Support for tall, thin object?  

RE: Support for tall, thin object?

It it a double sided ruler, or single sided? If single sided, you might want to consider designing a break-away support system on the unused side? Might be trickier post processing to get a flat side, but it might work out.

Disclaimer: I've never tried something like this. Take my idea as just spit-balling to see what sticks to the wall. 😉

RE: Support for tall, thin object?

I would never try to print that; just too many things to go wrong.  Instead I'd print it horizontal, one edge down so the height is the rule width, rather than length.  I'd add block supports at the two ends to help hold it vertical. And I'd probably use a brim to help with warp and lifting.

I know you lose resolution, but vertical will be hard.

A part like that printed vertically will need dozens of supports along the way, and even a sleeve isn't out of the question.  If one of the edges doesn't have to be perfect, adding a breakaway support to make it a T, or even redesign it to be the typical triangular architect rule might be best.

A manually made support contact can be as small as 0.25 mm, a minimal scar where the support was will be visible, but much better than a wobbly tower of scribbled plastic.

If you're able to share the STL - drop it into a ZIP and post it; I like paying with hard design problems; I usually learn something in the process.

RE: Support for tall, thin object?

Something like this ...

RE: Support for tall, thin object?

@sembazuru: The ruler is double-sided. However, there is some unused area along the middle of the top/bottom side (the sides with the largest area).

@tim-m30: I'm curious, why one edge down instead of layout it flat? To get a smoother edge?

Here is the STL: Ruler-v5-10

I have played with the sizes of the cut-outs. If I make them smaller than this, with 0.1mm layer height, they tend to get filled.

If you try a piece, please tell me if you also get problems with the cut-outs "going up" at the outer edge on one side (The image should be clickable). I thought it was the seams and tried setting them to "Random", but it does not seem to have helped.

Thanks for the support example picture, it makes it much clearer! I think I might have a go at this.

RE: Support for tall, thin object?

Those deformations are are unsupported bridges, so the filament simply pulls to the nearest point. Think hanging a stretchy string out to a point in free space.  It's difficult for FDM to print 90 degree bridges without a lot of extra work in planning.

Best if you can redesign those notches to be 45 degree Vees, not square cuts. That or make them less deep, under 0.4 mm so the filament has something to hang on to.

RE: Support for tall, thin object?

I edited the lines to about 0.25 deep - they print fine, and have adequate relief to be visible. Printed at 0.1 mm there seems to be some weirdness going on (or I didn't spend enough time looking at all the scales)... so trying 0.05 - but it'll be 23 hours. Lol. Also trying an easier to remove support method.

I'll report more when I know more. :~)

Ruler-v5-10 with supports

RE: Support for tall, thin object?

0.05 mm layers a fail with the Prusa Beige ... lol.  Plus, thinking my bed is warping and it's past time to install the new bearings and rods sitting next to my printer.  Back to a 0.1 mm layer with support pins rather than a continuous strip.   So far, looks like the matte filament is going to be a problem for this part.  Going to let it finish and will try a short sample using PLA2, which behaves fairly well at 0.07 mm.

RE: Support for tall, thin object?

Posted by: thomasa88

[...]

@tim-m30: I'm curious, why one edge down instead of layout it flat? To get a smoother edge?

The disadvantage of printing flat (with the current FFF technology) is the sides of a printed object get a higher resolution than the top or bottom.

Looking at the results of the test prints, I'm thinking that Tim's suggestion of printing on one of the long edges would lead to better results as then the overhangs will be at the end of the graduations closest to the center, not along the edges. Also, having the graduations perpendicular to the layer lines (I think) would help them stand out and be recognized for what they are.

RE: Support for tall, thin object?

Wow! Thanks for all the testing.

I played with the depth of the gradations and 0.25 still looked good, as you said Tim. 0.1 was too flat.

I still get the edge overhangs, so I'm thinking about trying two different things:

* Put the ruler on the long thin edge, as first suggested by Tim, due to the info from sembazuru above.

* Let the gradations end a little before the edge of the ruler, to try to help the bridge.

0.25 gradation depth, standing:

RE: Support for tall, thin object?

In addition to being easier to print (albeit, with less resolution) horizontal edge down will increase the strength of the ruler if flexed. 

But after handling a 2" chunk of the rule, why 1,2,3 gradations?  Six notches per half cm seems a bit odd.  What industry uses 1/12 a centimeter as a measure - scale modeling?  

RE: Support for tall, thin object?

Final 0.10 mm layer height print complete; beige filament not performing well; and likely needs drying.

RE: Support for tall, thin object?

Looks like your print came out quite good and the support worked! Would you mind sharing the STL including the support? It looks like you did the crosshair touching the ruler at just a few places?

Odd gradations: It's time markers for a journal, with changing hour lengths 🤣 (some hours during the day have gotten more space than others). The longest markers are 1 hour apart, the middle are 30 minutes and the shortest are 10 minutes.

My posts got stuck waiting for moderation, but I did try my two ideas. Putting the ruler on the long edge failed already in the slicer, with missing details, due to the original problem of the gradations being small and not far part.

My added outer edge (0.45 mm) on the gradations came out quite well, getting rid of the bridging problem 🙂 .

STL: Ruler5-0.45-from-edge

I performed some end user testing, and it turns out that the ruler is to thick, since it is hard to align a pencil flush to the lines / in-between the lines. I will try making the long edges tapered and lose the mirrored backside.

I'm learning a lot 😀 !

RE: Support for tall, thin object?

The stl is in the zip I posted above: Posted : 15/08/2019 12:43 am

1.2 or 1.5 mm works well for a wall thickness (3 or 4 perimeters), but you'll lose strength.  Interlayer adhesion drops fast and the rule will snap quite easily if it's too thin.

My PLA2 version will be done in a few hours, decided to let it finish. Outside surface of the support looks much better than the Prusa Beige. I am hopeful the rule will look better, too.

RE: Support for tall, thin object?

Can I ask the obvious question, why print a ruler? Is it a special kind of ruler?

It's not going to be very accurate and you'll spend more in filament and time than it would take to run to the store and buy one.

Just curious.

RE: Support for tall, thin object?

Posted by: richard.l

Can I ask the obvious question, why print a ruler? Is it a special kind of ruler?

I agree - I'm for buying a ruler rather than making one.   

I'm printing it because it is a challenging part that represents some of the things I have had problems printing before and was never satisfied with how I got supports to them.  This gives me a chance to experiment, and maybe help someone while learning myself. 

But I will also say I have never used a rule with the scale this one has: it is special.  My guess it is a modeling ruler for folks building 1/6th or 1/12th scale models.  

Final test print: PLA2 prints a bit better, but still showing positional inaccuracies I subscribe to my seriously worn bearings (and maybe slightly loose belts).

ps: hmm - maybe I am printing that Prusa filament a bit on the hot side....

RE: Support for tall, thin object?

Tim: Thanks, I had missed that file.

Richard: It's for marking in a journal, where the hours rows are not evenly sized: (Also, I just got a printer and want to see what I can do 🙂 )

I tapered the edges down to 0.8mm and 0.6mm respectively. (0.4 mm did obviously not look so good in the slicer )
I think both look acceptable:

I will have a go at adding the support.

edit. The close-up photos show off much more defects than I saw with my eyes x) .

RE: Support for tall, thin object?

Posted by: richard.l

Can I ask the obvious question, why print a ruler? Is it a special kind of ruler?

It's not going to be very accurate and you'll spend more in filament and time than it would take to run to the store and buy one.

Just curious.

the scale is time. (Hour)

RE: Support for tall, thin object?

Try changing seam position, it helped when I was playing around.  I think it was "aligned" that gave best results, and "rear" that gave the worst results.

RE: Support for tall, thin object?

I just completed a full print. I removed the hole, as it was cumbersome to design the support in Onshape and Prusaslicer wanted to extend my enforced support outside the ruler, all the way to the bottom. I missed to play with the seam, but I think the result is OK. I did some sanding of the edges, as the "holes" on the edges tended to be between the markers, making a pencil snap to the wrong places.

I'm happy with the end result 🙂 . Thanks for all the help!

STL: Ruler-V8

Printed:

Ruler directly from the printer:

Sanded:

In use: