Benbox Laser Machines/CO2 Lasers/3D Printers

3D Printers => General Discussion => Topic started by: GD George on April 12, 2020, 04:30:49 PM

Title: Controller Card Swap Out...
Post by: GD George on April 12, 2020, 04:30:49 PM
Some time ago, the MOSFET controlling the bed on my printer stick open.  As I've been printing PLA, I didn't really need the bed, so I disconnected it and continued on my merry way. At some point, I ordered a couple of MOSFETs and another ramps board.  Fast forward to yesterday.  I'm working on a prototype touchscreen to replace the audio head in my car, and I want to print it in ABS.  So now I'm replacing the ramps card. I swapped out the card, plug by plug and have checked my wiring but there's weirdness...

Steppers on manual control from the LCD are intermittent. Sometimes they work and sometimes they don't.
Neither the bed nor the top will heat.
The LCD seems to be getting power from ramps. BUT... It's also getting power from the USB, if I connect it.

I'm getting power to the ramps card from the PS. (And my multimeter just crapped out.)

So tomorrow, I'm off to pick up a new multimeter. Any ideas what to check next? I can go back to the old card for a bit, but I am going to need the hotbed eventually.

Any suggestions greatfully accepted.

Best,
Jerry
Title: Re: Controller Card Swap Out...
Post by: ggallant571 on April 13, 2020, 07:22:06 AM
Did you test the current limit on the stepper drivers?
Title: Re: Controller Card Swap Out...
Post by: GD George on April 13, 2020, 03:06:45 PM
Thanks for getting back. That's the little pot on each driver, right?  I haven't touched them since I built the machine. How do I test them?

Jerry
Title: Re: Controller Card Swap Out...
Post by: ggallant571 on April 13, 2020, 03:36:26 PM
You use a volt meter. Connect the negative  lead to Gnd and the other to the trim post case. For single 12V motors with A4988 drivers the voltage should be about 0.45V. Higher allows more current which will also increase the heat dissipated in the motor. If you have 2 motors you need about twice the current so set the voltage accordingly. www.pololu.com has some excellent tutorials.
Title: Re: Controller Card Swap Out...
Post by: GD George on April 19, 2020, 08:32:30 AM
Thanks, George. I took it apart and put it back together again and the motors are turning now. I also replaced my multimeter, so I'll check the current limit later.  I need to wait for it to warm up a bit out in the garage to see if the tip and the bed are working as they toss mintemp errors right now.  Quick question: can I put 12v from the PS directly to the bed long enough to ensure that it goes on? If I'm still having issues, I'm going to re-flash the arduino and see if that helps.

Jerry

Title: Re: Controller Card Swap Out...
Post by: ggallant571 on April 19, 2020, 11:35:02 AM
It should be safe to drive the hot end and heated bed with 12V. Mine are 24V and some of the newer are 120V AC.
Title: Re: Controller Card Swap Out...
Post by: GD George on April 19, 2020, 12:54:36 PM
OK, I just ruled out the bed or the tip as issues. Both heat up when hooked to 12V. The thermistors are correctly connected and both read within a couple of degrees of the actual temperature...

This is either a bad card or something stupid...
Title: Re: Controller Card Swap Out...
Post by: GD George on April 19, 2020, 01:02:24 PM
Oops... Should have sent this one before the last...

OK, so...  No power out to the tip or the bed (d8 and d10) but the fan (d9) switches on when I run the preheat for either.  I have 12v from the PS into the 5A. Right now I have the other 12v into an external MOSFET and the signal for that into d8. The tip goes directly to d10 and the fan to d9. I reflashed the printer but no dice. 

(Which begs the question: do I still need power into the 11A, even with the external MOSFET.) Note that I tried this with the power and bed directly to the RAMPS and it's still acting the same way.

What about LEDs on the RAMPS board? I've got a single red, and an intemittant green.
Title: Re: Controller Card Swap Out...
Post by: GD George on April 20, 2020, 05:25:43 AM
To do:

*I'll check the polyfuses this afternoon.
* bypass the thermistors in Marlin and see if the machine heats up. If so, do one at a time. I think I have a spare or two.
*If all else fails, go back to the old board and see if the the issues persist.

Title: Re: Controller Card Swap Out...
Post by: GD George on April 29, 2020, 05:41:21 PM
I decided to wait on some ferules and a crimper before reassembling my printer. Also bit the bullet and ordered another card and an arduino. Today, I reassembled the thing.


Best,
Jerry
Title: Re: Controller Card Swap Out...
Post by: GD George on April 30, 2020, 10:30:56 AM
MOSFET on ramps is stuck partially open.  (How is that possible?) 

Anyway, I hooked up another external MOSFET and the control LED lit up as soon as I started the printer, and the tip ran away.  Swapped control circuits (to make sure the external MOSFET wasn't the problem) and it responded correctly when I turned on the bed.

OK, I've got another card and just need to swap out parts. The question is: should I just swap motor controllers, arduino, etc? Or should I just replace the while kit-n-kaboodle? I have the parts, but I know everything in the existing setup (except the one MOSFET works...

I guess I could also take a MOSFET off the original board and put it on the current one...

Jerry
Title: Re: Controller Card Swap Out...
Post by: ggallant571 on April 30, 2020, 04:46:32 PM
PWM on the input. Perhaps a cap for filtering. Do you have a scope?
Title: Re: Controller Card Swap Out...
Post by: GD George on May 03, 2020, 09:52:16 AM
No scope.  I may have a scanner for my car that works as a scope though. But that's a different project for another day.

Thanks!
Jerry
Title: Re: Controller Card Swap Out... Printing Again!
Post by: GD George on May 09, 2020, 08:26:15 AM
Printing again! I wound up replacing the RAMPs card. I think that the original and the other replacement card each have a bad MOSFET, one for the bed, and one for the hot end.  While I had it apart:

Title: Re: Controller Card Swap Out...
Post by: ggallant571 on May 09, 2020, 09:29:34 AM
Now that you have "free" time while waiting for the prints to complete perhaps you could do a quick write-up on how you got octot print to play nicely.
Title: Re: Controller Card Swap Out...
Post by: GD George on May 09, 2020, 01:58:45 PM
Is there something specific?  Octoprint is running on a Raspberry Pi 2b+. I do my slicing on my desktop using Slic3r, and that send the code directly to the RPi. To set up Octoprint, I used the OctoPi Image and set up the printer using the settings that I had used for Slic3r and Repetier. I don't think there was any trick to it.  The Pi is also running a RPi Cam that does a pretty nice job.  For this go-round, I actually had to reinstall it and then restore a backup as I had added a plugin to control my laser that overwrote a bunch of things.

Jerry

Title: Re: Controller Card Swap Out...
Post by: ggallant571 on May 09, 2020, 07:06:09 PM
Is the rpi connected via ethernet to the computer that does the slicing? Is the rpi connected to the printer via USB? How does a print get started, paused, or aborted? If you have more than 1 printer do you need a dedicated rpi per? My last three tries at getting started with octo print ended in frustration.
Title: Re: Controller Card Swap Out...
Post by: GD George on May 11, 2020, 01:39:56 PM
Network

Printer Connection
Control
Slicing
Probably too much detail but I hope this helps!
Jerry
Title: Re: Controller Card Swap Out...
Post by: ggallant571 on May 11, 2020, 05:56:40 PM
I have a similar setup for home networking. Due to a ordering mistake I have two RPI4 modules sitting idle.

My printer contains a Lerdge X controller with an almost Marlin compatible command set. This may have been the major cause of frustration. Connecting to the printer via Cura fails but works with Pronterface.
Title: Re: Controller Card Swap Out...
Post by: ggallant571 on May 12, 2020, 08:03:31 AM
I have a similar setup for home networking. Due to a ordering mistake I have two RPI4 modules sitting idle.

My printer contains a Lerdge X controller with an almost Marlin compatible command set. This may have been the major cause of frustration. Connecting to the printer via Cura fails but works with Pronterface.
Title: Re: Controller Card Swap Out...
Post by: GD George on May 12, 2020, 08:46:17 AM
I'm sure you've looked into it but the issue with the Lerdge gear looks to be both firmware and connection speed. There are reports on the OctoPrint forum that it worked with Octoprint up to a specific version and then poof.  (The thread move from S to the X series towards the bottom. ) There's also something on Youtube about switching the x over to Marlin.

https://community.octoprint.org/t/lerdge-s-controller-connection-issue/2313

Title: Re: Controller Card Swap Out...
Post by: ggallant571 on May 12, 2020, 04:49:40 PM
The problem I have observed is the Lerdge firmware reacts properly to most generic motion & heating commands. It does not respond correctly to the "standard" line number scheme and formats responses to temperature and position in a non-standard way. Both items should be trivial to fix.

I am quite confident that Lerdge just ripped off Marlin. Last year there was a Marlin bug uncovered and the same bug existed in the Lerdge.