Hello,
I hope somebody can help me.
I have constructed some parts in google sketchup, and in that part i have a hole from 19mm
I wanted to place a bearing from 19mm in this hole, but the printed part is not 19mm but 18.7mm.
I use the standard settings from the velleman site, and made the Gcode with repetier host en slic3R
Do i have to change settings, or is some thing else not correct?
There are 2 main causes of this:
1 The .STL file is made up of a triangular mesh; the straight sides approximate a curve, so in the middle of the straight piece, the hole is smaller and at the corners it is bigger. How much depends on the mesh.
2 When the filament comes out of the nozzle and the nozzle makes a change in direction, the extrudate doesn’t follow the nozzle exactly, but is drawn towards the new direction of the nozzle. Try dragging a piece of string along the floor and changing direction - watch what the string does.
For the .STL files I create using SolidWorks, I make the holes 0,2 to 0,3 mm bigger to compensate.
Wally
Well described Wally!
Additionally most printers tend to print small holes mor undersized than bigger ones, which results from
extrusion width combined with the approximation of the hole throug the stl.
If you need to print correct hole sizes you have to nicely calibrate extrusion width too.
You might have to design holes little a little bigger too, especially for smaller holes.
By the way, if the hole for the bearing isn’t extremely undersize you can fit the bearing in
by carefully heating the part with a lighter or hotair gun( hair dryer and push the bearing in the stoftened filament.
This also makes it sit quite stiff.
cheers,
Christian
Thanks for the answers.
I have taken a solder iron, and have maked the holes a little bigger, then i pushed the bearings in the hole.
It worked, but the tip of using a hotair gun is a good one to.
The biggest problem is when i use a construction from thingiverse, then i can not make the holes a little bigger.
Only when the original cad files are deliverd.
Can i find somewhere a guide how to exact calibrate the K8200?
I would first starting with a print of a let’s say 50mmx 50mm x 50mm hollow cube with 1mm walls and 0.25mm layer.
That way you can measure your overall precision.
Are x and y dimensions correct and are the walls correct thickness?
Start witch calibrating your extrusion to get correct wall thickness first.
By setting correct (measured with caliper) average of filament diameter and calibrating extruder steps/mm.
This is quite hard to do with the stock hotens. But i think you should be able to end up with a wall thickness
not more than 0.15mm off measure.
After that you can change the clibration for x and y.
cheers,
Christian
[quote=“WallyL”]
1 The .STL file is made up of a triangular mesh; the straight sides approximate a curve, so in the middle of the straight piece, the hole is smaller and at the corners it is bigger. How much depends on the mesh.[/quote]At one time Slic3r tried to detect these faceted arcs and convert them into controlled arc moves (G2, G3), which Marlin can interpret. It’s not a trivial task and isn’t included in current builds.
It’s a feature that would improve quality in several ways and greatly reduce the size of the G-code.
Don’t change the motor steps to correct the size of a part. If requesting a 100mm move results in a 100mm move then everything is perfect. If the part isn’t coming out to size, then it’s down to extrusion width and the limits of 3D printing. Adjust the part file to achieve the right end size.
[quote=“Paul Compton”][quote=“WallyL”]
1 The .STL file is made up of a triangular mesh; the straight sides approximate a curve, so in the middle of the straight piece, the hole is smaller and at the corners it is bigger. How much depends on the mesh.[/quote]At one time Slic3r tried to detect these faceted arcs and convert them into controlled arc moves (G2, G3), which Marlin can interpret. It’s not a trivial task and isn’t included in current builds.
It’s a feature that would improve quality in several ways and greatly reduce the size of the G-code.
Don’t change the motor steps to correct the size of a part. If requesting a 100mm move results in a 100mm move then everything is perfect. If the part isn’t coming out to size, then it’s down to extrusion width and the limits of 3D printing. Adjust the part file to achieve the right end size.[/quote]
That’s why i told him to get his extrusion right in first place.
You can only start to calibrate axes (if even necessary),after that is done.
I have measured the amount of filament when i extrude 100mm of filament in repetier host.
I measure for 3 times
first time 55 mm
second time 56 mm
third time 55 mm
So it is not enough filament.
How can i adjust the prinser so it takes 100mm of filament.
I don’t kwow how i can adjust this.
[quote=“dutchronnie”]I have measured the amount of filament when i extrude 100mm of filament in repetier host.
I measure for 3 times
first time 55 mm
second time 56 mm
third time 55 mm
So it is not enough filament.
How can i adjust the prinser so it takes 100mm of filament.
I don’t kwow how i can adjust this.[/quote]
You would have to set a higher steps/mm value for the extruder.
This can be done via repetier in firmware config.
Take your current value, divide it by 55 and multiply by 100 to get the new value.
Should be a little less than twice at large. (for example : current steps/mm=300 - new value = 300/55*100 = 545,45)
Then enter it in repetier and click save to EEProm.
After that measure again. You should now extrude nearly exact 100mm.
cheers,
Christian
Thats clear,
But how do i know the current steps?
In repetier with Alt-E, firmware configuration?
In that menu, nothing happens when i push the button " Load configuration"
[quote=“dutchronnie”]Thats clear,
But how do i know the current steps?
In repetier with Alt-E, firmware configuration?
In that menu, nothing happens when i push the button " Load configuration"[/quote]
Make sure the following line is uncommented in marlin :
#define EEPROM_CHITCHAT <- uncomment this
you find it in configuration.h
// EEPROM
// the microcontroller can store settings in the EEPROM, e.g. max velocity...
// M500 - stores paramters in EEPROM
// M501 - reads parameters from EEPROM (if you need reset them after you changed them temporarily).
// M502 - reverts to the default "factory settings". You still need to store them in EEPROM afterwards if you want to.
//define this to enable eeprom support
#define EEPROM_SETTINGS
//to disable EEPROM Serial responses and decrease program space by ~1700 byte: comment this out:
// please keep turned on if you can.
//#define EEPROM_CHITCHAT <- uncomment this
If it is commented out, uncomment it and recompile/reflash the firmware.
Then the window in repetier should show your values.
cheers,
Christian
Ok, This is the first time i am going to flash the K8200.
I have installed Arduino 1.0.6
Which board do i have to choose?
Downloded the firmware from the vellema site, Version V1, Is that alright?
I dont have a LCD, i think it must be version 1
Then loaded the file “Marlin.ino”
i see a tab with configuration.h and uncomment the line EEPROM_CHITCHAT
Now i can Flash?
And there is nothing what can go wrong?
Edit,
I just did the firmware upload, it seems that everything is working wel.
My step setting is 600
The new setting will be: 600/55x100 = 1090,99
[quote=“dutchronnie”]Ok, This is the first time i am going to flash the K8200.
I have installed Arduino 1.0.6
Which board do i have to choose?
Downloded the firmware from the vellema site, Version V1, Is that alright?
I dont have a LCD, i think it must be version 1
Then loaded the file “Marlin.ino”
i see a tab with configuration.h and uncomment the line EEPROM_CHITCHAT
Now i can Flash?
And there is nothing what can go wrong?[/quote]
You should use the v2 firmware, cause it disables the endstops during print.
This would prevent trouble when printing large parts.
The LCD is only an option. The firmware runs also without it.
As board you hav to choose : Arduino Mega 2560or Mega ADK
Set the correct com port too and make sure repetier is closed.
Then short the jumper next to the endstop connectors (the 2 pins closest to the usb port)
Make sure it is absolutely well connected and does not disconnect during upload!
Then go to Arduino ide and press upload.
It will compile then and show the progress in the lower right corner.
If it reads upload done, you are ready to go.
cheers,
Christian
Now i have updated the V2 software.
But when i start repetier, it says that it is the V1 software?
Strange
Tomorrow i take another look.
Thanks so far
V2 will still report V1.
As long as it completed and the printer still works you should be ok
[quote=“Wrong Way”]V2 will still report V1.
As long as it completed and the printer still works you should be ok[/quote]
It is exactly as Wrong Way mentioned.
They simply didn’t change the name string, hardcoded in the firmware files.
cheers,
Christian
It is getting strange:
I have noted the following values:
In Repetier extrusien set 100mm, then extruded en measured and i get a value of 70
so:
600/70x100 = 857.14, extruded and i get a value of 60
857.14/60x100 = 1428.56, extruded and i get a value of 105
1428.56/105x100 = 1360.53, extruded and i get a value of 60
I don’t understand, something is wrong.
Then i take a close look to the speed the filament goes trough the extruder, and that speed is not constant.
Sometimes fast, slow en sometimes it almost stops.
I have tried to add more pressure on the filament, but it doesn’t matter.
Does somebody knows what is wrong?
What material do you use at what temp?
Check the voltage set at the extruder stepper driver, is it 0.55v?
Can be your motor losses steps.
Can you post a video (youtube) of the extrusion?
Might help to evaluate what’s going wrong.
cheers,
Christian
I use as material PLA with a temperature of 190 degrees.
The voltage on the stepper driver is 0,425V as mentioned in the build instructions
Some are 0,423 or 0,426, i could not get all precise on 0,425V
I have put a video on this link, the marks omn the filament are 1cm
Looks just as i thought. Your extruder looses steps.
Set the stepper drivers to 0.55v on all steppers. This prevents them from loosing steps from undercurrent.
cheers,
Christian