120V Heatbed

About

• OSE Reasons for using a nichrome 120V bed are scalability and lower cost for large beds.
• Reason for DIY nichrome beds is clear for larger beds, which would be rather expensive.
• Significant testing is needed for a safe method. Fiberglass coated wire, insulated bed, clamp-on as opposed to double sided tape is preferred for higher temperature printing. For small beds, we can make whatever size we need.
• Hackaday article - [1]

Sourcing

Pad

• 400+ watt 8" beds do not exist - [2]. It is questionable whether this one has 500W on 120V - [3]. Closest is the Ultimaker clone - [4]
• 8" bed on amazon is $84. [5]
• Expensive 12" on amazon - [6]
• Silicone rubber sheet - to 450F - [7] - $6/sf
• 10x10" heatbed aliexpress 500W - $10 - [8]
• 200W 8x8, $13 - [9]

Silicone Rubber Sheet

• Silicone rubber sheet - 20x20", 1 mm - $10 - [10]
• McMaster - <$5/sf for 1/32" thick - [11]

Double Sided Tape

• $3/sf - [12]

Single Sided Tape

• Kapton tape, 4"x100ft - $25 - [13]

• Enough for 300 small beds (4"), or 33 12" beds.

Coated Nichrome Wire

• Need 30 Ohms of wire, about 10' long
• See Nichrome Wire

Uncoated Nichrome Wire

• Need 30 Ohm resistance for the length of wire at 120V to get 480W, for P=IV, V=IR, I=V/R -> P=V^2/R = 120^2/30 according to Electrical Power Calculator.

Sleeving

• 20 cents/foot, 1/16" ID - [14]
• Wire sleeving - [15] - 15 cents/foot for 16 gauge.

Other Options

• Carbon fiber is also used as a heating wire - [16]. Interesting. But it appears it can only do 15W/meter? Why is it limited? Limitation appears to be encapsulating materials - [17]