Sunday,17-May-2020

3D printer Anycubic Mega S - some thoughts and mods

EN
Hello,
I`m one of the many people who bought that new Chinese version of that famous brand.
Right from the box it produce few prints quite well:

old_print.jpg

After some prints and maybe two weeks of time since I have it, got misprint. The whole bed adhesion somehow went off..
I read some articles that after few prints is wise to wipe the bed with cloth and some rubbing alcohol.
I have done that few times, and every time the make up cleaning pad become yellow. First I thought it was something left from the PLA material when get hot (like liquid). Later on, I start to suspect that was some adhesive coating sprayed over the bed.
Why? Because after 5-6prints..it happen that:

new_print.jpg

And no matter rubbing the hotbed with pure alcohol, dry paper, oil remover or other “magic” it just didn`t keep any plastic.
Initially, my attention went to the hotend department. New nozzle - same shit. Other PLA roll, ABS.. nothing.
Reducing the print and fan speed, playing with the temperature levels did not give me any improvement.
Then found that nice video tutorial : Reliable 3D printer bed, adhesion fix
I did`t sand the bed surface. Just light touch with P800 sand paper and water. Clean the table with soft cloth and then use the mixture Stuff U. K. suggest : 6-6.5parts water and 1 part white glue for wood.
After it dry on free air (not preheated bed) , the first print went like that:

after_woodglue.jpg

Yep! We are back in business…

So now about my mods:

1. - new stepper drivers. I bought TMC2209 ones (LERDGE TMC2209). That are amazing small devices and highly recomend
Only two things I had to do on them:
- cut both CLK and UART pins (or desolder them)
- pull and turn 180° the motor connector JNC socket. That`s because the DIR pin is inverted on them compared to A4988. And that was really fast solution without need to modify anything else

new_drivers_2.jpg

2. replace the fans:

-power supply : replaced with new 60mm silent one. Much more quiet than the original one.

new_drivers_1.jpg

Also, you can see that I have cut the safe top part. Anyway it is inside the “frame” , so for sure no need to guard anything and will help the flow. That is new type power supply, so can`t be used bigger fans like 70-80-90mm. Actually 90mmx14mm Noctua is really good option but unfortunately it not fit because the capacitor location.

- new hot end design with 50mm side fan and blower.. Seems, for me despite the size of the blower it not produce such big flow I expected.. Still the noise is much low. There are many samples by using for nozzle blower Noctua 40×40 fan. The problem is that when you get some wall type surface after the fan - due the design position, part of the flow instead going toward the nozzle it acts as reverse back flow and you can feel it going out toward outer direction.. What is not such as good idea.

hotend_a.jpghotend_b.jpg

- drivers and mainboard cooling : for that one, I use 120×120x15mm fan. It is reasonable quite, and actually much better than the original 50mm one.

Originally, I just rotate the bottom plate 180°, and add the fan:

bottom_fan_1.jpgbottom_fan_2.jpg

Well, that worked but not as expected. So, next step was - surgery
After mark the holes and some place for “window” I decide to put my angle grinder into work:

bottom_fan_3.jpg

After that ugly job, Some tape used to hide the bad part.. Or if you wish, can add filler, sand it, and repaint.. But anyway it is all the time on the bottom.. So, tape and shield added:

bottom_fan_4.jpg

Next the fan:

bottom_fan_5.jpg bottom_fan_6.jpg

Next in the list was to add external mosfets to control the hot bed and the nozzle heater. First I print two frames and using adhesive tape, I fix them on place

mosfets.jpg

After they are on place, Some new cables where added. From the image below, you can see what polarity I`ve used.
The hot bed on left, power supply right.

mosfets_2.jpg

There are two led diodes on them. Red ones that show the power been ON and blue one when the board control,them:

mosfets_3.jpg

So far, I`m pleased with the result and the printer itself. Not bad at all..
Thanks for reading!

Add comment

Fill out the form below to add your own comments