How many Db15 pins for hot end?

Or conversely how much power can you put through one pin of a db15/db9 socket? Also how much power does a heater capsule use? Never thought to look

Ta

Typical 12V hot end heater capsules take 3 to 4A. Best assume up to 5A to allow for increasing the 12V supply voltage a bit, in case you find yourself needing more power for the heated bed.

The current rating of a D connector probably depends on the manufacturer, but one by ITT Cannon that I just looked up is rated at 5A per contact, see [www.farnell.com]. So one pair of pins is enough. However, you might prefer to use two pairs to share the current.

I use Molex KK series connectors to connect hot end wires to my hot end PCB.

Edited 3 time(s). Last edit at 12/26/2014 05:54PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Yes, I've just tried to solder up a DB15 and it was far from fun, so I think I'm going to go molex shopping tomorrow. I like the compact nature of the DB15, but thinking about it, as I've moved the connection from the X Carriage end, to the point where it mounts to the printer, I don't need it so much now.

Thank you for the information though. I was trying to look it up on datasheets on my phone and it wasn't working >_<

... for oxidation and possible contact resistance issues I'm calculating roughly 1Amp for standard contacts and 2Amps for gold coated ones.

So for 5 Amps I'll count 5 or 3 contacts for each polarity ...

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Viktor
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I looked up the Mendel90 wiring, and Nophead uses 6 (3+ve, 3-ve) in case anyone else comes across this

The limiting factor may not be the pins. In the case of a Mendel90 for instance, the design calls for a ribbon cable. A 28ga ribbon cable is only rated at 1.4 amps per conductor. A 40 watt cartridge heater will need 3.3 amps @ 12 volts so 3 wires would be pushing it with little room for safety.

Yes good point. My original plan was to join the pins with something substantial which would feed a "proper" rated cable. I like the ribbon idea, I've got a set ready for my Mendel 90 build, but I was a bit unsure about some of the more techy aspects. Nophead mentions on his blog (I think, might of been the wiki) that there's a risk of cross talk and various other things that I have no interest in dealing with