Quoteo_lampe @Glacian When you´ve killed the heatbed MOSFET, you´re screwed...those SMD MOSFETs are hard to replace without special soldering-equipment.... Now, that you´ve done the V-regulator mod, MakerBase sure won´t replace the board, you´ve lost warranty.... -Olaf Anyone that's burned out their SMD heatbed MOSFET and can't handle an SMD replacement can look at using an SSD or manually wiringby Learner - Controllers
Advanced Circuits in the last year or two expanded their capabilities from 24 layer up to 40 layers.by Learner - Controllers
Take a look at Advanced Circuits ( 4PCB ) in Colorade. That's who I use for all of my board fabrication work.by Learner - Controllers
Most people will be satsfied with IRLB8743 or IRLB3034 MOSFET's unless they spend a lot of money on a good SSR. You have to check the specs of the SSR to see what the On Resistance is or the expected votlage drop to fully decide. The MOSFET solutions work well as long as the PCB runs, connectors, and wires are all good quality and heavy duty. Some of the cheap boards skip on the connectors, runs,by Learner - Controllers
Cheap SSR's have higher resistances than good quality MOSFET's for controlling the current due to using cheaper parts. People also underestimate the impact of a little bit of extra resistance when it comes to heatbeds & high current applications. Every 1/10th of an ohm can have a significant impact in heat bed heating times, and cheap multimeters are't good for measuring values that lot unlesby Learner - Controllers
Thr IRF2804 may not be a good choice due to the Vgs(thr) rating (look at Fig 3 for 5V). Most heatbed drivers are controlled by the MCU directly so you need to select what is commonly referred to as a logicalLevel MOSFET or subLogicLevel. It's a good idea to check what the RDSon for 4.5V is if they don't claim to be Logic Level driven. I've always recommened IRLB8743 or IRLB3034/IRLB3036 as goodby Learner - Controllers
The voltage regulator is sitting between B & D and is trying to regulate the voltage on the output, from the Input to the Output. A & C are simply the common ground. I'm suprised there aren't one or two capacitors on the board as well (most regulators need them). Don't be confused by the vary resistance from A-B & C-D, that's just the regulator trying to operate outside of specs. Whaby Learner - Controllers
For the MOSFET resistance , you should use the 4.5V rating, not the 10V rating when possible. For the IRLB8743 that means Vgs=4.5V is 0.0035 ohms typical not 0.0025 for Vgs=10V. But I do agree those MOSFET's are great for that. The reason to use the 4.5V value is that most MCU's drive the MOSFET's with 5V, not 10V, so the 4.5V rating is closer to real world.by Learner - Controllers
Others should comment a well because I admit I'm biased. The fact that changing from a 22A to a 16A improved your temps does say the first PSU was having problems despite it's ratings. You really should have a good quality PSU with > 20A on the 12V rail or a dedicated non-ATX PSU for the heatbed for good ABS temps. The MOSFET change can help, but I think you're still not getting enough powerby Learner - Controllers
Quoteianmcmill The three MOSFETS on my Ramps 1.4 are P55NF06L ; 7SABF ; V6 ; PHL 243. None of the ones you named there. Might this be the bottleneck ? I insulated the alu plate with a 3mm cork sheet. I just received my Teensylu v0.8. Gonna give this a shot as soon as I get another hotend. P55NF06L is how STP55N06L is marked which is the 0.016 - 0.020 Ohm part spec'd out for use and the L at theby Learner - Controllers
Also, which MOSFET is being used to drive the heaters on yout PCB? Current wisdom is that IRLB8743PBF or for extreme cases IRLB3036PBF be used, and the schematic I looked at on RepRap spec'd out STP55NF with a higher RDSon, plus if a non-Logic Level part was used by accident, that'll make it even worse. The IRLB8743 works nicely with about 3mOhm vs 15mOhm resistance when on and with high currentby Learner - Controllers
For most eBay power supplies, I would recommend getting one with extra amperage compared to what you need since most are cheaply made in China and the quality& ratings are usually over stated. Best not to run those at their full rating. Plus, when you run them below their max rating they usually run cooler and at higher efficiency.by Learner - Controllers
Having your signal wires in a different sheath from the motor wires can help since the motors are a big source of spikes. In theory, twisting the motor wires could help also. If you do twist the motor wires together, it will work best if the pair used for each phase of the stepper motor windings is done together as a pair. That will improve the motor functionality for each phase. But unless you hby Learner - Controllers
There are always amp limitations, but most circuits are designed for 10A - 15A as long as you use the right connectors as well as MOSFET and heatsink choices. You do need to watch the connectors because some of the cheap ones are only rated for 8 amps.by Learner - Controllers
How bright do you really want the lights? There are some LED strips that can get very bright, but you usually want to made sure they are securely attached to something that will help dissipate excess heat or you'll shorten their life. I made myself some PCB's measuring 1.4"x3" with 24 of the 5050 SMD LED's that uses 12V @ 0.48A total and one to two of them make a nice bright desk lamp (my favouby Learner - Controllers
I prefer ro buy my board US made, spend a little extra for the boards, but I've had VERY good experiences with Advanced Circuits in CO ( 4pcb.com ). They have a good special for two sided boards up to 60 sq inch's for $33 each, qty 4 they turn around in a week. Their extended services I often get 2 oz copper instead of the 1oz standard and it rarely changes the cost of my boards.by Learner - Controllers
I would try to scope out the signals on good vs bad power supplies to see if you can narrow down where the problem is. The symptoms you give are similar to the smps reacting to an over-current situation, many have a output resistor with a voltage comparitor on the output someplace for current sensing and feedback through an opto-coupler into the PWM circuitry to disable the P/S if the drop is tooby Learner - Controllers
Also, look into Logical Level MOSFET's that turn on most of the way at 4.5V or lower. They can cost a little extra each, but are great for being driven by normal logic levels. If you dig around you can often find some 30V 60+A MOSFET's in the $0.30-$0.60 range in qty (the price does go up quickly in the qty needed for a single 3D printer from some suppliers).by Learner - Controllers
Anyone doing new designs should consider adding TVS diodes on the motor outputs to reduce the chance of frying electronics if you do make the mistake and plug/unplug your motors with power on that'll help cut the induction spikes down to something less likely to fry the drivers.by Learner - Controllers
slymike Wrote: ------------------------------------------------------- > You could always put the 1284 chip on, > I'm willing to do it for anyone who's interested, > only takes 5 minutes with the right soldering kit! Another reason to always use CPU sockets (along with when you blow the chip by accident).by Learner - Controllers
My thoughts were the heaters PWM & sensors would be off loaded, not the steppers. If you offload the steppers you MUST kill the latency which isn't practical.by Learner - Controllers
Actually, I was thinking of fewer per ATMEGA48P, and reserve several lines for low bits on the Addressing, then connecting via I2C people can hook up as many as they need based on their needs since not veryone needs a huge number.by Learner - Controllers
One reason I commented on designing around a micro, is you can probably offload the ADC & PWM functions to the same device, freeing up more pins for other things, like additional servos. Of course that does require code changes in the main mcro as well as the auxilary. A quick look showed that the ATMEGA48P or similar may be good candidates for the job based on cost, features, & pin counby Learner - Controllers
Or add a small cheap microcontroller that accepts I2C or SPI to produce the additional PWM channels? This assume you can do the coding or find someone to do it for you. Maybe I might just have to look into something like that for a future project myself as a generic module, not just for RepRap extensions.by Learner - Controllers
When you enclose a printer, you should place as much of the electrics outside of the enclosed area as possible since most things don't like temps greater the 75C and prefer even lower temps, but the actual printing likes temps closer to 105C.by Learner - Controllers
From what I'm seeing, you're using sockets for the Servo Drivers. Any issues with those that anyone has seen at the 2A level? Any potential issues with those at 3A, or do you think in that case we're better off soldering the servo drivers in to get better contact and improve the heat dissapation through the PCB runs?by Learner - Controllers
Agreed, with most FET's, you are limitted to 20V without having something to drop the voltage down. someone wanting to run 24V would need to supply a lower voltage to the FET driver from someplace else or provide a simple source such as from a 7812/7815 or resister + zener since current is minimal. As I said in that posting, it's at least worthwhile to run a test with existing boards by wiring sby Learner - Controllers
Having read through this thread and looking at the schematics, I would highly recommend testing having an opto-coupler between the ATMega and the Heater FET's. From what I read in the specs of the IRFZ44N FET's at 5V they aren't all the way on yet, which helps account for some of the heat they are producing. By adding the opto-couplers, you can drive it easily with a full 12 Volts which will satuby Learner - Controllers
Have you considered using one resonator intead of a crystal and two caps? The Murata-Electronics CSTLS20M0X53-B0 is ideally suited for this, lowers the parts count as well as the cost.by Learner - Controllers
What's the current status on the Gen7T, including availability? I've been thinking about tackling my own double sided version of the Gen7T since the Wiki info was so old, then I stumbled on this. I found the proper thread at thank you for your time.by Learner - Next Wave Electronics Working Group