Hotend never reaches Temp

[omnibus]

Hello all - So far owning my rostock max v2 has been a dream. Almost 300 prints for 30 days of print time. Even printed a t-rex head.
I print a lot of small things (I am piecebringer on thingiverse - check my stuff out and comment if you play some dnd!)

BUT yesterday my printer's extruder does not reach the printed temp for specified filament (210 for pla)
Symptoms:
It hovers around 10 degrees below the temperature. (Even if I raise the preheat temp, tried 200-230 always about 10-20 points below)
I re-ran the PID autotune a few times. - most of the time it times out and the hotend doesn't reach temp.

I flashed the rambo eeprom. And re-installed per the original rostock max V2 manual I had.
Re-ran PID autotune... doesn't reach temp.
loaded old eeprom doesn't reach temp.

Checked ohms accross heating resistors (have old bowden hotend with two thermal resistors) get about 10 ohms... seems high?
https://www.seemecnc.com/products/seeme ... den-hotend says they are supposed to be 7 ohms.

wiring - checked and rechecked. seems fine, nothing loose. (did have to replace a terminal a while back)

I adjusted the eeprom's
PID drive max (Tried 150 to 255 in 15 point increments - default 205)
PID P-gain ( 20 to 40 in 5 point increments - usual is around 33)
PID I-gain ( 2-3.75ish - honest just kinda random here - usual about 2.8)
PID D-gain (60 - 120 - usually around 75)

I would love suggestions to help my printer from becoming inert!

Thank you in advance.
-Charlie

[Mac The Knife]

I was going to post that that you need to tighten the power supply connections at the RamBo, but you say you've already done that.

[geneb]

Chances are that one of the resistors has cooked off.

g.

[omnibus]

@Mac the Knife - The terminal that burn out was the ones that power the bed and extruder. This terminal was replaced in my last fix. I double checked my solder work, the wires and the wires from the power supply.

@Geneb - So either I change out the resistors or get a new hot end? I will try this - I have a E3D hot end that I was going to put on another printer... I will try to install it on the Rostock and report back. (I just noticed that you too live in Wa! Nice, I am in Seattle!)

Thank you for your responses!
-Charlie

[Mac The Knife]

Gene has a video on youtube showing how to replace the resistors with a heater cartridge in the hotend. Myself, I installed two,,,,, to keep the hater block balanced.

[geneb]

The E3D is a good upgrade if you've got one on hand.

g.

[omnibus]

Still working on this...

The hot end I had was: https://www.amazon.com/gp/product/B010M ... UTF8&psc=1
It is a 12v (the rostock max 2 is a 12 volt right?)

I have tried a few mounts:
https://www.matterhackers.com/store/dig ... x-or-orion
https://www.thingiverse.com/thing:1064131
https://www.thingiverse.com/thing:137140

I searched and it looks like some have used: https://www.thingiverse.com/thing:2098268

Some of the issues I having is that the mounts seem loose, when I install the hotend it wobbles a bit. I feel like it should be tighter.
The hot end when installed still does not reach temperature... even worse than the original - maybe I damaged something.

I am going to get a temperature gun tomorrow to check it.
I am also thinking of giving up on the new hotend and getting the replacement: https://www.seemecnc.com/collections/pa ... den-hotend

Thoughts would be helpful!
-Thank you in advance
Omnibus

[Xenocrates]

The rostock max is a 12 volt machine, yes. Do you have a multimeter, especially one with thermocouple support? The IR temp guns do not work accurately on aluminum, as it has the wrong reflectance for the settings in the cheap ones (You can buy ones which will work well with aluminum, but it's much more expensive to get those). I would check three things. the voltage at the Rambo input terminals (If it's not 12 volts, you may have a problem with the power supply. If it's one of the newer V2s, you can adjust a potentiometer on the power supply to increase the voltage). You also want to check the resistance of the heater. Both the seeme and the E3D clone should be 5 ohms or less. If it's above 5 ohms, they will not draw enough amperage to work properly.

Finally, you want to use a thermocouple to check the hotend temperature compared to the displayed temperature. You may have a thermistor issue, a configuration issue, or a cable issue, all of which can cause issues with the temperature.

Additionally, those cheap E3D clones can cause issues with tolerances on the heater cartridge (you may have accidentally gotten a 24V cartridge, for example), as well as machining tolerances. A good E3D style mount is the 713maker design.

[omnibus]

Aaaannnd paper weight status....

I think I fried the rambo board trying to test voltage. No lights come up on the board now. there is still 12volts power coming in... but board no light.

Unless I am wrong - this would mean I need a new board?
Thoughts?

Fuse looks good.
Edit: ahh more fuses -
Have 12volts going through Fuse 3 (F3)
No volts through Fuse 2 (F2)
and none through Fuse 4 (F4) the big one
Where is Fuse 1?....


I swapped Fuse 3 and Fuse 2 - I got one light... So it looks like a fuse is blown
Does anybody know the replacement fuse (the tiny ones)?
EDIT 2: Found on seemecnc: https://www.seemecnc.com/products/5-amp ... -for-rambo (Going to order this)

No signs of burned spots/wires.


-sad day
omnibus

[omnibus]

Hello,

So I put my printer aside because I still could not figure out what is going on with it.
Replaced the fuses in the rambo board.
Tried new E3D hotend - still doesn't reach temp.
Got a Bowden hotend (like original w/ new thermometer) - still doesn't reach temp.
Have a multi-meter with temperature gauge and verified that the temperature is ready pretty accurately.

It still never reaches the desired temperature....
Tried re-flashing the board...
Checked the wires...
not sure what to do.

Any Suggestions please?
Should I get a new board? If so seemecnc doesn't carry boards for the V2 anymore.

Thanks,
Charlie

[geneb]

What temp are you setting? How close does it get? Have you contacted support about this?

g.

[omnibus]

I am trying to get to 200 - its gets to 180ish.
If I try 210 its gets to about 190ish.
It always seems to be about 10-20 degrees under the recommended.

No, I haven't contacted support... I didn't know/think of it.
Will try support.

Thank you

[geneb]

I should have thought of this earlier - start heating both the bed and the hot end and then check the voltage coming out of the power supply. You can use the terminal screws for the RAMBo input power as your test points. If you see anything less than around 11.5-ish, you've got a power supply problem.

g.

[omnibus]

I should have thought of this earlier - start heating both the bed and the hot end and then check the voltage coming out of the power supply. You can use the terminal screws for the RAMBo input power as your test points. If you see anything less than around 11.5-ish, you've got a power supply problem.

g.

Good news! It is alive and working again like a champ.

It was the power supply.
After checking ohms, software, wires, hotends, etc...
Got a temp sensing Multimeter and verified it now reaches temperature.

I also took the time to update the wires into the power terminal with those shoe-lace type wire ends. Makes it so much nicer.

Thank you for saving it's life!
-Charlie

[geneb]

\o/

g.