Only disadvantage is the same as all methods - need to relevel if you dislodge (intentionally or not) the plate. The crusty hairspray underneath can be a detriment to ensuring your second installation is identical in plane with the first. Short of cleaning both bed and plate completely each time, clips with clean bare alu underneath is slightly better for repeatability between installations IM. I could often get away with taking the plate out, putting it back in, and going straight back to printing. Any warp in the bed will kill you though!!

I hate having to tiptoe on eggshells with the bed, can't wait to build a new printer with a bed that doesn't cantilever and need to be treated like some kind of hyper-sensitive pea princess.

Hence my interest in any development / experimentation in a novel clip solution!

On a side note, glass bed is one of the mods most of us would jump at as a first mod. But the tape on the corners is overkill.
Remove the masking tape and retrieve the glass. Cleanup any glue you may have on the bottom as this can clump and harden over time. Grab some Extra Hold Aquanet and give the bottom of the glass a few good coats. Mist the top lightly then place the glass on your bed. Cycle your bed heat up to temp and them back down to ambient about 3 times. Once this is done, you will have no need for tape or binders. I am about 70 prints in on one and it still refuses to budge!

I have probably over 200 prints on adhering the glass to the bed using that method - hasn't moved yet, and doubt it will unless I get the putty knife in there and pry it off. it sticks very, very well if you let it cool completely after heating.

I am running both of my sd4 printers an average of 8 hours a day at least 5 days a week, sometimes 6. One has the mirror attached using this method, the other has some kind of thin, rubbery sheet that is kind of tacky, between the glass and stock bed. Not sure what it is (came with the printer that was purchased used) but it seems to work very well, too.

jagowilson wrote:

That's an SD2 frame then, sadly you won't be able to upgrade without a frame replacement. The Thingiverse link AZERATE provided seems useful. a minimal carriage will give you the largest print volume.

Ok, thanks for the info. Can I ask from your signature what all the critical mods are considered to be?

What AZERATE said plus direct drive Y axis--that is, driving the back rod with the motor and a coupler directly instead of using the short-looped belt.

what all the critical mods are considered to be?

* Lawsy's MK5 Should be numero uno on your priorities. The acrylic jigsaw (which it seems you still have) will cause you a headache and a half. Print this in the event you have to take yours apart and have problems.
* Lawsy's carriages is another good one. Stock Solidoodle printed parts have 40% infill and can fall apart over time. Basically what I'm saying her is this: If you can replace it with a printed model, make it. Whip it up before you have a deadline for your print(s) and you find yourself dead in the water.
*Consider upgrading your hotend. While some users can use their stock PEEK hotends, They wear out over time, the thermistor is in an odd place, and the PEEK limits you to just a few materials. Upgrading to something like the E3D hotend will provide a fantastic printing experience and unlock the ability to print other materials the PEEK could not.
*E3D is an exceptional company. And they also make a wonderful gear for the extruder called the Hobb Goblin. You can read my review here . It is a quick and simple mod that even a total newbie can complete

On a side note, glass bed is one of the mods most of us would jump at as a first mod. But the tape on the corners is overkill.
Remove the masking tape and retrieve the glass. Cleanup any glue you may have on the bottom as this can clump and harden over time. Grab some Extra Hold Aquanet and give the bottom of the glass a few good coats. Mist the top lightly then place the glass on your bed. Cycle your bed heat up to temp and them back down to ambient about 3 times. Once this is done, you will have no need for tape or binders. I am about 70 prints in on one and it still refuses to budge!

That's an SD2 frame then, sadly you won't be able to upgrade without a frame replacement. The Thingiverse link AZERATE provided seems useful. a minimal carriage will give you the largest print volume.

Ok, thanks for the info. Can I ask from your signature what all the critical mods are considered to be?

11.5 W x 12 T x 12 D, I measured this from edge to edge on the outside of the machine. My glass plate is 3mm thick and I don't have a lot of hours of extended printing so hopefully it hasn't had time to warp yet. Most of my prints have been 2 hours or less.

I don't have a dial indicator but I was only using the clips as a necessity, I really hate them and they're always in the way of the print head. My temporary solution while I gather soda cans has been a modification of the advice given here.
I spread on a thick layer of white glue stick over the aluminum bed and then pressed my glass on top and squished it around in a little circle until it felt good. I then taped the corners with masking tape for extra hold. So far it has been a nice solid hold.

don't use clips on your glass. it warps it. if you don't believe this, get out your dial indicator and do some measurements. it warps the glass significantly. spray the bottom with hairspray to make it stick, you will have much better results. (edit: thanks Carl)

from my experience, black binder clips will melt over time after repeated exposure to a 105c bed. they will still be usable, but they will get goopy and leave black marks on the glass. the load they are under causes this in combination with the heat.

OP may have a Solidoodle 2.5, in which case he only needs a bigger bed frame. When they ran out of SD2 frames they started using SD3 frames.

Heat creep and instantaneous deformation are two different things. The thing to be interested in is the VICAT softening temperature. For MG94 ABS, that's 98C:

https://www.sabic-ip.com/gepapp/eng/wea … ype=Online

That's the temperature at which a polymer will deform over time if loaded. pirvan, the headlight deal worked because it was a short time and there was no load on the parts. It is also possible they weren't pure ABS, lots of automotive parts are a ABS-PC blend. A bed is not something you want any deformation on, even 0.1mm of deformation is bad news. Depending on how the bracket is built, a deformation of 0.01mm may result in 0.1mm of bed movement.

I don't disagree with any of the above, in fact my last link and next to last paragraph mention the same thing.  But there's one thing I think we lost track of, the OP's intended use for the ABS part.

These are simple plastic clips that hold the glass on top of the bed.  I don't see how that could subject the plastic to enough pressure/load to induce any kind of deformation.

Then there was Grob statement that ABS gets goopy at 105°C, which is not the case.

https://www.sabic-ip.com/gepapp/eng/wea … ype=Online

That's the temperature at which a polymer will deform over time if loaded. pirvan, the headlight deal worked because it was a short time and there was no load on the parts. It is also possible they weren't pure ABS, lots of automotive parts are a ABS-PC blend. A bed is not something you want any deformation on, even 0.1mm of deformation is bad news. Depending on how the bracket is built, a deformation of 0.01mm may result in 0.1mm of bed movement.

Haha I'm no expert on plastics either of course!

I'm a bit unsure about your summation about the outside/inside thing and the 170C thing there though Pirvan.

I've had a look at the following, which helped a bit:
https://en.wikipedia.org/wiki/Glass_transition
http://plc.cwru.edu/tutorial/enhanced/f … orient.htm
http://plc.cwru.edu/tutorial/enhanced/f … /therm.htm
https://en.wikipedia.org/wiki/Viscoelasticity
https://en.wikipedia.org/wiki/Creep_(deformation)

From what I've worked out, the material will be solid below Tg (c. 105C for ABS), and above Tg will gradually become more and more viscous. We extrude at 240C or so because by this point it's viscous enough to be mostly viscous and flow/extrude, but not hot enough for the material to chemically break down (much).

The real glass transition temperature depends on how quickly the material is cooled, as this affects how it structures (abs is amorphous, but I guess it's similar to crystallisation in this way), but the transition does reverse. The value in the datasheet is determined according to a standard (at a fixed cooling rate).

I reckon ABS would creep slowly just above 105C, definitely well before 170C, but depending on the use might be fine, not sure!

The way I read  all this is that glass transition occurs during the cool down process as the polymer solidifies/hardens.  Here is an excerpt from the send link, and the wording they use:

[*]An amorphous solid is formed when the chains have little orientation throughout the bulk polymer. The glass transition temperature is the point at which the polymer hardens into an amorphous solid. This term is used because the amorphous solid has properties similar to glass.[/*]

Since the material is solid already at that temperature, it can't go through the glass transition process.  It first needs to be liquefied, then cooled down in order to reach the transition point.  Here is a schematic from the 3 link.  Notice the direction of transition.   I have yet to see any articles that describe the glass transition as occurring during heating, or that it's bi directional.

All this being said, I understand that ABS will deform as the temperature increases, but it doesn't become rubbery (in the normal sense of the word) when it reaches 105°C.  ABS has a deflection temperature of 98°C, which means is that at that temperature, you have to apply a load of 66psi to deflect the material .25mm.  Hardly anything to worry about, considering we're not applying those kinds of loads

http://www.matweb.com/reference/deflect … ature.aspx

FWIW, a couple of years ago I needed to separate 2 halves of a car headlamp assembly.  The headlamp is made of ABS plastic, and the 2 halves were held together with a very viscous glue.  The instructions were to place the assembly in an oven that was preheated at 300°F for about 10-15 minutes until the glue melted and then pull the 2 parts apart.  I did all that and the ABS never melted or deformed.

Just some food for thought.