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Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 2:12 pm
by GPriv
Hi-
I printed an hour's worth of material as a starter/learning tool. I'll show the pics then ask questions at the bottom:
(Here's my printer setup. The box is to keep out drafts, the light bulb is to warm the place up. I may have to construct a fourth wall (with window) and place it at opening after printing commences.)
This will be a (rectangular) "box" about three inches tall, with an additional three inch (tall) 45 degree sloped "roof":

- example 2.jpg (43.11 KiB) Viewed 12594 times
The two problems I encountered were the obvious de-lamination, and that the glue came unstuck on one corner of the print. That corner curled up slightly (about 1/4") but the printer just kept chugging along as though everything was as it was meant to be.
Q1: How to I get rid of the de-lamination problem? Here's my ABS default setup in MatterControl:
BUT, I do not recall the temp getting past 220 degrees. I'll have to reprint and keep a closer eye.
Q2: Temperature settings. Are there any other places to control temps? I did this print via SD card...'puter USB was unplugged upon commencement printing.
THANX in advance!!
-G
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 3:05 pm
by bot
You can control the temps via the LCD panel. Push button to enter menu, you should be able to find it there. If your hotend is only getting up to 220, I'd look at the electrical connections to the heaters because something isn't right (if it's set at 228) This will be the major factor in your delamination.
That print is going to be hard to do with ABS and the stock setup without much experience. You're going to have to nail your horizontal radius value as good as it can be, and you may need to squish the first layer thinner than it should be.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 3:14 pm
by GPriv
Difficult as it may be it's a must-have. Must use ABS as this will be used outside.
I'm tinkering, learning, printing smaller things first before I tackle the complete shape.
I have the horizontal radius pretty spot-on, as far as I can see (as determined, ultimately, by the travel path of the nozzle when printing the first layers of the skirt.)
Hot end IS getting to 228... (my mistake in not checking before previous post).
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 3:45 pm
by Polygonhell
That's a difficult object to print in ABS, sharp outside corners are the worst case for warping both warping things off the bed and delamination later in the print.
Pretty much all you can do outside of making sure everything about the printer is perfect is add Micky mouse ears (and probably a Brim) to the model (at lease 2 layers deep) and print hotter probably at least 240 (which is as high as I'd go with the stock hotend) and ideally hotter.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 3:56 pm
by GPriv
I understand that practice and experience is an awesome guide--in the meantime: Forums! And, I do appreciate all replies.
I can round the edges, no prob. I'm curious how this helps.
I only need the width, height, length dimensions to be this large for the end product.
Forgive my naivete, re: the Mickey Mouse ears. Is this a joke? Or, is this some esoteric jargon skilled 3D-ers understand?
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 4:03 pm
by bot
Mickey mouse ears are a way to fight the lifting of the corners from the bed. Big circles are added to the print near the base to enlarge the surface area at the bed. I find it to be quite a ridiculous technique. Turn up your bed temperature first, to like 110 minimum and see if that helps.
Also, ABS is not actually better for outdoors. ABS performs HORRIBLY under UV light exposure unless it's treated with a protective spray/treatment. PLA actually works better outdoors. If you're worried about PLA melting, unless it gets 140 degrees Fahrenheit outside where you live, you'll be fine with PLA. PLA is also stronger. ABS is only better if heat is an issue or impact resistance is important, in the case of an object that might fall or be knocked around a lot.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 4:06 pm
by teoman
As i replied in your other post, it is like making a big skirt around the object except, because the corners are the worst part you make small flat circles around that. Which looks like mickey mouses ears.
And if when you do get lifting, the mickey mouse ears lift and hopefully the lifting does not happen or it does not reach your actual print.
Later you just cut them off.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 4:12 pm
by GPriv
Gotcha! Big Thanx!
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 4:17 pm
by Polygonhell
The reason rounding corners helps is because it better distributes the warping forces as the plastic shrinks, with sharp outside corners, the forces are all applied directly to the corner. A Circle is the object least likely to warp off the bed, but even that will warp.
Mickey Mouse ears are circles added to sharp angles, both to increase surface area and remove the sharp corners where the warping is worst at the bottom of the print, there is an example with the Kossel mini motor mount here
https://github.com/jcrocholl/kossel/blo ... _motor.stl though I would have places the center of the circle at the middle at the vertices.
Increasing the bed temperature will probably also help, but at some point you start to introduce other issues, notably elephant feet where the first 5-10mm of the print display a slight hour glass shape.
I tend to agree that PLA is fine for outside.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 4:23 pm
by GPriv
Okay on the ears/circles. Totally agree on the placement of them in example (if you're going to print such mass, why not have the center of it all be at the center of the problem area??).
Is PLA easier to print (than ABS), or does it have finer results? I've got about four-five spools of ABS so I'm stuck with ABS for a while!!

Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 4:28 pm
by geneb
If you're going to use this ABS thing outside, paint it. ABS degrades in sunlight without stabilizers, and unless the stuff you bought specifically lists it, it doesn't have UV stabilizers in the mix.
g.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 4:34 pm
by GPriv
Okay. Thanx.
The box will be used outside--all at this stage for prototyping. Eventually, the item will be mold-injected...so I can worry about the (ultimate) material then.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 5:31 pm
by GPriv
bot wrote:If your hotend is only getting up to 220, I'd look at the electrical connections to the heaters because something isn't right (if it's set at 228) This will be the major factor in your delamination.
New problem: the hot end will not climb higher than 225 now--hovering around 224-ish. What's the deal? It was fine before... UGH!
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 5:43 pm
by teoman
Assuming you have stock hotend, probably some of the rtv you had there went crunchy muncy. So it does not insulate well. Or you resistors increased resistance a bit.
As a result your system has changed a little bit.
What you can do:
Pump up the temp to 240 and see if you can still reach high temperatures where you will print. If you can that means you can retune your pid and continue.
I had this problem yesterday and what i did was to remove the hotend and coat the heating block (disk) with RTV. You do not want to coat the shaft coming out of the top going to the PEEK (Plastic part) of the hotend.
If you have capton tape you can use that aswell.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 5:46 pm
by GPriv
ah...the PID... yes. Got that part. Will try 240 set temp in a little bit. I'm trying 230 now.
Thanx!
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 5:46 pm
by teoman
Is your house / mailbox / birdsnest thingy full inside?
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 5:48 pm
by GPriv
Huh?
The thing I'm printing? The large footprint thingy?
It's a battery box--to house a PO4 battery. It will be used exclusively outside.
Oh...do you mean is it hollow? Yes, it is hollow. It is a "box" to house a battery.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 6:05 pm
by teoman
Before you start i recommend you watch McSlappys youtube videos. (Doodaddoes on youtube).
This is what i had done. You should do this everytime you get a new brand / color of filament, so keep the gcode file.
RepRap Neo - How to set the perfect extruder temp…:
http://youtu.be/FSOPsRiiOZk
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 6:07 pm
by GPriv
Thanx. Will do.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 6:17 pm
by teoman
If it is hollow i recommend printing roof separately and base and walls separately.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 6:21 pm
by teoman
Also, it is menyionned by the gurus that these peinters print best inside the triangle formed by the towers so try to place maximum àmount inside it.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 6:37 pm
by GPriv
You're joshing, right? You cannot print outside the triangle...
How cool is this:
My desktop lamp broke--the little thing here : (these are supposed to be mirror images of each other. One side is obviously broken.)
So I designed a new one, printed it, and Viola!
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 6:39 pm
by teoman
I found the gcode file:
This is what i chose to do.
Extracts fromt the GCODE file:
Starts at 232
; LAYER:50
M104 S228
; LAYER:100
M104 S224
...
; LAYER:450
M104 S196
It has a total of 500 layers so 10 cm at 0.2mm per layer. 50 layers for every cm.
SO, it starts off at 232 and drops 4 degrees every cm.
While it is printing you should monitor it. Your printer must be tracking accurate temp or you cannot draw proper conclusions.
If you want to change the temperature to somethign different open the file in a text editor search for "Layer:50" and multiples of 50, then insert or modify the code you want such as M104 (set the temperature) SXXX (setpoint).
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 6:43 pm
by GPriv
Thanx.
I'll work on figuring it all out then apply.
Re: Suggestions on large footprint print, please
Posted: Sun Sep 20, 2015 6:48 pm
by teoman
You can directly use the gcode i posted, it will print.
Use a permanent marker and with a ruler draw 1 cm lines, mark the temperature on it. Then look at it and squeeze and try to pull it apart. You can then decide for yourself which will be your favourite temperature for that filament.
While you are at it, print 2 of these:
http://www.thingiverse.com/thing:356583/#files
and then attach them to your pushfit conenctors.
Nice fix on the lamp.