Hi PianoPrint,
Thank You! Absolutley, my bed system is different to gCreates, im not too sure how the 1.5+ works now. My bed is built as follows from the bottom up:
- V-Slot H-Frame Using 8 V Wheels.
- 6mm Bakelite / Phenolic Sheet.
- 9mm Cork Sheet With Cutout for Heatbed Wiring.
- Silicone HeaterPad Approx 2mm Thick.
- 4mm Toughened Glass.
The bed is fairly heavy, but as long as it moves freely on the rails it hasn't been a problem.
The Heated Bed is 240 Volt, 1500 Watt (
http://www.aliexpress.com/item/Sili...adhesive-abd-100k-thermistor/32400676471.html) - It is powered directly from the mains AC, and is controlled using the RAMPS via a DC / AC Solid State Relay. The heater is obviously quite powerful, but it heats up very quick and doesn't produce heat in the wrong places (Wiring, SSR etc) like you get when trying to power a bed this size through 12 or 24 Volts as they require a lot more Amps.
It will heat to 80c in about 15 seconds, and can heat to 130+. 1500 Watt sounds juicy, but in reality it takes 15 - 20 seconds to heat, then is run Bang-Bang mode, meaning that it only switches on for a couple of seconds at a time to maintain temperature.
There are things to consider, in the earlier revisions of my heated bed, the plastic parts on the bed would warp from the heat and eventually become unusable, I solved this by using the Bakelite Sheet and 9mm Cork Sheet at the bottom, this insulates the Bed Carriage from the bulk of the heat, I bought some Reflect-A-Gold tape to take this further but so far have not had the need to. An amount of heat still transfers to the Bed Carriage but not enough to warp parts, my printer parts are also printed in PETG now so are not as easily deformed by heat. I'm not sure what the 1.5+ bed uses in terms of plastic parts.
Parts like the Fan Shroud and other Extruder parts will feel the heat if left performing bottom layers for long periods of time, they will sag and eventually get pulled off when they clash with the print. Heat resistant materials should be used to re-print the extruder.
In terms of Auto Level, this has been in Marlin code for some time now, originally i used the Servo Kicker Probe method, which proved very very good for the time i was using it, i have now switched to using the BLTouch Probe (The same one gCreate has been testing) and it is a fantastic probe! Its very accurate and very cheap, i have made modified 1.5 extruders (both dual and single extruder) with built in adjustable mounts that you can use:
I'm not sure which version of Marlin the 1.5+ firmware is using, but i would recommend that you use the latest RC3 Release of Marlin, this has a more refined version of the Auto Bed Level code that shows good improvements from before - the 1.5+ firmware may already be using RC2 or RC3 Marlin.
Hope that helps.
Thanks
Alex