heatbed and bed leveling

ultibots.com for power supply and kapton heatbed,, be aware if you run a 24v heatbed you'll need a 24v power supply and make necessary changes to firmware and what not.
I would not get that combo..get a kapton heater with aluminum spreader and boro glass on top.

 

i used a circuit breaker..pick a fuse or circuit breaker. that is within limits of the heat bed your wiring it to.. ie if it uses 18amps, get a 20amp fuse or circuit breaker.. ..etc..

 

heatbeds dont always run at max amps...they peak while they are heating up. then drop to nominal current as the temperature reaches the set point.

proof..example..

 

Depends on the ∆T above ambient. A heatbed running at 110C will probably be pulling near max power since it requires a large amount of energy to maintain this on such a large surface area. I could see the hbp running at >90% power to maintain 100C, but don't really feel like going through the calculations to verify how much energy it actually takes

 

umm nope..

 

well said

 

THANKS!

 

It's ok. You're allowed to be intimidated by my intelligence. Most people are.

 

ok..if you say so

 

word of warning.... if you have any questions regarding my heat bed set up please feel free to ask directly. There are a lot of other things to it other than what i show.. just because i used a 24v power supply doesn't mean you have to.. my configuration is different from stock and done this way for a reason...

 

Hi - I fixed it!

See my fix at the Relay Switch string. You may like the solution?

http://forums.robo3dprinter.com/ind...ddition-to-prevent-heat-bed-cutting-out.1299/

Brian.

 

pretty long drawn out write up.. and the simplest solution to your problem (which is not related to this thread) is to just add a fan.. or have the manufacture fix the problem rather than you fixing their screw up..

 

Ha, ha... yeah wordy - I'm alone.
This thread diverted and was talking about HBP amp draw, delta_T , power, circuit breakers, fans, 24V, etc. Sorry for the wrong post.

Using The Fan is an excuse and cluge. The board design was good when the designs were made - HBPs were running 4-6 Ohms and people over heat their stepper drivers because many mis-calibrate or do not calibrate the stepper driver power. This RAMPS board design was earlier in 3D printing for hobbyists years.

The RAMPS components are Not a True Manufacturer's problem. The boards are built per design. It was in Design and NOT a problem but, with the production company users. Definitely - the screw up is the guys going to production without actually fully testing this off the shelf item. Many of us have it screw up immediately so the problem should not have been hard to find before selling and shipping many. The Robo guys are beginners, like us all, too....

Thanks....

 

Jerry, the only benefit you'll get out of using that insulator, is the heat bed will get to temperature quicker than without an insulator. It wont reduce how much current the heat bed uses. The only way to change how much current the bed uses is to get a heat bed that uses less current.​

 

How would you adhere it? Insulating the air side would help with the thermal requirements during operation as you're directing more of the energy into the borosilicate which has a high thermal conductivity, so only a little.

BTW I did some math on the energy requirements. I assumed during steady state operations the immediate ambient air surrounding the boro would be ~40C to make the numbers work. As the heater only has 110W of power it didn't make sense it would require 130W of power to maintain 100C at a 20C ambient. Though that does make more sense if you were blowing cool air or something else to maintain an 80C differential.

https://docs.google.com/spreadsheet...STRfUXd2akw1VkxMVlNNREVULVE&usp=sharing#gid=0 If someone wants to check my math