Instead of the paper test why don't we use feeler gauges?

Why do we use the paper test to set z home position, is it because it's easy? I've got an i3 rework with inductive autolevel probe when calibrating or after adjusting anything, I manually set an arbitrary z home level by adjusting the probe aiming for anything roughly between positive 0.3-1.0mm from the build plate, then measure it after autolevelling with feeler gauges. It is then just a case of adjusting the z probe offset in the firmware to a negative number, which is 0.1mm less than the actual offset (the thickness of a piece of paper). Its exactly the same process as shown in the youtube video Tom's guide to autolevelling, except you don't need to set z+10, then drop z in 0.1mm increments until it hits a piece of paper.

Just seems to me that for a couple of bucks a set of feeler gauges saves a lot of time and is much more accurate.

I do have a set of feeler gauges, and I use them very occasionally. But the paper test is accurate enough for most purposes, is quick easy to do, and finding a sheet of paper is quicker than getting the feeler gauges out. Usually I trust the Z probe. When I don't, I start at 0.5mm height and drop the head in 0.05mm increments until it grips the paper. I don't subtract 0.1mm for the thickness of the paper, because there is generally at least 0.1mm of elasticity in the head.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I was thinking the metal might damage the nozzle.

---

Newbie with Folgertech 2020 i3.

Dc42 I subtract 0.1mm as this is the clearance I want between the nozzle and the bed for an ideal (IMHO) first layer.

Because it's extremely simple, does not require feeler gauges or any other special tools, and works well enough.

I am going to add one more reason that I noticed. You should feel a little friction with the paper and since feeler gauges are very smooth you can't really accurately feel if there is friction but the rough surface of paper makes it very easy to tell how much pressure there is.

And it's just so dead simple, why not?

I'll add everyone owns a sheet of paper. Junk mail finally has a use.

I was using feeler gauges last night to set up my 3d printer.

My method is as follows.

I take a rough estimate of the height first with a ruler or tape measure. subtract about 3mm from that and flash.

I set the printer head down and use business cards stacked ontop of eachother to get closer to the measurment.

Then I switch to my feeler gauge set, you can feel friction in the feeler gauge, thats why its called a "feeler" gauge.

Flash the firmware and double check for flatness.

Next up I will be leveling to .05 or maybe as low as .03mm as I have the gauges, and .1mm seems too sloppy for me. I measured standard printing paper (with a starret paper gauge) and it seems it is also .1mm

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Feeler gauges aren't much fun when the bed is heated. A business card is more friendly than a 90C metal feeler gauge.

I use a feeler gauge because I have one on hand. Heat isn't really a problem, stainless is a poor conductor and testing with a feeler only takes a few seconds.

Frankly it doesn't really matter what you use because there is so much compliance in most 3d printers. If I can fit a .08 gauge under the nozzle it won't take much additional force to get a .14 in there as well. Feeler gauges are most useful when measuring rigid alignments so that you can, say, fit a 0.01 but not the 0.015.

Note that paper comes in a huge variety of thicknesses so you should try to use the same type each time.

Edited 1 time(s). Last edit at 08/05/2015 11:05AM by 691175002.