Pinda 2 dilemma
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@oliof you can build your own pinda v2. when you set it up its basically same thermistor as the 100k thermistor we used on beds. its just inside of the probe. I think it will still work even if you kapton tape a bed thermistor to any regular probe. its just very unsightly.
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@fcwilt said in Pinda 2 dilemma:
Without knowing how a probe changes trigger height with temperature how can a fixed compensation scheme work?
You measure that as I outlined in my process, but instead of having your own thermistor you use the bed thermistor. It will be less precise, but may be sufficient. It would be worth to do as an experiment.
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@sinole Sure, but it's not required with a high resolution probe like SuperPINDA and the various probes that are the same or quite similar OEM product.
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@oliof said in Pinda 2 dilemma:
@fcwilt said in Pinda 2 dilemma:
Without knowing how a probe changes trigger height with temperature how can a fixed compensation scheme work?
You measure that as I outlined in my process, but instead of having your own thermistor you use the bed thermistor. It will be less precise, but may be sufficient. It would be worth to do as an experiment.
I wasn't clear.
The firmware uses a formula that makes an assumption of how the probe trigger height changes with temperature.
Is it a given that all such inductive probe follow that formula?
Thanks.
Frederick
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@fcwilt no idea (-: Marlin uses a table with discrete values and interpolates between them.
I'll leave the experimentation to others, since I'm happy with probes that are resistant to temperature changes.
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@oliof I'd be open to any option that you can suggest. problem is that I live in US and only real heat resistant probe that I know is superpinda you have to buy directly from prusa. I have to pay more than probe price for shipping. Its really not budget friendly. printed solid was purchased by prusa, they are the official prusa distributor now, hopefully they will carry it soon.
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@sinole said in Pinda 2 dilemma:
I'd be open to any option that you can suggest. problem is that I live in US and only real heat resistant probe that I know is superpinda you have to buy directly from prusa. I have to pay more than probe price for shipping. Its really not budget friendly. printed solid was purchased by prusa, they are the official prusa distributor now, hopefully they will carry it soon.
Why try your current probe using the steps outlines by oliof?
Frederick
Do you by any chance know the switching frequency of the Pinda probe?
Generally the higher the switching frequency the faster the response time of the probe and thus the faster you can probe.
I get my sensors from these folks - I have preselected the inductive sensor selection.
AutomationDirect Inductive Sensors
One nice thing about this site and their sensors is they provide actual specs covering all aspects of the device.
None of the ones I use have temp sensors but I have not found that to be necessary.
Frederick
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@fcwilt its not really a perfect solution. the probe doesn't really behave linearly and it doesn't behave exactly the same every time, but marlin algorithm with 2 tables for bed and probe temperature makes a pretty good use of it.
PINDA is a name licensed by prusa i think. its justa regular inductive probe. pinda v2 has a thermistor in it. and super pinda is just a very expensive accurate inductive probe. as I said you can kapton tape a thermistor to your favorite probe. put it on the back or something make it look nice. dont open the probe though. they come with vacuumed seal to prevent humidity. -
btw if it helps, I probe really fast with pinda and repeatability is pretty good. i basically probe as fast as tr8x8 can handle going. you dont need 80$ probe.
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@sinole said in Pinda 2 dilemma:
the probe doesn't really behave linearly and it doesn't behave exactly the same every time, but marlin algorithm with 2 tables for bed and probe temperature makes a pretty good use of it.
Well it would be easy to implement a table or two with firmware 3.3.x or 3.4.x
Frederick
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@sinole said in Pinda 2 dilemma:
repeatability is pretty good
What is "pretty good"?
Thanks.
Frederick
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@fcwilt standard deviation of 8 micron
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@sinole said in Pinda 2 dilemma:
@fcwilt standard deviation of 8 micron
0.008 mm? That is very good. And that is at what probing speed?
Thanks.
Frederick
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@fcwilt need to mention my setup triple probes everytime at 5000 speed it backs of only 0.4 mm each probe. you can set that stuff up in marlin, im noobi here i hope i get to do that here too. its a very nice probing setup. you can mitigate a lot of hardware errors with a good software. thats why im using RepRap now the motion system is more advanced.
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With v3.3.x and 3.4.x you can control:
- travel speed (XY movement)
- probe speed (Z movement)
- dive height (the height above the trigger height where probing starts)
- tolerance if probing for 2 consecutive readings
- probing behavior (how many times to probe - either for 2 consecutive readings or averaging all readings)
- optional delay after XY move before doing Z move
When you say 5000 is that mm/sec or mm/min and is that for XY moves or Z moves?
Thanks.
Frederick
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Personally, I would use SuperPINDA which is temperature compensated internally. Not much more money, a lot less headache Been there, did that.
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@boa I second that. My initial setup was pinda2 that I had in hand that kind of worked. But since I went for super pinda my 600x400 bed in 60 deg C chamber bed leveling is in 0.08 mm every time
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@sinole the SuperPINDA is made by Pepperl+Fuchs, no Prusa magic. In Europe there are various sellers (VonWange, CR3D, RatRig) selling very similar or identical probes. In the US, SquishWorx carries the SuperPINDA (ref https://squishworx.com/prusa-superpinda/ ) which is the same P+F part Prusa procures as far as I know, for 39$.
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@oliof Basically any internally temperature compensated probe will do (with proper output type obviously). I did some research once and Prusa's was cheapest one that works with 5V power supply (original prusa board back then, not required for duet) and is temp. compensated and in 8mm diameter).