Aluminium plate

Hi everybody. Do you know the difference between the aluminium plate and glass plate?

Aluminium plate is made of aluminium, glass one of glass

I'm sorry, but you have to be a bit more specific with your question. Is it in relation to a heated bed?

What's the difference in relation to what? Print quality? Stickyness? Warping?

I like aluminium because it allows me to drill holes in it without needing special tools. I can add thread in it to I can use bolts to secure it to something else. Kapton sticks to it really well and the heating properties are great.

---

http://www.marinusdebeer.nl/

Sorry for my wrong question. I would know the difference about warping. Now I use a glass plate with hair spray to it.

To be honest, I don't think it matters, the material of the bottom plate. What's more important is what you put on top of it. Probably hairspray on glass or aluminium will work just as good.

If you put something on the aluminium or glass, that is the factor that decides what sticks best. I have tried printing on bare aluminium, and it didn't work, I printed on bare glass and that worked better. However, with aluminium there are many different types of aluminium, so it's very hard to predict. With glass there are a few main types, the ordinary window glass, but these break easily when heated up, then there is borosilicate glass, this glass had the internal tensions handled differently so it can withstand high temperatures and thermal shock without shattering. I am sure different types of glass will also have different properties of sticking, but they are probably more alike than the different qualities of aluminium that you can get.

My advice would be to always use some kind of material on top of the print surface, like hairspray, elmers glue, kapton tape, blue painters tape etcetera. It all depends if you're printing with ABS or PLA and if you use a heated bed or print on a cold surface.

---

http://www.marinusdebeer.nl/

Thank you very much for the exhaustive answer. Now, I'm printing with ABS and I use a heated bed. But, recently I had a problem with the glass. It broke! (You can see it in the attachments) Do you know why of this break? For this reason I would change my glass plate with an alluminium plate...

Oh, that doesn't look good. By the way, exhaustive? I think you mean extensive

What is going on, is that I think the glass isn't taking heat too well. Ordinary glass can break under the influence of heat, this is why in 3D-printers they use a type of glass called 'borosilicate glass' to print on. This glass can resist heat and thermal shock way better than ordinary glass.

If you want to print on aluminium I suggest covering it with kapton tape. Since you are already using glass I think it would be easiest to find a piece of borosilicate glass in the same size so you can just replace it with that. Your printer's heated bed is probably designed to use a glass pane.

---

http://www.marinusdebeer.nl/

But my glass is in borosilicate. This is the problem!

The pictures did not seem to show how the glass was attached to the heated bed. How did you have the glass attached? My first thought is that the glass had a pressure point on the heated bed where the break is. You may have had the glass clamped down too tightly?

Quote
Vjk
The pictures did not seem to show how the glass was attached to the heated bed. How did you have the glass attached? My first thought is that the glass had a pressure point on the heated bed where the break is. You may have had the glass clamped down too tightly?

Exactly, could it be that maybe the thermistor was directly below that point where the damage was?

---

http://www.marinusdebeer.nl/

The glass was attached to the heated bed with binder clip. You can see it in the attachments. In that case I used Vinavil on the glass

Something that occured to me after I posted last night was that I have a similar looking crack on my vehicles front window that came from a rock impact at highway speeds.
Is there a chance you rammed your hot end into the glass at some point in the past creating a micro-fracture? I did that once already because I had not noticed that my z endstop had slipped down.

As for switching to an Al plate for the bed, I have no experience with that. My opinion is that there is a chance for creating a circuit which would create a fire hazard and the possibility of electrocution. Depending on the thickness of the Al plate, the hot bed pcb may not be powerful enough to get to the temperatures required for printing ABS. Finally something that may or may not be an issue is that Al expands more readily than glass. (PM me for the science)

Quote
Vjk
Something that occured to me after I posted last night was that I have a similar looking crack on my vehicles front window that came from a rock impact at highway speeds.
Is there a chance you rammed your hot end into the glass at some point in the past creating a micro-fracture? I did that once already because I had not noticed that my z endstop had slipped down.

As for switching to an Al plate for the bed, I have no experience with that. My opinion is that there is a chance for creating a circuit which would create a fire hazard and the possibility of electrocution. Depending on the thickness of the Al plate, the hot bed pcb may not be powerful enough to get to the temperatures required for printing ABS. Finally something that may or may not be an issue is that Al expands more readily than glass. (PM me for the science)

No trouble here with the Alu expansion, the bed stays flat too. Also, it seems that it actually doesn't need more heating to stay on the same temperature for my experience. The bed heats up fast and maintains a good heated surface during the whole print.

---

http://www.marinusdebeer.nl/

Quote
Vjk
Something that occured to me after I posted last night was that I have a similar looking crack on my vehicles front window that came from a rock impact at highway speeds.
Is there a chance you rammed your hot end into the glass at some point in the past creating a micro-fracture? I did that once already because I had not noticed that my z endstop had slipped down.

As for switching to an Al plate for the bed, I have no experience with that. My opinion is that there is a chance for creating a circuit which would create a fire hazard and the possibility of electrocution. Depending on the thickness of the Al plate, the hot bed pcb may not be powerful enough to get to the temperatures required for printing ABS. Finally something that may or may not be an issue is that Al expands more readily than glass. (PM me for the science)

I don't remember any impact of hot end on the glass. Maybe did I use many binder clip and its have generated the break of the glass?

Edited 2 time(s). Last edit at 12/11/2014 02:47PM by calogerom.

Quote
calogerom
I don't remember any impact of hot end on the glass. Maybe did I use many binder clip and its have generated the break of the glass?

if you don't recall any impacts, then there is either a high point in the bed applying pressure to that spot or a defect from manufacturing the glass.

I dont think that the binder clips would have much of an affect on the glass other than if there was a high point. These would increase the pressure and result in glass failure.

Quote
Ohmarinus
No trouble here with the Alu expansion, the bed stays flat too. Also, it seems that it actually doesn't need more heating to stay on the same temperature for my experience. The bed heats up fast and maintains a good heated surface during the whole print.

That is interesting. What thickness of Al are you using? How is adhesion? Is something like painters tape needed?

I will have to check this out and pick some up next time I am at the metal supplier.

Quote
Vjk
if you don't recall any impacts, then there is either a high point in the bed applying pressure to that spot or a defect from manufacturing the glass.

I dont think that the binder clips would have much of an affect on the glass other than if there was a high point. These would increase the pressure and result in glass failure.

How can I find an hypothetical high point in the bed?

Edited 1 time(s). Last edit at 12/11/2014 04:57PM by calogerom.

Quote
Vjk

Quote
Ohmarinus
No trouble here with the Alu expansion, the bed stays flat too. Also, it seems that it actually doesn't need more heating to stay on the same temperature for my experience. The bed heats up fast and maintains a good heated surface during the whole print.

That is interesting. What thickness of Al are you using? How is adhesion? Is something like painters tape needed?

I will have to check this out and pick some up next time I am at the metal supplier.

PLA on Kapton. The kapton is placed on the Aluminium.

The Aluminium bed is very nice, I have made indents for the screws so the heads of the screws that secure it are at the same height as the surface of the bed

Posted this image a few times before already. In-between the plates is insulation material so the heat doesn't leak out on the bottom of the heated bed, this keeps the temperature steady:


Before I made that the screws were like this, but I was annoyed by it. As you can see there is a spring in between the aluminium plates, the spring presses the heated bed onto the top plate and the spring is used to calibrate the print-surface to be absolutely flat in relation to the rest of the machine:


Top alu plate is 3mm and bottom plate is 4mm. Bottom plate has material removed, top plate only has holes:


It's commonly known that cats like to sabotage printers:


I've made a hole where the electronics are on the heated bed, and covered the electronics with kapton, to make sure there wont be any short circuit. The damage on the kapton was from an endstop failure, the day before my assessments at the art academy hehehe. My hotend dragged through the kapton :O


Edited 4 time(s). Last edit at 12/11/2014 07:04PM by Ohmarinus.

---

http://www.marinusdebeer.nl/

Quote
calogerom
How can I find an hypothetical high point in the bed?

On my heated bed there is a resistor and set of LEDs attached to one surface. These would be the most obvious high point as they are quite tiny and can create the pressure point. I originally had my bed set up with these pointed upwards because I prefered the look on that side of the pcb. The glass did not sit nicely on the bed this way, so I flipped the bed over. I also am only using two clips to hold the glass on.

To find any other highspots, take the glass/whatever you are using off the heated bed and use some sort of flashlight that is on the same level as the board. Shine the light across the board and any high points should leave a shadow. You can deal with those as they appear. I doubt there to be any, but I have found them in other pcb projects (basically left overs from manufacturing).

Finally do a good clean of the bed with a lint free cloth or soft tooth brush and something like methyl hydrate. Be careful what you use. Acetone and similar solvents can dissolve the pcb. I find methyl hydrate works well enough and doesnt leave a residue. Be sure to follow the safety instructions on whatever you use.

At this point I am suspecting that you just had some bad luck with your glass. If you haven't already decided to go with the Al, check it out and let us know how well it works. I will probably go and find some in the next few weeks to try out.

Quote
Vjk
On my heated bed there is a resistor and set of LEDs attached to one surface. These would be the most obvious high point as they are quite tiny and can create the pressure point. I originally had my bed set up with these pointed upwards because I prefered the look on that side of the pcb. The glass did not sit nicely on the bed this way, so I flipped the bed over. I also am only using two clips to hold the glass on.

To find any other highspots, take the glass/whatever you are using off the heated bed and use some sort of flashlight that is on the same level as the board. Shine the light across the board and any high points should leave a shadow. You can deal with those as they appear. I doubt there to be any, but I have found them in other pcb projects (basically left overs from manufacturing).

Finally do a good clean of the bed with a lint free cloth or soft tooth brush and something like methyl hydrate. Be careful what you use. Acetone and similar solvents can dissolve the pcb. I find methyl hydrate works well enough and doesnt leave a residue. Be sure to follow the safety instructions on whatever you use.

At this point I am suspecting that you just had some bad luck with your glass. If you haven't already decided to go with the Al, check it out and let us know how well it works. I will probably go and find some in the next few weeks to try out.

I verificated if there are high point on the heated bed. I saw that the center of the heated bed is lowest than at the edges. Is it right?

Edited 1 time(s). Last edit at 12/12/2014 12:23PM by calogerom.

Quote
calogerom
But my glass is in borosilicate. This is the problem!

I have five borosilicate build plates, and they all have those kind of "divots." I asked my glass guy about it, and he said it was due to microscopic imperfections on the surface of the glass. Remember, this glass was probably not designed to have stuff stuck to it.

This has happened with both ABS and PLA, using either hairspray or ABS juice directly on the glass. As near as I can determine, it is caused by forced cooling without letting the glass cool to room temperature. The sudden change in contraction causes the break.

My work-around is to use the other side of the glass, or arrange the parts on the build plate to avoid the divots.

I consider it a minor annoyance, considering the extensive use the glass plates have provided.

Quote
DonaldJ
I have five borosilicate build plates, and they all have those kind of "divots." I asked my glass guy about it, and he said it was due to microscopic imperfections on the surface of the glass. Remember, this glass was probably not designed to have stuff stuck to it.

This has happened with both ABS and PLA, using either hairspray or ABS juice directly on the glass. As near as I can determine, it is caused by forced cooling without letting the glass cool to room temperature. The sudden change in contraction causes the break.

My work-around is to use the other side of the glass, or arrange the parts on the build plate to avoid the divots.

I consider it a minor annoyance, considering the extensive use the glass plates have provided.

I'm happy to know another person with my same problem
Have you ever thought to replace glass plate with Al plate? I think that with Al plate there would not be problem of "divots". That's right?

Edited 1 time(s). Last edit at 12/12/2014 12:23PM by calogerom.

Good god in that picture you had 10 clips on the glass!
I just use two, one on each side and I havent had issues the whole time I have had my printer.
Im using 2.5mm glass without issues. Got it from Lowes for about $1 a piece.

Quote
calogerom
Have you ever thought to replace glass plate with Al plate? I think that with Al plate there would not be problem of "divots". That's right?

That's a good suggestion, but a nice piece of .25" Mic6 aluminum plate would weigh more than twice as much as the glass I'm now using. And cost twice as much.

Performance would suffer as the printbed moves back and forth in the Y direction, don't you think?

Quote
DonaldJ
That's a good suggestion, but a nice piece of .25" Mic6 aluminum plate would weigh more than twice as much as the glass I'm now using. And cost twice as much.

Performance would suffer as the printbed moves back and forth in the Y direction, don't you think?

I agree with you. Unfortunately, there are advantages and disadvantages.

Quote
calogerom

Quote
DonaldJ
That's a good suggestion, but a nice piece of .25" Mic6 aluminum plate would weigh more than twice as much as the glass I'm now using. And cost twice as much.

Performance would suffer as the printbed moves back and forth in the Y direction, don't you think?

I agree with you. Unfortunately, there are advantages and disadvantages.

Did my images help a bit with looking at how an aluminium plate would function on a printer?

---

http://www.marinusdebeer.nl/

Quote
Ohmarinus
Did my images help a bit with looking at how an aluminium plate would function on a printer?

I saw your images. Can you tell me about warping with Al plate?

Quote
calogerom

Quote
Ohmarinus
Did my images help a bit with looking at how an aluminium plate would function on a printer?

I saw your images. Can you tell me about warping with Al plate?

It doesn't have influence on the plastics behaviour, but the plate itself stays flat absolutely! The kapton makes the PLA or ABS stick to the aluminium very well.
I also use thinner aluminium on my other machine, 2mm instead of 3mm and works just as well.

---

http://www.marinusdebeer.nl/

I got my aluminum off eBay. Works great. Has machined areas for temp sensor(s).