Archives de catégorie : Lit chauffant

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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.

PID auto tune

Temperature management by your 3D printer is often made using PID controller.

Requirements:

  • Pronterface (Windows, Mac)
  • Arduino IDE (optional)
  • 3D printer with active PID for the target heating element

Pronterface installation:

Pronterface is a cross platform host software for your 3D printer. It allows to send commands to your 3D printers in a simple way.

This application is stand alone and doesn’t require any installation

In order to be able to connect to your 3D printer you need to install the serial drivers of your electronic board.

Scalar 3D printers are using arduino MEGA 2560, so you only need to install Arduino IDE in order for the proper drivers to be installed.

Once you have downloaded the proper version of Pronterface , you will need to unzip it’s content in a folder.

Inside you should have the following file tree.

Pronterface PID

At this stage you will need to connect your 3D printer using a USB cable.

Once the drivers are installed, your OS will assign a specific COM port to your 3D printer.

Now you can launch « pronterface.exe »

The following window will appear

Pronterface PID

Warning!

Depending on your OS you might need the proper user rights in order to acces COM port

Consider running your application as Administrator

Once the drivers for the seria COM port are installed your 3D printer COM port should be visible inside the drop down list of Pronterface (1)

  1. You should see the proper COM port asigned to your Arduino MEGA inside this drop down list
  2. Select the baud rate to 115200Bps (at least for Scalar 3D printers)
  3. Push the Connect button.

Pronterface PID

Once connected you should have a lot of information coming into the console window on the left side of the application.

Pronterface PID

PID Auto tuning

PID auto tune has to be made when your heating element is at Ambient temperature. Otherwise you will get wrong parameters!

 

In the bottom part of the console view, you have a text box where you can enter single commands for your 3D printers,

Hot end PID

Iin order to perform the PID tuning of your hot end you will need to send the following command :

 M303 E0 S210 C8

E0 is for Extruder 0 (your hot end)  , S210 is the target temperature (here 201°C) and C8 is the amount of iterations to perform , Here 8. The higher the number the more accurate your PID will be.

Pronterface PID

you will need to wait a few minutes in order for the algorithm to converge to a set a values.

Pronterface PIDhere we found out

bias: 92 d: 92 min: 196.56 max: 203.75
Ku: 32.59 Tu: 54.92
Clasic PID
Kp: 19.56
Ki: 0.71
Kd: 134.26
PID Autotune finished ! Place the Kp, Ki and Kd constants in the configuration.h
#define DEFAULT_Kp 17.28
#define DEFAULT_Ki 0.63
#define DEFAULT_Kd 118.87

your PID values will be different from the one here

Take theses PID values into account

Use the following command in order for your controller to take the Ki, Kp, and Kd values into account

 M301 P17.28 I0.63 D118.87

Make sure you have updated the command with the PID values that you found!

Save your settings into the EEPROM

 M500

M500 allows to save your settings into the controller EEPRO


Heat bed PID Command

M303 E-1 S60 C8

Take the Heatbed PID values into account

 M304 P1 I2 D3

Save into EEPROM

 M500

 

 

(source http://reprap.org/wiki/PID_Tuning )

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.

 

Heatbed V2 Assembly (Full Aluminum)

List of parts:

  • Scalar S : 1 silicone heater (190x190mm 250W 220V)
  • Scalar S: 1 aluminium plate (220x230x2mm) (Base)
  • Scalar S: 1 aluminium plate (220x230x3mm) (Plate)
  • Scalar M : 1 silicone heater (300x200mm 400W 220V)
  • Scalar M: 2 aluminium plates (300x220x3mm) (Base + plateau)
  • Scalar L : 1 silicone heater (300x300mm 600W 220V)
  • Scalar L: 2 aluminium plates (300x330x3mm) (Base + plateau)
  • Scalar XL : 1 silicone heater (400x300mm 700W 220V)
  • Scalar XL: 2 aluminium plates (435x320x3mm) (Base + plateau)

 

  • Scalar XL Premium : 1 silicone heater (400x300mm 700W 220V)
  • Scalar XL Premium: 2 aluminium plates (435x320x3mm) (Base + plateau)

 

  • 1 aluminium sheet used for cooking
  • 1 wired thermistor (1 meter)
  • 1 pen
  • 1 pair of scissors
  • 1 50mm polyimide/Kapton tape
  • 1 piece of aluminium tape

 


 

Take the aluminium plate corresponding to your print surface.

It has only 4 holes, one on each corners.

 

 

 

This pate has 1 face with a protection film and the other face with a raw surface.

In this picture you can see the face with the protection film.

This face is used for printing.

 

 

The other side with raw aluminium is destined to be the bottom of the heatbed where you are going to stick the heating element and the thermistor.

Take the raw side of the plate in front of you.

 

 

 


 

Place the heating element (orange) – don’t stick it yet – and place it in the middle of the aluminium plate..

Place some markings so that the silicone heater is at the center of the aluminium plate.

This pictures shows the example of the Scalar XL.

The silicone surface is smaller on all sides than the aluminium plate..

 

 

This picture shows the example of Scalar M.

Here the silicone heater has the same length but smaller width.

Make sure to have enough space around the corner-holes for later use.

 


 

Place some markings on the sides of the silicone heater.

This will help you later on to stick the silicone heater in the center.

 

 

Do the same at the top and bottom of the plate for Scalar M and also on the sides for Scalar XL.

 

 

 


 

Now take your thermistor .

Place it so that the end of the thermistor is located at 1/3rd of aluminium plate length from the side.

 

 

 

This will allow you to reuse the maximum of the thermistor wire’s length and keep a goo thermistor placement..

 

 

 

 


 

Take a small piece of aluminium tape (or Kapton / Polyimide tape) that will help you secure the thermistor end.

The main point in using these kind of tape is that they can support heats over 110°C..

 

 

here a picture showing the overall placement of the thermistor.

 

 

 

 

Once the thermistor ending secured your assembly should look like the picture.

 

 

 

 

In order to finalize thermistor placement, it’s interesting to stick the wires right on the edge of the aluminium plate..

 

 

 

 

 

 

 

 

 

Here is a picture showing the thermistor fully secured.

 

 

 

 

 


 

Now you can remove the 3M tape from the silicone heater .

 

 

 

Place it on the aluminium plate using your previous markings to make sure it’s centered.

make sure to properly press on all the surface of the silicone hater in order to evenly stick it on the aluminium plate.

 

 

Th thermistor should be right between both aluminum plate and silicone heater.

This ensures that the thermistor is properly secured and will provide proper measurements.

 

 


 

in order to optimize the thermal insulation, you can use aluminium sheets used for cooking so that it covers the maximum surface of the silicone heater..

Make sure that you remove the part of the aluminium sheet that extends over the silicone element..

This will help you to secure the aluminium sheet using kapton tape.

 

The aluminium sheet should have 2 different faces

  • 1  « mirror » side
  • 1 « mate » side
  1. Make sure to place the « mirror »  side toward the silicone heater. This will increase the efficiency of the aluminium sheet and will reflect a maximum of Infra-red radiation toward the useful part of the heatbed.
  2. Then push it against the silicone heater. it should stick naturally to it.
  3. Cut the excess of aluminium sheet that goes past the silicone heater surface.
  4. Secure the aluminium sheet with kapton tape and make sure to avoid air bubbles.
  5. Cut the parts of Kapton/polyimide tape that goes past the aluminium plate using a scalpel or a cutter.

 

 

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!

 

 

Heat bed Study for Scalar XL – Test 5

In this solution, we are studying the use of a single Aluminum plate 435x320mm, 3mm thick) with addition to a foil insulation sheet, used in test 2 that seem.

The Setup

We can see here the insulator below the aluminum 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: 2mm insulator 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 3 min 07 (187 sec)
  • 100°C in 23 min 01s (1381 sec)

The system can barely reach 100°C and 102°C seems to be the maximum!

And we need to wait 6 min 35 sec (395 sec) to cool down from 100°C to 60°C

Comparison with the previous test:

Compared with test 4 it seems a little bit better :

  • The heating time to reach 60°C has decrease by 42%
  • The heating to to reach 100°C Max has decreased by 30%.

We have a gain in heating time between 30% and 40% by simply changing the insulator below the aluminum plate. This foil insulator is more performant than the cork sheet for this kind of application.

Regarding the cooling time we get the same results as previous test..

Here we see that the foil insulator is radiating the infrared radiation toward the aluminum plate, increasing the performance between 30% to 40%.

Comparison with the Initial test:

  • We decrease by 7% the heating time to reach 60°C.
  • We increase by 41% the heating time to reach 100°C
  • The print surface is Increased by 74%.
  • In this system the max temperature seems to be limited to 100°C Max!
  • However, even by increasing the heating surface by 74% the time delta to reach 100°C is only 41%.

 

Heat bed Study for Scalar XL – Test 4

In this solution, we are studying the use of a single 435x320x3mm aluminum sheet compared with 2 20x20cm mirrors.

The Setup

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: 1 a3mm thick aluminum sheet (435x320mm in size)
  • Insulator: 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 5 min 22 (322 sec)
  • 100°C in 32 min 45s (1965 sec)

The system can barely reach 100°C and 102°C seems maximum!

And we must wait 6 min 36 sec (396 sec) to cool down from 100°C to 60°C

Comparison from the previous test:

compared with  test 3  It seems worth but let’s see the differences in numbers:

  1. We have to note however that the surface to heat up has greatly increased from 800cm² to 1392cm² , it’s 74% more surface to heat up.

So it can be normal that the heating time is worth!

  • We increase by 68% the heating time to reach 60°C
  • We increase by 172% the heating time to reach up 100°C MAX!

The system seems dimensioned to reach 60°C, However it’s impossible to bo beyond 102°C with an open system.

Regarding the cooling time, the aluminum plate properly dissipate the heat, the temperature go from 100°C to 60°C in 3 min 36 sec( 396 sec)

So the time to cool down is decreased by 29% compared to test 3.

Comparison with the Initial test:

  • The heating time to 60°C is increased by 61%
  • The heating time to 100°C is increased by 100%
  • The print surface is increased by 74%.
  • The overall systems seems less efficent based on the initial test.
  • The heat spread into aluminum is far better than using mirrors.!

 

 

Heat bed Study for Scalar XL – Test 3

In this solution we are studying the use of 2mm insulation cork sheet, placed below the heating element.

The setup

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: 2x3mm thick mirrors (20x20cm)
  • Insulator: 2mm cork sheet

The 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 3 min 12 (192 sec)
  • 110°C in 17 min 29s (1049 sec)

We must wait 9 min 11 sec (551 sec) to cool down from 110°C to 60°C

Comparison from the previous test:

Compared to  test 2 It’s globally worth , we are waiting 42 secondes more to reach 60°C and 2 minutes 35 (155 sec) more to reach 110°C.

Comparison with the Initial test:

It’s a little bit better:
We reduced by 4% the heating time compared with test 1
We reduced by 12% (141 seconds the cooling time of the bed
We can see that the heatbed inertia is very similar to the initial test, and the overall heatbed performance is worth than the  test 2.
It seems that we need to heat up the cork insulator before the heating surface can increase it’s temperature.
However the cork can keep up the heat a little longer in the cooling phase.