Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 03, 2016 03:07PM |
Registered: 9 years ago Posts: 1,035 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 04, 2016 07:32PM |
Registered: 8 years ago Posts: 1,671 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 04, 2016 07:58PM |
Registered: 9 years ago Posts: 1,035 |
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MechaBits
can't we just use something like this, wire it into the ramps,
[www.ebay.co.uk]
there are so many nicely machined items be a shame not to be able to use them,
but they are a little large if all that's really needed is an accurate micro switch.
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 04, 2016 08:47PM |
Registered: 12 years ago Posts: 548 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 03:15AM |
Registered: 9 years ago Posts: 58 |
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realthor
Do you guys know of any actual direct nozzle to metallic bed current loop implementation? Am i unlucky or there is hard to find such a thing?
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 04:46AM |
Registered: 9 years ago Posts: 1,035 |
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lyscanthrope
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realthor
Do you guys know of any actual direct nozzle to metallic bed current loop implementation? Am i unlucky or there is hard to find such a thing?
Did the schematic that I post a few posts earlier not sufficient ?
I'm not sure it is totaly correct but I expect so.
Some precisions :
- The switch represent the contact with hotend and bed.
- The 5V comes from the ramps
- The GND from the ramps to
- the last port is the entry of the ramps
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 04:58AM |
Registered: 9 years ago Posts: 1,035 |
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stephenrc
Those center finders when they touch the metal object to find the edge, it completes an electrical circuit between the ball and spindle via the part mounted on the mill bed through the mill to the spindle. There is no switch in the center finder.
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 05:15AM |
Registered: 9 years ago Posts: 58 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 06:46AM |
Registered: 9 years ago Posts: 1,035 |
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lyscanthrope
I was refereing to this post [forums.reprap.org]
Well I haven't tested the circuit yet ...
It may look a bit "over specified" but I wanted to avoid any issue so I built an isolated circuit for the probing
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 07:23AM |
Registered: 9 years ago Posts: 1,873 |
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realthor
It seems totally doable to me. The electronic edgefinder has a led that goes on when touch is achieved.
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 07:40AM |
Registered: 9 years ago Posts: 1,035 |
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JamesK
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realthor
It seems totally doable to me. The electronic edgefinder has a led that goes on when touch is achieved.
It's designed to approach a work piece from the side, it's not particularly useful for approaching straight down. It also takes you back to only working on a conductive surface.
[...]I may be missing something, but I think in this context the edge finder is a diversion.
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JamesK
The idea of probing a reference block of known XY dimensions for auto-calibration is sort of interesting, except I never had any problems with XY calibration and it's a one time thing anyway, so probably not enough benefit to justify the effort.
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 07:41AM |
Registered: 9 years ago Posts: 58 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 08:00AM |
Registered: 9 years ago Posts: 1,035 |
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lyscanthrope
@Realthor
I don't really see how you will manage to have a normaly closed circuit that goes open on contact AND on loose wire .
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 08:23AM |
Registered: 9 years ago Posts: 58 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 08:33AM |
Registered: 9 years ago Posts: 1,035 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 10:40AM |
Registered: 8 years ago Posts: 1,671 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 05, 2016 05:11PM |
Registered: 9 years ago Posts: 1,035 |
Re: Using FSR at hotend level for an unoptrusive bed probing via the nozzle February 09, 2016 06:41AM |
Registered: 9 years ago Posts: 1,035 |
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lyscanthrope
What we want to avoid is that the 5v is directly connected to the 0v of the ramps.
The problem is that we have
-hotend side :heat cartridge and thermistor
-bed :the same if heated bed
We expect them to already be isolated from the metallic structure (hot end and bed) for them work correctly.
The bad point is that we will put the bed(or hot end) to a given potential.... So if there is a problem with their isolation... We may have a short circuit.
I m not sure that there is a better solution between 5v on head or bed!