Inductive bed sensor

[tsteever]

Currently I am using a servo mounted switch for my ABL. Since upgrading the bug fix version of the new firmware I am having intermittent issues with the angle that the servo is being deployed at causing the nozzle to crash into the bed.

I am thinking about upgrading to a inductive probe to take some of the moving parts out of the equation. Will an inductive probe work with the stock maker farm heated bed with glass on top?

[uncle_bob]

Currently I am using a servo mounted switch for my ABL. Since upgrading the bug fix version of the new firmware I am having intermittent issues with the angle that the servo is being deployed at causing the nozzle to crash into the bed.

I am thinking about upgrading to a inductive probe to take some of the moving parts out of the equation. Will an inductive probe work with the stock maker farm heated bed with glass on top?

Hi

Inductive probes work against conductive surfaces. It the MakerFarm (or any similar) approach, the nearest conductive surface is the heated bed PCB. That is on the other side of your glass and also on the other side of whatever you have on the glass to get things to stick down. Based on what I have here, the heated bed can bow away from the glass by 0.5 to 1 mm. The glass it's self can bow away from the heated bed by about the same amount. Manual bed leveling can get you within 0.1 mm without a lot of trouble. If you want something that works at least as well as manual bed leveling, inductive sensors simply are not the way to go. If you have an aluminum heated bed or a "print on the PCB" setup, then they do work. The MakerFarm (and a few thousand other designs) simply are not built that way.

Bob

[kd7eir]

Inductive sensors work just fine with MakerFarm printers. This is the one that I use and it works fine through 3mm borosilicate glass. It has a sensing distance of 8mm, which works out to about 3.2mm to 3.6mm when you account for the target correction factor of the MakerFarm construction.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Target correction factors http://www.ab.com/en/epub/catalogs/1...y-Sensors.html

[uncle_bob]

Hi

If you have a build surface that is already flat to < 0.1 mm ... why bother with automatic bed leveling?

Bob

[kd7eir]

Hi

If you have a build surface that is already flat to < 0.1 mm ... why bother with automatic bed leveling?

Bob

Because a 3D printer is a moving machine, and moving machines are incapable of maintaining perfect alignment due to the laws of physics.

[uncle_bob]

Because a 3D printer is a moving machine, and moving machines are incapable of maintaining perfect alignment due to the laws of physics.

Hi

To the limited extent that is true, a bed leveling probe is totally useless to fix the problem. A properly assembled Pegasus will hold level to < 0.1 mm for 100's of hours of operation.

Bob

[kd7eir]

ABL is a PROVEN TEHCNOLOGY. Just because YOU don't like does not change that FACT.

Empirical evidence has proven that ABL works, and works very well. The anecdotes of naysayers are incapable of changing FACTS.

[uncle_bob]

ABL is a PROVEN TEHCNOLOGY. Just because YOU don't like does not change that FACT.

Empirical evidence has proven that ABL works, and works very well. The anecdotes of naysayers are incapable of changing FACTS.

Hi

Since you have decided to ignore the most basic fact that an inductive probe (which is not the only way to do ABL, there are much better approaches in this case) DOES NOT LEVEL TO THE PRINT SUFACE(it levels to the pcb which is not attached to the print surface). There is nothing at all to your claim to have facts on your side, you simply have an opinion. Fact wise, I've put up measured data. The only thing we've seen from you so far is a absolutely nonsensical rant.

Bob

[kd7eir]

Hi

Since you have decided to ignore the most basic fact that an inductive probe (which is not the only way to do ABL, there are much better approaches in this case) DOES NOT LEVEL TO THE PRINT SUFACE(it levels to the pcb which is not attached to the print surface). There is nothing at all to your claim to have facts on your side, you simply have an opinion. Fact wise, I've put up measured data. The only thing we've seen from you so far is a absolutely nonsensical rant.

Bob

NEVER did I say that an inductive probe was the only way to accomplish ABL, so stop putting words in my mouth. YOU stated that "a bed leveling probe is totally useless to fix the problem." I hate to break it to you, but Josef Prusa disagrees with you. I suppose from your attitude as displayed on here that you consider yourself to be the expert and Josef Prusa to be just some punk kid. Also, Colin sells inductive sensors for his printers, perhaps you should tell him that he's clueless as well.

I merely answered the op's question, and you chose to take a dump on the thread and proclaim everyone but yourself to be clueless.

As for your "DOES NOT LEVEL TO THE PRINT SUFACE" statement, many printers use aluminum heat beds as the print surface, so the inductive sensor is leveling to the print bed. I see zero "measured data" from you, but I did post scientific data regarding target correction factors for various surfaces.

As for your insinuation that inductive sensors will not work on MakerFarm printers,I guess my printer failed to get that memo.

Lastly, your personal attacks against me prove that you have nothing to back up your statements, so you accuse me of being nonsensical. I am the ONLY ONE in this discussion to post scientific data, your "measured data" only exists in your mind, not in this thread. I'm through engaging with your narcissistic attitude.

[uncle_bob]

Hi

I'm not the one who started the all caps nonsense or the flames about un-doccumented "laws of physics". The discussion here is in the MakerFarm area and it's about a printer with a glass bed over a pc board heater. If that's not apparent to you, you might actually want to read the posts in the thread you are responding to. If you can't figure out the difference between a MK42 bed and a MK2 approach, then I would strongly suggest you go study the "laws of physics" you keep vaguely referring to.

To summarize, the printer in question does *not* have a conductive print surface. It's a piece of glass. An inductive probe *only* works against a conductive surface. Unless you change the print surface to something conductive (or something with high permeability if you want to get pedantic) an inductive probe will not "see" the surface. Instead it will level to whatever is under that surface that *is* conductive. In the case of a MakerFarm printer, the conductive surface warps independently of the glass on top. An inductive probe will not measure the height of the print surface. If you want to bed level a stock MakerFarm printer, don't get an inductive probe. Get something that will work instead.

Bob