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Large-scale 3d printer

Posted by asifjahmed 
Re: Large-scale 3d printer
November 12, 2015 12:02PM
Quote
etfrench
Are you sure? I was under the impression that ABS worked the same as acrylic where glued joints are just as structurally sound as the rest of the material.

Hello, etfrench,

I plan to print with other materials in the near future.
Not so sure splitting would work for, say, ceramics.
Better to be sure from the beginning.
Re: Large-scale 3d printer
November 12, 2015 01:37PM
Quote
davew_tx
Val,

For your big glass idea, be prepared for non flat conditions all over the surface. Pulling the edges down will only work locally near those points, but the center of the glass will not respond to any edge manipulations.
The cork in the center will not care that you tweaked some edge. it has no reason to compress even if you moved an edge 1" or more.

To solve that, you could use rear view mirror glue and put an array of bolts across the under surface. File the bolt head flat first and glue to the glass. I've had this idea hold together for a couple of years now.
Then, using double nuts or springs and wingnuts on brackets you could push up or pull down specific areas on within the large area.

It's a solution, and there are other ways to solve the issue, but know that the flatness will not be achieved without specific design solutions in multiple places.

The large Stratasys 900 does it that way (patent 8153183) and you have a similar size bed.
I've been inside one of those, and they have a precision ground 15mm thick stainless (?) sheet and they can't keep it flat without this multi-point mounting method.

In my experience, the electronics, like the board and the motors would survive in chambers at 70C or more. given the small size of most control boards, those are easy to mount outside, but the motors can handle it.
I'd guess you could run motors up to 80-90C before the lacquer on the windings smokes.

Stratasys has misc pcbs inside on many of their machines, but they have the logic outside.
The expensive machines that run high enclosure temperatures for printing the Ultem material have the motors outside the enclosure.
They put LED boards, switch boards, encoder readers, and thermocouple reader boards on the inside of UPrints and Dimension machines. The logic and control is outside.
They do bring fresh air into the print head and dump it on a few places, which might create a cooling cloud/shroud near some of the boards.

Hi Dave,

I plan to discuss the surface flatness tolerances with my supplier prior to ordering. There is also the possibility of using high quality base glass, but the price will go up accordingly. For instance, these guys manufacture borosilicate precision glass:
[www.schott.com]

Obviously, there are many other manufacturers, and I am still studying the flatness issue. Also, I am looking into other materials that could replace the glass, be acceptably flat and able to support 120-130 C temperature.

Regarding the mix of electronics and high temperature, most of my electronics are outside that area, except for the two x axis steppers and the two steppers attached to the extruder. There is a gap of approx. 65 mm (2.55") between the platform and the machine frame, which is ample space to place the enclosure, if I play my design cards right. The only issue I foresee is where the enclosure meets the moving double x axis at the top top. I'm thinking some sort of bellows might do the trick, but I haven't researched this venue enough for the time being.
Re: Large-scale 3d printer
November 12, 2015 09:43PM
Hi Val

If you find a online deflection calculator, you will understand what Dave is talking about.
The thickness and the self weight are racing each other. You will be surprised about the thickness required in your design to achieve the flatness.

Multiple point adjustable support is the right direction and I am designing that in my printer too. my glass is 880mmx580mm. I am planning to have 6 points.
My goal is not to be absolute flat. I will use those 6 points to adjust the surface to follow the extruder XY plane, which isn't absolute flat either. as long as these two surfaces match, I am happy.


Printer I bought: 2015 Sunhokey Prusa i3
Printer I am designing: Another big CoreXY machine
Re: Large-scale 3d printer
November 20, 2015 01:45AM
So, I finally received the new port extruder. Please see attached pictures. Pictures 139, 141 and 142 show the port extruder mounted, with the dual extruder on it. Picture 140 shows the reinforcements I designed in order to keep the two x axis rail at the prescribed distance, and reinforce the whole assembly. Now, moving on to the glass and the issue of leveling it parallel to the xy plan (tramming).

Quote
bonmotwang
Hi Val

If you find a online deflection calculator, you will understand what Dave is talking about.
The thickness and the self weight are racing each other. You will be surprised about the thickness required in your design to achieve the flatness.

Multiple point adjustable support is the right direction and I am designing that in my printer too. my glass is 880mmx580mm. I am planning to have 6 points.
My goal is not to be absolute flat. I will use those 6 points to adjust the surface to follow the extruder XY plane, which isn't absolute flat either. as long as these two surfaces match, I am happy.

Hi bonmotwang,

I understand your point of view. I am going to have to get back to you about this.
Attachments:
open | download - picture139.jpg (397.6 KB)
open | download - picture140.jpg (408.2 KB)
open | download - picture141.jpg (386.5 KB)
open | download - picture142.jpg (395.3 KB)
Re: Large-scale 3d printer
November 20, 2015 09:27AM
Hi Val

I like your machine. very solid, which is my way into this.
I just kicked off CNC machining last night. There are 26 different kind of alum. parts.
But I have been debating with myself at late stage of corexy design of my machine: Do I really need corexy or just use normally way.
My frame is about 1000mmx880mm and 900mm height.
Total weight of the machine may hit 50Kg.

I put my work order on hold now, and give myself a couple more days to decide. Right now I am thinking about abandon corexy and go back to normal way because the motor weight isn't an issue in this type of big frames.


Printer I bought: 2015 Sunhokey Prusa i3
Printer I am designing: Another big CoreXY machine
Re: Large-scale 3d printer
November 20, 2015 11:02AM
Quote
bonmotwang
Hi Val

I like your machine. very solid, which is my way into this.
I just kicked off CNC machining last night. There are 26 different kind of alum. parts.
But I have been debating with myself at late stage of corexy design of my machine: Do I really need corexy or just use normally way.
My frame is about 1000mmx880mm and 900mm height.
Total weight of the machine may hit 50Kg.

I put my work order on hold now, and give myself a couple more days to decide. Right now I am thinking about abandon corexy and go back to normal way because the motor weight isn't an issue in this type of big frames.

Hi bonmotwang,

Solid, yes.
Massive, no.
Too big leads to inertial forces hard to contain, thus reduced speed.
I am a fan of metal parts too. Wouldn't put my trust into an ABS printed part to do its job, eapecially when subject to high temperature.
I would have considered corexy approach myself but, don't laugh, I didn't know about it when I started the project. The reason is, you eliminate moving motors in corexy, and greatly reduce weight and inertia.
More as a mechanical engineer and less as a first time printer builder, I would recommend corexy. The dimensions you have there, 1000 x 880 mm, make it more suitable, considering the timing belt length and its behaviour during operation (guitar string effect, etc). In this respect, it's easier to use it on 1000x880 than 1500x1500.
Lastly, not sure what does the weight has to do with anything, unless you plan to make a portable machine.

Edited 1 time(s). Last edit at 11/20/2015 11:14AM by val c..
Re: Large-scale 3d printer
November 20, 2015 11:16AM
Great recommendation Val.
You are right, and I should get it kicked off. and see what we get. A lot of work has been poured into design the whole assembly. Changing direction at this time is no fun.
Thanks Val.
Again, nice chat :-)


Printer I bought: 2015 Sunhokey Prusa i3
Printer I am designing: Another big CoreXY machine
Re: Large-scale 3d printer
November 20, 2015 11:25AM
Quote
bonmotwang
Great recommendation Val.
You are right, and I should get it kicked off. and see what we get. A lot of work has been poured into design the whole assembly. Changing direction at this time is no fun.
Thanks Val.
Again, nice chat :-)

Hi bonmotwang,

Just an afterthought. Should you ever decide to enclose the machine, you get to keep the motors out of the heated areas. And yes, it's no fun changing the design mid way.
I wish you best of luck with your build.
Re: Large-scale 3d printer
November 23, 2015 12:04AM
If I decided to enclose the chamber, motors are outside.
But first step is just PLA.


Printer I bought: 2015 Sunhokey Prusa i3
Printer I am designing: Another big CoreXY machine
Re: Large-scale 3d printer
November 24, 2015 04:08PM
Quote
bonmotwang
If I decided to enclose the chamber, motors are outside.
But first step is just PLA.

Indeed, for PLA only, enclosure is overkill. But you might want to use other materials in the future, obviously ABS being the next choice up. Apart from that, there's HIPS, nylon, and god knows what other materials, out there. I hear they even have conductive plastic for 3d printers, as an example of 'exotic' materials. The reason I'm saying this is, allow yourself some room for that during the design process, so that if you decide in the future to use other than PLA, at least you know your machine is more easily adaptable to the requirements, and keep the modifying work at a minimum. There is a post above, suggesting I should use several smaller printers to print smaller parts, which can then be glued together. While this is ok for ABS, it doesn't work for other materials. I plan to use ceramics in the future, and I tried to keep that in mind when designing my machine in early stages, so as to have less headaches, possibly major overhaul, later.
Re: Large-scale 3d printer
November 24, 2015 05:41PM
My machine was designed to print ABS.
But I decided to learn how thermal stress is going to affect my machine first. So mechanically, only minimal moving parts will be in the chamber if walls would be added.


Printer I bought: 2015 Sunhokey Prusa i3
Printer I am designing: Another big CoreXY machine
Re: Large-scale 3d printer
November 24, 2015 10:55PM
Finally, the port extruder assembly is ready to be wire connected to the controllers. Had to make an improvisation (for the time being) regarding one of the belts, it is the back angle with two idle pulleys, because in its natural position, this belt was touching the steppers connectors at the back of the extruder stepper motors. Picture 144, if zoomed, shows where the wires come out of the motors at the top back edge, and the belt was rubbing a bit against those connectors. In retrospect, I should have lowered the extruder's position a bit further down, but that will be a project for the near future.
So, I'm left with connecting the wires and buying the glass, which I'm in the process of doing so, and then finally I can start fine tuning my baby.
Attachments:
open | download - picture143.jpg (403.5 KB)
open | download - picture144.jpg (405.2 KB)
open | download - picture145.jpg (381.9 KB)
Re: Large-scale 3d printer
November 24, 2015 10:56PM
Quote
bonmotwang
My machine was designed to print ABS.
But I decided to learn how thermal stress is going to affect my machine first. So mechanically, only minimal moving parts will be in the chamber if walls would be added.

As a general idea, the smaller sections will heat faster and more. Also, the geometry of the section greatly influences the way heat spreads through it. However, the best way to test it is to actually do it and put it to work.
Re: Large-scale 3d printer
November 25, 2015 03:16AM
The sE1X is very customizable in which, with just some longer 2020 extrusions/smooth rods/threaded rods you could easily get 20" out of one..just a thought. The original design is 11.8"x11.8"x10" and is available as a kit at [mobious.org] . Also has dual extrusion available now. If you'd like to discuss more about making a larger sE1X, let me know!

Edited 1 time(s). Last edit at 11/25/2015 03:17AM by papabur.
Re: Large-scale 3d printer
November 25, 2015 04:30PM
Quote
papabur
The sE1X is very customizable in which, with just some longer 2020 extrusions/smooth rods/threaded rods you could easily get 20" out of one..just a thought. The original design is 11.8"x11.8"x10" and is available as a kit at [mobious.org] . Also has dual extrusion available now. If you'd like to discuss more about making a larger sE1X, let me know!

That's a really big printer for the money.
Re: Large-scale 3d printer
December 18, 2015 05:49PM
here's mine, not as big, but next one be bigger smiling smiley

My First Design
Re: Large-scale 3d printer
December 20, 2015 03:33AM
so, dear reprap diary, while building away at my printer, some better ideas came along. it's unbelievable how much the hand assembling can screw up one's design.
with that in mind, i think i solved some torque issues by adding an extra arm with two horizontal wheels on it, to each end of my two x axis.. those wheels will graciously roll on a reinforcing rail placed nearby, not pictured. and prevent one end of said x axis to skip ahead of the opposite end. the two stumps in the pictures are for illustrative purposes only, the real x axis are much longer. you can actually see them in two of the pictures attached.






my x axis are not so lean as before, but the trade off is worth the time spent to make the changes. after a couple of issues with openbuilds gantry plates and wheels wobbling on the v slot rail, i got them fixed, and it's time to move on to re-assembling the x and y axis and reinstalling the timing belts on them. i made a mistake in the design of the port extruder assembly, also pictured in the far back, and now i'm waiting for a new part from china. once that comes, i will be able to finish and set the glass on the bed.
Re: Large-scale 3d printer
December 20, 2015 02:49PM
i figured a quick drawing might help, on top of the pictures from the previous post. this drawing shows the reinforcing rails with the two wheeled arm sliding along them, viewed from outside (left picture) and from inside (right picture). the reason i added this extra reinforcement is that when dealing with two long rails attached at the ends with gantry plates whose dimensions are small compared to the span, a tendency of skipping ahead might occur, where one end of the two x axis might move separately from the other end, this leading to a loss of perpendicularity of the x axis onto the y axis. the wheels on the gantry plate (shown green in this drawing and black in the previous pictures) are 60.64 mm apart, center to center. by adding the extra arm with the two horizontal wheels, the sitting of the whole gantry plate assembly is improved, and the twisting of the x axis assembly is avoided. to illustrate that, i added a second sketch, called twisting. despite its poor quality, it should be obvious why a larger distance between the wheels is desired. since i didn't want to compromise the design i already had, and didn't want to bite too much from the displacement along y axis, which would lead to a smaller printing area, the only solution for me was to run this parallel reinforcing rail right along the main y axis rail. thus, I get to keep the best of the two worlds.
last but not least, this is an issue which I believe is more frequent seen in large printers. smaller printers should not have this, since the ratio between the length of the rail (x axis in this case) and the width of the end gantry plates does not allow for this twisting movement to occur.
Attachments:
open | download - CARRIAGE REINFORCEMENT V.4.0.jpg (295.4 KB)
open | download - TWISTING AT X AXIS.pdf (19.6 KB)
Re: Large-scale 3d printer
December 20, 2015 07:25PM
To make something that big in ABS would require a heated chamber at about 70C.
Re: Large-scale 3d printer
December 20, 2015 10:17PM
Quote
JuliaV
To make something that big in ABS would require a heated chamber at about 70C.

I thought about that and allowed for it in the design. The printer sits already on a 3/4" mdf board, with the frame bolted down on it. If you have a look at picture 147, you can see there is ample room between the corner of the heated bed and the inside of the frame, 64 mm each direction, to be more precise. That's where I plan to install screens for the heated chamber, in the near future. One side will be hinged or removable, to allow for the model to be taken out.
Re: Large-scale 3d printer
December 24, 2015 12:21PM
You don't have to build a frame if you don't want to: Clerck the hanging RepRap


torbjornludvigsen.com
Re: Large-scale 3d printer
January 14, 2016 12:38PM
Any updates on the beast?
Re: Large-scale 3d printer
January 19, 2016 12:24PM
Quote
davew_tx
Any updates on the beast?

hi dave,

only a few, my re-designed port extruder front plate arrived from china. due to an unfortunate family loss, i am half way around the world right now, but i will return home end of january, when i plan to resume work on the 'beast'. i expect things to go downhill really quick from there, pretty much got all the parts i need, and i will keep all of you posted about the progress of my work.
last but not least, you threw a monkey wrench a while back, on my plans to use a piece of tempered glass, so i will have to get back to you on that, regarding a way to use this to my advantage.
my experience with the glazing industry only goes 18 years back, but if my idea will work, i will be more than happy to share it here.
however, i think i shouldn't have to wait until then to thank you in advance for said monkey wrench.
despite the sleepless nights it caused me, it only strengthened my resolve while chipping away at my naiveté.
after all, as i was saying sometime earlier, this is my first 3d printer ever.
Re: Large-scale 3d printer
January 19, 2016 12:47PM
Quote
davew_tx
Any updates on the beast?

and, by the way, 'the beast' is already trademarked. smiling smiley
[www.cultivate3d.com]
Re: Large-scale 3d printer
January 21, 2016 04:20AM
Small russian printer.


Re: Large-scale 3d printer
January 21, 2016 05:48AM
Quote
karabas
Small russian printer.


In Russia you don't print RepRap, RepRap prints you winking smiley


[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]
Re: Large-scale 3d printer
January 21, 2016 04:52PM
Thanks for the update and I'll be checking in from time to time to see your solutions.
It's a fun hobby.
Re: Large-scale 3d printer
January 21, 2016 06:37PM
Quote
karabas
Small russian printer.


And it doubles up as an earthquake shelter...
VDX
Re: Large-scale 3d printer
January 21, 2016 06:52PM
... there are several cartesian- and delta-based frames with up to 12 meter building height for 3D-printing architectural parts nad complete houses out from concrete.

In future this will get common and even bigger - especially in Japan and China they're fond of "printed houses" ... and NASA too has plans to install 3D-printers on the moon or on Mars to 'print' habitates ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Large-scale 3d printer
January 28, 2016 06:33AM
Quote
VDX
... there are several cartesian- and delta-based frames with up to 12 meter building height for 3D-printing architectural parts nad complete houses out from concrete.

In future this will get common and even bigger - especially in Japan and China they're fond of "printed houses" ... and NASA too has plans to install 3D-printers on the moon or on Mars to 'print' habitates ...
Yes large printers exists but
but one problem - large scale prints do not exist
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