Archives de catégorie : Imprimante Scalar

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Scalar S: Belt installation under the bed

bed installation under the bed

In this section you will need:

  • Scalar S: 0.9 meters GT2 belt for 300mm VSlots

Take as a reference one side of the guide

You have only 1 guide support on each side and a 300mm long extrusion profile between.

On each side you have 1x 16 teeth pulley

The belt goes inside the extrusion profile groove on top and is then tighten at the bottom under the carriage plate.

Here is a sliced view of the whole assembly.

belt installation under the bed

The final goal is to have the belt in this state

Note that the Belt’s teeth are always facing the pulleys.

Take the belt and push it on one side, inside the top groove. The teeth must be facing downward.

Push it until it exists on the other side.

Once at the end, turn it so that it goes inside the bottom groove of the extrusion profile this time.

When the belt arrives at the middle of the carriage , it needs to go inside the middle hole of the bottom plate of the carriage.

Pull it enough so that you can clamp it with the dedicated plastic clamp. Make sure you have enough belt left so that you can tighten it later on.

Remove the 2 xM3X8 thermo screws that keeps the clamps screws, push the belt between and screw back the clamp.

On the other side, it’s similar, you need to push the belt inside the bottom part of the extrusion profile up to the middle of the Carriage. Then push it in the middle hole. Don’t clamp it yet.

Note, if one side of the belt is properly clamped you should be able to tighten the belt and perform the final clamping of the belt.

You can also tighten the belt on both sides if you feel the need for it. One side should be enough .

Here is a view of the bottom plate of the carriage.

The belt arrives near a kind of belt guide that will keep the belt centred.

The belt is then pushed inside the middle groove and is placed between the clamp and the bottom carriage

If needed we tighten the belt (Only if 1 side is properly clamped).

 

Tightening the Pulleys

 

Now that your belt is installed you Must screw your pulleys on both motor and idler side.

Installation of PTFE liner inside E3D lite hot end

E3D Lite installation du tube ptfeThe E3D Lite hot end is provided with a PTFE liner

It is destined to be inserted all the way inside the hot end.

it allows the filament to be properly guided inside the hot end. Also it reduces all the friction of the filament with the hot end body.

E3D Lite installation du tube ptfeA quick connector is available to prevent the liner from going out.

To remove the liner, just push the connector down and pull the liner at the same time.

 

E3D Lite installation du tube ptfeOnce inside you need to remove the excess of liner

For Scalar S, the total length of the tube must be7.9cm.

It will allow the liner to reach the extrusion gear inside the extruder.

E3D Lite installation du tube ptfeThe adaptor part must then be placed on top and go through the left over liner.

The 4 fixation holesmust be aligned with the hot end support holes at the top.

Please note the position of the adaptor shaped as a bat.

E3D Lite installation du tube ptfe

Extruder Calibration

Why do we need to calibrate our extruder?

It allows you to make sure that the proper amouint of filament is provided to your hotend.

Why do we need to calibrate the extruder on each machine?

The quantity of plastic pushed by the extruder depends mainly on the diameter of the extrusion gear.

Why calibrate the extruder?

It will increase the procission and quality of your prints because the proper amount of plastic will be provided to the hot end..

Why do you need to do this calibration on each machine?

The quantity of plastic pushed inside the hotend depends mainly on the drive gear diameter of the extruder.

This gear is machined with a different tolerance. So the gear diameter will vary from one model to another one and from one brand to another one..

How to proceed?

We adjust the amounts of steps / mm required to push the filament 1mm.

The overall procesdure is as follow:

  1. We extrude a certain length of filament, let’s take 200mm.
  2. We measure with a graduated ruller how much filament has been pushed.
  3. We then use a cross product to adjust the value of our machine.
  4. Then we check that the new value is good by extruding again 200mm and we measure again.
  5. We adjust when needed and we reapeat step 4 ntill we find the proper value.
  6. Finally to ensure the measurment error is very small we extrude 400mm or 600mm  of material (something you can measure with your ruller) , We then slightly adjust the EStep/mm to get our final setting.
  7. At this stage your extruder should be properly calibrated and the quality of your prints should greatly increase.

Step by Step :

  • If you are in Bowden mode, remove the PTFE tue at the exit of the extruder. (You need to push the small cap at the base of the tube and then pull the tube at the same time)
    Then push the filament so that the tip is at the same level as the extruder shell.
  • If you are in Direct drive, you will need to unmount the extruder from it’s support, so that you can measure at the very edge of the extruder exit.
  • Cleanly cut the filament to that it’s easier to measure.

  • The Provided SD card contains a set of Gcode that will help you in this process. You can find them here:

 

  • You will find severall files (ExtrudeXXXmm.gcode and RetractXXXmm.gcode)

  • Depending the firmware version, you will need to pre heat your hot end before extruding.
  • With your LCD browse inside the SD card into the folder  and print « Extrude200mm.gcode » .

  • Measure how many mm of filament is extruded. (IMake sure to use a fine Ruller to avoid measurements issues)

  • In order to make sure to avoid any slippery that may affect your next measurements (and probably make your measurements weird), It is strongly advised to perform these steps several times by resetting the filament position and extruding again 200mm.
  • If your measurements are consistent you can proceed to the folowing steps.

Slippery case:

  • In the opposite scenario, you will need to investigate where the slippery comes from.
  • Here are some hints :
    • The extruder spring is not tight enought.
    • The filament spool is forcing on the filament, preventing the extruder to pull it properly ( Look for any nodes on the filament, the spool itselft must be free)
    • The extruder compression finger might be broken, and the bearing is improperly applying pressure on the filament.
    • your Extrusion gear is improperly screwed, the motor is turning but your extrusion gear is slipping.
    • The extrusion gear might be full of plastic or dirty
    • Something is tempering with your filament
  • If you solved this issue you will need to check again by doing again the previous steps.

 


 

Computation of the proper Epas/mm value
Use of « cross product »

  • Once you have checked that your extruder is slippery free you will be able to compute the new ESteps/mm by using the following formula:

 (Actual EStep / mm ) * (Expected extruded filament length) / (Length of measured extruded filament) = new EStep/mm

Example detailed below : 150 * 200 / 198 = 151.5 ESteps/mm

In order to obtain the ESteps/mm of your extruder you will need to navigate inside your LCD display  » Controle>Mouvements>EStep/mm » (last parameter of the list)

Example explaination :

if you have extruded 200mm of filament

  • Expected extruded filament length = 200mm

If you measured 198mm

  • Length of measured extruded filament = 198mm

if your Estep/mm is 150 step/mm ( » Control>Mouvements>EStep/mm« )

  • Actual EStep / mm = 150 pas/mm

you get:

New EStep/mm = 150 * 200 / 198 = 151.5 (Please take good care of the decimale)


 

Applying our new EStep/mm

  • Now that you calculated the new EStep/mm for your extruder you need to apply this parameter to you machine using the LCD display:  « Control>Mouvements>EStep/mm« 
  • Do again the test to extrude 200mm of filament. The extruded filament length should be better .If you still have some error it’s often due to the precission of the initial measurement. (90% of the time)
  • Once you get something close to 200mm , then extrude again 200mm, you should be able to measure 400mm. This steps allows you to reduce the measurement error based on 200mm.
  • At this stage you can apply your final fined tuned EStep/mm..
  • You can also use « Retract200mm.gcode » to double check that your filament properly comes back to it’s position of orgine.


 

Congratulation, Make sure to save your settings !

You have now completed the calibration process of your extruder.

Make sure that your new setting is properly saved inside your printer EEPROM:

  • « Control> Save config« 
  • Wait a few seconds and switch down the printer. Switch it back on and check that the setting has properly been saved (« Control>Mouvements>EPas/mm« )

 

Resources :

For those that lost the content of the original SD card provided with the Scalar M or Scalar XL you can download the calibration Gcode here by clicking in the Zip icon or the link below:

Calibration_Gcodes.Zip

 

12V 220W Heatbed wiring

This page is explains how to wire your 12V 220W heatbed using static relay


What is a static relay?

A static relay is an electronic relay able to switch Power.

You can find different types for different voltages and different powers.

In our case 12V 220W heatbed , you will need to use a  DC-DC static relay, driven by 12V input voltage, and able to drive DC output power voltage.

This type of relay has MOSFET power transistor able to drive DC output voltage.

If you are using a 220V heatbed directly powered by your grid you will need to use a DC-AC static relay.

These have power triacs able to drive 220V alternative output voltages.

How to choose the power of your static relay?

The power your can draw out of a static relay depends on many factor. It’s type, it’s rated power, it’s ability to dissipate heat.

DC-DC Relays

For DC-DC relays , They ofent get hot very easily, so take into account to always select one with   2 or 3 times it’s nominal load.

With a 220W 12V heatbed, the max current is around 18.3A.

  • A 25A relay will be too small  (max usable load would be 12A => 144W Max)
  • A 40A relay will be just enough  (2 times the nominal load) and might get hot
  • A 60A relay ( able to support 3 times the nominal load) will be well adapted and should dissipate very little heat.

DC-AC relays

These have power tyristors or triacs.

For the 3D printer power range a simple 25A relay is enough for most usage.

If we take the Scalar XL with it’s 700W 220V heatbed,

Power(W) = Input Voltage(V) x Curent (A) x Cos Phy

Current= Power/ (Input Voltage x cos Phy)

If we take CosPhy = 0.6

Curent = 700W/(220V*0.6) => 5.8A MAX

This relay is 4.3 time more powerfull than it’s load.

Why a static relay?

With these powers, a static relay will protect you electronics from being damaged, and will also increase it’s lifepan.

If you are using Ramps boards with it’s Green power connectors, they can support only 11A.

Using more current is possible but you will need a very good cooling of the power components and of the power connector itself.

However with time you might kill the power connector, or even the Power transistor of the Ramps board.

 

 

 

 


 

Hopefully these can be easily replaced.

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However, using a Static relay will prevent such issues.

 

 

 

 

 

 

 

 


Heatbed Wiring using the Static relay.

Directly from your power supply

If you have enough outputs on your power supply, you can connect directly the heatbed to the power supply following this schematic..

The +12V output de l’alimentation est relié directement au lit chauffant.

The heatbed output is then connectod to the « + » (pin 2) of the static relay

The  « – » (pin 1)  output is connected to the 0V of your power supply.

Pins 3 and 4 of the static relay are connected to D8 output of your Ramps board

Pay close attention to the polarity!

Between the Ramps and your static relay, you can use thin wires (24AWG for example) because very little power is transmitted to the static relay.

However, on your static relay output, make sure you are using proper wire diameter.  (use 2.5mm² wires). The bigger the diameter, the lower the power loss, and your wiresd will stay cold.

Also attache the static relay on the aluminum extrusions.

For Scalar 3d Printers, you can attach it directly on the extrusion profiles. it will be greatly spread static relay heat.

 


With terminal strips

The assembly is very similar.

We will use terminal strip to connect with the available wires.

see above comments for more details.

 

First use cautions

Introduction

This page  purpose is to help you to check a few points before using your 3D printer in order to avoid any possible known issues.

Check that the stepper motors are properly connected to the stepper drivers on the Electronic board..

Check that the stepper motors are properly connected on your electronic board before powering on. The drivers don’t support to be powered on without any motors attached.

In certain cases you can damage them and the stepper motors will react in a random manner.

Precautions to take before powering your heatbed.

Certains heatbeds can use up more than 200W.

Depending on how the heatbed it driven, you will need to check that the driving power transistor is properly cooled down, and that there is a proper airflow around it.

On Scalar M, the heatbed is conected directly on the power transistor.

It’s mandatory that the 80cm fan inside the electronic box is connected, powered and generates a good airflow.

On Scalar XL, the 700W 220V heatbed is powered through a separate 25A solid state relay.

The 80 cm fan is then used to cool down the stepper motors drivers in order to keep optimal performances.

Keep the stepper drivers always close to ambiant temperature.

Stepper motors drivers are responsible to properly driver the stepper motors. When they get hot, the avaiable power drops and you might get some missed steps after a few hours of printing.

PLA and FullMetal hot ends (E3D or AllInOne)

With Full metal hot ends, if you are using PLA, it’s MANDATORY to keep the hot end’s heatsink cool.

These hot ends are provided with auxiliary fans wich purpose is to keep them close to ambiant temperature.

if the fan is not running, is stopped or that the airflow is not enougth, PLA will expand inside the hot end.

Expnading PLA inside your hot end will, if you are lucky, only expand on a small portion of the hot end. You should still be able to push or pull it from the hotend manually using some pliers.

In other cases, it can expand out of the hot end’s heatsink.

in this case you will need to deassemble the hotend, clean it and fix your fan cooling issue.

Precautions to take before switching off your 3D printer

Some plastics will expand on full metal hot ends if you switch off your 3D printer while the hot end is still hot.

To avoid possible issues with plastic expantion, make sure the hot end temperature goes below 75°C before switching off your 3D printer

Heat bed Study for Scalar XL – Test 9

Now that we know better the impact on the insulation material over the heatbed performances, we are going to see how to reach 110°C.

For this we are going to test a custom made 700W 220V silicon heater (400x300mm)

Update : this model is installed by default on our Scalar XL!

The setup:

Very similar to the previous test. here we keep the aluminum plate that has a great heat spread on the whole surface.

We add the insulation foil previously tested.

From top to bottom:

  • Aluminum plate
  • 1 700W silicone heater
  • Insulation foil
  • Wood plate

Setup details:

  • Heat beds: 1
  • Heater: 1x700W 300x400mm
  • Initial Temperature: 22°C
  • Target Temperature: 110°C
  • Print Surface: 1x 3mm aluminum plate (435x320mm)
  • Insulator: Foil insulator

Temperature profiles:

The red curve is the heating profile, when we apply the 110°C target.
The blue curve is the cooling profile, when the target temperature is set to 0°C.Here the power supplies are OFF.

At the bottom of each graph you have the time in seconds

On the left of the graphs you have the temperature in °C

 

Conclusion

While heating we have:

  • 60°C in 1 min 07 (67 sec)
  • 110°C in 3 min 06s (186 sec)

The system can easily reach 110°C! The temperature profile is nearly linear and we feel that we can go higher in temperature!

We need to wait 8 min 12 sec (492 sec) to cool down from 110°C to 60°C

Comparison with previous test :

Here the results are barely comparble because we go from 400W to 700W. However we can still have a notice a few things:

  • We can easily reach 110°C in 3 minutes
  • The ability of this system to keep the heat has also increased!

Compared with test 2, which is giving us the best results until now over 8 differents tests, we have:

  • The heating time to reach 60°C has decreased by 123%
  • The heating time to reach 110°C has also decreased by 80%!

 

Heat bed Study for Scalar XL – Test 7

In this case, we are studying the impact of the insulation when we swap the cork and the insulator foil compared with test 6.

The setup

IMG_0412

In a similar manner, the corkis now placed on top of the insulator foil, against the heating element.

From top to bottom we have:

  • Aluminum plate
  • 2 heating plates
  • Cork
  • Insulator foil
  • Wood plate

Setup details:

  • Heat beds: 2
  • Bed 1: MK1a (with the thermistor) powered by PSU N°1 (360W)
  • Bed 2: MK2B powered by PSU N°2 (300W)
  • Initial Temperature: 24°C
  • Target Temperature: 110°C
  • Print Surface: 1x 3mm aluminum plate (435x320mm)
  • Isolant: 2mm insulator foil + 2mm cork sheet

Temperature profiles:

The red curve is the heating profile, when we apply the 110°C target.
The blue curve is the cooling profile, when the target temperature is set to 0°C.Here the power supplies are OFF.

At the bottom of each graph you have the time in seconds

On the left of the graphs you have the temperature in °C

 

Conclusion

While heating we have:

  • 60°C in 4 min 09 (249 sec)
  • 100°C in 30 min 54s (1854 sec)

The system can barely reach 100°C !

And we must wait 6 min 40 sec (400 sec) to  cool down from 100°C to 60°C

Comparison with the previous test:

Compared with  test 6 the performances are slightly better at 100°C but slighly worth around 60°C

  • Heating time to reach 60°C has increased by 4%
  • Heating time to reach 100°C MAX has decreased by 0.5%.

In the end , the insulation foil has better performances when placed directly against the heating element allowing it to push back to the aluminum plate the whole IR radiation.

Also the Cork seems to have some kind of heat capacity that decreases the heat bed performances.

However it allows to keep the heat longer during cooling times.

 

 

Heat bed Study for Scalar XL – Test 6

in this solution, we are studying the addition of the cork layer below the foil insulator. We are ading the 2mm thick cork sheet to the systems described on test 5.

The insulation fois allows to revert back the IR radiation to the aluminum surface, it seems to be the best location for it to be against the heating element.

The cork sheet here will telle us if we can get an extra gain of performance for all the heat spreading below the plate.

The setup

Very similar to the previous test, the cork layer is against the MDF plate .

From to to bottom layer we have:

  • Aluminum plate
  • 2 heating plates
  • Insulator foil
  • Cork
  • Wood plate

Setup details:

  • Heat beds: 2
  • Bed 1: MK1a (with the thermistor) powered by PSU N°1 (360W)
  • Bed 2: MK2B powered by PSU N°2 (300W)
  • Initial Temperature: 24°C
  • Target Temperature: 110°C
  • Print Surface: 1x 3mm aluminum plate (435x320mm)
  • Insulator: insulator sheet + 2mm insulator sheet

Temperature profile:

The red curve is the heating profile, when we apply the 110°C target.
The blue curve is the cooling profile, when the target temperature is set to 0°C.Here the power supplies are OFF.

At the bottom of each graph you have the time in seconds

On the left of the graphs you have the temperature in °C

 

Conclusion

While heating we have:

  • 60°C in 3 min 59 (239 sec)
  • 100°C in 31 min 03s (1863 sec)

The system can barely reach 100°C!

And we need to wait 6 min 22 sec (382 sec) to cool down from 100°C to 60°C

Comparaison par rapport au test précédent:

Compared with  test 5 it still seems worth even with the addition of the cork layer:

  • The heating time increases by 28% to reach 60°C
  • The heating time increase by 35%  to reach 100°C MAX!
  • The heated cools down 3% faster

Adding the cork below the insulation foil strangely decreases the performance of the insulation!