Calibration Questions

[Toyguy]

I started posting some of these in the Build Log but thought I would move them out here just in case there are members who don't read Build Logs

I'm starting through the calibration process in the Assembly Guide and am generating some questions. Any insight into these would be helpful...

1. When using the Z manual control arrows in Repetier-Host, the motion up and down is quite slow. Is that normal? When Homing the carriages move quite quickly, so I am guessing this is just something Repetier-Host does, but wanted to be sure.

2. Does the mentioned Home-X and Home-Y button bug still exist in the 0.90c release of Repetier-Host? It would be nice to have those working. On a related note, do the unlabeled Home (Home All?) and the Z-Home work correctly?

3. When tuning the hot end PID, the process completed successfully, but I noticed the PEEK fan never came on. Should that have been on or does the Autotune not use it? Is there a simple way I can test the fan?

4. When tuning the heated bed PID, should I do so with the glass plate on or off? Make any difference in the PID calculation?

5. While the hot end was coming up to 200C during the tuning process, I detected a small stream of smoke from around the nozzle end. I watched it very carefully and could detect no burning insulation, nothing touching the hot end that I could see. It stopped after a brief period and did not reappear while the tuning process continued. I'm hoping maybe just some oil or something on the metal bits but has anyone seen this before? I am wondering if I need to disassemble the hot end.

Thanks, and Happy Thanksgiving for those partaking!

Dave

[dpmacri]

I started posting some of these in the Build Log but thought I would move them out here just in case there are members who don't read Build Logs

I'm starting through the calibration process in the Assembly Guide and am generating some questions. Any insight into these would be helpful...

1. When using the Z manual control arrows in Repetier-Host, the motion up and down is quite slow. Is that normal? When Homing the carriages move quite quickly, so I am guessing this is just something Repetier-Host does, but wanted to be sure.

2. Does the mentioned Home-X and Home-Y button bug still exist in the 0.90c release of Repetier-Host? It would be nice to have those working. On a related note, do the unlabeled Home (Home All?) and the Z-Home work correctly?

3. When tuning the hot end PID, the process completed successfully, but I noticed the PEEK fan never came on. Should that have been on or does the Autotune not use it? Is there a simple way I can test the fan?

4. When tuning the heated bed PID, should I do so with the glass plate on or off? Make any difference in the PID calculation?

5. While the hot end was coming up to 200C during the tuning process, I detected a small stream of smoke from around the nozzle end. I watched it very carefully and could detect no burning insulation, nothing touching the hot end that I could see. It stopped after a brief period and did not reappear while the tuning process continued. I'm hoping maybe just some oil or something on the metal bits but has anyone seen this before? I am wondering if I need to disassemble the hot end.

Thanks, and Happy Thanksgiving for those partaking!

Dave

1. That's normal. You can specify a speed for move commands. The UI buttons appear to use a slow speed.

2. I don't know . I don't touch them

3. You need to manually turn on the fan with "M42 P6 S255". You can put that in startup g-code for prints.

4. Put the glass plate in. The PID values are dependent on how thinks respond in practice, so a different thermal mass would likely change the values. I'm not sure how much, but better to be on the safe side. Most likely, your bed heating would take longer with the glass if you calibrated without it.

5. Probably just oils like you thought. If you have a thermocouple, you could verify that the temperature readings are correct.

Happy Thanksgiving! Have fun with you first print

[geneb]

I don't know if the Home X and Home Y buttons have the same issue, but because you're working with a delta configuration, they really don't need to be used anyway. The un-labeled home button does the same thing as a G28. (home all)

g.

[Toyguy]

Thanks for the input guys. I don't have a thermocouple - guess I should get one. I do have an infrared heat reader for my reptile cage, so I tried that out during the bed Autotune. It was within 3 degrees of what the bed thermistor was saying. I'll check the hot end next time I fire it up.

A question on the PID autotuning - when I did the hot end, the calculated values weren't all that far off the defaults. On the bed, however, the calculated values are considerably higher than the defaults. Is that fairly normal?

I also got an error at the end of the bed autotune. It reported Autotune finished successfully, but then printed an Unknown Command error followed by Resend: 38 in red text. Any clue what that's about?

Finally, should I repeat the hot end autotune with the PEEK fan on? Now that I know I control that manually, I'm wondering if it affects the PID tuning at all?

Oh, and is there any benefit to repeating PID tuning? Will it get more accurate over several iterations?

Thanks!
Dave

[626Pilot]

When I want to move on the Z axis I usually just issue a G1 command with F5000. I prefer to keep the default Z speed low for nozzle height calibration. The little box where you can type individual commands will remember what you type, and you can scroll through it with the up/down arrows. I usually have G28 and G1 Z100 Y-100 F5000 sitting in there (brings the platform to about eye height and towards the front of the printer for maintenance) and I just pull up the one I need with the arrow keys. It's pretty convenient.

For the bed autotune you should expect to see values way up in the hundreds. The default value that comes with Repetier is for some other heater that doesn't behave the same as ours.

Smoke coming out of the nozzle is normal the first time it's heated up after construction, or when you re-cement anything with RTV. It has to outgas for a little while. There can also be some tiny amount of oil left over from the machining process.

[Toyguy]

Thanks again guys! I've run into a minor snag with the process - the bed autotune is popping the 20A circuit breaker in the house panel

I don't have a way to measure the current easily, but this reminds me of the post I saw from another member who noted his Onyx was pulling 20A. I wonder if there has been some design change recently that's somehow increasing the current demand?

I'll have to go figure out what else is on this circuit and see what, if anything, I can turn off. Next week, I'll have to get a quote on a dedicated circuit

I did go ahead and re-tune the hot end with the fan running. It made a minor difference but probably wasn't truly necessary.

[Polygonhell]

Thanks again guys! I've run into a minor snag with the process - the bed autotune is popping the 20A circuit breaker in the house panel

I don't have a way to measure the current easily, but this reminds me of the post I saw from another member who noted his Onyx was pulling 20A. I wonder if there has been some design change recently that's somehow increasing the current demand?

I'll have to go figure out what else is on this circuit and see what, if anything, I can turn off. Next week, I'll have to get a quote on a dedicated circuit

I did go ahead and re-tune the hot end with the fan running. It made a minor difference but probably wasn't truly necessary.

The Onyx should be pulling < 20 A at 12 V, the house circuit is 20A at 110V, the onyx would need to pull close to 180A at 12v which it can't without blowing the fuse on the RAMBO, to blow the house fuse, so I'm guessing the circuit is already near max load without the printer.

[geneb]

Keep in mind that the Rostock MAX uses a PC power supply, so no matter what it's not going to draw more than 450 to 500 watts maximum.

g.

[Toyguy]

Yeah, it seems like it shouldn't be possible, but it did trip the breaker. While it was off, I looked for non-working things around the house and it's basically just my room, with my PC, laptop, MAX and a couple phone chargers plugged in plus a pair of fluorescent lights in the basement. That's it.

The wiring was just done back in the Spring, so I'm going to call the contractor and have them come check it out - maybe put a load meter on it while I run the autotune a few times. Maybe the breaker is just weak. Everything worked fine after the trip, so no fuses on the Rambo were blown, tending to rule out a 20A load in my mind. I was also able to run the autotune once after the trip when I shutdown my desktop PC and put the laptop on battery but that's probably coincidental.

More testing and tuning tomorrow!

[geneb]

Well you figure that in a perfect world, a 550W power supply can pull about 4.5A maximum (Watts/Volts = Amps) with a 120v circuit.

You might have a dodgy breaker - it happens.

g.

[cope413]

Not sure that's right...

it's 120vac input, but it's running ouptut at 12vdc, which means in a perfect world, the max draw would be 45a. Correct?

[geneb]

Well if the INPUT was 12vdc, then that would be correct.

The real world figure might be a bit higher than 4.5A, but it'll be close.

g.

[cope413]

Can you explain your rationale?

The 12v rail in my PSU is rated for 216watts, which I believe means that it can draw 18a... What am I missing here?

[cope413]

The table on page 16 here would also seem to suggest otherwise...

http://www.formfactors.org/developer/sp ... DG2.01.pdf

[geneb]

1. You're referring to a table that discusses DC. We're talking about AC draw here.
2. The formula to derive amps is (and will always be) Watts / Volts. A PC power supply rated for 550 watts at 120v will pull about 4.6A in a perfect world, assuming 100% efficiency of the power supply.

This is the kind of thing I know cold. (Why? N7MOS. That's why.)

Instead of trying to explain the science at all, I'm just going to prove it.

The following pictures show an Orion and a Rostock MAX plugged into a Kill-a-Watt. A device that has a number of functions, including telling you to two decimal places how many amps the currently connected device is pulling.

Orion, idle: (220 milliamps)
[img]http://www.geneb.org/orion/orion-idle.jpg[/img]

Orion, Preheat ABS: 1.79 Amps.
[img]http://www.geneb.org/orion/orion-preheat.jpg[/img]

Rostock MAX idle: 240 milliamps
[img]http://www.geneb.org/rostock-max/rmax-idle.jpg[/img]

Rostock MAX, Preheat ABS: 2.76 Amps.
[img]http://www.geneb.org/rostock-max/rmax-preheat.jpg[/img]

So yeah, running a 3D printer doesn't pull near what you guys seem to think it does.

g.

[cope413]

Ahhh, I wasn't following the thread above. You're talking about pulling 4.5a from the wall socket - hence the breakers popping in his house.

On the same page.

[geneb]

\o/



73 de, N7MOS.

g.