Printing more or less tight fitting parts.

[vladimir]

Hello.
I am printing a mechanism from Thingiverse.

It is one STL file. Parts come out very tight when I assemble them

I use Flashforge replicator with Makerware.

What printing profile values do I modify to set surfaces back when my machine prints?
Should I use different software?

What firmware update can I use on my plywood flashforge 3D printer?

Thank you.

--Vladimir

[LambdaFF]

Sometimes, it's not the printing but the deisgn that's creating the issue. You never know until you make your own designs.
In this case, can't you just file it a bit ?

[iDig3Dprinting]

It is possible to scale parts in the slicer software but this may not produce a workable end product. We don't know the print that you are wanting but it is possible that the designer made the dimensions the way they were for a reason.

As to firmware updates, it depends what you are running currently. Also before you attempt any updates make sure that you have a copy of your existing firmware settings, that you know work, so that you can roll back if you encounter any issues.

[curious aardvark]

no need to change firmware in the creator x.
I never have and haven't missed anything.

Tolearance wise it depends on a number of factors.

what the original designer printed it with. if he used abs and you used pla - your's will be different dimensions to his.
What brand of filament you use, how hot you print, what the conditions in your workshop are: heats humidity etc.
There are so many variables, it's really just trial and error until you know what works on your machine in your workshop and what doesn't.

I did some nuts and bolts recently.
Without modification they were a very tight fit and I needed to sand them to get an easy to turn fit.

second set i printed I reduced the bolt by 1% and enlarged the nut by 1 %.
Came off the bed perfect, nice looses fit that still tightened and worked correctly.

So start at 1% reduction and see what happens.

[djprinter]

There are so many variables... frankly, outside of plain luck, I don't see how it's possible to print the same STL file on two different printers/filaments and end up with two working "tight fitting" mechanisms.

When I print parts with tight tolerances I always print a bunch of small tests to get the fit just right--making slight adjustments in 3d software based on the results.

[Ama-fessional Molder]

There are so many variables... frankly, outside of plain luck, I don't see how it's possible to print the same STL file on two different printers/filaments and end up with two working "tight fitting" mechanisms.

In theory, perfect control of your environment, extrusion speeds, melt temperature (distinct from hot end settings and as best I can tell you guys don't measure this), nozzle size, print speeds, and everything else should give you the exact same result on two different machines with the same filament...

But that's the theory in molding too. We know it all goes out the window in reality.

Getting the same result from different machines is a combination of process control, trial and error, and adjusting the machine while measuring the output.

I find it fascinating to see the same things at play between the two opposing ends of the plastics spectrum.

[vladimir]

Thank you. It is not a design flaw because I printed a part with 6.40mm hole in it. When I measured the part with a caliper it is 6.32mm.
The outside diameter of the part turned out to be 47.95mm but in the design it is 48.35. I can compensate by adjusting the scale over x and y in the printing profile?

Are there any new 3D printer slicing STC to G code programs in developement?
Slicr is very user unfriendly (as most open-source software is) while Makerware is not open source.

[iDig3Dprinting]

Thank you. It is not a design flaw because I printed a part with 6.40mm hole in it. When I measured the part with a caliper it is 6.32mm.
The outside diameter of the part turned out to be 47.95mm but in the design it is 48.35. I can compensate by adjusting the scale over x and y in the printing profile?

So the difference in your models may be due to the calibration of your xyz axis being out slightly. The printer is moving the steppers X number of steps per mm but the value of X may be too low, it has to move more steps to make up a mm.

try printing out a calibration cube to check and re-define your printers steps per mm. The instructions on the calibration calculations are also on the page.

[djprinter]

In theory, perfect control of your environment, extrusion speeds, melt temperature (distinct from hot end settings and as best I can tell you guys don't measure this), nozzle size, print speeds, and everything else should give you the exact same result on two different machines with the same filament...

But that's the theory in molding too. We know it all goes out the window in reality.

Getting the same result from different machines is a combination of process control, trial and error, and adjusting the machine while measuring the output.

I find it fascinating to see the same things at play between the two opposing ends of the plastics spectrum.

Leave the theory's to the professors and scientists. Makers will stick with practice over theory.

[Ama-fessional Molder]

Leave the theory's to the professors and scientists. Makers will stick with practice over theory.

Professionals stick to practice too usually, but...

Theory can help you even as a maker (or professional), if you know what should be done you can take steps to get closer to it. But we all know full well that theory doesn't translate into real world results a large percentage of the time lol

If you know what the perfect result should be, and know what your actual result is, you ought to be able to find the source of the problem.