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Large-scale 3d printer

Posted by asifjahmed 
Re: Large-scale 3d printer
October 16, 2015 01:51AM
i'm almost done building a printer with a 50x43x45 inch printing volume, since i don't have the kind of money to buy a big rap or a 3dp.

you can see a couple of pictures of it attached.
Attachments:
open | download - picture085.jpg (382.6 KB)
open | download - IMG_8539 - Copy.JPG (608.4 KB)
Re: Large-scale 3d printer
October 16, 2015 01:55AM
about done building a 50x43x45 inch printing volume cartesian 3d printer.
pictures attached.
Attachments:
open | download - IMG_8539 - Copy.JPG (608.4 KB)
open | download - picture085.jpg (382.6 KB)
Re: Large-scale 3d printer
October 16, 2015 02:03PM
Wow, it's going to be challenging maintaining flatness over that size bed! What nozzle size/layer thickness are you going for?
Re: Large-scale 3d printer
November 09, 2015 10:09PM
Hi James,

I plan to solve the flatness issue with a thick piece of glass (10 mm at least) and clamps. The whole thing sits on a framed bed cross braced in the middle, over which I added a marine (plastic) board 6.35 mm thick, bolted onto the frame. On top of the board sits a 1" cork mat, and finally, said glass will sit on top of that. Since cork has its natural elasticity, I believe edge clamps places in certain spots along the (more rigid) glass edge, can help bring flatness into the fold. The extruder is a Micron 3DP dual, and I ordered me some extra 0.8 mm nozzles just in case. I could probably get 1.2 mm nozzles, like Vulcan's extruder but I have to check first with Micron.
Re: Large-scale 3d printer
November 09, 2015 10:13PM
What is your anticipated print layer thickness?
Are you planning to heat the bed?


Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]
Re: Large-scale 3d printer
November 10, 2015 11:46AM
@val

I did a big piece of glass and it wasn't close to flat. 22x17x1/2 inch
there was about 1mm (5 print layers) twist from corner to corner. really not usable for large printing and it kept me confined to one side.
I mounted it with 3 wingnut screws to the z-plate and I might have been able to solve the twist with 4 screws and adjustments.

tempered glass is heavy but I see you have 4 motors with screw advantage. You could move 200lbs+ I'd guess.
I think my z stage comes in around 35lbs with 1 NEMA 17 screw motor handling it nicely.
Caution: when your z-drive is unpowered, the weight might backdrive your 4 motors and send a significant power spike into your board.
Mine would freeze up the RAMBO board and required a full power off restart. luckily it did survive. I usually kept my hairspray bottle under the bed to limit the fall.


I put 2 12x12 silicone heaters on the underside and with 2 12V/30A power supplies it heated ok, but was power hungry.
the glass is also not a good conductor of heat, so without full coverage of heaters, there are very cold areas next to very hot areas.

I was somewhat worried about the glass shattering when I only powered one heater section, but it never did.
a jig plate aluminum solution would have at least spread heat away from the silicone heaters a bit.

on this machine, i'm refitting it with a PIR foam bed, a Broan Big Heat space heater ($30) with a bangbang control, and a .8mm nozzle for ABS.
it's fully enclosed when I slide glass sheets into the top groove and the front groove.
I'll insulate the outside with PIR to keep the heat in. I'm hoping for 50-60C solving the delamination issues.
70C used by stratasys is known to be higher than needed for repraps.
I assume they run their chamber higher because they also run their extruders at 290C while printing.


i'd suggest using PIR foam on top of your marine board. i'd ditch the cork.

Dentist has shared some of the logic and calculations for powering a bed in this thread. thread
To summarize his thoughts, you won't be able to heat a bed that size without many KW of power.
It would be far easier to enclose, insulate and heat the interior, allowing time for temperature normalization.
PIR is light, flatness is nearly irrelevant. cheap, replaceable, great adhesion.
Dentist has a video that shows the struggle to remove his part off of foam. vimeo

you already have a subframe for it. if your printer has any PLA parts and choose to enclose and heat, they'll need replacement with ABS parts since PLA will soften at 50C.

Edited 4 time(s). Last edit at 11/10/2015 12:21PM by davew_tx.
Attachments:
open | download - 20131004_093726.png (420.5 KB)
Re: Large-scale 3d printer
November 10, 2015 01:19PM
On the topic of large nozzles, you need to have a long heat zone or you will be limited in print speed.

I've used heater zones of 1" and 1.5" long and found that when shoving filament into the hotend, the cold filament can reach all the way to the nozzle exit hole.
this of course causes a loss of steps, or a striped out condition at the drive wheel. Only slower printing or longer heat zones improved this.

you can test your extruder for max filament speed using most hosts. Just set your feed at 10, 20, 30, 40 or 50mm/s and go for a 100mm extrude.
if it skips steps, you need a longer heat zone.

If you choose a 1.2mm nozzle I'd guess you;re using 3mm filament. I'd start with a heat zone of 2" long.
Drool/ooze will be fun to deal with also. You might consider an O-ring where the filament enters the coldend. This will increase the piston effect and ensure a retraction will put negative pressure into the hotend.
Without a good seal, you can pull the piston apart allowing air into the hotzone, and the large nozzle will let the molten hotend ooze. This pulled apart piston is a jam causing issue, as the pulled piston forms a pointed dart shape, then that plunges back into the other half of the piston upon restart. It kind of wedges. Cutting off the dart end usually allows for a restart.

Here is an old video showing a Jhead swallowing some ABS at probably 5mm/s. .4mm nozzle.
It was able to do about 8mm/s at best, running at 230C. This was my first attempt back in 2012 and I overdrove the whole idea and it smoked about $50 within minutes of shooting this video.
old idea

I'll post a video soon of my latest idea. 0.8mm nozzle, 1.3inch hot zone extruder. pic attached.
I'm hoping for 30mm/s of 1.75mm filament swallowing performance.
I'll have no problem running 300C, so that'll help.
100K thermistor will limit the max temp.
I used about 8 inches of nichrome wire (dia 0.0285), with a fiberglass sleeve, coiled around my hypodermic needle. 10ohm resistance means about 32Watts at 18V.
I used Cotronics 919 powder mixed with a few drops of water to keep it together with itself and the thermistor. Great stuff and good for 1530C.
When I short this across a 18V Dewalt drill battery, it heats from cold to ABS smoking temp within about 3 seconds. I think I'll post a video of that after lunch. too much fun.
I hope Marlin can PID tune it and I plan on putting the RAMBO amperage at 50% to start off. That should be 18v at 1amp or so?

Edited 1 time(s). Last edit at 11/10/2015 01:28PM by davew_tx.
Attachments:
open | download - 20151110_110435.png (429.3 KB)
Re: Large-scale 3d printer
November 10, 2015 01:23PM
I too am in the process of designing a large scale FDM print around the same size as that Objet 1000 with 6 extruders, and it will have a build chamber, and keeping electronics outside of the chamber as well which is a bit tricky, but it can be done and can be done well, the printer just be a lot bigger than the printable size, surely thats not really much of a problem, look at the elephant Objet 1000. the whole thing is more than 3 times the volume than it can print

currently I'm making parts for a dual hotend 300x300x400 which I will use to make a bigger printer, plastic sink and metal inside

I wont be using any belts

Edited 2 time(s). Last edit at 11/10/2015 01:34PM by deaconfrost.
Re: Large-scale 3d printer
November 10, 2015 01:34PM
maybe the large machine size is meant to help customers accept the $700,000 price.

To go large, 80/20 is hard to beat. It just makes sense, given all the pros and the few cons.
Re: Large-scale 3d printer
November 10, 2015 05:43PM
did the extrusion test today
just shorted it across the battery as mentioned.

nichrome around hypodermic needle
Re: Large-scale 3d printer
November 10, 2015 09:19PM
Hi ddentist,

I don't know yet, December will be the month of calibrating and experimenting with it. From what I understand, layer thickness cannot be larger than nozzle diameter. I have several options here, given my dual extruder: I could go both 0.8 mm and be faster, or I could keep one 0.4 nozzle next to a 0.8 one, and do detail with the small one and infill with the other. I will know more when I get down and dirty.

Sorry, forgot to answer the heating question, yes, if you look in the picture you will see the red/orange heated bed, it has around 8000 watts at 220.

Edited 1 time(s). Last edit at 11/10/2015 09:29PM by val c..
Re: Large-scale 3d printer
November 10, 2015 09:51PM
Hi Davew,

Thank you for bringing that to my attention. I plan to use (obviously) tempered glass, which has a slight elasticity. As you said, weight is not so much of a problem, given the 4 Nema23 steppers tied to the lead screws. The screws themselves are single start, 3 mm travel, trapezoidal, from roton.
I thought long and hard about backlashing, but given the low slope helix of the screw, I don't believe backlash will be an issue. The dry tests have not shown any problem. As for underpower, I deliberately chose nema23 with 425 oz.in holding torque to handle it. On top of that, as I said, the mechanical characteristics of the lead screw should help with preventing it. Regarding the weight the platform can take, it's been calculated to about 400 lbs. I once put two kids on it and drove it down, it went all ok.
Now, about heating, the heating pad is split into four areas (quadrants) each having their own lead wires. I was (and still am) concerned of what would happen if partially heating only, but not because of glass fracturing (tempered glass can take quite a punishment, I believe around 130-140 Celsius) but rather because the heat distribution into the glass area which is not directly heated. Again, only tests will allow me to know more, coming December.
The reason I didn't use PIR is because cork is more rigid than foam. Imagine, as your model gets heavier, that the foam will slightly give in under it, lowering the whole glass platform and model with it. In that case, I would end up with an ever so slightly gap mid print, or at least this is my opinion. Of course, if cork won't be up to the job, I will be looking at other options.
The heated silicone pad has around 8000 watts of power in it at 220. Obviously, I wasn't going to use 12 volt for that, so main grid is the only option in this case. The printer has absolutely NO plastic part in it, except for the cable chain carriers for x and y, which are not in the affected areas. All parts under load are made of T6 aluminum and designed by me with a fearful mind.
I am considering enclosing the entire behemoth, but I am still studying this venue. I wasn't aware of the relation between the extruder and enclosure temperature. I believe enclosure is more to prevent warping and deformation, whereas the nozzle one affects what materials one can use, but I will always and gladly stand corrected, and hopefully learn something in the process.
After all, this is the first 3d printer I ever built.
Re: Large-scale 3d printer
November 10, 2015 10:02PM
Hi again, Dave,

I am not too worried about my extruder, I purchased it as is from Micron 3Dp, it's an all metal dual extruder. This is one of the reasons why I bought it, the other being how ease it is to replace the nozzle without having to recalibrate the whole thing. Thank you kindly for your suggestions, I already pdf-ed them for safeguarding. I sure will need them when testing times come.
To further answer your question, the extruder is an 1.75 mm filament type. I chose so because the strain on the motors is less when compared with 3 mm, which allows for smaller motors. Mine uses nema 11.
Being an off the shelf extruder, I doubt there's much mechanical intervention/improvement I can add. At best (or worst) I could look for another extruder and go from there. Let's hope it won't be the case.
As for the nozzles, I think I mentioned earlier, I have some 0.4 mm and some 0.8 mm nozzles. The maximum temperature of the extruders is 450 Celsius, this theoretically allowing me to play with exotic materials, possibly even ceramics. From your picture, I understand your extruder is more or less made by you. Please find below the link to Micron 3DP extruder manufacturer:

[micron3dp.com]

If you look at their video, there's a demonstration of how easy it is to replace the nozzle without having to go back to calibrating and the works.
Please post the dewalt batteryvideo demonstration when you have time, that should be fun watching, I mean, 3 secs. wtf?

Edited 1 time(s). Last edit at 11/10/2015 10:03PM by val c..
Re: Large-scale 3d printer
November 10, 2015 10:07PM
the envelope size was an issue for me.
since I am not Rockefeller with a big house, the whole sucker takes up my living room. as you said it yourself, the machine size being 3 times the building size is definitely not an option. also, be careful about other considerations that might arise. I remember reading about a large industrial printer which requires special floor underneath it to support all the weight.
regarding belts, I decided to start slow and use microstepping for the time being. if that will not be enough, lead screws will be the next thing, after some re-designing.

Edited 1 time(s). Last edit at 11/10/2015 10:20PM by val c..
Re: Large-scale 3d printer
November 10, 2015 10:16PM
Hi Dave,

I believe 700,000 dollars is a bit too much. From what I hear, the bigrep is around 70,000 dollars (up from 40).
3/4 million would most likely buy you one of those fancy industrial machines. Either way, that's too much money for me, that's why I decided to go this way.
SO far, I sunk about 10-11,000 dollars in my machine.
80/20 seems to be the aluminum extrusion, if I'm not mistaking, but that's T-slot.
I used openbuilds v-slot, 80mm x 20mm, slightly different but does the same job.
I saw just now the video you mentioned earlier. Thanks, it was fun.

Edited 1 time(s). Last edit at 11/10/2015 10:17PM by val c..
Re: Large-scale 3d printer
November 11, 2015 12:00PM
val,
nice work for sure. you have solid ideas and I'd say your next batch of challenges will come once you start slicing/hosting/printing and learning about how the machine reacts to heat, time, motion, etc.

As for the 4 screw z axis, I had a 2 screw axis (18" parker daedal linear stages, 5mm lead screws, impossible to backdrive) on my first machine and found that I fiddled with the screws trying to coordinate them. As the head moved around the bed I'd see a need to adjust the z height by like a layer or two, especially on the first layer where adhesion and first layer laydown is critical. I ended up removing one side and just cantilevering the bed and was much happier. with one side driving, I then only had to fiddle with the 3 leveling screws, which was also done often. I know you can't cantilever your bed, but a large single motor and belting around each screw could be a solution IF you encounter what I did. You might not.

If I understand what you're proposing correctly (marineboard-heater-cork-glass) for a bed stackup, I wouldn't approach it that way, but this is your journey and thank you for sharing and not getting all butt hurt about critiques. This record of your discussions will help others.

I put away all my 3d stuff for a year and was liberated and felt happy not being immersed and obsessed. I'm getting my head back into it and fear my addiction is returning.winking smiley



I see a reference article stating the Objet1000 is $600k plus $40k for a material loading.
I found $675k given by someone who received a quote.
I saw an article stating $40k, but that can't be correct as the basic small Fortus is above that, and a Uprint Plus setup will run you $20k.

I'm in the ballpark at $700k.

Cheers and give your beast a good name!
I called mine Mitus, as in My Fortus.
I had a need for some large parts (vacuum cleaner development) and got the quotes for parts and was shocked.
So I decided first to create a printer while developing a vacuum. broken logic. I need a car, so develop the engine first, but first I need to make a cnc mill to make parts, but I need a foundry to cast the engine block,

Edited 1 time(s). Last edit at 11/11/2015 12:18PM by davew_tx.
Re: Large-scale 3d printer
November 11, 2015 12:10PM
edit out, double post

Edited 1 time(s). Last edit at 11/11/2015 12:19PM by davew_tx.
Re: Large-scale 3d printer
November 11, 2015 01:12PM
Quote
val c.
I am considering enclosing the entire behemoth, but I am still studying this venue.

Looking at the photos, I think it's more or less the case that the room is the enclosure! I'm amazed and impressed by your ambition with this project, it makes my own attempts seem so very moderate.

Quote
davew_tx
So I decided first to create a printer while developing a vacuum. broken logic. I need a car, so develop the engine first, but first I need to make a cnc mill to make parts, but I need a foundry to cast the engine block,

That sounds oh so familiar. I have quite the list of half finished projects that are on hold while I make something else.
Re: Large-scale 3d printer
November 11, 2015 02:47PM
Quote
davew_tx
val,
nice work for sure. you have solid ideas and I'd say your next batch of challenges will come once you start slicing/hosting/printing and learning about how the machine reacts to heat, time, motion, etc.

As for the 4 screw z axis, I had a 2 screw axis (18" parker daedal linear stages, 5mm lead screws, impossible to backdrive) on my first machine and found that I fiddled with the screws trying to coordinate them. As the head moved around the bed I'd see a need to adjust the z height by like a layer or two, especially on the first layer where adhesion and first layer laydown is critical. I ended up removing one side and just cantilevering the bed and was much happier. with one side driving, I then only had to fiddle with the 3 leveling screws, which was also done often. I know you can't cantilever your bed, but a large single motor and belting around each screw could be a solution IF you encounter what I did. You might not.

If I understand what you're proposing correctly (marineboard-heater-cork-glass) for a bed stackup, I wouldn't approach it that way, but this is your journey and thank you for sharing and not getting all butt hurt about critiques. This record of your discussions will help others.

I put away all my 3d stuff for a year and was liberated and felt happy not being immersed and obsessed. I'm getting my head back into it and fear my addiction is returning.winking smiley



I see a reference article stating the Objet1000 is $600k plus $40k for a material loading.
I found $675k given by someone who received a quote.
I saw an article stating $40k, but that can't be correct as the basic small Fortus is above that, and a Uprint Plus setup will run you $20k.

I'm in the ballpark at $700k.

Cheers and give your beast a good name!
I called mine Mitus, as in My Fortus.
I had a need for some large parts (vacuum cleaner development) and got the quotes for parts and was shocked.
So I decided first to create a printer while developing a vacuum. broken logic. I need a car, so develop the engine first, but first I need to make a cnc mill to make parts, but I need a foundry to cast the engine block,

Hi Dave,

First of all, apologies for the fine mess I might have caused with my replies yesterday. Finally, I found out what the 'quote' link is for.
I initially wanted to go with 8 mm acme metric screws from openbuilds, but they won't cut it at these lengths, so that's how I started looking into it and found Roton. My lead screws are Tr16x3, and each can take about 150 lbs, more than enough for my application. I hope I won't run into the problems you encountered, but if I do, I will surely revisit this page for some fine points.
You are correct in your understanding of the platform structure: plastic board as base, 1" cork mat, silicone, 10 or 12 mm tempered glass on top. The reason why I went with this is that glass is pretty stiff, yet allows for a bit of elasticity, especially tempered glass. Also, the glass overlaps the silicone pad by some 30 mm (1 1/8"). That being so, I'm planning to use clamps at the edges of the glass in that overlap area, and slightly adjust the flatness should the necessity arise. The glass will be 1332x1170 mm (52.44x46.06") A simple calculation for 10 mm thickness shows its weight would be around 80 lbs.
That's 80 pounds pressing down on the more flexible cork sheet underneath, which will work to my advantage. I am familiar with the technique of burying the nozzle in the foam and building the first layer there, but I keep that as a backup.

I mentioned yesterday about the 700k 3d printer, but I wasn't aware it's the very printer being discussed, namely the objet1000. I remember reading somewhere about special floor requirements just to be able to work with it safely. I was wrong in saying the objet is 40 to 70 k, I was referring to the german made bigrep. Obviously, objet costs much more, seeing how it's an industrial printer. Apologies if my brain fart got anybody confused over that.

Funny you should mention your hiatus in this 3d printing business. I remember taking a break of some two months this summer, just didn't want to do anything on it. If I am so late with the project is because most of the idle time (other than taking that break) was spent waiting for the parts I designed, to be manufactured and shipped from China. But, to back up a bit, that's how I started myself: I need some large models for other research I'm doing, and the quotes I got were thru the roof, so I decided to take on the beast myself.
As I said yesterday, I have never built or designed a 3d printer before, this is the first. I rely on my formal education as mechanical engineer, and whatever little experience 25+ years of CAD can give. Obviously, I will make mistakes, run into things I didn't even know they exist, but this is part of the process. The learning curve leaves no room for personal emotions, such as feeling hurt over a different idea.

As for the name, I first went with "HomeMade" because that's what it is, then I flirted with "KitchenMade" but that's pretty awkward and sounds like a kitchen utensil. I gave up eventually, since I don't plan to manufacture and sell it. If anything, my next project will be a laser 3d printer, same size, just for the hell of it and the fun of the journey.
Re: Large-scale 3d printer
November 11, 2015 02:55PM
Glad we are talking about big printer here, because I am building one too.

I brought up the topic of thermal expansion in my other thread, but nobody commented anything. LoL.
At 1 meter length, the expansion is about 1mm from 20C to 60C.
Do you think this will cause any issues in your design?


Printer I bought: 2015 Sunhokey Prusa i3
Printer I am designing: Another big CoreXY machine
Re: Large-scale 3d printer
November 11, 2015 03:11PM
Quote
JamesK
Quote
val c.
I am considering enclosing the entire behemoth, but I am still studying this venue.

Looking at the photos, I think it's more or less the case that the room is the enclosure! I'm amazed and impressed by your ambition with this project, it makes my own attempts seem so very moderate.

Quote
davew_tx
So I decided first to create a printer while developing a vacuum. broken logic. I need a car, so develop the engine first, but first I need to make a cnc mill to make parts, but I need a foundry to cast the engine block,

That sounds oh so familiar. I have quite the list of half finished projects that are on hold while I make something else.

Hi James,

If only I could use my dining room as enclosure, lol.
Unfortunately, no can do, the main door is feet away from the printer, so I'm a bit worried about those pesky air drafts and all. Eventually, I will have to come up with some enclosure. Don't laugh, but my first idea is to buy a roll of wide wrap plastic foil and just do a burrito around it and on top. The bottom is already enclosed by a 3/4" thick, melamined MDF board, in order to disperse the stress from the frame into that surface. The bottom board acting also as an enclosure is a welcome bonus. When I need to remove the model from the machine, a box cutter will do the job, then it's back to wrapping again. In time, I will design a mounting system for an enclosure, that will act also as frame stiffener, but one thing at a time.

Thank you for your kind words, you seem to have more faith in it than my own wife, who kept asking me for 1 1/2 years if it's gonna work. Glad I got that out of the way by showing her my first dry tests a while back. Nothing like working in silence.

I feel embarrassed a bit by your comparison. Obviously, I didn't build this machine with competition in mind, it was rather a dimension driven decision. I have other research in my mind, the kind that takes a lifetime, and said dimensions are essential for a good start. I thought long and hard about how big it should be, and after careful consideration I settled for 1 cubic meter. But if size is any indication, you could be working on a, say, SLS printer with a small print area, yet it could burn ideas thru your mind at a faster pace than my old fashioned machine. In such endeavors, size is not the best descriptor, rather the value of ideas. Seeing how this is the first 3d printer I ever designed and built, I feel it is me who's being overshadowed by smaller projects by more experienced guys.
Re: Large-scale 3d printer
November 11, 2015 03:16PM
Quote
bonmotwang
Glad we are talking about big printer here, because I am building one too.

I brought up the topic of thermal expansion in my other thread, but nobody commented anything. LoL.
At 1 meter length, the expansion is about 1mm from 20C to 60C.
Do you think this will cause any issues in your design?

Hi bonmotwang,

I am not familiar with the thread. Could you please re post it here, so we can at least try to keep things under one roof?
Regarding expansion, I took that into consideration. My bed sits on a rectangular frame, cross braced in the middle. Obviously, this frame being aluminum, will expand, but I designed the bed brackets with slots in them, pointing outward from the 'cold' position, to allow for such expansion. The rest of the machine frame is too far from the silicone heated bed, so I don't expect major issues there.
Re: Large-scale 3d printer
November 11, 2015 03:38PM
Hi bonmotwang,

Please see attached picture. The four horizontal slots are designed for thermal expansion. The 'cold' position is the side of the slot closer to the nearest vertical face. As thermal expansion occurs, the screws and the bed assembly will 'travel' outward, towards the rounded surface that connects the horizontal and the vertical faces. Hope this gives you an idea.

Edited 1 time(s). Last edit at 11/11/2015 03:39PM by val c..
Attachments:
open | download - BED BRACKET V2 single.pdf (176.6 KB)
Re: Large-scale 3d printer
November 11, 2015 05:54PM
Hi Val

The thread is in my signature.
Understood that if the only heat source is the heated bed, there is no too much of problem.
I have no concern about that in my design either.

I am just thinking ahead if I make an enclosure to get the internal chamber to 60C. Then the problem may show up in some ways.


Printer I bought: 2015 Sunhokey Prusa i3
Printer I am designing: Another big CoreXY machine
Re: Large-scale 3d printer
November 11, 2015 11:53PM
Just from thinking this over while taking the time to read the thread, I think it might be better to just have 4 printers with a decent size and split your 3d model so you can print multiple parts at once. It's like have a printer running 4x as fast if you don't mind piecing them together later. Ex: running a computer program designed with multithreading/multicore support for higher performance.. Though, 1 whole printed object could be more structurally sound.

Edited 2 time(s). Last edit at 11/11/2015 11:55PM by Slaghton.
Re: Large-scale 3d printer
November 12, 2015 01:00AM
Quote
bonmotwang
Hi Val

The thread is in my signature.
Understood that if the only heat source is the heated bed, there is no too much of problem.
I have no concern about that in my design either.

I am just thinking ahead if I make an enclosure to get the internal chamber to 60C. Then the problem may show up in some ways.

Hi bonmotwang,

I am still learning the ropes with regards to this forum and the way it works. Thank you for the tip about your thread.
I have an idea about how I could make an enclosure so that the outside frame of my printer stays, well, outside. I have about 65 mm gap between the platform and the frame, which I could use to build just that. Not there yet, but when I will have some drawings, I will post them here.
Re: Large-scale 3d printer
November 12, 2015 01:02AM
Quote
Slaghton
Just from thinking this over while taking the time to read the thread, I think it might be better to just have 4 printers with a decent size and split your 3d model so you can print multiple parts at once. It's like have a printer running 4x as fast if you don't mind piecing them together later. Ex: running a computer program designed with multithreading/multicore support for higher performance.. Though, 1 whole printed object could be more structurally sound.

Hi Slaghton,

Well, you said it yourself, a one piece printed object is more structurally sound.
Re: Large-scale 3d printer
November 12, 2015 03:20AM
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.
Re: Large-scale 3d printer
November 12, 2015 09:06AM
Quote
val c.
Quote
bonmotwang
Hi Val

The thread is in my signature.
Understood that if the only heat source is the heated bed, there is no too much of problem.
I have no concern about that in my design either.

I am just thinking ahead if I make an enclosure to get the internal chamber to 60C. Then the problem may show up in some ways.

Hi bonmotwang,

I am still learning the ropes with regards to this forum and the way it works. Thank you for the tip about your thread.
I have an idea about how I could make an enclosure so that the outside frame of my printer stays, well, outside. I have about 65 mm gap between the platform and the frame, which I could use to build just that. Not there yet, but when I will have some drawings, I will post them here.

Sounds good. I had the same the idea of leaving the frame outside of the printing envelope. I am interested to see how you are going to do it..


Printer I bought: 2015 Sunhokey Prusa i3
Printer I am designing: Another big CoreXY machine
Re: Large-scale 3d printer
November 12, 2015 11:27AM
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.

Edited 1 time(s). Last edit at 11/12/2015 11:36AM by davew_tx.
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