Solved 120 v. Heater upgrade
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Hey there everyone !!
So sometime ago I started to convert from a 12v
Bed heater on a creality cr10-5s to a 120v 1000w unit.
Well actually haven started the process quit yet
I've got everything I need but wanted to check to see if someone could give me some insight
Here are my concerns..
First off the old bed heater is seriously underpowered.. the aluminum 2ft x2ft acts more like a heatsink than any thing else. surprisingly, the bed is fairly flat but takes almost 20 min. to heat up and I'm lucky to reach 70c
Plans are to use a ssr. then, after that I'm just guessing. (Bad idea) !! I would think, so if switching to a 1000w 120v heater, will I warp the bed?? By applying to much heating power too quickly, orDr do I need to sw. To a dif. heating protocol in the g code?? Or am I OK with how it's set up now? Also if there is someone out there who has done this and already had and fix the pitfalls I might encounter. I k own that after the upgrade I will have to retune my p.i.d to avoid a heater fault and ha e that down.
please feel free to chime in... any advice will be greatly appreciated. Thanks -
@ziggymanpopo, I have a CR10-5S and use a 120V heater (although I believe it's more like 1200W). It works just fine except you still need a bit of time for everything to heat equalize.
No, the bed does not 'warp' however there is a difference in dimensions from cold to hot. This would be reflected in a bed scan (do the scan at operating temperature or close to it I think I use 65C) . It will not damage anything and is perfectly normal.
I have the underside of the print bed insulated somewhat to give better overall performance. My heating protocol is a tad different to compensate for the longer heat stabilization but that is strictly optional and is nothing to worry about at this point.
Oh, my heater is a 500500 heater rather than the much smaller size of heater that comes with the CR10-5s. I did not trust the smaller footprint of the 'as built' setup to provide even heat. The underside of the print bed has strengthening bars - these were pulled, heater was placed and the bars were re-attached (over top of the heater). I wasn't entirely happy with doing things this way but I thought it to be better than running a 300300 heater on a 500*500 bed.
Don't forget to hook up a ground wire to the bed and a thermal safety switch is also recommended. -
This calculator gives pretty accurate estimates of the time required to heat the bed to a target temperature based on the bed construction and the heater power applied.
A 600x600 mm aluminum bed will expand about 1mm in each direction when heated to 100C. That can put a lot of stress on the mounts unless they are designed to accommodate it. A kinematic mount allows the bed to expand without creating any stress on the mounts or the printer's frame.
A thermal cut-out should usually be attached to the bed heater, not the bed plate, especially if you're using adhesive to hold the heater on the plate. Don't get a self-resetting cut-out and don't buy a no-spec part from China. Spend $1 to buy a fully speced part from a reputable manufacturer.
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Missed the bit about the termal overload good idea and thanks for the temp calculator that will help. I was thinking best would be a bi-thermal with a reset button. That way it won't come back on when it starts to cool great ideas. Thank you.
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@ziggymanpopo, you might want to think about using a bi-metal anything. If you trip the thermal cutout switch you have a big problem somewhere and I wonder if it is a good idea to offer the user the possibility of just hitting the reset button.