Heated Bed Upgrade

[3DprintedLife]

Hey guys, I recently picked up one of these bad boys from eBay, and while I haven't been able to hook it up yet it looks like it should be quite the upgrade. Has threaded countersunk screw holes for added asthetics and convenience, the aluminum plate has polished edges and looks really nice in person, and the best part is a 200W heater. Which brings me back to why I couldn't hook it up yet, as drawing 17A through the Azteeg board is probably not the best idea Instead I'll be waiting until I go home and I'll use an old automotive relay to control it.

I just wanted to share this in case anyone else was interested, it's relatively cheap ($45ish) and should be a very substantial upgrade in terms of looks and heatup times. I'll finally be able to print ABS once I get this installed!

Here's the link, there's a number of other sellers on ebay as well and he also sells just the aluminum plate in case you don't want a heated bed!
www.ebay.com/itm/222013132570?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Will post heatup time comparisons to mk3 bed once I get everything running!

[niloc]

Hi, I picked up one of the silicone bed heater as well.
Do I set the thermistor as EPCOS100K or set beta as 3950?
Thanks for your help. 

[3DprintedLife]

Aug 10, 2016 8:09:17 GMT niloc said:

Hi, I picked up one of the silicone bed heater as well.
Do I set the thermistor as EPCOS100K or set beta as 3950?
Thanks for your help. 

Set the thermistor to EPCOS100k, you could set the beta value manually but its probably safer to just use the built in values for popular thermistors like this one!

[edinnh]

Be sure to check the temperature readings you get using the  EPCOS100k setting.  EPCOS has several 100k thermistors each with a different beta/ temperature curve.

For example two common thermistors are:

    EPCOS 100K Thermistor (B57560G1104F)  beta: 4072 ( reprap.org wiki says 4092 the table at DigiKey and the EPCOS data sheet says 4072)
    EPCOS 100K Thermistor (B57540G0104F000)   beta: 4066

A search for EPCOS 100k thermistor on DigiKey shows 63 thermistors with beta values ranging from 3988 to 4600.


I was looking up this information this weekend.  I am installing one of the "Modular Screw-on M3 Stud Thermistor" from Amazon.   

The Smoothieware firmware table entry is for B57540G0104F000. My new thermistor assembly uses the B57560G1104F.

I don't know if the difference between 4072 and 4066  is significant.

The difference in the reprap.org wiki value appears to be an inconsistant reading of the data sheet.  The wiki used the B 25/85 value for one thermistor and the B 25/100 for the other.