Heat-Resistant Borosilicate Glass vs window glass etc.

I have true Schott Borofloat™ borosilicate print beds in 200mm x 214mm(8"x8.5" approx.) x 3mm thick with ground edges for $15/each here >>

http://trinitylabs.com/products/borosilicate-glass-table-for-prusa


I don't want to fan any flames about the boro wars either and also don't want to just jump into your forums here and link to my web shop so I will back up why *I* personally prefer boro over all other print surfaces and share some tips and tricks if you do decide to go for it.

I'll preface this with full disclaimer about being the founder of TrinityLabs and designer of the Aluminatus TrinityOne printer and also let it be known that I have been a borosilicate glass artist as well as scientific boro lampworker for over 20+ years now so I do know a few things about boro's properties as well as have the cheapest sources for it at $15 for what everyone else charges $25=$35 for, and I garantee the glass will show up unbroken during shipping or I will keep shipping new glass beds until you get a non broken one(thousands of print beds shipped and *one* broken in shipping so far!)

There is a difference in flatness with the hjigher quality bork as well as a better adhesion of your bottom layer even to plain boro compared to soda lime glass or window pane/mirror glass. One of the nicer properties of boro as a prinbt bed is the coefficient of thrmal expansion is very low. Meaning even if you heat the glass very fast it will not expand or contract very much at all. This is a desirable property because normal glass will expand and contract when heated and cooled much more. This can lead to frustrating artifacts in your z layer alignment that look like z-wobble but is actually much worse as it is hard to figure out.

With normal soda lime glass as your heater for the bed(kapton, silicone, PCB heater, etc) heats up and cools down as well as turns on and off the current flow during printing while trying to keep the bed at the desired temperature, the normal glass can actually be bowed and concaved by the heater element enough to cause inconsistent Z layers and make you think your z axis is out of alignment or your leadscrews or smooth rods are bent. But what is actually happening is the glass is bowing up as much as 1mm in the center when current flows through the bed heater and then flattening back out or even going concave when the current turns off.

PID tuning the heated bed instead of using bang bang style heating will help a lot with this issue but boro will help even more as long as you don't try to stick a kapton or silicone heater directly to the glass with adhesive.

As far as getting your prints to stick to the glass with the true borofloat i carry as long as you keep it clean from fingerprint grease or oils with windex and lint free newspaper or lint free towels or clean it with acetone every now and then you can get amazing results with just straight glass uncovered for both PLA and ABS.

But to make things easier for PLA I recommend mixing PVA glue(white elmers glue you used to eat in 2nd grade 1 part glue to 10 parts water. Then heat up your bed to 65C and spread/wipe a thin layer on with wadded up tshirt or newspaper.

This works ok for ABS as well but what works better if you are having issues sticking ABS directly to the *clean* boro is either ABS Juice or Aquanet hairspray. The magic recipe for ABS Juice is 4" of 3mm high quality ABS filament or 8" of 1.75mm chopped into bits and disolved into 1 fluid oz of acetone. For making multiple fluid oz's aty once just keep the same ratio and let the ABS particles dissolve for 12-224 hours in a mason jar or some other non plastic corrosion resistant container. Then when it is time to apply the ABS juice heat your bed up to 9%C or so and wipe on a thin layer with an old tshirt or wadded up newspaper or paper towels. The acetone will evaporate immediately on a hot bed and leave behind a thin milky film that makes your bned look like lightly frosted glass.

Applying hairspray is pretty much self explanatory

If you still have issues then it is time to get some PET or Kapton tape and apply it to the entire glass bed and then apply the {VA glue, ABS juice or hairspray right on top of the tape.

Hope the tips make it ok to post a link to my web shop but I will beat any advertised price on boro print beds online And I also do cheap wholesale in bulk as well.

 

if you sold and shipped anything on time, id recommend it.

One your boro is smaller in size we need a 10x10.

 

@Ezra, I would be interested in a 10x10 piece of boro, and I'm sure others would be too. Right now there are not that many people here, but once they start getting their RoBos we should see more people, and more interest in boro glass. What would a 10x10 piece end up costing?

 

What do u mean by binder clip ? There is no room for binder clip to go on the sides.

I use 9X9 inch $5 mirror from wallmart. There is no way i can attach it front to back.
There;

Is there another way to do it ? Maybe something i can print ?
I tried many things and many designs but nothing worked as well as expected.
I need something that would allow me to easy remove.
Just cant think of anything anymore

 

That's because you are using 9x9 and not 10x10. Get rid of that mirror (whats on the back? Probably not great for heat) go pick up a 10''x10'' x 1/8'' piece of glass for like $3

 

Tony, have you thought of using magnets to hold the plate in place? You would want neodymium ones so they're super strong.


Sent from my iPhone using Tapatalk

 

10x10 glass for $3 from where ?
Sure i could use slightly bigger build platform but then that stupid bed wire will get in the way of the nozzle. Cant think of anything to hold it in place.

 

This sucks. You removed handles on those clamps. + its hard to remove your bed now.
I want my bed to be removable just my lifting it up, otherwise there is no use for it for me.
i will try to model some clamps that are eazy to modify, will see where i get.

 

Dont these clips scratch bottom of ROBO3D heat bed ?
That was 1st thing i saw when i tried them.
Not only they did not work (because handles would get in a way) but also damaging the bed.

I have a simple solution:
Back screws are somehow longer then front (or so it is with my printer)

 

So as i go shop for a tempered glass earlier to day, i learned something.
While back when McDonalds Big Mac was BIG, some idiot who could not control his eating amounts made McDonald to change Big Mac size making it nearly half. (yet the price did not go down but up.)
Not too long ago (maybe year or two) another idiot went to a store buying sheet of glass. He ended up cutting him self. Since then DomeDepot Lowes and Ace Hardware etc do not sell GLASS SHEETS nor tempered once.

So my question is this:
Is there a store where idiots dont usually shop at that is left unaffected and still sells glass as well as tempered glass sheets cut to size ?

I tried Speedy Glass but they were closed for the weekend.
Any other US stores that aren't hard to find ?

Life gets harder every day

 

I live in Washinghton. Lots of people here (minority such as idiots and gay) dictate laws that effect majority.
Too far to travel to border so ill just order online for $3+$17 shipping

 

Or, you could just google a local glass shop. Lowes and Home Depot aren't the only places in existence.
In fact, you would probably have better luck getting scrap glass for almost nothing from a glass shop.