Custom FDM Needs Print Bed

hey guys n gals,

Im in search of a 24" x 48" piece of material to use as my print bed ,any ideas?

I am assuming the bed is stationary, otherwise you have big problem.

A big slab of 6mm aluminium tooling plate to spread the heat and then a sheet of 3mm glass for printing PLA or ABS. Plus about 1.2kW heater.

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[www.hydraraptor.blogspot.com]

ebay has a good variety of aluminium. im thinking of switching from glass as well. im just a bit worried about the bending from all the heat and cool cycles.

Yes it'll be a stationary bed , using a 1.2mm volcano setup with bowden . What is recommended for heater?

40 watt should be enough if you slow down. it depends what you extruder can handle, but the heater is definitely a weak point. would be interesting to see how 60watt cartridges behaves

I wouldn't use normal float glass, I don't think it's usually flat enough. If you look in the window, your reflection bends a little as you move, right? So I second (third?) the suggestion of a thick aluminum plate. I might also suggest steel, since it's stiffer and sometimes cheaper, though expect it to weigh quite a lot.

still expands less under heat, so less bending, good idea

Sungod you mentioned cartridges... Have a link? With such a large build area, true flat will be a issue no matter

This I just found [www.ebay.com] but I have to check if the board can handle the higher load. 5 amp is quite a lot. maybe a conversion to 24V would be a good idea then.

As for the bed. I think the bigger you get the more glass becomes the only alternative, because it is stiff enough. you will need a very straight bed frame to keep any metal from bending all over the place.
what printer are you using for this big bed? It would be easiest to have a stationary bed I guess.

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sungod3k
40 watt should be enough if you slow down. it depends what you extruder can handle, but the heater is definitely a weak point. would be interesting to see how 60watt cartridges behaves

I honestly think he was refering to a heater for the bed and at that size it would have to be a custom made heater with in the order of 1-2 kW of power and would probably be a custom made Silicon heater running on AC Supply voltages certainly wouldn't go below 1 kW.

I use an AC Heater at 300 mm diameter on my Kossel and that is 220V 500W and takes approx 3.5 - 4 minutes to get to 115 degrees C.

HTH

Doug

I have decided to use true tempered glass for the thermal transference


Perhaps 2 of these [www.zoro.com]

or $900 on [www.oemheaters.com]

Edited 1 time(s). Last edit at 06/09/2015 08:29PM by Tinkerhabits.

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epicepee
I wouldn't use normal float glass, I don't think it's usually flat enough. If you look in the window, your reflection bends a little as you move, right?

Sounds to me that you have a bad piece of glass. I have only seen that effect in very old windows having glass that was not produced by the float process.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

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Tinkerhabits
I have decided to use true tempered glass for the thermal transference


Perhaps 2 of these [www.zoro.com]

or $900 on [www.oemheaters.com]

Not sure why you want tempered glass rather than ordinary float glass. It's quite common for prints to stick to the bed so well that when you remove them, small fragments of glass come off with the print, leaving a small indentation. Using float glass, the bed is still usable, if you don't mind an imperfection when printing over that point, or you can turn the glass over. The glass is also cheap to replace. Using tempered glass, the whole sheet would shatter - although it's possible that the print would be less likely to pull small fragments out of it anyway.

These people [www.aliexpress.com] will manufacture a silicone heater to your size, power and voltage specifications at a very reasonable price.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].