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Re: Help setting up FSR on Maxv2 /Rambo

Posted: Tue Feb 16, 2016 11:02 am
by Jimustanguitar
geneb wrote:So basically, we're talking cow hooves per square ounce, right?
I think it's carat-ounces :)
[img]http://i.imgur.com/iDOzAa5.jpg[/img]


Thanks for the clarification, Michael! Yeah, force - not weight... Derp. Makes much more sense now.

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Tue Feb 16, 2016 11:07 am
by mhackney
LOL! I love that answer!

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Tue Feb 16, 2016 12:02 pm
by geneb
Well ya gotta admit, it's right in the name. Force Sensitive Resistor. :)

(what book is the page scanned from?)

g.

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Tue Feb 16, 2016 12:07 pm
by Jimustanguitar
I wasn't thinking of the physics definition of force, I was thinking about the FSRs like a load cell...

I guess for those that don't get the difference, it's all about change. It's the delta of force, like a car accelerating compared to going the same speed. Not how much you weigh, but how much you make the elevator bounce when you jump :)


Not sure about the book, I always just google it.

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Tue Feb 16, 2016 8:00 pm
by Eaglezsoar
Would a horse work?

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Tue Feb 16, 2016 8:06 pm
by mhackney
No horsing around Eaglezsoar!

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Wed Feb 17, 2016 5:33 am
by enggmaug
I feel like there is some confusion in what has been said here. I'm sorry if I repeat what has been already said, or if it's not really the subject of the thread, but I believe I need to intervene.

FSRs are like weigthing scales. When you depress on a scale, the displayed value changes. When you depress on FSR, their resistive value changes in the same way.
Weighting scales, as well as FSR, actually measure the force applied onto them (in Newtons).

If you place whatever object on an FSR, the mass of the object combined with earth gravity applies a constant force on it as long as the object is there. The output of the FSR is thus constant... like when you climb on your scale.
Now you remove the object, the output of FSR changes, but that new value remains constant...

The magic comes from the interface board. This board detects when there are changes in FSR outputs, and it is the interface board that triggers a signal to indicate that the force applied on the FSR is different. If you have a digital weighting scale, it probably turns on when you step on it. It will not stay on if you stand there for hours. The digital weighting scales detects when you step on it the same way the FSR interface board does.

The confusion bewtween force and mass is actually coming from the weighting scales. They translate the force in Newtons applied onto them to a weight in Grams by supposing that earth gravity is constant... and it is false, but acceptable by many.

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Wed Feb 17, 2016 6:34 am
by barry99705
geneb wrote:Well ya gotta admit, it's right in the name. Force Sensitive Resistor. :)

(what book is the page scanned from?)

g.
https://kindle.amazon.com/work/wild-thi ... 0316032190

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Wed Feb 17, 2016 8:17 am
by geneb
Thanks barry!

g.

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Wed Feb 17, 2016 4:31 pm
by Eaglezsoar
Thanks enggmaug, you explained it very well so that even I can understand, you da man!

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Sun Feb 21, 2016 8:11 pm
by Jimustanguitar
My FLUX printer came in this week, and it uses FSRs to level and calibrate. I'm pretty impressed.

[youtube]http://www.youtube.com/watch?v=TcLhqFXAmN0[/youtube]


Definitely doing this to my Rostock ASAP.

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Sun Feb 21, 2016 8:30 pm
by mhackney
Very odd probing behavior! A single probe at each point is all that's needed.

That is an interesting looking printer!

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Sun Feb 21, 2016 8:50 pm
by Jimustanguitar
mhackney wrote:Very odd probing behavior! A single probe at each point is all that's needed.
It taps each point 6 or 7 times, and it moves down a little bit each time. You can hear it "ting" on the metal bed the last 2 times of each cycle...

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Sun Feb 21, 2016 10:06 pm
by Windshadow
You must have been an early supporter to get one this early. How is the engraver gadget? Have you done a review of it yet?

NM i see it here
http://forum.seemecnc.com/viewtopic.php?f=61&t=9911

Re: Help setting up FSR on Maxv2 /Rambo

Posted: Mon Feb 22, 2016 9:09 am
by DeltaCon
My guess is that it does probe more often at each point to tune in to exact zero point while compensating for the momentum of the head at the time of the impact.