A Different Direction..............

[Neil Merryweather]

the big issue with support in FDM printing is the support INTERFACE.
CURA has settings for this ,I don't know about your programme.
What you will be tweaking is the AIR GAP -ie the space between the top of the support and the model itself. it's frightfully hit and miss, I'm afraid, and probably different for every brand of FDM.
Good luck
N

[Jim R]

Well Dave this is certainly taking a lot of time, thought and study. I'm sure you'll get there in the end and it's keeping you out of the pub! Well maybe not - a few hours trying to juggle all the possible setting combinations could actually send you to the pub

[Dave Ward]

Ah Supports! I'd printed the spool support arm with the PrusaSlicer automatic generation of supports. I started trying to break them off. The PLA is tough stuff - I've removed a lot, but when I managed to break a scalpel blade I gave up for the day!!

Whilst I was doing this I printed out a couple of small models
A wooden crate

The resolution just isn't there, printing at its finest & slower speed. Still, prime it, paint it & it would do as part of a lorry load.
This took about 1 1/2 hours to print it's about 55 to 60mm in diameter - from Thingiverse, a Viking brooch by 'Prot0typ1cal'

When the brim & supports cleaned up

And the back more or less cleaned up of supports

The layer height I was using was 0.08mm, but I think the limitation is due to the nozzle diameter of 0.4mm. You can get smaller nozzles, but this adds another complication of flow rates. You can see why cinematic props are made by FDM, prime it & paint it silver, then a fine black wash - at more than 3-4m, it'd pass as real! I'm beginning to see the lower end limits of FDM printing
Dave

[langy71]

Dave, can you not cut the supports away with a pair of sprue cutters / nippers? It might save you a fortune on scalpel blades..

[Dave Ward]

Dave, can you not cut the supports away with a pair of sprue cutters / nippers? It might save you a fortune on scalpel blades..

That's how I started off - I was using the scalpel to reach bits the sprue cutter couldn't - I've got out the big guns now - the Stanley Knife!
Dave

[langy71]

You can't beat a good ole Stanley Knife,

[Neil Merryweather]

Ah Supports! I'd printed the spool support arm with the PrusaSlicer automatic generation of supports. I started trying to break them off. The PLA is tough stuff - I've removed a lot, but when I managed to break a scalpel blade I gave up for the day!!
[ATTACH=CONFIG]n1193143[/ATTACH]
Whilst I was doing this I printed out a couple of small models
A wooden crate
[ATTACH=CONFIG]n1193142[/ATTACH]
The resolution just isn't there, printing at its finest & slower speed. Still, prime it, paint it & it would do as part of a lorry load.
This took about 1 1/2 hours to print it's about 55 to 60mm in diameter - from Thingiverse, a Viking brooch by 'Prot0typ1cal'
[ATTACH=CONFIG]n1193139[/ATTACH]
When the brim & supports cleaned up
[ATTACH=CONFIG]n1193140[/ATTACH]
And the back more or less cleaned up of supports
[ATTACH=CONFIG]n1193141[/ATTACH]
The layer height I was using was 0.08mm, but I think the limitation is due to the nozzle diameter of 0.4mm. You can get smaller nozzles, but this adds another complication of flow rates. You can see why cinematic props are made by FDM, prime it & paint it silver, then a fine black wash - at more than 3-4m, it'd pass as real! I'm beginning to see the lower end limits of FDM printing
Dave

Try building it on its edge, Dave. You might be surprised. A dome is generally self supporting, and if you put the brooch pin vertical you shouldn't need any at all. It will take longer,of course.
Generally speaking it's not the layer height that is restricted by the nozzle size, rather the detail definition.
0.4mm is not a problem on real life objects, but scale down to 1.35....

Yes we use them a lot in film prop making, but we still have to finish the parts to within an inch of their lives, because you can bet the director chooses to zoom right in on what you thought was for the background! :rolling: :tears-of-joy:

[Neil Merryweather]

That's what I meant by the support interface, you need enough to do the job but not so much that you ruin the piece whilst removing it. THAT'S the dark art part!
Stay focused, Grasshopper :tongue-out3:

[Dave Ward]

I printed out a few calibration models, then levelled the bed, sliced a new model with a few settings tweaked & it's about 3 hours into a 4 our print....................
I have put the printer on a cork mat ( from a model railway bits shop ), and it's much better
I primed yesterday's Viking brooch, painted silver, then a light wash of black............

One thing that I have found a problem with, due to my fat fingers is, putting the micro-sd card into the mainboard. I've dropped the cards several times already, so I've ordered one of these

The small end is permanently plugged into the mainboard, and you can use a standard SD card ( or micro with adapter ) at the other - the one I've ordered is 250mm long, so the free end should be able to be placed on the top of the printer, in full view, and easy access!
Dave

[Dave Ward]

OK this is the Dark Knight from Thingiverse by MustangDave

On the printer bed - a little bit of stringing between his ears, but nothing to worry about. I still haven't used the glue stick on this magnetic plate - the print stuck well.

Looks more like Predator than Batman! The supports added hold up the chin. nose & brows.
Again, the supports are a real pig to remove and there's surface detail & texture lost

I'm really going to have to get this support business figured out - otherwise the bust is pretty good


The tweaks I've applied to the settings seem to have worked, the layer lines are not apparent under normal light.
I'm going to have another go at this, paying extreme attention to the supports & make them as light as possible. I must also calibrate the Z-axis stepper motors- it may be that one side is slightly higher than the other. Of course this will mean re-levelling the build plate, but I'm getting the hang of that. I'm happy with progress so far, and I may venture into printing some of my own creations. They will be engineering orientated, the sculpting side of CAD modelling ( using Blender ) are a total unknown to me
Dave

[Neil Merryweather]

OK this is the Dark Knight from Thingiverse by MustangDave
[ATTACH=CONFIG]n1193253[/ATTACH]
On the printer bed - a little bit of stringing between his ears, but nothing to worry about. I still haven't used the glue stick on this magnetic plate - the print stuck well.
[ATTACH=CONFIG]n1193254[/ATTACH]
Looks more like Predator than Batman! The supports added hold up the chin. nose & brows.
Again, the supports are a real pig to remove and there's surface detail & texture lost
[ATTACH=CONFIG]n1193255[/ATTACH]
I'm really going to have to get this support business figured out - otherwise the bust is pretty good
[ATTACH=CONFIG]n1193256[/ATTACH][ATTACH=CONFIG]n1193257[/ATTACH]

The tweaks I've applied to the settings seem to have worked, the layer lines are not apparent under normal light.
I'm going to have another go at this, paying extreme attention to the supports & make them as light as possible. I must also calibrate the Z-axis stepper motors- it may be that one side is slightly higher than the other. Of course this will mean re-levelling the build plate, but I'm getting the hang of that. I'm happy with progress so far, and I may venture into printing some of my own creations. They will be engineering orientated, the sculpting side of CAD modelling ( using Blender ) are a total unknown to me
Dave

If you tilt him back about 20 degrees the support would be on the back and underneath rather than the face, and much easier to remove, and to make good.
It's all about the orientation.

[Dave Ward]

t's all about the orientation.

Good thinking Batman! :tongue-out3: That seems to make a lot of sense - it's a new way of looking at things. I'm just beginning to wonder what happens when my present spool of PLA runs out. I have a new box, another maker, another colour - I'll have to see how different that is.................
Dave

[Neil Merryweather]

In my experience there's little to choose between brands of pla. I always go for the cheapest- usually from the 'rainforest'

[Dave Ward]

Postie just dropped this off - 1 kg spool of 'Florean' blue PLA - £9.85 delivered from ebay 'buy it now'


The Dark Knight - I looked at the file, and, I thought - there aren't any bigger overhangs than the 'Benchy' I printed out a day or two ago, so decided to print without any supports...........................


I think that can be counted as a success - in normal daylight the layer lines are almost invisible!
I did true up the Z-axis, there was about 0.75mm difference between the ends. Then I re-levelled the bed. Still no glue stick used. When the print has finished, you remove the magnetic build plate & gently flex it. The print comes away easily, with a faint crackling! This is such an advance over the tape & glue stick of the original configuration. A quick wipe with IPA to remove any grease, and it's ready for the next print.
Dave

[Tim Marlow]

Postie just dropped this off - 1 kg spool of 'Florean' blue PLA - £9.85 delivered from ebay 'buy it now'
[ATTACH=CONFIG]n1193285[/ATTACH]

The Dark Knight - I looked at the file, and, I thought - there aren't any bigger overhangs than the 'Benchy' I printed out a day or two ago, so decided to print without any supports...........................

[ATTACH=CONFIG]n1193286[/ATTACH][ATTACH=CONFIG]n1193287[/ATTACH][ATTACH=CONFIG]n1193288[/ATTACH][ATTACH=CONFIG]n1193289[/ATTACH][ATTACH=CONFIG]n1193290[/ATTACH]
I think that can be counted as a success - in normal daylight the layer lines are almost invisible!
I did true up the Z-axis, there was about 0.75mm difference between the ends. Then I re-levelled the bed. Still no glue stick used. When the print has finished, you remove the magnetic build plate & gently flex it. The print comes away easily, with a faint crackling! This is such an advance over the tape & glue stick of the original configuration. A quick wipe with IPA to remove any grease, and it's ready for the next print.
Dave

Very nice Dave. Interesting that you see layer lines like this on some moulded products these days. They must sculpt and print digitally, then make the moulds from the prints.