Slow getting to 110C bed target on 10" i3v

[printbus]

OME, the 10-inch version of the printers from MakerFarm like jimg has come with a heat bed relay. They have to. The larger heat bed on those printers can draw 17-18 amps, which is way beyond what the RAMPS board itself can handle.

[old man emu]

You PSU might be 350W @ 12V, but what is the amperage at that level? Theoretically it should be 29W, but what does it say on the spec panel?

OME

[old man emu]

OME, the 10-inch version of the printers from MakerFarm like jimg has come with a heat bed relay. They have to. The larger heat bed on those printers can draw 17-18 amps, which is way beyond what the RAMPS board itself can handle.

I'm running a converted ATX PSU that puts out 18A and the temperature readout on my mere 8 x 8 bed rolls over like the amount reading on a petrol pump.

OME

[AbuMaia]

It takes my 8x8 bed about 8-20 minutes to get up to 120C, running through a relay off my 12v 30A power supply, with cork between the HBP and the wood Y bed.

[JimG]

You PSU might be 350W @ 12V, but what is the amperage at that level? Theoretically it should be 29W, but what does it say on the spec panel?

29A.

http://www.meanwell.com/search/se-350/SE-350-spec.pdf

Jim

[JimG]

It takes my 8x8 bed about 8-20 minutes to get up to 120C, running through a relay off my 12v 30A power supply, with cork between the HBP and the wood Y bed.

The 8" bed, in theory, should only require 64% the energy needed by the 10" to maintain a given temperature. Something I did not consider before pulling the trigger on the 10"!

Jim

[printbus]

The 8" bed, in theory, should only require 64% the energy needed by the 10" to maintain a given temperature. Something I did not consider before pulling the trigger on the 10"!

What's interesting is that the heat bed on the new 12-inch printer just released by MakerFarm should likewise require 144% of the energy needed by the 10-inch. The product page for the 12-inch heater, however, says it needs 20 amps, which isn't all that much more than the 10-inch.

[usarmyaircav]

I just bought and installed 12 AWG wires to go between the PS and the heatbed relay. I also forgot that I need to remove the glass and heatbed and cut out a hole in the corkboard where the thermistor is. I think between the two of those I should be in good shape for heating my bed. A cloth over the top of the bed is a good idea. slight fire hazard I would think.

[JimG]

I just bought and installed 12 AWG wires to go between the PS and the heatbed relay. I also forgot that I need to remove the glass and heatbed and cut out a hole in the corkboard where the thermistor is. I think between the two of those I should be in good shape for heating my bed. A cloth over the top of the bed is a good idea. slight fire hazard I would think.

If you are OK with the corkboard below the heater, then you should also be OK with the cloth on top ;-) The biggest problem with the cloth, or anything else on the top, is that you have to be there to remove it when the bed is warmed up. 'Membering things like that when I am working in the "lab" is not my strongest skill.

I have cardboard below mine. The piece of silicone foam rubber I bought for this turned out to be too thick.

Jim

[usarmyaircav]

If you are OK with the corkboard below the heater, then you should also be OK with the cloth on top ;-) The biggest problem with the cloth, or anything else on the top, is that you have to be there to remove it when the bed is warmed up. 'Membering things like that when I am working in the "lab" is not my strongest skill.

I have cardboard below mine. The piece of silicone foam rubber I bought for this turned out to be too thick.

Jim

DOH! I didn't really think about the cork underneath LOL.