Two problems for the price of one.

[Franticke]

Hi Everyone, I got my Egg-Bot last December and have been having a
great time. I took a break from using it for a bit but started back
up yesterday. I am having 2 problems, the pen keeps bouncing in the
up position. When it starts a new segment it skips (bounces) a couple
of times before making the straight line. It doesn't do this all the
time. I have tried adjusting the CUR ADJ as instructed but to no
avail.

The second problem is that I created a pattern with some geo designs.
They look great on screen, but when I plot them some of them are not
connecting. I've zoomed in on the screen and the lines are connecting
there but not on the egg.

Help please.

Thanks,
Fran

[Windell H. Oskay]

On Mar 24, 2012, at 7:13 AM, Franticke wrote:

> Hi Everyone, I got my Egg-Bot last December and have been having a
> great time. I took a break from using it for a bit but started back
> up yesterday. I am having 2 problems, the pen keeps bouncing in the
> up position. When it starts a new segment it skips (bounces) a couple
> of times before making the straight line. It doesn't do this all the
> time. I have tried adjusting the CUR ADJ as instructed but to no
> avail.

Are you saying that the pen tip is physically bouncing because it hits the surface too fast? If so, try adjusting some of the timing settings:
http://wiki.evilmadscience.com/Eggbot_Control#Timing

Decrease the "pen lowering speed." This will make the pen approach the surface more slowly. If the Eggbot then begins drawing before the pen is all the way down, you may also need to increase the "delay after lowering pen" to compensate.

> The second problem is that I created a pattern with some geo designs.
> They look great on screen, but when I plot them some of them are not
> connecting. I've zoomed in on the screen and the lines are connecting
> there but not on the egg.

Depending on the particular type of "not connecting," the most common issues of this sort are due to poor contact between the egg and the coupler, such that they can slip a tiny bit with respect to one another.

See all of our tips for things like this at: http://wiki.evilmadscience.com/Improving_precision

[Franticke]

Hi Windell

Thanks for answering me.

The pen is bouncing, not when it touches the surface of the egg to
begin with, it is when it is in the up position (transitioning to the
next line), then when it comes down it bounces once maybe twice
(giving me the dots) then it draws the line straight, finishes the
line and then it goes up and starts to bounce and continues that
cycle. I had it fixed once but can't remember what I did. I do know
that at one time I taped a penny to the pen arm and that worked, but
only once, silly I know but I was desperate :-/ We will try the
timing and see what that gets us.

Talked with my husband about the second problem and we are going to go
over the tips on this.

Thanks,
Fran

[Windell H. Oskay]

On Mar 24, 2012, at 7:31 PM, Franticke wrote:
>
> The pen is bouncing, not when it touches the surface of the egg to
> begin with, it is when it is in the up position (transitioning to the
> next line), then when it comes down it bounces once maybe twice
> (giving me the dots) then it draws the line straight, finishes the
> line and then it goes up and starts to bounce and continues that
> cycle.

I'm afraid that I'm having trouble understanding the situation. It sounds like you are actually describing exactly what I was asking about-- that the pen tip is bouncing when it hits the surface. If that is the case, my prior advice is probably still your best course of action: to use the timing controls to set the pen down more gently.

[Stu Kabakoff]

I may have had a similar problem. The pen would go up, then while it was moving to the start of the next line it would be dropped onto the egg and lifted again quickly. Sometimes it would also draw with the pen up or move to the next line without lifting the pen.

I had the pen up and down positions at around 85 and 95, adjusting the plastic lifter and changing those to 55-65 fixed the problem.

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[Dan Newman]

On 26 Mar 2012 , at 7:35 AM, Stu Kabakoff wrote:

> …. Sometimes it would also draw with the pen up or move

> to the next line without lifting the pen.

That issue can also be addressed with the delay settings which add
a delay to wait after issuing the pen down or pen up command and before
drawing or moving. Of course, you first want to minimize the travel
time for pen up and pen down moves by adjusting the pen height and
the servo's up/down positions. But, if after doing that, there's
still an issue with, for example, the line draw starting before
the pen is down all the way, then you need to increase the delay
time. (The delay time needs to at least account for the difference
between pen up/pen down servo positions divided by the rate at
which you let the servo move: distance/rate = time.)

Dan

[Stu Kabakoff]

In my case, all the timing settings were correct, the problems the eggbot was having appeared to be bugs. It was tracing paths with the pen up, dropping the pen randomly while it should have been up, then raising it again immediately, and probably some other erratic behavior. It may be a coincidence, but repositioning the lifter arm to around 55% from 90% fixed it. This was several months ago, but I believe it only happened with one file. I still have the file if you're interesting in trying to repro it.

[Windell H. Oskay]

On Mar 26, 2012, at 10:04 AM, Stu Kabakoff wrote:

> In my case, all the timing settings were correct, the problems the eggbot was having appeared to be bugs. It was tracing paths with the pen up, dropping the pen randomly while it should have been up, then raising it again immediately, and probably some other erratic behavior. It may be a coincidence, but repositioning the lifter arm to around 55% from 90% fixed it. This was several months ago, but I believe it only happened with one file. I still have the file if you're interesting in trying to repro it.

If the pen is dropping *randomly* then it's almost certainly not a bug in the software. It does sound like it could be a bad electrical connection, perhaps located in the servo itself. If mine did this, I'd change the servo setpoint positions to fix it, or replace the servo.

[Franticke]

Hi Again,

We followed your advice and still no go. We played with the timing(s)
and the pen still bounces. What I call bouncing my husband says is
vibration. When the plotting first starts, the pen goes down (doesn't
bounce) makes the first line, then when the pen goes up it begins to
vibrate / shake (what I call bouncing), it continues to do this as it
comes down, because of that vibration it bounces once or twice before
it stops and draws the line straight. Then it goes back up and it
starts to vibrate again. We have adj the CUR ADJ per instructions,
but in order to get it to stop completely it gets adjusted to the
point where the motor begins to whine.

Sorry, not the most technical of people, my hubby is though. So if I
get to confusing I will ask him to ask the questions.

Thanks,
Fran

[Windell H. Oskay]

> What I call bouncing my husband says is
> vibration. When the plotting first starts, the pen goes down (doesn't
> bounce) makes the first line, then when the pen goes up it begins to
> vibrate / shake (what I call bouncing), it continues to do this as it
> comes down, because of that vibration it bounces once or twice before
> it stops and draws the line straight.

Can you please describe vibration in greater detail? Exactly *what* is
vibrating, and in which direction?

- Is the servo motor oscillating in position?
- Is the pen motor moving back and forth when it should not?
- Is the egg motor moving back and forth when it should not?
- Is it the case that the whole pen arm is mechanically wiggling back and
forth after a sudden movement of the pen motor?
- Is it the case that the pen arm is flexing and "bouncing" while in the
"up" position, along the flexure hinge in the pen arm?

> Then it goes back up and it
> starts to vibrate again. We have adj the CUR ADJ per instructions,
> but in order to get it to stop completely it gets adjusted to the
> point where the motor begins to whine.

The motors *should not* whine. If you have them turned up high enough
that they do, then you are very likely to get uncontrolled shaking of the
motors. In our experience, there is always a "happy medium" adjustment
just below where it starts to whine, where the print quality is very good.
One of the tricks to this is to remove the screwdriver between minor
adjustments to make sure that the presence of the screwdriver is not
affecting it.

[Brian Schmalz]

What would make this even easier for us to diagnose would be a movie of it having the bouncing problem. Any chance you could shoot a couple minutes (including sound) and put it up at YouTube or somewhere we could view it? I've found this helps with problems like this-

*Brian

 

Home www.schmalzhaus.com
Work www.logicpd.com

---

From: Windell H. Oskay <win...@oskay.net>
To: eggbo...@googlegroups.com
Sent: Monday, March 26, 2012 12:49 PM
Subject: Re: [EggBot] Re: Two problems for the price of one.

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[Franticke]

Okay, when Bob gets home we are going to sit down and answer these
questions and post them. In the mean time, I believe that this best
describes what is happening:

> - Is it the case that the pen arm is flexing and "bouncing" while in the
> "up" position, along the flexure hinge in the pen arm?

That to me is what I call "bouncing", when it lifts off the egg it
starts to "bounce" up and down (sort of like a kid when they are
waving bye-bye), then it touches the egg and bounces off the egg a
couple of time before settling down and drawing the line, then it goes
up and starts the bouncing again. Now, at times it "bounces" faster
than others.

I really appreciate this, as when my egging friends (17 of them) get
theirs in a couple of weeks, if this happens to them we will be able
to help them out or send them your way.

Thanks,
Fran

[Franticke]

Hi Brian,

I am going to try to capture it on my Droid, them post it somewhere.
I've avoided posting any video so this will be a first for me, yippee,
love a life full of first :-}

Fran

On Mar 26, 11:20 am, Brian Schmalz <brian_schm...@yahoo.com> wrote:
> What would make this even easier for us to diagnose would be a movie of it having the bouncing problem. Any chance you could shoot a couple minutes (including sound) and put it up at YouTube or somewhere we could view it? I've found this helps with problems like this-
>
> *Brian
>
> Homewww.schmalzhaus.com
> Workwww.logicpd.com
>
>
>
>
>
>
>
> >________________________________

> > From: Windell H. Oskay <wind...@oskay.net>

> >To unsubscribe from this group, send email to eggbotuser+...@googlegroups.com.

[Franticke]

Here is the video

http://www.youtube.com/watch?v=-eQxzIfwMBc&feature=youtu.be

Thanks.

Fran

On Mar 26, 11:20 am, Brian Schmalz <brian_schm...@yahoo.com> wrote:

> What would make this even easier for us to diagnose would be a movie of it having the bouncing problem. Any chance you could shoot a couple minutes (including sound) and put it up at YouTube or somewhere we could view it? I've found this helps with problems like this-
>
> *Brian
>
> Homewww.schmalzhaus.com
> Workwww.logicpd.com
>
>
>
>
>
>
>
> >________________________________

> > From: Windell H. Oskay <wind...@oskay.net>

> >To unsubscribe from this group, send email to eggbotuser+...@googlegroups.com.

[Windell H. Oskay]

> Here is the video
>
> http://www.youtube.com/watch?v=-eQxzIfwMBc&feature=youtu.be

Well, that's one that I've never seen before. It's a very serious
malfunction of the servo motor.

The most likely cause of this is not correctly centering the servo in its
range of motion. Unplug and remove the servo motor and go back to steps
31 and 32 of the instructions, to correctly center the servo in its range:

http://cdn2.evilmadscience.com/KitInstrux/eggbot/ebk_html/index33.html

If you find that the servo motor does not have firm "ends" to the travel
now, but skips steps, then the gear train has been damaged, and the servo
motor should be replaced.

[Brian Schmalz]

Yup, that looks like a possible defective servo to me. It's oscillating in one position (which it should never do) and not the other.

Adjusting the stepper motor current should not affect this problem at all.

Great video BTW - very easy to see what's going on.

See if Windell's suggestion works with regards to centering the servo. That's a very good idea. If not, you may need a new servo.

*Brian

 

Home www.schmalzhaus.com
Work www.logicpd.com

---

From: Franticke <fran...@gmail.com>
To: EggBotUser <eggbo...@googlegroups.com>
Sent: Monday, March 26, 2012 2:54 PM
Subject: [EggBot] Re: Two problems for the price of one.

> >To unsubscribe from this group, send email to eggbotuser+unsub...@googlegroups.com.

> >For more options, visit this group athttp://groups.google.com/group/eggbotuser?hl=en.

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[Franticke]

Thanks Brian. I was hoping the video would be okay, great first try!
Just talked with Bob and he said, "I told you so", then why did you
have me post the question, silly man ;-}

On Mar 26, 1:21 pm, Brian Schmalz <brian_schm...@yahoo.com> wrote:
> Yup, that looks like a possible defective servo to me. It's oscillating in one position (which it should never do) and not the other.
>
> Adjusting the stepper motor current should not affect this problem at all.
>
> Great video BTW - very easy to see what's going on.
>
> See if Windell's suggestion works with regards to centering the servo. That's a very good idea. If not, you may need a new servo.
>
> *Brian
>
> Homewww.schmalzhaus.com
> Workwww.logicpd.com
>
>
>
>
>
>
>
> >________________________________

> > From: Franticke <franti...@gmail.com>

> >> >To unsubscribe from this group, send email to eggbotuser+...@googlegroups.com.

> >> >For more options, visit this group athttp://groups.google.com/group/eggbotuser?hl=en.
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[Franticke]

I would say bummer, but until Bob gets home and does the steps to see
if that corrects the problem, I will refrain from saying it ;-/

Thanks for all the help. I was just glad that my first attempt at
posting a video went smoothly, well sort of.

[Mike Wing]

I had a similar problem. I solved it by making sure the servo arm just went down enough to let the pen contact the surface and the up position was just above the surface. I also slowed down the raise speed a bit. I saw this as a feedback loop where the pen was raised in such a way that it caused the pen lever to continue to move up when the servo stopped. When it came back down, it pushed the servo down and out of position. This caused the servo to correct it's position, pushing the lever back up and causing the cycle to repeat. I could be way off here but my solution seems to have worked.

Sent from my mobile phone

[skbe...@gmail.com]

Fran, Your egg-bot is really nervous, with all of that shaking. I hope that you find out what the problem is soon.           -------Original Message-------