- Thread starter ukracer
- Start date
Yes you are spot on thanks. Cura has mangled it a bit on the bottom!
Cura has only done what you've asked it to do.
Lay Flat (middle option), and Select face to align to the build plate (right option) are your friends.
Also if you rotate the view so you're looking up from below the build plate, the red indicates unsupported areas, whereas the blue indicates contact with the plate
Flat on the bed in the slicing software..
DAPPH
as dyslexik as I'm daft
- Messages
- 7,154
- Location
- Near to Cross Hands Llanelli SouthWales GB
I think that the initial bed levelling might need redoing , going through the initial new build set up , then sorting out it again on a test calibration print to fine tune things build plates & heater plates do warp in microns ever so slightly over time
I say this because for a couple of days I've been trying to print a block of 10 x 5 mm id x 12.5 dia base tall top hat washers .. the print starts off in the first row like a letter c for the first three passes which only prints the first three rows in a diminishing amount of extrude by slice 6 the full washer base is formed in the front row and the last row are starting to get pinheads of extrude . Using Cura for " place flat to plate " did not help .
It was only tonight whilst driving back home & starying at the bad print that it came to mind for me to re read the Joe \Prusa hand book several more times Seems that every now & then , after going through Prusa's 3D printing hand book ( several times ) , the initial bed leveling exercise needs doing ....... .. after checking all nuts screws & bolts for tightness needs doing as part of your servicing schedule as microscopic variances can & will eventually develop over time / usage .
I say this because for a couple of days I've been trying to print a block of 10 x 5 mm id x 12.5 dia base tall top hat washers .. the print starts off in the first row like a letter c for the first three passes which only prints the first three rows in a diminishing amount of extrude by slice 6 the full washer base is formed in the front row and the last row are starting to get pinheads of extrude . Using Cura for " place flat to plate " did not help .
It was only tonight whilst driving back home & starying at the bad print that it came to mind for me to re read the Joe \Prusa hand book several more times Seems that every now & then , after going through Prusa's 3D printing hand book ( several times ) , the initial bed leveling exercise needs doing ....... .. after checking all nuts screws & bolts for tightness needs doing as part of your servicing schedule as microscopic variances can & will eventually develop over time / usage .
Yes I always level the bed.
Turns out it was a problem with the model created in Blender. For some reason the base wasn't truly flat. Only visible when zoomed right in. A few jagged bits.
Now it is creating a nice brim. 10 hour print so will start it Sunday morning. Don't trust them to run overnight!
DAPPH
as dyslexik as I'm daft
- Messages
- 7,154
- Location
- Near to Cross Hands Llanelli SouthWales GB
My Prusa does a nine point bed level check every time I put a card in it .
What I referred to in my above post is ( I think ) referring to the mesh bed levelling that can be moved back front centre left middle & right in some 24 or more positions & stored in the printers memory according to how the test print down load prints out . Think it says each point can be moved to a max of 50 micron but that it's likely to be far less adjustment needed to get the microscopic differences allowed for in the first layer of extrusion.
Seem to think there are some of these fine tune test prints down loads available on Thingyverse . I'll be looking tomorrow when I'm more awake.
I still haven't it done it ..it was planned for today .
Instead , today was spent cleaning out the back of my Turismo people carrier after two 6 foot x 2 foot 6 mm tempered black glass shelves I was carrying for my daughter slipped , nicked a bit of metal then exploded into many many thousands of bits . It filled 1 & 1/2 buckets with the broken glass & took me four hours in short stages to super vacuum clean the microscopic shards out the cars carpets. I even found some in the froot footwell's ,nearly four feet away from where the glass shattered.
Correction comments welcome if I've got the wrong end of the stick or for encouragement to say I've got it right . 
What I referred to in my above post is ( I think ) referring to the mesh bed levelling that can be moved back front centre left middle & right in some 24 or more positions & stored in the printers memory according to how the test print down load prints out . Think it says each point can be moved to a max of 50 micron but that it's likely to be far less adjustment needed to get the microscopic differences allowed for in the first layer of extrusion.
Seem to think there are some of these fine tune test prints down loads available on Thingyverse . I'll be looking tomorrow when I'm more awake.
I still haven't it done it ..it was planned for today .
Instead , today was spent cleaning out the back of my Turismo people carrier after two 6 foot x 2 foot 6 mm tempered black glass shelves I was carrying for my daughter slipped , nicked a bit of metal then exploded into many many thousands of bits . It filled 1 & 1/2 buckets with the broken glass & took me four hours in short stages to super vacuum clean the microscopic shards out the cars carpets. I even found some in the froot footwell's ,nearly four feet away from where the glass shattered.
Correction comments welcome if I've got the wrong end of the stick or for encouragement to say I've got it right . 
Bladevane
Forum Supporter
- Messages
- 1,030
- Location
- Harwell, Oxon
I think you’ve got it right. IMHO if you get the first layer set up correctly (level bed and nozzle height) and the print/filament settings near perfect the print success rate improves dramatically. I did all the above on my Prusa and Caribou and 5 months later both are still printing perfectly to the point that my confidence in success allows me to relax during 7-8 hour prints.
daedalusminos
Member
- Messages
- 2,246
- Location
- Norwich
The Prusa MK3/S incorporates mesh bed leveling and 1st layer Z offset to ensure good consistent 1st layer heights and thus adhesion.
The mesh leveling is the 9 (by default) measurements taken after bed heating and just prior to every print, it's to calibrate out any warp in the bed and is fully automatic. There is an advance setting where you can manually fine tune the height of the points but this shouldn't be required.
The 1st layer offset is how close the nozzle comes to the bed during the 1st layer print (it's what you're adjusting during Z calibration) and will usually need to be set for each build plate and (textured/smooth but once set is stored in memory), may require tweaking for different materials or to tweak bed adhesion.
There is also a live Z adjust - this allows you to adjust the Z calibration during the 1st layer print, I think you have to press the knob to store the figure for use on subsequent prints.
This sounds more like your model was not flat on the bed during slicing or the model surface is not flat. Why are you using Cura? The Prusa slicer is more than adequate.
The mesh leveling is the 9 (by default) measurements taken after bed heating and just prior to every print, it's to calibrate out any warp in the bed and is fully automatic. There is an advance setting where you can manually fine tune the height of the points but this shouldn't be required.
The 1st layer offset is how close the nozzle comes to the bed during the 1st layer print (it's what you're adjusting during Z calibration) and will usually need to be set for each build plate and (textured/smooth but once set is stored in memory), may require tweaking for different materials or to tweak bed adhesion.
There is also a live Z adjust - this allows you to adjust the Z calibration during the 1st layer print, I think you have to press the knob to store the figure for use on subsequent prints.
This sounds more like your model was not flat on the bed during slicing or the model surface is not flat. Why are you using Cura? The Prusa slicer is more than adequate.
DAPPH
as dyslexik as I'm daft
- Messages
- 7,154
- Location
- Near to Cross Hands Llanelli SouthWales GB
I've discovered that I was using Prusa's Cura incorrectly . I think I was only putting each part to be flat to the printing late in cura once then copying it to get numerous prints. Looks like I'd picked up and error nd kept repeating it Yesterday I get a popup warning just after slicing was done on a 50 mm dia sleeve saying this item will not print it is not level .
I discovered how to get it back to editing ( I didn't know you could do that that till then ) I rotated the part to the opposite end then hit level item to the plate & got the warning message again . Frustrated I redrew the item went through the make & export STL , about to get gcode for it & still it came up as a fault . Didn't realise what the little stack of layers on the bottom of the Cura screen meant till then . I saw the disparities & wondered what to do .
Hmm looked deeper into the drop downs and found on the left most one has repair STL at the bottom , took it through that command , levelled it sliced it got the g code &it's printed off perfectly ..
Just need to take care
when allowing a 0.40 mm clearance is to take it off the right part 
Question when you want to print a dozen small items in Cura do you only level the first one , then copy & paste the levelled item eleven more times or do you have to individually level all of them ?
I discovered how to get it back to editing ( I didn't know you could do that that till then ) I rotated the part to the opposite end then hit level item to the plate & got the warning message again . Frustrated I redrew the item went through the make & export STL , about to get gcode for it & still it came up as a fault . Didn't realise what the little stack of layers on the bottom of the Cura screen meant till then . I saw the disparities & wondered what to do .
Hmm looked deeper into the drop downs and found on the left most one has repair STL at the bottom , took it through that command , levelled it sliced it got the g code &it's printed off perfectly ..
Just need to take care Question when you want to print a dozen small items in Cura do you only level the first one , then copy & paste the levelled item eleven more times or do you have to individually level all of them ?
tflnemesis
Member
- Messages
- 650
Usually just sort the 1st then copy.
If you are doing lots of small items it might be worth checking the print sequence.
change from 'All at once' to 'One at a time'.
This way if one of them doesn't print or moves on the bed it will still carry on and print the rest and you don't waste all of them if one fails.
If you are doing lots of small items it might be worth checking the print sequence.
change from 'All at once' to 'One at a time'.
This way if one of them doesn't print or moves on the bed it will still carry on and print the rest and you don't waste all of them if one fails.
DAPPH
as dyslexik as I'm daft
- Messages
- 7,154
- Location
- Near to Cross Hands Llanelli SouthWales GB
Thanks for that TFL.
Yes I've had a single bracket in a block of 20 failing to print right in the middle of the print plate , the resultant false extrude tangled up and caused the last 4 mm of the print to be pulled to one side before I realised it had happened . Had to watch the next hour or so of printing and keep removing the ball of waste extrude out the hole where the missing part should have been . Happily not anything great to worry about as the parts were for angling micro spray heads in the glasshouse , I doubt the tomatoes will complain about the strange looking parts holding up their drink.
I'll need to relook deeply into Prusa's Cura slicer ( now called Prusa Slicer ? ) .. a little knowledge is dangerous 
Yes I've had a single bracket in a block of 20 failing to print right in the middle of the print plate , the resultant false extrude tangled up and caused the last 4 mm of the print to be pulled to one side before I realised it had happened . Had to watch the next hour or so of printing and keep removing the ball of waste extrude out the hole where the missing part should have been . Happily not anything great to worry about as the parts were for angling micro spray heads in the glasshouse , I doubt the tomatoes will complain about the strange looking parts holding up their drink.
I'll need to relook deeply into Prusa's Cura slicer ( now called Prusa Slicer ? ) .. a little knowledge is dangerous 
PhillipM
Member
- Messages
- 3,000
Careful with that if the parts are big enough you'll hit the already printed ones with the head
Can someone stop my head going round.
Not sure if anyone has the same problem but there are times I doubt myself and the more I try to be logical I get more confused.
I have a part I downloaded . Well two parts. A nut and and a bolt (with large flange) for a safety gate.
Well the stupid part is I sent them both to cura with the same settings and the bolt is too tight to go on. Only just though.
So I made the Nut 102%. This normally works with parts that fit in something. But...
Whilst I think it would work if I decreased the bolt to 98% as it just shrinks.
When made the Nut 102% it does not even go near the bolt. I think it's enlarged the nut but reduced the thread diameter..... But I did not expect it too....but should it have?
Not sure if anyone has the same problem but there are times I doubt myself and the more I try to be logical I get more confused.
I have a part I downloaded . Well two parts. A nut and and a bolt (with large flange) for a safety gate.
Well the stupid part is I sent them both to cura with the same settings and the bolt is too tight to go on. Only just though.
So I made the Nut 102%. This normally works with parts that fit in something. But...
Whilst I think it would work if I decreased the bolt to 98% as it just shrinks.
When made the Nut 102% it does not even go near the bolt. I think it's enlarged the nut but reduced the thread diameter..... But I did not expect it too....but should it have?
DAPPH
as dyslexik as I'm daft
- Messages
- 7,154
- Location
- Near to Cross Hands Llanelli SouthWales GB
Look at some of the Fusion 360 YouTube videos about threads & printing them . The better ones explain that the nut thread form should be a fraction bigger than the bolt thread to give you clearance.
I know you don't/ didn't use Fusion 360 but it's thread nut & bold making programme allows this thread to be automatically calculated to several slight different tollerances that work when printing nut & bolt threads .
The videos also show that some threads will need to be printed on their side or at an angle using a support so that the shearing tendency of the bolt is reduced
I know you don't/ didn't use Fusion 360 but it's thread nut & bold making programme allows this thread to be automatically calculated to several slight different tollerances that work when printing nut & bolt threads .
The videos also show that some threads will need to be printed on their side or at an angle using a support so that the shearing tendency of the bolt is reduced
Thing is I expected the thingiverse files to fit as they were designed to fit together. Loli ended up increasing the nuts to 105% on the X and y and they fit perfect.
Dev
8th generation, Weyland type
- Messages
- 1,295
The fit is highly dependant on the calibration of the printer. So even if the tolerance is spot on in the 3d model your flow rate, material shrinkage, over/underextrusion all affect it.Thing is I expected the thingiverse files to fit as they were designed to fit together. Loli ended up increasing the nuts to 105% on the X and y and they fit perfect.
Plus some models on thingiverse are posted without ever having been printed.
