1 (edited by pastprimitive 2014-02-15 06:21:08)

Topic: my Panelolu feed rate steadily creeps up

So I have a panelolu module for my SD3, and the other day I noticed that my feed rate which is controlled by an encoder knob on the panelolu board was slowly creeping up over time. A print that took 1:40 started at 100% and ended up at 239%.  Fortunately the print was fine, but for obvious reasons this is disconcerting. 

Anyhow I have reset it multiple times, unplugged power, messed around with the actual encoder knob a bunch. 

Any suggestions on what else to try?

Thanks!

Update: The feedrate only creeps when the I turn on the heated print bed.  Everything else works fine. But when I turn on the heating for the print bed alone the creep starts happening. Seems like a voltage leak, or something... but not sure exactly where to look.

2

Re: my Panelolu feed rate steadily creeps up

I had the same problem that crept in over time. I added gcode for each layer change that reset the rates.

3

Re: my Panelolu feed rate steadily creeps up

That sounds like a great work around.  The more I study the more it sounds like my rotary encoder is going bad, or more likely that the hardware debouncer for the encoder is going bad.  I confirmed that there were indeed some voltage anomalies when I would switch the heated print bed on at the encoder pins.  So I am thinking it may be a simple cap replacement, but I don't know if I want to mess with the risk of damaging the board. Where did you implement your gcode change?

4

Re: my Panelolu feed rate steadily creeps up

never mind I found the layer change gcode in sli3er.

5

Re: my Panelolu feed rate steadily creeps up

Curious what command you used for setting your feedrate?

6

Re: my Panelolu feed rate steadily creeps up

Hey guys

I am monitoring this closely - long posts with pastprimitive on the think3dprint3d blog (google Think3dprint3d pastprimitive, I cant post links to the forum as a band new member apparently)

In summary its an unusual problem so two of you having it is very odd. Any additional information you can provide would be useful in pinpointing the source of the problem.

7

Re: my Panelolu feed rate steadily creeps up

Since I'm not a new member, I got you covered for the link to our thread on your blog.

http://blog.think3dprint3d.com/2012/07/ … board.html

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Re: my Panelolu feed rate steadily creeps up

AND DUH DUH duh.... I think I found the solution Lawsy, Tony.  At least one I am happy with.

So here is some hopeful good news.  I believe I found the magic bullet for a firmware fix for this problem, and at the same time it allows for better precision when dialing in the feedrate to exact percentages...

in UltraLCD.cpp:

Original Code:

#define ENCODER_STEPS_PER_MENU_ITEM 5

Change to:

#define ENCODER_STEPS_PER_MENU_ITEM 2

Original Code:

#ifdef ULTIPANEL
        if (encoderDiff)
        {
            lcdDrawUpdate = 1;
            encoderPosition += encoderDiff;
            encoderDiff = 0;
            timeoutToStatus = millis() + LCD_TIMEOUT_TO_STATUS;
        }

Change to:

#ifdef ULTIPANEL
        if (encoderDiff)
        {
            lcdDrawUpdate = 1;
            encoderPosition += encoderDiff / 2;
            encoderDiff = 0;
            timeoutToStatus = millis() + LCD_TIMEOUT_TO_STATUS;
        }

Not exactly sure why this works, I can only theorize it adds a little extra layer of debouncing to the rotary encoder implementation in the firmware. I mean I didn't just randomly change numbers, but I don't have the skill to explain what I was thinking as I made these changes... yeah... I know. Anyhow,  all I know is I couldn't get my print bed to heat up to more then 30C before the creep would come on in. 

So far I have reached full temp, and no signs of the feedrate creep.  Plus it's a little easier to adjust now.

Anyhow I'll of course need to run a print of some length to see if it really is the silver bullet. but so far, I am feeling much better:)