thanks @Dat_Chu … let me see if @Eclsnowman will verify thermistor lead location, and voltage he went with for the Eustathios V2 that he’s been working on. I’ll have you definitive response for my order as soon as I get confirmation on matching specs for his V2 build. again, thanks for organizing this little group buy.
Seth. My current Eustathios bed is 320x320 , 400w, 24v. This requires a minimum of 500W 24v PSU. I would go 500w or 550w 120v AC through an SSR. Then you can use a smaller power supply for the board and steppers.
thanks @Eclsnowman and add ed to my notes this time.
@Dat_Chu FYI Alirubber is out of the office until Feb 26. I placed my order on the 10th and was informed they have their spring festival holiday from Feb 11 - 25. So I’m waiting :’(
Thanks Dan. I am in no rush since I am celebrating Chinese New Year as well. I was surprised they responded to my price quote. I got @Matt_Miller specs. Just waiting until the end of the week to see if anyone else wants to go in.
Ya last I heard was they did not receive my payment and then an ok picture
@Dat_Chu how do you have your power supply setup will you be using to handle the 1000w version?
I use a ssr and plug directly to the wall since the rubber is specced for 120v. The psu is just any 24v psu from eBay.
@Dat_Chu man that was quick reply. thanks. ok put me down for 1000w, 320x320, with the 1.5m cable, i’m assuming, too, that we’ll want the adhesive backed version? and thermistor position like the one @Eclsnowman has in his HeruLien drawing/link.
i’ll be picking up a similar 24v PSU and SSR setup as well.
@Dat_Chu I would run it through a fuse first, not direct to the wall. I use this: http://www.amazon.com/dp/B0050HH70E/ref=cm_sw_r_awd_KN94ub03KVENK
Down stream of the fuse/switch I go to my power supply, then daisy chain on the terminals on the power supply over to the SSR and bed. I will try to make a wiring diagram later.
@Seth_Messer I run a 400 watt on my Eustathios and it runs great. 1000 will be like putting in a finishing nail with a sledge hammer. I run my HercuLien on 800W and the bed is almost 17x17" and 1/4" thick. Even then I had to limit max output in firmware not to overshoot so bad that pid tuning would fail. I would say 600W absolute max for Eustathios and even that is overkill. Otherwise you chance warping the 1/8" heat spreader Eustathios uses by the thermal shock when that many Watts hit one side of thin plate.
@Eclsnowman sounds good. how long does it take, at present, on your Eustathios to heat the bed to your target temperature usually?
@Dat_Chu
I’m changing my order is as follows:
320x320
550w
120v
1.5m long
Adhesive back
Thermistor in center leads coming from back side off center 30mm.
3.5min to reach equilibrium for PLA at 70, 6.5min to reach equilibrium for ABS at 110. Heating is all about balance. Too small and it has to be on 100% of the time to maintain heat. Too much and you will have trouble pid tuning because deltaT is so fast that maintaining an even temp becomes impossible. Thermal expansion with large temp swings will change your bed to nozzle distance. This shows itself as z ribbing.
That is why I reset Z on my printer when I change from PLA to ABS. If I go from PLA to ABS without resetting Z there will be way to much squish and the nozzle drags around plastic. Conversely if I go from ABS to PLA the PLA will lift because it is just falling onto the bed. that’s how much differences 40deg makes.
Allowing the system to reach equilibrium is equally critical. Otherwise things will still tend to have a crown. The center will be higher because the sides and top are still cooler than the bottom where the heater is located.
@Seth_Messer like I said earlier 500w would be fine, it may even help abs temps, even 550W. But 1000 would be difficult (in my opinion) to get balanced.
Right on, i switched it to 550w then. Either way, the cost isn’t awful, so if it ends up that 550 is too high, etc then i can always just re-order.
@Seth_Messer if its too much just turn down max output in Marlin: #define MAX_BED_POWER 255 // limits duty cycle to bed; 255=full current
// This sets the max power delivered to the bed, and replaces the HEATER_BED_DUTY_CYCLE_DIVIDER option.
// all forms of bed control obey this (PID, bang-bang, bang-bang with hysteresis)
// setting this to anything other than 255 enables a form of PWM to the bed just like HEATER_BED_DUTY_CYCLE_DIVIDER did,
// so you shouldn’t use it unless you are OK with PWM on your bed. (see the comment on enabling PIDTEMPBED)
I assume Smoothie has something similar. Once my azteeg x5 mini is operating I guess I will find out where that is (since I plan on testing it on Eustathios as well as HercuLien)
@Dat_Chu Is it possible to wait a bit longer to place my order, so that @Eclsnowman can post his documentation for his Eutathios V2 build? I only have the main frame on order and waiting on everything else.
@Gus_Montoya I would just go 500W or 550W 120v 320x320 like @Seth_Messer . That is plenty, but you can always dial it back via firmware if it is too much.