IPad Glass As 3D Printing Build Platform

1. Are you tired of scratches on your Kapton tape, or the bubbles that show up when trying to remove your parts?
2. Are you fed up with having to change your tape after every 3-4 builds to get optimum results?
3. Are you having trouble with your parts warping and delaminating?
4. Do you want a reliable 3D printing build platform which is durable and low maintenance?

Then this is for you!

I was inspired by the work of others who have tried printing on sheets of glass and mirrors, yet at the same time I wanted to have a flexible platform that I could bend to release the parts (like NinjaPlate from adafruit). Gorilla Glass from Corning looked like the perfect candidate. After searching for thin sheets of the stuff that I could cleave down to size for my MakerBot 2X, I realized the iPad screen is the closest thing and fits all the requirements:

• Thin, yet flexible tempered glass
• Scratch-proof (well, scratch-resistant, but the only thing I found to scratch it was diamond or tungsten carbide tip scribers)
• Great thermal conductivity (for uniform heat distribution)
• Very low thermal expansion/distortion (at the usual printing temperatures of 110-120C)
• Resistant to pretty much all solvents I could find (Acetone safe)
• Pretty cheap (bought mine for $15 on Amazon)
• Not too hard to hack it into a build plate (see instructions)

Step 1: What You Need

You need a very flat surface in a well ventilated area. I wouldn't do this on a surface that you may later prepare food on!

Here is the shopping list:

• Generic replacement iPad screen (I got mine for $15 on Amazon)
• Single sided razor blades (or a sharp flexible scraper)
• Acetone and IPA (rubbing alcohol will also do)
• Lint-free cloth (TexWipe works great)
• Binder clips of the right size depending on your hotplate thickness
• Disposable gloves and eye protection

Step 2: Removing the Touch Sensitive Circuitry

This step can get a bit messy! There is a second glass sheet glued to the back that I believe acts as a capacitive plate. I don't know the exact specs for the adhesive spacer used, but the way it smells, I would guess it is a cyanoacrylate derivative and would produce toxic fumes when heated. So it must come off!

start by removing the wires and the button and the camera fixture.

Fortunately the second sheet has similar properties to sugar glass, so it breaks into small pieces quite easily. Be sure to wear eye protection as the needle-sharp pieces fly everywhere. Don't use any solvent at this stage as the glue will help keep the glass shards bound when they shatter.

Step 3: Cleaning the Glass

When all the capacitive plate and the double-sided tape on the edges have been scraped off, it's time to remove the residual glue.

• What I found to work best is to first cover the surface with IPA and scrape off the glue with the razor blade.
• Then put acetone on your rag and start rubbing off what is left.
• Finish by putting IPA on a fresh piece of TexWipe and rub off the acetone smudges.
• Wash the whole thing with warm water and dry.

You could even scrape off the paint around the edges, the glass is pretty tough and won't scratch as I attacked it with a chisel! But you have to be very careful not to put a dent on the sides or your glass will start to shrink (happened to me on the first attempt ... towards the very end ... Facepalm!).

Step 4: Measurements!

You don't have to do this but since I had a very precise height gauge I wanted to test the thickness variation across the whole thing. It turned out to be around 19-25 microns bending up from the center, which is pretty decent. The plate thickness is about 1.6mm.

Step 5: Mounting the Glass

You are almost done!

I used large binder clips to attach the glass to my heated plate. You can either bend the handles in a vice or remove them after placing the clips in the right place or they will get tangled up in your extruder assembly. I am not planning on editing the gcode for every build to make sure the extruders don't hit the clips but it is pretty easy to squeeze 3 clips in there (see the intro picture as a guide).

The glass is very thin so you don't need a custom spacer, but I strongly suggest that you lower the plate by 2-3mm before alignment to prevent the extruder nozzles from crashing into your glass. Also, I suggest heating the plate up to your usual printing temp and then doing the build plate alignment. For MakerBot users, I would manually jog to each position instead of using the "level build plate" option so I can control the travel paths.

Step 6: Printing Prep

I got good results with just printing on the glass with nothing added (no raft either) but you can also use hair spray or glue stick to increase your filament adhesion for peace of mind. I spray onto the TexWipe and dab the surface. You can also try spraying a couple of coats directly on the surface. I usually print 2-3 times then clean the surface with acetone/IPA and re-apply the spray.

Remember, no matter how hard the part is stuck to your glass you can still scrape it off without having to worry about scratching your plate!

Hope you enjoyed this instructable and best of luck printing :)

A.S.

Comments

[AcrimoniousMirth]

This is a pretty cool idea! Looks like it'll work out cheaper than any specialist build platform.

[AcrimoniousMirth]

This is a pretty cool idea! Looks like it'll work out cheaper than any specialist build platform.

[mtattoohead]

Could you please explain what you mean when you say don't "put a dent on the sides or your glass will start to shrink"? That's the only piece of info I'm not quite comprehending at the moment... Thanks!

[cvbrg]

I meant don't chip the glass or it will cleave :)

[akdrama]

After flexing the gorilla glass does it stay flat? Or after some time did it warp and create issues for you?

[cvbrg]

I've been using this method for more than a year now. I only killed my glass once! As I was scraping the part off, I tried to rotate the chisel to pry off the part quicker and my glass cracked in half. Apart from that one time I have not had any other issues.

[edward.sutherland.56]

Question, how well would the Gorilla "bomb proof" Tempered glass protectors work? I'm thinking $15 and none of the work.

[Activseo]

I am owner of www.1click3dprint.com, I am very keen to develop such products to my customer. Thanks for sharing

[Activseo]

I am owner of www.1click3dprint.com, I am very keen to develop such products to my customer. Thanks for sharing

[repkid]

Brilliant!

[AJMansfield]

At first when I saw this instructable, I thought you were using an actual iPad as the build platform...

[waldosan]

i thought the same but also that he had added google glass to make a 3d editing tool. Such is life that such a thing will never be...

[white_phox]

Yeah, there are apps that turn it into a trackpad, and I believe some do both relative and exact positioning.

only thing is, most use WiFi or Bluetooth

[bfk]

Hair spray works 99% of the time. The others can be held down to glass with a mixture of scrap ABS and acetone... Just use the same color that you're printing.

I use thermal grease between the platform and the glass and a heat gun to speed up the heating process (saves tons of time). Standard glass shatters if the gun doesn't heat the entire sheet evenly. Does the iPad's glass resist shattering?

[cvbrg]

Yeap, ABS slurry works real good, too good actually that the Kapton would scratch or peel (bubble) when removing parts. But with the iPad glass I don't have that problem anymore; can scrape the part off with a sharp single sided razor blade.

The heating takes no longer than without the glass on my Rep 2X. The glass is very thin, yet shatter resistant. I've been printing at 120C with no problems so far. Actually, the nozzles take longer to heat up to 230C than the plate!

Though the MakerBot has a handy pre-heating feature which saves a lot of time, so I never had to hold a heat gun to the plate. I usually start heating the setup while slicing and then print off of an SD card.

[bfk]

Great response. Normal glass is subject to thermal shock that weakens and eventually shatters it. My heating element times out even without the glass at 110c. The heat gun sidesteps the need for me to attend to correcting that. Corning isn't making Pyrex any more and all the other suppliers of heat resistant glass are offshore. Looks like the iPad is the way to go. Thanks for the ible.

[philperryman]

After I built my 3D printer I spent weeks trying to get the PLA to stick to my heated glass bed. After trying hairspray, tape and all sorts I found a comment about using 1 part PVA mixed with 10 parts water. First make sure the glass is clean and free from grease then using a lint free cloth smear a thin layer of the pva mix over the glass while it is heating. once the mix is dry, it will leave a thin white smear on the glass, make sure you have covered the print area if not repeat the process until you have coverage. Better to do 2 or 3 thin coats than 1 thick. Once complete start printing, I set my bed temp to 90 degs to start then drop to 70 once the first 2 layers are printed, PLA temp is set to 195 deg. Once finished allow the bed to cool, when it gets to around 50 you will hear a cracking noise, leave it in until about 35 degs and the printed part will just pull off. I have used this method for 18 months or more now with very good results. If you still have bubbling! I would check to see how level your bed is, I use a clock gauge attached to the print head to test mind and level it to +/- 0.03 mm over the print bed area, if that's set correct that should stop the pulling you get when laying down the 2nd layer which sometimes causes the bubbling.

[Klappstuhl]

Well, that sure is one way to reuse those iPad glasses once everyone trades it in for the new version. I wonder if it could also be reused as a diy USB Wacom Tablet for drawing... hmmm... *scribble scribble*

[efahrenholz]

This is by far the most exotic build platform I've seen. At one time I considered just laying down an old broken tablets touch screen for the build surface but said screw that. Apparently I'm missing out!

[crafter26]

where can i find a 3d printer? and how much is it's average price?