Aggravating (Serial?) Issue

Hi-

This is a very annoying occurrence for me.
Here is what happened:

I was printing a scaled up twisted bottle. It was a ~4 hour print, i was 3.5 hours in. All the light were off in my room and I was downstairs. I went up to check on it.
I could hear it printing.
As I walked into my room I hit the light switch... well, I accidentally hit the switch for my ceiling fan.
The printer stopped.
This has happened more than once and I obviously know the fan is the problem. Ive had problems with a few other devices/appliances.

My question is simple:

How do I fix it?

-Nick

If you see my "prusa locks up" topic below, below, you know you are not alone. I wonder if a small UPS might be your solution. Or are you asking how to rescue your 3 1/2 hour run, which I would guess would require a text editing of the g- code, and a lot of luck

I have read that thread. Correct me if I'm wrong but that thread seems to deal with "random" freezing/disconnecting... Mine happens with very particular actions.
No I am not trying to recover the print.
-nick

It's probably because the fan is on the same circuit as the socket in the room, short of fixing your house wiring, which is likely not an option a simple surge protector might be enough, if not then I'd try a small UPS.

Yes, my freezes seem to be random, but there have been those who have attributed it to an outside cause, like the compressor turning on in another room, but on the same power line as my instrument, causing lockup voltage spike. Mostly, I was just suggesting you try a small ups

Are your electronics powered by both USB and external power?

IF you read the new posts in the thread you will see that we are talking about interference comming from other applicances in the house.

Its very possible that power fluctuations or emi in the AC line causes issues. When you turn on a ceiling fan there is a motor in there that draws a lot of current on startup, that alone is probably what cause your problem. You should try pluggin into another circuit (different breaker).

A UPS wont do much unless its a very expansive model that does double conversion (eliminates all the noise in the AC line by converting ac to dc and back to ac again). I doubt you have that.

Its probably easier to plug somewere else or work with us to figure out how to properly shield and filter our electronics. There is also a possibility that windows isnt helping. You should join us in the other thread and please let us know more about your setup, electronics, psu, what your plugged into and how, your os, etc...

The other thread

Edited 1 time(s). Last edit at 09/14/2012 12:59PM by thecrazy.

And btw, the only reason our problem is random and yours is not is that your interference comes from the ceiling fan that YOU turn on. Ours probably come from our refrigerator. Come to think of it I have a freezer plugged into the same circuit... stupid me.

Have you considered printing from SD? That would remove at least one cause of spurious serial lockups due to motor induced EM or conducted noise from shared AC. I know am guessing it's probably not "the solution" you wanted hear, but it's far more certain than a suggestion to solve this or that issue with shielded electronics, cabling issues, resolving all coupled power supplies, adding isolated USB interfaces, etc. Solution could be as simple as adding a beefy cap to your power supply or as complex as gutting your present electrical/electronics system to redo it from scratch.

If nothing else, if it continues to happen once you're printing from SD, then you know you have issues in your wiring and or unshielded microcontroller if the printer continues to seize when it encounters known triggers like switching on your fan.

If you just caught the skip, just pause the print, and home on both X and Y axis, and continue printing.
It will continue printing from at the correct location.

Specs:

12Volts, RAMPS 1.4, Old dell (probably like 2002-2005ish), pronterface.

Not to be dumb but Im no engineer, whats a UPS?

-Nick

Uninteruptable power supply, it is used to allow computers to be shut down in the event of a power cut and also evens out power surges. My power tools do the same if I use them on the same electrical circuit

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__________________________________________________________________________
Experimenting in 3D in New Zealand

Ive found a few cheap UPS's on amazon.

[www.amazon.com]
[www.amazon.com]
[www.amazon.com]

Do you think these would solve the fan surge issue?

-Nick

Edited 1 time(s). Last edit at 09/15/2012 10:51AM by N314.

"It might help in your situation if your issue is caused by conducted noise" is about the only safe answer I can give. The power line filtering provided by many UPSes can reduce some conducted transients, but UPSes are disparate in their level of filtering from model to model, they don't catch everything, and they should not be considered a "universal solution" to the noise issues, even if it works for your fan. I suppose it's worth a try to solve your particular issue in your particular situation if you happen to have one handy, but personally, I wouldn't say "yeah go buy one, it'll fix it fer sure!". It's worth a try if you have one and it's rated for at least the maximum current load the printers' power supply(s) demand.

Known causes of print freeze include:

1. Turning on appliances that draw lots of current, like microwaves, ceiling fans, Air Con.

2. Windows 7 64-Bit.

3. Some Arduino MEGA 2560 R3.

4. USB power management enabled.

jcabrer Wrote:
-------------------------------------------------------
> Known causes of print freeze include:
>
> 1. Turning on appliances that draw lots of
> current, like microwaves, ceiling fans, Air Con.
>
> 2. Windows 7 64-Bit.
>
> 3. Some Arduino MEGA 2560 R3.
>
> 4. USB power management enabled.


Yes 1. Definitely

No 2. Running windows (not 7)

No 3. Arduino Megan 2560 is not an R3

Perhaps 4. Never thought about that... Ill have to check on that

-Nick

Ok something weird has happened.

I found an old UPS and plugged both computer and printer into it.
It didn't work.

But in one last test I was running a dry print. I had someone else turn on the fan... The serial connection did not stop and the print kept running. Then, They turned off the fan. The Serial lights stopped, and the printer a few seconds later.

So the Serial connection is the problem, because the printer can run after the fan, the only reason it stops is it receives no command.

Does this lead anyone to some different ideas/solutions?

-Nick