Size of bed

which version of the printer?

 

10" x 15"

 

Big-Assed tape measure and old eyes

Looked close at 15

 

That 1/8 inch won't make any difference.

Sent from my SAMSUNG-SM-N910A using Tapatalk

 

Making the plate bigger won't affect build dimensions unless you move the endstops also. It will still be 8.7 x 10, and don't forget that the heated area is even smaller. If you want more Y, It would be much simpler to just replace both 8 mm rails with slightly longer ones, no redesign necessary.

You still have the issue of no heat on the ends of the build area.

 

In theory, with external power, you could lengthen the bed and have two heating pads.
Just don't try that with the stock power supply.

 

But @mark tomlinson, honestly, if you are going through the trouble of replacing the glass, why not have a custom sized heater pad made. Here is a good source: Shenzhen Ali Brother Technology Co., Ltd.

Just use the contact link and ask Sivia for a specific size, wattage, voltage, etc. They will custom make the heater pad for you. I ordered one from them and had it in two weeks.

This way there is no issue removing and possibly damaging the original pad, and you get the added benefit of heating the entire build area.

 

Good idea.
If you were to side-by-side two pads the 'gap' would be small, but sure -- if you are going custom -- go custom.
(The old pads are easy enough to safely remove, but I like 'why bother' as an answer)

If you want a larger build area then building it out custom is certainly the best approach. I was merely pointing out the cheaper one (and cheaper is almost always not the best answer).

 

I only knew all this stuff, researching my Eustathios build, but I am likely going to have to replace my Robo bed as the last time I printed ABS, when I pulled the part off a very small chip came off the build surface. Figured when it's time to replace (after a few more chips) I will also upgrade the heater to make full use of the build area. Will also go to 3/16" (4.76 mm) glass or maybe, if I am feeling flush, I will go 1/4" (6.35 mm).

 

@Nathanfish what I ordered wasn't for the Robo, so I asked them to build me a 120v 325 mm square 500 watt pad, which is exactly what I got. For the Robo I would ask them for a 240 mm x whatever you end up with for length, 12 v, adhesive backed silicone rubber pad, 250 watts. That will cover the entire build area and only consume 21 Amps. You will no longer be able to heat up the bed and extruder at the same time. but the 30 amp PS will be enough to maintain the temperature. If you want to be safer, you could drop to 200 w, which will drop the load on the PS to 17 amps, during heat up. The compromise is slightly slower heating, but in either case much faster than the Robo supplied pad. By comparison the extruder only consumes 3.5 amps maximum.

$11 for borosilicate glass or plain float glass (window pane stuff)?

 

Borosilicate glass (Pyrex was one name brand, pre-1998*) handles thermal shock better than float glass and can sustain longer periods at high temperatures without to much thermal induced size changes. Float glass not so much, but many makers use it and say it is perfectly fine. Plus you could likely buy 4 or 5 float glass panes for the price of one similarly sized borosilicate pane.

*Post-1998 the Pyrex brand name was sold to World Kitchens and they stopped making their stuff out of borosilicate glass and used the cheaper to manufacture tempered soda-lime glass instead.

A side note, Float glass has about 3 times the expansion rate of borosilicate @ 100°C, but we are speaking in terms of microns here; 9 microns vs 3.5 microns per square meter.