Wire thickness

What diameter of wire do you suggest for hot end wire connecting the heater cartridge and separately for the heated bed?

Thanks

I believe I used 14ga for the bed, 16ga was not quite enough.
For hot ends, I usually just strip an old computer cord.

Cool, I'm wiring up sockets to help me switch heads easier, so figured I'd check

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sheepdog43
I believe I used 14ga for the bed, 16ga was not quite enough.

Why was 16ga "not quite enough"?

The advantage of heavier gauge wire is to lower resistance, preventing voltage drop and the wire acting as a heating element. However if you're only using a few feet of wire, the amount of resistance is pretty minimal. 4 feet of 18ga wire running at 10 amps has a voltage drop of .26 volts. 16ga and 14ga have drops of .16 and .10 volts respectively. The 1.6 watts difference between the using 18 or 14 gauges I doubt you could even measure in a real world application. The advantage of smaller diameter is it us usually more flexible as well as lighter, both of which are advantageous when they are moving around.

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cdru

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sheepdog43
I believe I used 14ga for the bed, 16ga was not quite enough.

Why was 16ga "not quite enough"?

The advantage of heavier gauge wire is to lower resistance, preventing voltage drop and the wire acting as a heating element. However if you're only using a few feet of wire, the amount of resistance is pretty minimal. 4 feet of 18ga wire running at 10 amps has a voltage drop of .26 volts. 16ga and 14ga have drops of .16 and .10 volts respectively. The 1.6 watts difference between the using 18 or 14 gauges I doubt you could even measure in a real world application. The advantage of smaller diameter is it us usually more flexible as well as lighter, both of which are advantageous when they are moving around.

Of course you could be really cunning and use a large gauge wire, but make it hollow so it doesn't weigh much

The current rating depends on the cross-section of the conductive area. It does not matter if its round, square or oval. Just the conductive area, like in mm^2 (squared). If it has a hole in it, that hole gets removed for not being conductive.

If you want higher current rating you could use a solid copper conductor. For the same cross-section the solid wire will conduct more, around double. But then instalation is fixed, like for a printer which has the bed completely stationary in all directions.

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UkIan
Of course you could be really cunning and use a large gauge wire, but make it hollow so it doesn't weigh much

While getting off topic, for DC I believe it still ultimately comes down to the effective cross sectional area. DC utilizes the entire conductor for carrying current. Now if you were talking about a high frequency AC application, then using a hollow tube would save you money and weight as the skin effect results in almost all of the current to be carried around the surface of the conductor. The only thing using a hollow metal tube for DC would be adding stiffness and expense.

I think my winky emote wasn't winky enough

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cdru

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sheepdog43
I believe I used 14ga for the bed, 16ga was not quite enough.

Why was 16ga "not quite enough"?

On dual 16ga, the wires warmed up, they weren't hot, but they were more than room temp. So I bumped then to a single 14ga, not only did the wires no longer heat up, the bed heated faster. These were only 8-12inches of wire.

A HUGE number of people people are under powered so they aren't pushing their beds as much. Most Prusa beds claim 10 amps, but in reality they are 10-12 depending on model and maker. Not to mention Ramps and associated electronics using more than claimed. If you have a 20 amp psu on a Prusa style bed, you probably need more power.