Export or Print Print Setup for comparison

[JefferyS 0]

I know that a lot of the settings are dependent or calculated from other settings that can be changed.

I have a print with little plastic studs to hold a circuit board in place and they break off easily with 20% infill.

 

I tried doing 100% infill, which the print time was actually less than the 20%, and I get lots of strings on the studs. The supports for the openings in the walls of the box, some round some rectangle are very thick and hard to get out such tiny holes. Very little problems getting supports out at 20% infill.

 

I want to see what is all changing and how much between the 20% infill and 100% infill in all the settings for the print setup.

 

At 20% infill I get nice round studs with no stringing.

 

The box with the circuit board in it, you can see by the holes I had a heck of a time getting the supports out.

 

Any help would be most appreciated.

 

Thanks,

 

Jeffery

 

[gr5 2,172]

Breaks off easily?  That's not good.  I'm guessing this is not PLA.  I've never met someone with fingers strong enough that could break those support blocks off easily.  It would take about 30 pounds (15 kg) of force.  I mean if you had a screwdriver you could pry them off but not finger strength only.

 

I'm guessing these are printed in ABS and that you don't have good layer adhesion.  The solution is to enclose your printer and get the air up to 35C and also to lower the fan speed to the lowest it will go to but still blow - about 50% rpm of normal.  On an ultimaker 2 that would be 30% fan.  On an S5 that would be 5% fan.  Every printer is different.

[JefferyS 0]

Thanks for replying,

I'm sorry, I should have given more information though I didn't think of it at the time.

 

It may be hard to tell in the pictures but the boxes are 32mm x 42mm, 12mm tall. Walls are 2mm in CAD but actually 2.2mm.

 

Yes I'm using PLA.

The piece that is breaking off sits on top of the round studs by the rectangle holes. There 2.5mm in diameter and 3mm tall. At 20% infill they broke off the first couple I made.

 

My biggest problem is a lot of stringing on the studs at 100% infill. That is mostly what I'm trying to solve but It may be better after thinking about it to use  screws but I'm trying to conserve on weight because it is going on a quad-copter. Oh and the supports being to thick to pop out easily. When I did 100% the infill change to lines.

 

The lid that I haven't made yet was going to keep the circuit board held down.

 

Thanks,

 

Jeffery

 

[JefferyS 0]

I thought they all broke off but actually one left. These are the two printed at 20% the stud is nice and clean and the hole in the circuit board fits great. My holes were a tiny bit off as well as some other holes in the side.

 

Strange, I tried to edit my other post and add the picture but gave me -200 errors.

[gr5 2,172]

Oh.  Okay.  Those pins are smaller than what I first thought you meant.  Well the amount of force it takes to bend that pin (break it the easy way as opposed to compressing or stretching) goes up by the fourth power of the diameter (assuming the length stays the same).  So if you can double the diameter it will be 16X stronger.  But if you only make it 10% thicker it will be 46% stronger (I'm 80% sure it's 4th power - I'm about to go to bed so my brain could be remembering it wrong - maybe it's cube but I'm pretty sure it's 4th power).  The infill won't make much difference.

 

Is it possible to design the pins a little thicker?

 

Even at this size they look quite strong.  Maybe there was a pretty strong force that broke those?  Maybe once the pcb is in there they will be strong?

 

A 3rd option would be to replace those pins with steel pins and put holes in there instead.  Maybe screws could go through the pcb into the holes.

 

[gr5 2,172]

The title for this topic seems wrong - it probably will push away people from this topic who would be interested in this.  I can edit the topic if you tell me what to change it to.

[JefferyS 0]

" The infill won't make much difference." I'm not sure what you mean, I thought the infill made the thing more solid. A 100% infill would make it solid plastic. I would think that would have made it stronger.

 

In the last picture the box that is standing up you can see the hole in the stud where the top part of the stud broke off so it's mostly hollow. Maybe to small for the 20% infill to make a difference. Maybe increasing the top layer to make it thicker might work. Just thought of that.

 

The pcb holes are a set size and can't get any bigger but I have thought of the other options you mentioned though still not wanting to add any metal to save weight if possible.

 

As for the Title I'm not sure. I was mostly trying to figure out what was causing the stringing on the studs and the thickness of the supports at 100% infill. I wanted to see what in the print settings changed when I set it to 100% infill compared to 20% infill and maybe adjust what it changed to stop all the stringing and the thick and hard to remove supports in the walls of the box.

 

The stringing on the studs is like a rats nest of filament thin strings that I can't clean them off and the circuit board holes won't fit on them.

 

I'm guessing printing or exporting the print setting is a no so I'll have to either switch to another method of holding my circuit board in place so it doesn't move when pressing the buttons on the side.

 

I may manually copy down the setting to see what changes if I have time and maybe back it off to 50% infill to see what happens.

 

Your welcome to change the title to what you think would be good. I guess in hindsight the title should have been more about stringing at 100% infill more than anything.

 

I do appreciate all your help and suggestions. Back to the drawing board as they say lol.

 

Thanks,

 

Jeffery