3D Printer Upgrades - MOSFETS
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- เผยแพร่เมื่อ 5 มี.ค. 2018
- In this video we look at some options to improve Bed Heating of your 3D printer by using an external MOSFET power module and optionally a 24V power supply. The intention is to help you understand what these are and how they can help, I will also cover a couple of additional upgrades that should be considered at the same time.
This is a bit if a technical discussion, I will follow up with an actual upgrade in a separate video.
I have tried to keep the details fairly generic but GearBest was kind enough to send me a Driver Board to use in this tutorial so some details are focused arround that product, but these modules are so similar, nothing is lost relating to the upgrade or use.
The model I used works very well, has good quality parts and should be suitable for any 3D printer upgrade (Heated bed or Hot End ).
you can get one here:- goo.gl/RhcP19
For other GearBest goodies, just follow this link goo.gl/NSFb6w
As usual, if you have any questions, please post in the comments and I will do my best to answer. - วิทยาศาสตร์และเทคโนโลยี
![[TH] VCT Pacific - Playoffs Grand Final // PRX vs GEN](http://i.ytimg.com/vi/G345ud5yRGA/mqdefault.jpg)
I'm two years to late, but anyway ... "good quality content!!" Thank you, this is what I was looking for!
Your welcome, glad it was useful, more will be coming soon
learn alot from your videos than some other youtube videos with nothing of value! Thanks so much! Subscribed!
Thank you for detail information :)
Thanks Peter, good informative video, RobUK
Glad you liked it, I see too many videos with not enough detail on how these work and the consequences of not considering the effects to other areas of the printer like wiring ? so thought I would try to clear up some of the confusion
Good stuff!
Thank you for this info. On Mosfet A you use 12v DC thru the bridge to control PC817. Would you have to add a voltage divider to allow 24v DC to control this unit. I have 24v from my printer board mosfet at present.
nope, most of these will takes from 5 to more than 24v without issue
Hi, First of all, thanks for the video. I kind of hope you might answer my question, cause I'm almoast a newby in electronics. I have a Longer LK4pro and I'm changing the mainboard, I'll be using a SKR1.4 turbo, my PSU is a 24v 15A. The question, can I use this PSU whit a mosfet to the heatbed and have any benefit or should I buy another? Maybe a 24v 480W? Remember that the PSU would still power the mainboard and 3-4 fans.
Nice done
Thanks for sharing :-)
Hi, I am sorry if you answered this in the video, but circuits schematics is a bit confusing to me.
About that bigger one, with a red heatsink, what that "sig" and "-" connections used for?
There is 8 connector in total, and the smaller version you showed in the video only 6.
Thank you.
The sig is for low level control, from 5V or 3V3 for instance, this is why it has a low value resistor
the other one is for use with the full 12V or 24V from the normal Heat Bed output from a 3D printer controller.
If you feed 24V through the SIG connection, you may well fry the optocoupler LED
Great video. I realize this is a year old now but do have a question. I have a CR10s which has been working great up to now. The Heat bed stopped working. I checked the wiring for shirts and opens and all is okay. Upon checking my external mosfet (factory one) I have proper voltage, 12V, going into the mosfet terminal but nothing coming out. I am now not sure if it is the mosfet that has gone bad or if the main board is no longer sending the control signal. Is there a way for me to test the mosfet with my DMM and or the control cable to see if the board is sending the proper signal? Thank you in advance.
usually the + supply goes from the PSU to the heat bed, then out from there to the mosfet drain. the source of the mosfet would be wired to the 0V of the same power supply. if it is working then you should see the signal on the wire between the mosfet and the heat bed going from 12V to 0V when it turns on. if this is not the case then also check the voltage on the gate of the mosfet (The wire that leads from the printer control board to the mosfet board can also be checked. if you see this going between 0V to 12V then I would suspect the mosfet board. If you check directly on the mosfet gate pin and it is going between 0V (Approximately) when the mosfet is off to 4 or more (Up to 12V depending on the board design) and the mosfet output (Drain) is not switching then the mosfet is probably broken
I had the little black heatsink one and it burned me severely when it decided to die closed. My bed got to 132c and climbing. I replaced it with the red one and it got as hot but luckily did not die due to the heatsink being so big but a word to the wise and that is do not use PID with the red one as it will heat itself up so bad it will die for sure at some point. Use bang bang and it gets about body temp is all. The black one never ever even got warm so I am not sure what killed it but if PID heats up the red one this much it means they are using a slower mosfet so you need a slower PID switching frequency but I never could get my switching frequency low enough. Oh, and if too low then the PID is worthless.
21:20 FINALLY ... i found what im looking for... Thank you.
HaiHai glad to help
Hope you find more of my videos helpful
Do you have any instructional video that upgrade the Tronxy X5SA to solve its problems?
try this, th-cam.com/video/q1nfojoZUvA/w-d-xo.html it is were i upgrade the Tronxy X5S to use 24V and Mosfet, it should be close enough for you I would think. (I dont have an X5SA)
Bought a new mosfet and installed it. Seems the other two I bought were both faulty as this new one is heating my bed again. Also, my bed is heating again, so I guess it's not shorted out as I originally suspected.
I do have another problem though. I'm running an SKR v.1.1.3 main board with stock Marlin firmware. When I set the bed to any temperature, say 50 degrees, the led on the mosfet lights up red and the power supply fans start running full speed, letting me know that power is being diverted to the hot bed. All good so far. The problem comes in when the set bed temperature of 50 degrees is reached. Once there, the mosfet momentarily shuts off, but almost immediately turns back on and then starts to oscillate between on/off states in rapid succession, making the red led strobe in the process. This also makes the power supply ramp up and down rapidly over and over again. My stock setup, with the stock mainboard and stock mosfet did not do that. I've searched all over the web and have gotten no where. The supplier of the mosfet says that I have my firmware set to PID and should disable that, using Bang/Bang instead. I think he's just blowing smoke, as the original mosfet worked fine in PID mode. There was no rapid led blinking, no power supply fan constantly running up and down, and no change in the firmware with PID was enabled. I don't think this rapid ramping up and down to keep the temperature is normal, but don't know what to do about it? Have you got any ideas?
Actually he is not blowing smoke... that's exactly what your describing, a PID loop on the controller. to be strictly accurate, its not PID that is the problem, it is the PWM output that is used with it for fine control, so the suggestion for "Bang Bang" would be correct.
The rapid ramping up and down will actually keep the temperature more stable as it is making fine adjustments to the power applied to the bed, it does this by changing the on/off time ratio (PWM) and the PID tuning is used to improve the response time to heat and react to temperature changes.
I recently bought that eternal black Reliabot mosfet you feature here, do I want to drop my relay that originally was installed for my heatbed? My printer is a Tevo Tornado printer, 24v. I found the mosfet diagram via purchase on Amazon, but I forgot this printer has a relay in it.
Relay !!!, I have not seen a board using a relay for the board power control, or is this for shutting off all the 24v power
I'm having a heck of a time trying to connect one of these mosfets (the one at 19:32) to my CR-10 mini. Polarity of input doesn't matter (check) and connected (check). Negative in directly from 12V power supply (check). Positive directly from the power supply (check). Now the Creality hot bed has two thick black wires coming from it and two thick red wires. I connected the two thick reds on the second from the left terminal and the two blacks on the far left. From all I've read, the polarity of these does not matter as the bed is just one big resistor, right? As soon as I turn on the power supply, the mosfet gets too hot to touch and the bed starts heating up even though I did not set the bed temperature. The mosfet gets so hot it starts smoking at which point I immediately pulled the power. It does this even with the signal wire disconnected. Doesn't this point to a short in the bed? If so, how can I test the bed for a possible short? Very frustrated and looked all over the web for answers. Maybe you can shed some light on this?
Also, when I don't have the bed connected, the mosfet stays cool. As a test, with 12V connected to the DC in terminals, I get a reaqding of 12V on the very left hand bed connection? Is that correct? It shouldn't be, right as that means it would be heating the bed immediately and all the time as it seems to be doing now? Bad mosfet, bad bed? I just wanna get printing again, lol.
Tested as in diagram 32:22. Hooked up my bed to the mosfet just like the diagram. Printer turns on and mosfet stays cold. I then manually set the bed to heat to 60 degrees, but nothing happens. Power supply doesn't ramp up, heater doesn't heat, and mosfet stays cold. The blue led on the mosfet stays on though. After a few seconds, the printer display beeps and says that I need to reset because the bed is not heating.
Last thing to note, the motherboard is brand new, just installed, an SKR v 1.1.3.
from your description it sounds like you may have connected your mosfet backwards, this would account for all the heat and smoke, or you put it in parallel with the bed, not in series. without seeing a photo or diagram of the wiring, i cant be sure.
There should be a thick wire from the power supply +++ output to the bed (Preferably red wire), then the other side of the heat bed should have a wire going to the +++ of the mosfet, this would typically be black as this was what was on the bed in the first place. there would then be a third wire from the mosfet --- to the power supply --- completing the circuit.
The bed should only measure a few ohm resistance
If you mosfet was smoking it may well be destroyed now, accounting for why it no longer does anything. If you hook up as I described then the heat bed will warm up when the signal wire is powered, if the bed heats up without the signal applied it indicates the mosfet is shorted, if it stays cold after a signal is applied it is probably burned open circuit.
@@TheBreadboardcaThank you for helping me out.
Hooked it up as in the diagram at timestamp 32:22. Here's a pic: i1070.photobucket.com/albums/u494/eric5484/IMG_2128_zpssu8qzmyw.jpg. There is no connection on the second from the top terminal. In this configuration, my volt meter shows 12V on the mosfet power terminal, but also 12V on the top terminal where the two black bed leads are connected. This doesn't seem right to me as both black and red bed leads are now getting 12v. When I switched the dual black leads from the top terminals to the terminal just below, that's when it started smoking when I turned it on.
I ordered a different upgraded mosfet made specifically for the CR-10 which will hopefully get me back on track. I'm still unsure if my heated bed has a short or not? 12V, 220W, but only 0.8 ohm resistance between the heater leads? i1070.photobucket.com/albums/u494/eric5484/IMG_2124_zpscr8cltiw.jpg Right at the solder points in this picture is where a short occurred. It happened when one of the metal clips holding the printing surface touched a solder point - not sure which. I beieve this shorted out my mosfet and possibly the bed.
This is how it was originally wired: i1070.photobucket.com/albums/u494/eric5484/Original%20Wiring_zpsnpssreuh.jpg
nice video. enjoyed the mosfet rds part. power usage could have been simplified using i^2r, but tables good.
Great videos- so much better than the majority of useless muck on the tube. Thanks
thanks for the positive feedback, Appreciated. :)
I am trying to source a heat bed and power supply for my first 3d printer. They never seem to list the resistance of the bed. Is the resistance of the bed if connected to the 24v pads higher than the resistance of the 12v pads (like twice as much usually)? If so, it would seem that a 24v 15A supply would be enough to power the heat bed. I can't seem to find a 24v 30A PSU anywhere.
Where a heat bed has the option for 24V or 12V, you are correct, the 24V pads will be twice the resistance of the heat bed when wired as a 12V bed. Twice the resistance = half the current and therefor the same power is provided when in 12V mode or 24V mode. what you want to see is the wattage of the bed, perhaps 250 to 300 Watts for a 300mmX300mm bed. As a rough guide I found that 0.4W/cm2 seems to be able to get a bed upto 70-100Deg. so depending on your bed size, you should be able to work out the kind of watts you will need.
I too have been looking for a better 24V supply than 24V at 15Amps. I can find them on RS web site but not ebay and the like.
Here is the best I could find so I ordered them. The bed says nothing about watts or resistance in the listing and is 300mm x300mm.
www.aliexpress.com/item/MK3-Heat-Bed-12V-24V-Parts-For-Reprap-HotBed-3D-Printers-Part-Aluminum-Plate-3mm-hot/32842095969.html
www.aliexpress.com/item/Best-quality-24V-16-7A-400W-Switching-Power-Supply-Driver-for-LED-Strip-AC-100-240V/32318296978.html?spm=2114.13010608.0.0.vwn135
I plan to have 2 psu's one 12v and the other 24v for just the bed like in your diagram. I figure that if the bed is wired as a 24v, and the resistance when wired as 24v is 2.6 ohms, then it will draw about 9.2A (221 Watts) and the 17A PSU will be good.
But I am a little confused about the part in you response that says "wired as a 12v" bed. Wouldn't the bed then draw 18A?
24v/1.3ohms = 18.46A (443Watts).
I am also confused about "Twice the resistance = half the current and therefor the same power is provided when in 12V mode or 24V mode". The same power?
Using a 12v PSU to the 12v pads: 12v/1.3 = 9.2A = 110Watts
Using a 24v PSU to the 24v pads: 24v/2.6 - 9.2A = 221Watts
Did you mean same current?
You can probably run 2 12v 30amp supplies in series.
is a 160watt 11 amp psu good enough for 7 steppers hot end 2 fans and 6 end stops on a rumba plus my steppers are barely moving
if it is not driving the heat bed then it should be (7 steppers ??), what size steppers. and why 7?. if the steppers are barely moving then perhaps the current setting on the drivers is a bit low, can you provide more details on the parts being used and I may be able to give a better response.
@@TheBreadboardca nema 17 hybreds 3 extruders for dimound hotend
Steppers are minebea 17pmk374bn02cn drivers are drv8825
You can also drive a relay through the board and connect the heating device to the relay with different voltage
With this you can use low voltage fet or transistor to drive a relay which most time can sink up to 30amp depending on the relay
you could but would need to be careful with how you configure the control loop for it. I would not recommend using a PID loop for example and also limit the switching period so it is not turning on and off to often, this will cause a bit of temperature oscillation but minimize the noise created by hard switching heavy loads with bare contacts. I would recommend a solid state relay but then you need to normally have an AC supply for the bed. (This is actually a very cheap option even if it is a 12 or 24 v bed. just a low cost mains transformer is needed.
If your up to speed with wiring mains then you could also use say a silicon heat pad driven directly from the mains (SAFETY IS A MUST, SO GOOD WIRING AND PROTECTIVE CIRCUITS)
@@TheBreadboardca true using relay with PID may not work ...you right
Not sure if this is true or not, but if the mosfet blow it will stay at On ....?
Not 100% guaranteed to stay conducting (I think stays on is maybe implying it has some control in the matter, thermal runaway is more like that), but in a fault condition they can short out and therefor you will lose control of your heat bed, if your over driving it, that could be bad, this is why it is important to keep things safe, use the right wiring, fuses, good terminals etc. Another good idea is to have a smoke alarm in the vicinity of the printer, if your good with electronics then this could also shut off the power to the 3D printers ? or have a secondary temperature sensor on the bed set to trip the power or something ?
ist for that im thinking to put a thermofuse on the heatsink , wire in series of the heater of my hotend , so if the fan stop or run away on the hotend the thermo fuse with blow and cut the power to the heater, so now in think to do same on bed but cant put in series, need to cut all power
"FULL BRIDGE RECTIFIER" needs to be on a T-shirt with that guy's silhouette
I think he sells them already :)
You said "Doubling the current or doubling the voltage will quadruple the power" at 32:58. How so?? P =V*I, so doubling the voltage or doubling the current will double the power, will it not?
You might be thinking about resistance.
Great, 👍👍👍👍👍👍👍👍👍👍👍
36:51 no, no. If you need 10A with 12V, you will need 5A if you use 24V.
Assuming your only wanting the same power and you increase the resistance of the bed heater to 4.8ohms from 1.2 ish. This is not what I said, I said if you take the same bed and use a 24V supply with it then you will get twice the current ie. 20A (I = V/R ... I = 24/1.2 ... = 20A ). I understand how you came to that conclusio but I am afraid in this case you are mistaken. this would also result in 4* the power. so from 120W to 480W, thats a huge increase and you would have to ensure you bed can take it and your control circuit.
@@TheBreadboardca First I wanted to comment same like Eduardo, but about your answer I find out what you meant.. But.. Using a 12V heater or 12V hotbed on 24V, is a high fire hazard.
If anything goes wrong in control side (eg. a firmware faliure) and the bed or the hotend heating up uncontrolled, that will melting the aluminium plate and/or the hotend aluminium block.. Very dangerous idea IMHO..
Just the secondary "side effect" problem, because they heating much faster with 4times more power, very rarely can adjust the proper PID in that case.. Those heater elements not designed to use on double voltage and 4 times more power..
If somebody wants SAFELY upgrade the system for 24V, that is very good to reduce wire dissipations and if use TMC drivers, they very well known working much better on 24V, but have to change the hotbed and the hotend element for 24V one..
It's not complicated to find the polarity of the heatbed output, just use a $3 multimeter. More of a problem seems to be people making dodgy connections which put heat into the posts even with external MOSFETs. I'm a member of the Anet facebook group and the amount of burnt out wiring photo's people post is staggering. Not mine drive.google.com/file/d/1a_IsX1MkCu2SX_rEiBAs-o_ZyZzeyR1e/view?usp=sharing
Wow, great example of doing it badly, thanks for sharing
Yes, that was one of my points, your wire may not handle the current you push through it after the upgrade, in this case it also looks like the crimp connector was also badly done, increasing the heat at that point.
I have seen too many posts were people complain the FETS are faulty or the printer is crap, when in fact they just connected a 24V power supply, a MOSFET and left the older thin wiring dissipating 4X the power and wondered why things just melted away or worse, caused a fire. Also lets us re-state what seems to be the obvious, if you dont know what your doing, get someone that does, it can cost you more in the long run if you dont.
The finger test on the connectors with the printer working would have shown the problem before it burnt out if its warm its a bad connection. Many people who buy their kits have very little idea about electrics/electronics.
oh so true
great learning thank you so far but I had enough of this guy rectifier:-(
Can't see what you are doing with graphic covering 80% of screen covering up what you are doing.
The Graphics shows much better how the connections are made, unless im not seeing it the way you are... what is the time index ?
Screw it i may as well throw on 10 Gauge wire on that bad boy since its what i have laying around
buy peltier tec module...lets see if does not hot faster..
..
HotEnd and Bed run on 24V, control board can run on 12-24V
You know your stuff.. but u r a poor communicator (lacking structure, and rambling)