Early prints

I have made some test prints which came out fine so I decided to step up to the mark and print myself a spare driven gear for my Wades extruder (the large gear). Once the print had finished I removed it from the print bed (heated Kapton) and found it had domed slightly on the underside by about 1-2mm.

This had lifted the edges from the bed but because the middle was still well stuck it made no difference to the printing itself. I would like to be able to keep these bigger prints flat so some advice is needed, I have included the settings I used here for analysis encase they help.

Thanks
Gary

Skeinforge 41 settings
Here are the settings I am now using with a little help from various people on the Reprap forums and via IRC chat. I am currently printing myself a complete new set of gears so that I have a spare set.

Profile type – Extrusion
Profile selection – No 4 (I have several I just kept cloning them so I could keep track of changes)
Search
Version – 11.04.26

Craft

Bottom
Activate Bottom –– Yes
Additional height over layer thickness (ratio) 0.7
Altitude (mm) 0.0
SVG viewer webbrowser

Carve
Add layer template to SVG – Yes
Extra decimal places (float) 2.0
Import coarseness (ratio) 1.0

Infill in direction of bridge – Yes
Layer thickness (mm) 0.4

-Layers-
Layers from (index) 0
Layers to (index) 912345678

Mesh type correct mesh – Yes
Perimeter width over thickness (ratio) 1.8
SVG viewer webbrowser

Chamber
Activate chamber – No

Clip
Activate clip – Yes
Clip over perimeter width (ratio) 0.5
Maximum connection distance over perimeter width (ratio) 10.0

Comb, Cool
Activate – No




Dimension
Activate dimension – Yes
Absolute extrusion distance – Yes
Extruder retraction speed (mm/s) 50.0
-Filament-
Filament diameter (mm) 2.8 (measured with digital callipers)
Filament packing density (ratio) 1.0
Retraction distance (mm) 2.0
Restart extra distance (mm) -0.5

Export
Activate export – Yes
Add export suffix – Yes
Gcode small – Yes

Fill
Activate fill – Yes
-Diaphragm-
Diaphragm period (layers) 100
Diaphragm thickness (layers) 0
-Extra shells-
Extra shells on alternating solid layer (layers) 2
Extra shells on base (layers) 1
Extra shells on sparse layer (layers) 1
-Grid-
Grid circle separation over perimeter width (ratio) 0.2
Grid extra overlap (ratio) 0.1
Grid junction separation band height (layers) 10
Grid junction separation over octagon radios at end (ratio) 0.0
Grid junction separation over octagon radios at middle (ratio) 0.0
-Infill-
Infill begin rotation (degrees) 45.0
Infill begin rotation repeat (layers) 1
Infill odd layer extra rotation (degrees) 90.0
Line – Yes
Infill perimeter overlap (ratio) 0.15
Infill solidity 1.0 (good for PLA)
Infill width over thickness (ratio) 1.7
Solid surface thickness (layers) 3

Fillet, Home, Hop, Inset, Jitter, Lash
Activate – No

Limit
Activate limit – Yes
Maximum initial feed rate (mm/s) 75.0
Maximum Z feed rate (mm/s) 3.0



Multiply
Activate multiply – Yes
-Centre-
Centre X (mm) 100
Centre Y (mm) 100
-Number of cells-
Number of columns (integer) 1
Number of rows (integer) 1
Separation over perimeter width (ratio) 15.0

Oozebane
Activate oozebane – No

Preface (can’t be turned off)
-Name of alteration files-
Name of end file – end code.gcode
Name of start file – start code.gcode
Set positioning to absolute – Yes
Set units to millimetres – Yes

Your start and end codes are kept in the Skeinforge alterations folder

Raft
Activate raft – Yes
Add raft, elevate nozzle, orbit – Yes
-Base-
Base feed rate multiplier (ratio) 1.0
Base flow rate multiplier (ratio) 1.0
Base infill density (ratio) 0.5
Base layer thickness over layer thickness 2.0
Base layers (integer) 0
Base nozzle lift over base layer thickness (ratio) 0.4
-Interface-
Interface feed rate multiplier (ratio) 1.0
Interface flow rate multiplier (ratio) 1.0
Interface infill density (ratio) 0.5
Interface layer thickness over layer thickness 1.0
Interface layers (integer) 0
Interface nozzle lift over interface layer thickness (ratio) 0.45
-Object first layer-
Object first layer feed rate infill multiplier (ratio) 0.4
Object first layer feed rate perimeter multiplier (ratio) 0.4
Object first layer flow rate infill multiplier (ratio) 0.4
Object first layer flow rate perimeter multiplier (ratio) 0.4
Operating nozzle lift over layer thickness (ratio) 0.5
-Raft size-
Raft additional margin over length (%) 1.0
Raft margin (mm) 3.0
-Support-
Activate support cross hatch – No
Scale
Activate scale – No

Skirt
Activate skirt – Yes
Convex – Yes
Gap over perimeter width (ratio) 10.0
Layers to (index) 1
(Initially I wasn’t getting a decent extrusion on the first layer of my prints so I added a skirt 10mm out from the print to solve this issue)

Speed
Activate speed – Yes
Add flow rate – Yes
-Bridge-
Bridge feed rate multiplier (ratio) 1.0
Bridge flow rate multiplier (ratio) 1.0
-Duty cycle-
Duty cycle at beginning (portion) 1.0
Duty cycle at ending (portion) 0.0
Feed rate (mm/s) 30.0
Flow rate setting (float) 30.0
Orbital feed rate over operating feed rate (ratio) 0.5
-Perimeter-
Perimeter feed rate over operating feed rate (ratio) 0.4
Perimeter flow rate over operating flow rate (ratio) 0.4
Travel feed rate (mm/s) 50.0

Splodge
Activate splodge – No

Stretch
Activate stretch – Yes
Cross limit distance over perimeter width (ratio) 5.0
Loop stretch over perimeter width (ratio) 0.11
Path stretch over perimeter width (ratio) 0.0
-Perimeter-
Perimeter inside stretch over perimeter width (ratio) 0.32
Perimeter outside stretch over perimeter width (ratio) 0.1
Stretch from distance over perimeter width (ratio) 2.0

Temperature, Tower, Unpause, Widen, Wipe
Activate – No







My start code is
G21; metric is good
G90; absolute positioning
G92 X0 Y0 Z0 E0; zero the extruded length axes
G92 E0

My end code is
G91
G1 F70
G1 Z7 F70; lifts nozzle 7mm from finished print surface
G1 F2300
G1 X-100 F2300
G90
M104 S0; turns off extruder

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Experimenting in 3D in New Zealand

What temperature did you set your extruder and bed to? I've been able to print the Wade's and adrian gear without warping with the bed set at 110C and the tip at 240 for the first layer and 220 for the rest. Your feed rate of 30 and the 0.4 multiplier for the first layer should be fine.

I had the tip at 200C throughout and I can't change the bed temp as it is either just on or off at the moment but it only gets to around 40-45C I can still keep my hand on it without getting burnt

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Experimenting in 3D in New Zealand

That's why the object curls then. The bed needs to be about 110C to stop curling and sometimes hotter for the first layer, depending on the type of ABS.

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[www.hydraraptor.blogspot.com]

Ok will have to have a rethink on the hot bed then, I'm using PLA though not ABS

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__________________________________________________________________________
Experimenting in 3D in New Zealand

If you are using PLA, then try wiping down the bed surface with 70% Rubbing Alcohol just prior to printing. I suggest you try it first with a cold bed on Kapton.

Have you tried printing on Blue painters tape?
The attached picture shows a gear I printed with PLA on blue painters tape without a heated bed. The straight edge shows how flat it is in the worst direction.

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If you're printing PLA, then put a 3 mm glass plate (window glass works fine) on top of the heated bed. I think this is the best surface for PLA. But you may have to bump your bed temperature up by about 15 C to 55 or more. I usually set my bed temperature to 70C when extruding PLA on heated glass. My heated bed consists of 4 mm thick aluminum over Prusa PCB heated bed with a flame protector from home depot as insulation in the bottom. The thermistor is between the PCB and the insulation.

Edited 1 time(s). Last edit at 05/03/2011 09:10PM by brnrd.

I might try the blue masking tape next since I have no easy way to turn up the heat. Does PLA stick better to masking tape than it does to Kapton?

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Experimenting in 3D in New Zealand

It has to be the blue painters tape from Scotch / 3M, not sure why but after hundreds of test by the community over the last few years it is clear that its the one that works. (see picture attached)

Here's a link to Nopheads findings on the subject [hydraraptor.blogspot.com]

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Heating blue tape should work. I would guess that it would be easier to remove the part after cooling the bed. The problem I had with blue tape is that it's very inconsistent and I usually had to print the first layer at about 1/2 the layer thickness to get good adhesion.

Thanks, will give it a go once I have been to the shops as at the moment I only have narrow purple tape, non branded.

Just had a read through of Nopheads blog on the subject of tape, makes sense and his results are clearly good

Edited 1 time(s). Last edit at 05/03/2011 09:49PM by NelsonRap.

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__________________________________________________________________________
Experimenting in 3D in New Zealand

Nophead is right about abs curling at lower temps. I run my heated bed at 150deg constantly. it solves most of the curling issues, but at the sake of the bottom layer being more squished.



Another thing you might consider is a slower feed rate and lower flow rate for first layer.

slow down feed rate for 1st layer perimeter to .25 and compensate 1st layer flow rate through experimentation.



for the below it is speculation as i do not use above skein forge 39 yet.

you could also enable skirts.
would you not want to enable skirts? this enables a sacrificial wall barrier to be made in front of the part, and causes the part to cool more slowly to prevent warping.

it would be nice if someone here could add a link explaining skirts to people.

I have no issues with warping when I extrude black PLA on a 4mm glass plate @40-45 deg C. Small object can snap off on rare occasions, but if the first layer height is spot on, there are no problems.

I've tried many variations, and had good experience with regular white (low-stick) masking tape without any heating. Kapton or PET on 1mm aluminium also works fine when heated a bit with a heat gun, but it's difficult to keep it perfectly flat. Glass on heated bed is what I would recommend.

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--
-Nudel
Blog with RepRap Comic

I have a heated 4mm aluminium bed that heats to around 40-45C, will give all the ideas a try since I have some glass somewhere

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__________________________________________________________________________
Experimenting in 3D in New Zealand

Do any of you set the temperature for printing in SF? As at the moment I just set it in Repsnapper

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__________________________________________________________________________
Experimenting in 3D in New Zealand

Yes I use the temperature settings and have found them to be very important. Raft has to be enabled for the temperature settings to work, but you can set the raft's (integer) values to 0. I found that testing the minimum temp I could extrude at and then use 20degrees hotter for the first layer and 10degrees hotter than minimum for the rest. I have the support set at the minimum but haven't tried using support so I am not sure if its correct. I started my prints by warming up the hotend with the control panel and then starting my build when it was warm but didn't have raft enabled. This made the builds stay at the first layer temperature throughout which caused problems like, poor bridging, poor overhangs, melt zone moving up the thermal barrier which increases the pressure required to extrude, ooze, oxidation of the plastic.

Edited 1 time(s). Last edit at 05/04/2011 01:11AM by Sublime.

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I print PLA on a cold bed with the blue masking tape and have little issue with warping. I do get a small amount of warp, but even with the large Wade's gear I'd guess the warping was maybe 0.5 mm.

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Sublime Wrote:
-------------------------------------------------------
> Yes I use the temperature settings and have found
> them to be very important. Raft has to be enabled
> for the temperature settings to work, but you can
> set the raft's (integer) values to 0. I found that
> testing the minimum temp I could extrude at and
> then use 20degrees hotter for the first layer and
> 10degrees hotter for the rest. I have the support
> set at the minimum but haven't tried using support
> so I am not sure if its correct. I started my
> prints by warming up the hotend with the control
> panel and then starting my build when it was warm
> but didn't have raft enabled. This made the builds
> stay at the first layer temperature throughout
> which caused problems like, poor bridging, poor
> overhangs, melt zone moving up the thermal barrier
> which increases the pressure required to extrude,
> ooze, oxidation of the plastic.


So once the extruder is up to temperature, you then start the print. Will be giving that a try later (cooking dinner at the moment). I have raft enabled anyway as someone on IRC told me it would be best to but I don't actually fully understand it all yet. What temps do you extrude at as a bit of a guide?

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Experimenting in 3D in New Zealand

NelsonRap Wrote:
-------------------------------------------------------
> So once the extruder is up to temperature, you
> then start the print. Will be giving that a try
> later (cooking dinner at the moment). I have raft
> enabled anyway as someone on IRC told me it would
> be best to but I don't actually fully understand
> it all yet. What temps do you extrude at as a bit
> of a guide?

If using Repsnapper be sure to turn off the temp control in the panel just before starting to print, I believe it will try and change the temp if left on. ReplicatorG only sends one M104 to set the temp and then sends M105's to monitor it.

I can't say I understand it either. How can a program be written that no one understands, even the maintainers don't understand it. The online manual even has stuff like "Mesh Type Default: Correct Mesh, No idea what this does"

Everyone’s temperatures are a little different due to thermistor location, thermistor calibration, electrical noise, etc.

But mine are as follows:
Base layer/fill are 220c (20 over my minimum extrude temperature)
Next layers/fill are 210c (10 over my minimum extrude temperature)
Support layers/fill are 200c (my minimum extrude temperature)

Your start and end codes:
start code
G21; metric is good
G90; absolute positioning
G92 X0 Y0 Z0 E0; zero the extruded length axes
G92 E0 <--Redundant as it is in the line above
M109 S220 Set the first layer temp and wait. Not needed but makes sure the tip is pre heated and/or eliminates the need to preheat via the panel

end code
G91
G1 F70
G1 E-10 F30000 Suck the filament back quickly to stop ooze if used you should add G1 E10 F2300 to the start code to compensate on the next start
G1 Z7 F70; lifts nozzle 7mm from finished print surface
G1 F2300
G1 X-100 F2300
G90
M104 S0; sets temp to 0

Edited 1 time(s). Last edit at 05/04/2011 01:45AM by Sublime.

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Not sure if you have spent the time to read through all of Nopheads blog. I highly recommend taking the time to read every page twenty times. As always he's taken the time to document his experiences, tests and failures. PLA on glass. [hydraraptor.blogspot.com]

I ended up building a variation of his hotend design called Plumbstuder and it works a dream.

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FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
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Thanks sublime, something to play with tomorrow now. Off to read Nopheads blog

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Experimenting in 3D in New Zealand

Have changed to printing on masking tape, had some purple low tack stuff left over from a job so used that. My word I can't believe how well the PLA sticks to it i have trouble removing the printed piece afterwards but it stays perfectly flat now. Been playing with the temp settings too.

Can anyone confirm whether I do actually need to turn off the temp control in Resnapper to use the temp setting in SF please?

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Experimenting in 3D in New Zealand

I think you meant Temperature Update. When enabled in repsnapper, it issues the M105 command to read the tip (and bed depending on firmware) temperature(s) periodically. It is considered bad to enable this during the print since it can interfere with it and cause the printer to pause once in a while. So, it's a good practice to disable it before hitting the print button.

Thats cool was just wanting a second opinion to confirm what someone esle had already said.

Thanks

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__________________________________________________________________________
Experimenting in 3D in New Zealand

My large Wades gear came out excellently, so I decided to try the driven holder fro the same extruder, I did get a small amount of warp on the bottom as the masking tape let go.

However when it got to the layers where the horizontal holes are (the bolts with springs on go in these holes) the extruder looks like it has either moved sideways a fraction or shrunk at those layers, i'm not sure which has happened and clear PLA doesn't photograph well.

I thought I was making great progress until I tried to print this block now I seem to have taken a slight step backwards

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__________________________________________________________________________
Experimenting in 3D in New Zealand

NelsonRap Wrote:
-------------------------------------------------------
> However when it got to the layers where the
> horizontal holes are (the bolts with springs on go
> in these holes) the extruder looks like it has
> either moved sideways a fraction or shrunk at
> those layers, i'm not sure which has happened and
> clear PLA doesn't photograph well.
>
> I thought I was making great progress until I
> tried to print this block now I seem to have taken
> a slight step backwards

If its only off by a tiny amount the part is probably useable so I wouldn't call it a step backwards.

It sounds like a skipped step to me. This can be caused by having the driver current limiting set to low. But it is more likely that the axis is binding. Or it could even be that your extrude rate is to high for your layer thickness and after many layers the tip of the hotend is plowing in to the built up plastic causing skipped steps.

If its not being caused by the tip plowing in to excess plastic you will need to figure out which direction is skipping and then with the belt off that axis check if it moves smoothly. If it moves smoothly and dosen't bind anywhere I would try increasing the current by 1/8 turn on the axis that skipped driver.

I would also make sure your pulleys and belts are tight, any slack in the belts or slip of the pulley on the shaft will cause the same issues.

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The layer where the horizontal holes are (mounting holes, not the tension bolts) has a very thin section between the hole and the edge. That causes a very high frequency zig-zag which can cause resonance and lost steps in my experience if anything is on the limit. [hydraraptor.blogspot.com]

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[www.hydraraptor.blogspot.com]

Just looked at your Blog post nophead so I know what your talking about at least, I guess from reading the blog that their is still no way to do that in SF. I'm nowhere near at the stage of reading the Gcode properly yet. I don't suppose there is a way to put something in the alteration files for SF. It would need somebody that knows a hell of a lot more than me to know what though

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__________________________________________________________________________
Experimenting in 3D in New Zealand

I would also make sure your pulleys and belts are tight