Help Needed - End of My Tether With Heated Bed

Hi guys, i have built a printer based on the gMax 1.5 printer. It has a 450 x 450mm bed size, i have attached a rendered image of the printer below, so you can see how the Y Axis operates:



I have a sheet of 4mm bakelite that is fixed to the top the Y Carriage. Then on top of this i have a 1500 Watt 240v AC 450 x 450mm Silicone Heater, with a SSR, it gets upto temperature very easily and very quickly, the trouble is that the bakelite does not offer any thermal insulation to the plastic carriage parts, and over time they deform, at the moment they are only printed in PLA.

I need to find a way to insulate the bakelite from the silicone heater, i have previously tried MDF (With heat flective tape), 2 sheets of 5mm Hard Foam (With heat reflective tape). The MDF offered little insulation, the Form worked for a short while then melted in the middle. I am yet to try Cork Sheets.

How else could i stop the heat transferring to the carriage? Will cork do the trick? Should i concentrate on getting a gap between the bakelite and the carriage?

Any help, tips or advice is greatly appreciated.

Thanks

Alex

I use a silicone heater attached to the underside of an aluminium plate that is slightly larger than the heater, to allow me to use standoff pillars to attach the edges of the bed plate to the bed support. Under the heater I use a sheet of 7mm cork with aluminium foil glued on top. This is on a delta printer, but it should be applicable to other designs. Before I got the cork I used triple skin corrugated cardboard also with foil on top, and that worked well too.

---

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].

Ok Cork it is the, i will get some at lunch and update.

Thanks

Alex

The Cork is working well! I have also ordered some Reflect-A-Gold tape, a friend is using it on his Fan Shroud and it is stopping it melting even when touching the hotend!

[www.designengineering.com]

People put insulators on the bottom side of the heater because most have underpowered heaters supplied with cheapo kits that will take forever to heat the bed up to print temperature if they lose any heat on the underside. You don't have that problem.

My 1/4" X 12" X 12.5" cast aluminum bed has a 450W heater and there is nothing but air under it and it heats up plenty fast. With 3X that power you don't need to add anything.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
People put insulators on the bottom side of the heater because most have underpowered heaters supplied with cheapo kits that will take forever to heat the bed up to print temperature if they lose any heat on the underside. You don't have that problem.

The other reason is to protect whatever is under the bed from overheating, as is the case here (soft plastic parts under the bed) and on my delta (electronics and PSU under the bed).

Edited 1 time(s). Last edit at 09/30/2015 08:31AM by dc42.

---

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].

Quote
dc42
The other reason is to protect whatever is under the bed from overheating, as is the case here (soft plastic parts under the bed) and on my delta (electronics and PSU under the bed).

Oh yeah, there is that...

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Yeah it shouldn't be such a big deal once the parts are printed in ABS, however even the belt got too hot and stretched on one attempt.