Holes too small. February 12, 2017 05:38PM |
Registered: 7 years ago Posts: 8 |
Re: Holes too small. February 12, 2017 05:49PM |
Registered: 7 years ago Posts: 759 |
They suggested that where X mm was the required diameter of the hole then Y mm was the dimension needed to achieve it and that: a) for vertical holes Y = 1.0155X + 0.2795 mm b) for horizontal holes Y = 0.9927X + 0.3602 mm These figures were for PLA, and as I understand it, they take into account various factors including the fact that the inside of the hole is unrestrained against shrinkage.
Re: Holes too small. February 12, 2017 08:39PM |
Registered: 7 years ago Posts: 267 |
Re: Holes too small. February 12, 2017 09:59PM |
Registered: 7 years ago Posts: 8 |
Quote
obewan
Holes allways come out smaller than what you specify,due to shrinkage of the plastic and the fact that
holes are made up of many straight lines rather than pure arcs.
There is a forular to calculate the needed diamater as follows
They suggested that where X mm was the required diameter of the hole then Y mm was the dimension needed to achieve it and that: a) for vertical holes Y = 1.0155X + 0.2795 mm b) for horizontal holes Y = 0.9927X + 0.3602 mm These figures were for PLA, and as I understand it, they take into account various factors including the fact that the inside of the hole is unrestrained against shrinkage.
Re: Holes too small. February 12, 2017 10:00PM |
Registered: 7 years ago Posts: 8 |
Quote
scottybfg
Just buy some drill bits and drill them out.
I like having the holes come out smaller because I can drill them out to the correct size, get a good finish and know they are the correct fit.
Its much easier to fix an undersized hole then an oversize hole
Re: Holes too small. February 13, 2017 02:31AM |
Registered: 7 years ago Posts: 201 |
Re: Holes too small. February 13, 2017 07:39AM |
Registered: 8 years ago Posts: 413 |
Re: Holes too small. February 13, 2017 01:04PM |
Registered: 7 years ago Posts: 8 |
Re: Holes too small. February 13, 2017 07:07PM |
Registered: 7 years ago Posts: 181 |
Re: Holes too small. February 14, 2017 04:30AM |
Registered: 7 years ago Posts: 201 |
I agree with all of your points, but this one is even worser. There are no circles in .STL files, so no matter which tool you use to design something, after exporting it into .STL, the circles are history.Quote
Supermec
1. It depends on the slicer and firmware as to whether the printer can produce a perfect circle, or whether there is an approximation by a series of short straight lines. Most free slicers and most low cost printers will use an approximation. For minimum error part of the straight line will fall outside the true curve and part inside. Thus the inside diameter will be slightly smaller.
Re: Holes too small. February 14, 2017 07:52AM |
Registered: 8 years ago Posts: 413 |
Re: Holes too small. February 14, 2017 01:03PM |
Registered: 7 years ago Posts: 181 |
Quote
Inhumierer
I agree with all of your points, but this one is even worser. There are no circles in .STL files, so no matter which tool you use to design something, after exporting it into .STL, the circles are history.Quote
Supermec
1. It depends on the slicer and firmware as to whether the printer can produce a perfect circle, or whether there is an approximation by a series of short straight lines. Most free slicers and most low cost printers will use an approximation. For minimum error part of the straight line will fall outside the true curve and part inside. Thus the inside diameter will be slightly smaller.
Next point: All 3D printers (of which I know) use stepper motors to move parts in some directions. So even if you'd feed the printer with the G codes to make circles, the firmware of the printer needs to approximate the circle by small straight lines, because a stepper motor makes steps, no smooth movements. Yay, that's why they're called "steppers" ;-)
Re: Holes too small. February 14, 2017 04:27PM |
Registered: 7 years ago Posts: 8 |
Quote
MCcarman
Be careful with what you are adjusting. A 0.4nozle extruding at 0.77 shows way over extrusion. You don't directly fix that with extrusion width.
Those familiar with the software need to step in here because I am still confused by the extrusion width.
Check the filament size, extruder calibration and any extrusion multiplier settings first.
Re: Holes too small. February 15, 2017 04:56AM |
Registered: 7 years ago Posts: 201 |
Re: Holes too small. February 15, 2017 11:27AM |
Registered: 7 years ago Posts: 181 |
Quote
MCcarman
Be careful with what you are adjusting. A 0.4nozle extruding at 0.77 shows way over extrusion. You don't directly fix that with extrusion width.
Those familiar with the software need to step in here because I am still confused by the extrusion width.
Check the filament size, extruder calibration and any extrusion multiplier settings first.
Re: Holes too small. February 15, 2017 11:32AM |
Registered: 7 years ago Posts: 181 |
Quote
bkohn1
My nozzle is .4mm. I printed a hollow square with .4mm walls and my printed walls are .77mm. Pretty sure that's my problem. Does anyone know how to set extrusion width in Simplify3D?
Re: Holes too small. February 18, 2017 05:37AM |
Registered: 10 years ago Posts: 175 |
Re: Holes too small. February 18, 2017 09:52AM |
Registered: 7 years ago Posts: 56 |
Re: Holes too small. February 18, 2017 10:18AM |
Registered: 7 years ago Posts: 181 |
Re: Holes too small. February 19, 2017 11:13AM |
Registered: 7 years ago Posts: 56 |
Quote
Supermec
You have been given the magic numbers. These formulae were obtained from a professional 3d printing firm, and are what they use to provide the correct results. If there was a simpler way to arrive at the answer, then I would have given it to you. This is about the simplest formula that you can get, it's not advanced mathematics.
Re: Holes too small. February 20, 2017 06:44PM |
Registered: 7 years ago Posts: 181 |
Re: Holes too small. March 05, 2017 09:44AM |
Registered: 7 years ago Posts: 56 |