SoliForum - 3D Printing Community — Heater core resistor burning out too frequently

Re: Heater core resistor burning out too frequently

null@example.com (adrian) — Thu, 18 Jul 2013 12:39:37 +0000

Ghostling wrote:

i also have a prusa with chinese jhead mk IV that came with heater cartridge. it heats up super fast so it does outperform the resistor. but the resistor is way cheaper...

Cheaper in bulk and from a wholesaler.. but given they are a mis-appropriated component (they are actually just normal 'power' resistors, designed for high-power applications - the fact they dump a crap load of heat is a by-product of this process that is exploited to make them 'heaters'... but the body is not actually made to withstand this application for an extended period of time - hence their frequent and predictable inevitable failure) - its a false economy. A 'good' run will see you get 500 hours from them. Not bad for an 'improperly used' component I'll admit though ! Heater Cartridges on the other hand, are purpose built devices that are designed and engineered to do the task that is assigned to them. This is why they outpeform a 'standard' resistor, and also last significantly longer. Significantly. Also, thats a 6.8Ohm - the Solidoodle ones are 4.8 or 5.7 ... So they draw more current, and consequently heat faster. The 6.8Ohm ones will take marginally longer and have a shallower curve.

Having said all that - You can buy heater cartridges off of ebay.ca for as little as $5.50CAD.. delivered! Your listing is for a $1.50 resistor, +$2 Shipping... meaning its actually only $2 more expensive (not a difference I'd call 'way cheaper...'), and the moment you need to replace it more than once, its more expensive, so in reality the heater cartridge is cheaper.. anything more than once that is

Re: Heater core resistor burning out too frequently

null@example.com (Ghostling) — Wed, 17 Jul 2013 16:43:35 +0000

when my heat resistor failed after 8 days of ownership, and SD wouldn't send me a replacement i just used the ones i bought from http://www.mixshop.com/index.php?main_p … ucts_id=88 and replaced it myself. it has been working ever since.

i also have a prusa with chinese jhead mk IV that came with heater cartridge. it heats up super fast so it does outperform the resistor. but the resistor is way cheaper...

Re: Heater core resistor burning out too frequently

null@example.com (adrian) — Wed, 17 Jul 2013 14:52:48 +0000

nurmichl wrote:

Now I'm trying to take a resistor-wire instead of a resistor.
Then I can adjust the resistance and wattage (parallel) very precise.
Search for "kanthal wire awg 32"

Nichrome (the 'other' style of resistance wire) is the 'old' method of building hotends.. it works, but it can be a right royal pain in the backside.

My suggestion is - unless you are doing this for DIY kicks (hey, we do sometimes right ) - just grab a heater-cartridge and be done with it.. less mess, no fuss.. and it'll out perform your nichrome setup anyway

Re: Heater core resistor burning out too frequently

null@example.com (aed) — Wed, 17 Jul 2013 14:06:10 +0000

Thanks nurmichl - can you let me know if that ends up working well for you.

Some users on the other thread recommended using a heater cartridge which I will now try.

Thanks!
aed

Re: Heater core resistor burning out too frequently

null@example.com (nurmichl) — Wed, 17 Jul 2013 12:21:46 +0000

Hi aed,
I had the same problems with my 5.6 ohm resistors (5watt)
Until I print two or three hours my resistors burns out and then I have to replace this bucks.

Now I'm trying to take a resistor-wire instead of a resistor.
Then I can adjust the resistance and wattage (parallel) very precise.
Search for "kanthal wire awg 32"

Heater core resistor burning out too frequently

null@example.com (aed) — Tue, 16 Jul 2013 00:39:46 +0000

I've been doing some relatively larger prints (5 hours) and have lost two heater core resistors already in the span of three days.

I am printing at 195C so I'm not sure what could be causing this - any ideas? Looking at them the resistor legs seem to still be attached. It's been happening around mid-way through the print - the temperature curve was stable between 190-200 then slowly dropped.

To clarify, the multimeter reads an infinite resistance between the legs of the heat core resistor and the brand new ones show a couple of ohms before they get damaged.