Heated Bed 10AWG wire upgrade

[teoman]

The stock wiring for the heated bed is clearly insufficient (as many suspected and as demonstrated by KAS's infrared images and video).

Many people try to upgrade to a 24V power supply (which i also had done), but I feel that this is not really necessary and adds a lot of bulk to the unit hindering transportability.

So i decided to upgrade the wires going to the heated bed.

I had some noodle wire that I had bought for various projects including this one. Noodle wire is silicone coated and has many strands so it is very very flexible. You can wrap it around a pen with ease.

This wire is fairly thick (it is 10AWG) so you need to drill 2 more holes (or one big hole) to fit them through. The holes look bad, but after i vacuumed the holes, it took away all the debris and they became pretty presentable holes.

Then I removed the old wire (that had become fairly brittle) and I soldered on the 10AWG wire.

The wire is too thick to fit inside the rambo connectors, but with a pair of small scissors I trimmed some of the strands and made it fit the connector on the rambo.

My other connector was fried because of what i suspect was a loose connection. I had to solder the wire to the back of the board.

Now the bed heats up nicely. The performance is not quite the same as the 24V supply, but it is much faster. With my tshirt on the bed i was able to reach 115 degs in about 10 minutes.

The with the stock psu , I was measuring 11.38V at the input of the rambo board. And 11.07V at the output to the bed. Without the glass as an insulator on the bed the max temp i got was 87 degs.

The resistance of the bed was about 1.5 Ohms at 100 degs and 1.3 Ohms measured at room temp.

[Eaglezsoar]

Teoman, thanks for your post, it is a good alternative to using smaller wires.

[Shizuma]

I had done exactly that last year when I ditched the stock PSU the printer came with, it definitely made very noticeable difference in bed heat up time on mine too, with the stock PSU and smaller wires mine took 20-30 mins just to get to 85 with a towel and couldn't even get up to 90, with the larger wires and new PSU it's around 10 mins with no towel to 100C.

[teoman]

I plugged in a 15V power supply to the bed. And without any modifications it heats up nicely.


I did also place copper heatsinks (self adhesive) behind all the motor driver chips and the mosfet for the heated bed. They are compressed on by the melamine because i have had them fall off.


I really should open up the printer and completely replace the stock psu with a 20V one with power converters.

[KAS]

Bah, I keep forgetting to get the thermal images of the 10awg. I'll try to get them tomorrow before I start printing.

[geneb]

10ga is WAY over-kill for the application at hand.

g.

[KAS]

10ga is WAY over-kill for the application at hand.

g.

If my Hakko could handle it, I'd solder 2/0 gauge

But, this 10awg silicon wire is awesome to work with.

[teoman]

Yes it is overkill.

10 Awg can handle 35 amps.

12 awg, 25.


I would have used 12awg but i did not have any at hand. If one was using a 24v power supply, 12 awg would be good to have on there.


being thicker is not a problem, but if the wire was 12 awg, i believe i would not have had to trim a few of the strands off.