better heated bed for SD4? (Page 1 of 4)

I bought one of these on Ebay for $20 . Sold by Soliset

    NEW-Solidoodle-3-Silicone-300w-HeatPad
   
It works great ,covers complete bed heats up in 3 minutes . You must use relay to power it (draws 12 amps). I only print ABS and use a glass with hairspray . I routinely print items 7 + inches wide .and no problems.

eBay item number:
191399293305

The problem you're currently having (uneven heating) might go away with the larger heater pad, but I doubt it. 

I went through 3 silicon pads, and the only time they provided even heat distribution was when I replaced the aluminum surface with a pure copper surface.

The copper surface was great, but it's very expensive.  A plate 8"x8"x1/8" cost about $50, and weighs about 3 pounds.  However, even with a high capacity silicone pad , and with a 750W power supply, it still takes 10+ minutes to get the surface up to 95°C.  I'm not talking about when Repetier tells you it reached 95°C, that takes about 5 minutes, but when the whole surface is heated up evenly.

On the other hand, a PCB heater will heat up evenly, and very fast.  I'm now using a MK2A heater, and it gets up to temp in about 3 minutes, I usually leave it on for about 5 minutes before I start printing, just to make sure the glass on top has fully absorbed the heat. 

As far as adhesion, I use AquaNet hairspray, and it works great.

One note of caution, if you're going to go the PCB route, make sure the PCB bottom doesn't touch the Aluminum bed.  Put some spacers in there,  I used 1/16" thick cork and cut 5 little squares (corners and center of pad).

FYI, as long as you have a decent PSU (300W or better), you won't need a replay.  The MOSFETs (the large vertical transistor behind the PCB heater and Hot end connectors) on the logic board are good enough to support a 10A draw (120W).  The only reason to go the relay route is if you want to provide more power for faster heating.

Id go with the solid state relay solution. I don't have one yet, but they use AC power instead of DC and heat up very quickly. I can only imagine that they also  have very little oscillation if your PID autotune is done right.

I want a bed so powerful it makes the lights in my house dim for a second when I turn it on. Sounds great

It's a free country baby.  You can do what you want... we can agree to disagree... and no one feathers get ruffled.

I can only tell you what I currently have, and works for me.  After I had 3 silicone pads fail on me in fairly quick succession, I installed a PCB heater, and it's been working fine ever since.  It's also much faster heating than any of the silicone heaters I used before.

I'm not a big fan of the AC powered silicone heaters, I just don't like the idea of having live 110VAC current running through my machine, so the 12 VDC driven PCB heater I'm currently running works just fine for me.

Probably not a question as to what bed heater I think is best (signature).
That being said I wouldn't recommend an AC-SSR heated bed for most users.
There is simply too many things that can go wrong and the risks are too high.
So please if anyone is considering going this route, make sure you understand every aspect involved to install and operate safely.

+1 on the PCB heat bed...

I think most of the 200 x 200mm (8 x 8") PCB heaters are a direct replacement in regards to wiring without the need for an SSR, as long as the heater does not draw more than 16A.

I have a 250 x 250mm on my Ord Bot that requires 18-20A at startup which most boards cannot handle, therefore I use a SSR to run it.

Here is one...it is not the one Pirvan was referencing, so just Google that and I'm sure you will find that one as well.

http://www.makerfarm.com/index.php/prin … d-mk1.html

Notice on this site, they offer to pre-solder the power wires for only $2.00...

If having a full 8" x 8" heated area is your highest concern, I would check out the MK2A PCB heater as Pirvan outlined.  If you can procure the Heater pre-wired (soldered) with the power wires that would be convenient for you.  If not, you'll need to solder.

You would need to install a thermistor on the bottom center of the PCB (these mount with Kapton tape). 

I would suggest using a 1/16" thick x 12" x 12" cork tile (available at office supply stores) cut down to 8.5 x 8.5.  pop a hole into the cork so the PCB thermistor will have a place to sit into and then place the cork, the PCB, and then a glass plate over your current print bed and use binder clips to hold it all together.

You need to wire the thermistor and power leads to the control board.  You could actually cut and splice into the current wiring using crimp style connectors and heat shrink tubing to secure everything.

As I do not have an SD4, I can't speak with authority on the power supply, but if you are currently powering a silicone heat bed, then the power supply should be adequate...worst case you will need to upgrade the power supply as well.  See Pirvan's note about that above...

You'll need to PID tune the new setup in RH...google that and you will see how to do it...

Others who have done this mod to the SD4 please weigh in and correct me if necessary

I mean tnis in the least offensive way possible: if you don't know what a relay is, you should not consider an SSR bed. Wait until you learn more about electronics so you don't encounter a firey accident. A relay is an electronically operated switch which can be used for a variety of things. One of which is applying PWM to AC powered beds, or allowing a DC bed to be on a separate PSU, but still controlled by the motherboard.

I see no reason a PCB will not work on the Printrboard. Just make sure the output of those connectors matches the power requirements of the PCB. I'm sure both of these numbers are published.

The guy selling those pads doesn't seem to know a lot about them. Get a PCB from a reliable distributor that will do the soldering for you. The bed gets hot and has a lot of power so you don't want to mess around with it.

Now the question I have is - this is more to IronMan I guess- why would you keep the stock aluminum in place with a PCB? Mine is beginning to warp and I intend to print on glass attached to the PCB. I see a lot of people doing this and I don't see why you'd keep the warp-prone aluminum.

I'll eventually do an SSR but I have a lot of wire managing to do first before I add more and I need a better bed yesterday.

Some PCBs come with 3 holes,many of which match SDs spacing if I recall previous threads. It's only the platform that has tapped holes right, not the aluminum?

If you can find one with the SD hole layout, then yes...dump the aluminum bed and used the tapped holes in the platform.

On my SD2, yes, only the platform has the tapped holes (using threaded T-nuts).