int3man
Posts: 14
Joined: Tue Dec 08, 2015 5:24 pm

Newbie Question, have read Print Quality Issues.

Hi All, O.K. I jumped in. Had time between Xmas and new Years. Learning CAD and Printer. I have success with the CAD and getting there with the printer. I do have a Surface Quality issue that is not covered in the Guide. Also I have a Faying Surface on the Bottom of the part that is not being supported around a hole by the Auto Support feature. it is printing support for 1/2 of the surface but does not cross the hole and support the full diameter.

The part finish where the part sits on the raft Sucks! Very Coarse. Prior to sanding I was wondering if there was something else I could try. Skipping the raft? My part is a thin shell and 1.3" in Diam.

Thanks for any advise.
Double Thanks for Great Advice!
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dkightley
Posts: 2405
Joined: Tue Mar 10, 2015 4:09 pm

Re: Newbie Question, have read Print Quality Issues.

I'm sure we can improve things here for you....

Firstly, you do have a surface issue that is covered in the guide. Look for the piece printed in pink. The bottom of your print is exhibiting this symptom...both on the very bottom and in the raised area. You need to check your filament diameter and make adjustments if needed...then increase your extrusion multiplier a tad. You've probably got it at 0.9...increase to 0.95 and try a test print.

If the under surface improves in the raised section (and probably on any top face) but not the very bottom, then you need to move your bed nearer to the nozzle. This can be easily fine-tuned by altering the global z axis value (on the G Code tab) to a negative value. Try -0.05 and see what happens.

Re your issue with supports, I'd add manually. Open the Support tool, set the resolution to 0.2mm (or even 0.1mm if the part is not that big) and add manual support along the edges of the downward facing face....along the side and round the hole. Click "Done"...then edit your profile. In the Support tab, change Dense support layers to 1 and dense infill percentage to 70%, & check upper vertical separation layers is 1.

Do a test print and see if there's any improvement. You can save on plastic by setting the Stop printing at height (Advanced tab) to a tad higher than the unsupported surface.....or simply stopping the print at that point by cancelling.

It may take you a few iterations to get a finish you'll be happy with...but its worth taking the time playing with settings...
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net
int3man
Posts: 14
Joined: Tue Dec 08, 2015 5:24 pm

Re: Newbie Question, have read Print Quality Issues.

Thanks Mate. Next time I'll buy the Pints! I'll try those suggestions tomorrow.

Happy New Year to All!!
int3man
Posts: 14
Joined: Tue Dec 08, 2015 5:24 pm

Re: Newbie Question, have read Print Quality Issues.

dkightley wrote:I'm sure we can improve things here for you....

Firstly, you do have a surface issue that is covered in the guide. Look for the piece printed in pink. The bottom of your print is exhibiting this symptom...both on the very bottom and in the raised area. You need to check your filament diameter and make adjustments if needed...then increase your extrusion multiplier a tad. You've probably got it at 0.9...increase to 0.95 and try a test print.

If the under surface improves in the raised section (and probably on any top face) but not the very bottom, then you need to move your bed nearer to the nozzle. This can be easily fine-tuned by altering the global z axis value (on the G Code tab) to a negative value. Try -0.05 and see what happens.

Re your issue with supports, I'd add manually. Open the Support tool, set the resolution to 0.2mm (or even 0.1mm if the part is not that big) and add manual support along the edges of the downward facing face....along the side and round the hole. Click "Done"...then edit your profile. In the Support tab, change Dense support layers to 1 and dense infill percentage to 70%, & check upper vertical separation layers is 1.

Do a test print and see if there's any improvement. You can save on plastic by setting the Stop printing at height (Advanced tab) to a tad higher than the unsupported surface.....or simply stopping the print at that point by cancelling.

It may take you a few iterations to get a finish you'll be happy with...but its worth taking the time playing with settings...
Well I'm learning, but what I'm learning is to back my Multiplier back off. I'm back to .9 and wanting to go lower. Is there any problems that I am headed for? The bottom surface keeps getting smoother the lower I go.

Also is there a tutorial on how to manual install supports?

Thanks in advance.
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dkightley
Posts: 2405
Joined: Tue Mar 10, 2015 4:09 pm

Re: Newbie Question, have read Print Quality Issues.

The way I'd tune my printer would be to first get the extrusion multiplier set to its optimum value:

Find a calibration cube ( or generate one) and set the Top Solid Layers to nil and Outline/Perimeter Shells to 1(both on Layers tab) and Infill Percentage to nil. Set your Extrusion Width to what you want it to be (Auto...which will be 1.2 time nozzle width, or whatever manual setting you want...but don't go less than nozzle size or greater than 50% greater than nozzle size) and initially set the Extrusion Multiplier to 1.00.

Print sufficient of the cube so you have enough to measure the wall thickness. Remove the print and see what the thickness is. If its less than your setting, increase the multiplier, if more, reduce the multiplier. Print again to see what the effect is. Repeat until you get the right extrusion width.

Now you have the extrusion width set, you can take a look at the bottom surface. Look at the last test you did. Is the bottom smooth? If it is, then check for a small ridge indication plastic being squashed sidewards around the edge of the first layer. If there is one, your nozzle is a tad too close to the bed. If the bottom shows lines like in the photo you attached in your first post, then your nozzle is too far away from the bed.

If you bed is level, an accurate way of adjusting the height is to alter the Z-Axis Global G-Code offset. Adding to it or making it positive lifts the nozzle up; subtracting from it or making it negative lowers the nozzle. Adjust the value to adjust the nozzle height in the direction you've identified by half your layer thickness....and try printing. Adjust and print (by smaller values if necessary) to get the optimum finish.

You should now have a good starting point for developing your print settings to get cleaner and more reliable results.

And try this video for supports: https://www.simplify3d.com/support/tuto ... tructures/
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net
int3man
Posts: 14
Joined: Tue Dec 08, 2015 5:24 pm

Re: Newbie Question, have read Print Quality Issues.

Hi Doug, or anyone,
Got a borate glass bed installed and got the flood of ABS reduced to where it is presentable, printing the open box as Doug suggested. The trouble that I am having now is that the Raft material does not cohere. it sticks to the glass well (adhere) but not to it's self and when I try to remove the Raft from the part, strings of the raft stick to the part, and the raft falls apart in my hands. It seems to cohere to the part better than it's self.

Thanks again owe you a Pint!

Michael :- )

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