Using dilute PVA glue to stop curling

Wow, this really works! I used 1 part PVA glue to 8 parts water. I let the bed sit at 85 Degrees for 10 minutes to dry before printing.

Just printed a case for a Raspberry Pi with absolutely no curling.

Only one problem...

Anyone got any ideas how I can get the parts off of the glass sheet?

Normally, they just pop off when the glass cools, if they've not already curled off.

Trying now to head to 85 Degrees again to see if that works. Otherwise, I'm going to need a new piece of glass and some fresh ideas.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

Answer. Sort of!

I put it in the deep freeze which got it to release.

However, so did the surface of the glass!

That is the serface of the glass attached to the face of the case!

Should I dilute the PVA further? If so, what ratio are other people using?

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

I think it should be water soluble, so perhaps putting the glass in water would release it.

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[www.hydraraptor.blogspot.com]

That may take some time for a large print. I was a bit worried by how just putting it in the fridge made the glass delaminate, if that's the right word.

I'm not sure what type of glass was in thereprapkitstore.co.uk kit. I need to get some replacement glass. I'll try and pick up a toughened glass chopping board but I'm not sure how I should gut it down to size. Can toughened glass be scored and cracked in the same way?

An alternative, I suppose, is a glazed ceramic tile.

What ratio of mix did you use nophead?

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

I haven't tried PVA yet. I use ABS juice, very dilute and most parts come off very easily. If the juice gets baked on where a bit of the bed is not used then it can stick so hard it breaks the glass like your picture. I just make sure I always swill it round the whole glass each time I renew it and I haven't had a problem since.

I think glass is toughened after it is cut.

Edited 1 time(s). Last edit at 07/08/2012 08:30PM by nophead.

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[www.hydraraptor.blogspot.com]

Well, that was fun.

Been to B&Q and bought an unframed mirror to cut down to make a new bed. £8.81 but never mind.

Had a clever idea to drill two small holes to provide some relief around where my heat bed wires are soldered on. The idea was that, after being drilled and then the pane cut to size, I'd have to semi-circular cut-out around the wires.

Drilled first 8 mm hole using a masonry bit nicely. Drilled the second one half way through. turned over and started to drill through from the other size and BANG! £8.81 down the swany.

What can I use? I remembered that I had four old prints in the back of my workshop that had glass in them. First try at cutting picture glass with one of those tile cutters with a guide rail went as well as my mirror drilling escapades. The second was not much better but I did realise that I wasn't scoring the whole width of the glass.

My third try and this time I only scored using the cutter. I broke the score using the old 'pencil on the table' technique which worked a treat.

So, tonight, I have learnt how to cut glass.

Incidentally, when my wife spotted me cutting up picture frames, she locked me out the house and wouldn't let me back in until I convinced her through the kitchen window that I had managed to get the piece of glass that I needed without resorting to taking the pictures off of the wall in the house.

So, now trying again with a first layer bed temperature much reduced to 65 Deg (from 85) and then 55 there after. Extrusion temperature was 195 for the first layer and 175 there after.

I also reduced the PVA concentration to 1 part in 32. My little knowledge of homeopathy now worrying me as, theoretically, my glue is now 32 times stronger!

Parts came off the bed well so I think I can call that a success.

Now to have a go at this weeks Competition seeing as last week was a complete write-off due to problems with Slic3r 0.8.4 not printing to the correct dimmensions. Using 0.8.5dev from the new flow branch and I am liking it!

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

I messed about cutting up an old touch screen and some picture glass until I realised I can buy 2mm glass cut to size for about £2.50 from a local shop.

I also bought some 200mm mirror tiles from Ikea for a similar price, but haven't tried them yet. They are a bit too small so the clips aren't as close to where the PCB is supported for my liking.

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[www.hydraraptor.blogspot.com]

I've just got a quote for some toughened glass sheets for £8.63. There are a couple of provisos:- they can only do 200x300 and 4mm thick. Should I get some? Remember that toughened glass can't be trimmed.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

Take a look at this thread and this blog post where they are using PVA glue at 1:2 - 1:4 on a cold bed with no problems. Haven't tried it myself but it looks interesting. Perhaps the fact that the bed is heated in addition to the PVA glue is the reason there is excessive adhesion of your prints.

As far as glass is concerned there are typically two types: tempered (heat treated) and untempered. Untempered glass is what you will typically find in picture frames and can be cut and drilled. When drilling make sure to use LOTS of water as the process of drilling causes excessive heat buildup and will crack the glass (as I think you found out). Tempered glass has been heat treated at the factory after being cut/drilled and CANNOT be modified easily (I won't say its impossible). Tempered glass will typically shatter into lots of tiny cubes if you try and cut or drill it.

Hoping to meet RichRap this weekend at the West of England RepRap user group meeting. I can compare notes and experiment then.

archistrong Wrote:
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> Take a look at this thread and this blog post
> where they are using PVA glue at 1:2 - 1:4 on a
> cold bed with no problems. Haven't tried it
> myself but it looks interesting. Perhaps the fact
> that the bed is heated in addition to the PVA glue
> is the reason there is excessive adhesion of your
> prints.
>
> As far as glass is concerned there are typically
> two types: tempered (heat treated) and untempered.
> Untempered glass is what you will typically find
> in picture frames and can be cut and drilled.
> When drilling make sure to use LOTS of water as
> the process of drilling causes excessive heat
> buildup and will crack the glass (as I think you
> found out). Tempered glass has been heat treated
> at the factory after being cut/drilled and CANNOT
> be modified easily (I won't say its impossible).
> Tempered glass will typically shatter into lots of
> tiny cubes if you try and cut or drill it.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9