Tank3d printer build

[Boyan Silyavski]

Hi there,

Isn't it a high time to start and document a proper 3d printer build

These days the 3d printing bug bit me, so myself and my friend Jeff bought ourselves a Prusa MK2 printer. Not that i couldn't have made it myself but actually we both have some things ready to made so i did not want to waste time, plus i wanted to learn directly on a good enough printer and start playing directly with 4 colors and so on. So the Original Prusa obviously was the winner due not only to the innovative features, price, but when i analysed the design i saw and like its refined simplicity.

As its on a back order and i still dont have it in my hands i borrowed from another friend his Leon3d/ Spanish copy/ and these days i am starting to learn about printing. Frankly if you know me from the forum, you could guess that flimsy designs are not my cup of tea, so instantly i started to design a new printer.

I looked many designs from the web, and frankly i would have followed one, but there was no a single design which lived to my standard. I would say to "our " standard , as this forum is obviously the best for CNC design on the net , which is thanks to you guys!


Also looked at Chinese printers, copies of Prusa and other ones. Honestly for the price there were some that were tempting and then to fix the issues but the deeper i looked the more was disgusted by poor design. Arent these people even able to copy by the letter a working open source design? If somebody is interested just ask me about any Chinese printer and i will tell you its flaws on first glance. Not worth the money. Do not be tempted to save 300$ if you could permit it.


Lets say that i have the ambition to design the best truly universal semi pro printer for the money. Then simplify that design and make it so that even a child can put it together without any special tools or knowledge. That means many things had to be considered / thanks god for the multi core nuclear processor in my head/, needless to say last 2 weeks analysed all available on market. Lets say that most of the people making printers have no bloody idea of straightness, precision, speed, stiffness,repeat ability. And if some do, then the designs have so many mistakes, complexities or little details that spoil the deal, that honestly i stopped looking at any at all.

For the moment i did not dig too much into the electronics, and as i believe that guy Prusa knows his job and innovated some stuff, his printers work, are open source, so i will stick with his ideas about which board, firmware, etc. and focus on the mechanical and $$ side of things. With the only note that i am inclining towards servo motors or at least closed loop steppers. All will be Nema17. The reason is the long prints and very fine prints. But lets forget that for now and focus on the mechanical side.



One very important thing to note is that when i design something i prefer to start from scratch, then sketch the ideas, play with all possibilities and slowly purify the final idea. I have already done that. results, how and why- bellow; I will underline the main considerations.

Here is the plan:

1. Code name - Tank3d. First- it will look like a tank, second it will be strong like a tank, third- have you seen a fish tank

First i started with making the Prusa from aluminum profile. I found a nice printer designed by a guy and an aluminum version of the Prusa MK2
If you are lazy and want to stop here, there are the 2 designs i liked :
-http://www.reprapwilson3d.com/collections/frontpage/products/wilson-ii-complete-kit?variant=18734558981
-http://reprap4u.cz/navod-na-stavbu-3d-tiskarny-rebelix/


Then i said to my self: but it needs a double side beams for the gantry so its more rigid, does not vibrate and you could lift it and move it without need to adjust it again Then it looked like an almost finished half aquarium. So i said to my self- aluminum profile is not so expensive so better for 20 -30 euros more i make it so that if desired sheets to be bolted to profile and printer enclosed without any further modification or extra box needed.

2. The bearings.
8mm unsupported rods do the job if bearings are quality and shafts are hardened. The printer i borrowed is around 700euro and its rods are not hardened so they are scratched already, and my friend has that from a couple of months On the other side 10mm bearings and rods could be better. Also all this talk about acceleration and printing speed. This printer here starts vibrating after 40mm/sec which according to me is the top speed that should be used. We will see the original Prusa, but what i am saying here is that 3d printing guys obviously dont know a s%^^t about rigidity and the only thing that saves them is not using the printer to make money or staff that must be precise.

Not the case here. I intend to make money using that printer selling prints , especially after spending any money on it, and i want micro detail precision and repeatability. Obviously supported rails Hiwin. I have Zero doubts here.

It was interesting to decide which Hiwin exactly the 9, 12 or 15 series. I am a big fan of the MGW series which i believe is the best for laser and plasma machines using single blocks



As you see above at the snip, rail width and especially weight were main consideration as obviously 9, 12, 15 both normal or wide will work . But i believe 12H block and rail 12 size will work best as a compromise between block length, block weight, rail weight for printers up to 500x500x500 cubes.

3. Aluminum profile - 20x20

why:
-price 1/2 than 30x30
-enclosed structure
-rails size and especially the bearing block size is similar

Aluminum profile and linear bearing size and type choice was also influenced by the fact that this printer will be able to move at servo driven speeds and the Bowden type choice.


4. Bowden extruder.

I agree with mr. Prusa that this is the way. No double heads,increased fast speeds due to low weight as no need to move a motor, multi color easy, not unnecessary complications adjusting the 2 or more nozzles height and position, etc... We are almost year 2017. So at least 2 or 4 filament ability at the same time. many models will print better with support that can dissolve, especially if you sell them.


5. Self replicating.

In reprap tradition i decided to design it so that parts could be printed or milled from aluminum, without any further change to their design and withstand the scrutiny even of a hard OTT like myself, so thats a bit of a challenge here. Mostly cause i am still getting to know the plastics, but i printed here first parts today and i am quite happy. Needless to say - nothing flimsy or dubious.

Obviously once i finish the design i will open source it, but that does not mean that anyone can change it and achieve sth mediocre instead of a truly professional printer. Time will show if i will make it so good that the design itself discourage any changes as an unnecessary waste of time.

6. All parts must be self aligning to perpendicularity and maintaining same distances without the need of special tools when mounting. At most 1 precision square to be needed.
check pictures bellow.

7. All must be inside the envelope of the frame, no motors outside, etc,. So if one desires to enclose it by himself very easily, and keep warmth, noise, etc. there. Obviously the electronics have to be placed wiselt, so i think for now to be under the bed, isolated from the heat of the enclosure.

8. Bells to be tightened to specifications easily, means each belt has to have screw tensioner. But hey, not tlike the ones i have seen, that are so flimsy and move the belt around when reaching speed.

9. machine will be fully parametric, so design will not change at all up to 600x600x600 cube. Just lengths.


10. last but not least: the type of design. After much consideration Core XY designs, moving Z table and so on. Let me tell you. The simplest is the best for me. Moving table, double gantry z . I am quite happy to argue and explain why. If you have questions. But its a fact and no changes.

11. Work area size 400x200x(200-300-400)

I was tempted to make sth enormous or sth miniature. After a lot of thought to me 400mm width and 200mm depth , is the best compromise. Small enough to make everuthing precise so ultra miniature models using 0.2 nozzle and even smaller, big enough to use 0.8mm and even the Volcano nozzle.

12. Hot end

no doubts here, the E3d and the Volcano. When i have a printed 100kg of various filament, then will think more in this direction

13. which Bowden extruders??
unknown for now, to be decided.

14. Bed

Aluminum 6mm thick at least. more to come


Thats all for now, i hope you enjoy the build and forgive me for the bragging



So here are some picture of what i have done till now, ignore rail lengths , that will still have to be adjusted so all to fit inside ,all is still in a sketch phase: