tip will not be a perfect point), what if I did a flat surface along the diameter? Would a flat thin surface work better than a cylinder of the same thickness?

All the comments have me thinking about alternative designs that will accomplish the same goal, including maybe finding something else to attach for the thin end.

If you want to print standing up you will need to give it multiple tree supports branching at various points on its way up.

My concern about breakaway supports is similar to a raft - with such a thin object, cutting things away requires extra care.

Or design a support in)

Okay, that's an interesting idea. I did one design that was on a base for different reasons and I didn't think about including supports as part of the design. Good point!

Printing a thin column and to a point is tricky as the plastic doesn’t get a chance to go hard before the next layer. Slowing as the print and more as it gets near the top is a way around this.

Ah - thank you! I would not have thought of this.

It might be easiest to buy one.

If anyone made a tool like this - and, as best I can tell, they don't.

3d Printed is really the wrong technology for something like that.

Okay. This was my first shot at making this tool. I did think of using the CNC, but the thin point is an issue there, as well. Plus I can't really make a tiny round shaft like this. (Also, there's the shrinkage range issue - I need multiple versions of whatever I end up with.)

You can print multiple copies simultaneously to address the cooling issue John mentioned

That's a good idea! I'll be printing 8 different sizes (see my notes above about the shrinkage issues). There will be slight height differences, so I can just add a few extra copies of the tallest ones.

Does it have to be cylindrical? Would a hexagonal section be OK if you rotated it in your fingers?

My first thought was, "Yes! No way to print it in another shape," but then I thought about it and this is a very good point. I could do a hex and there might even be some cases where I wouldn't rotate it and could use the hex shape as part of the design. But then I considered the medium and clay will not give me the sharp corners to make a hexagonal hole that small. So, yes, changing the shape will work.

RE: Printing long thin cylinder

Just for the record, and to provide some sense of resolution, I went with a very different design. I did want a long probe, maybe 6", that I could use here, with the small end, but it's clear that's not something I can print reliably. The length I need, for now, is about an inch, so I'm sticking with that (for now) and it's on a flat platform. It comes to a point but does not have the long thin section on the end.

As I said, this is for ceramic work and different clay bodies shrink different amounts, so for my first run of this tool, I need to create the tool at the size I need - so, for reference, that'll be 100%. Then I need to make versions for clay that shrinks 8%, 9%, 10%, and so on, until 16%. So that's one issue I have to deal with and why I'm not doing something I can build in another way. It's pretty easy, for printing, to just scale the original up for the amount of shrinkage I need.