Quote Originally Posted by wirlybird View Post
I am also a bit confused on how the device gets a registration point to use. When i used a dial indicator to level I would bring the bed touching the nozzle and then zero the dial. Back to paper now though!
I could see if the device was a more permanent mount that was a known distance but even then what if I change nozzles and it is a bit different than the last one?
The same way that you use an IR sensor or inductive proximity sensor. For bed leveling the offset does not matter. But, it is essential for zeroing.
Apparently, alignG doesn’t know the coordinates of the print head. Through trial and error, only for the first time, you find the best extruder/bed gap; then mount and leave alignG in that spot. You also reset the alignG reading in the software in that position.
We also considered a tapped M3 hole on the back of alignG. You can just mount it using a M3 screw and simple mechanical structure. You can even glue it to the surface if you need a permanent attachment.
Remember that there are two very significant advantages for alignG when comparing with any dial indicator: (1) dial indicators in the price range of alignG always apply a (spring loaded) force to the surface, roughly about 1 Newton (100 grams). To make sure that the force is not displacing the dial indicator, you need a very rigid mounting for the dial. When speaking about 15-micron displacement, 1 Newton force is tremendous. (2) Dial indicators in the price range of alignG weights about 100-150 grams. So, you need to consider that in the structure of the mounting fixture. Besides, the weight of the mounting structure is often more than the weight of dial indicator, do take that into account!
alignG is a non-contact measurement device; so, no worries about the spring-loaded force to displace it. In the other hand, it weighs only 20 grams. A strong magnet tape can simply keep a 20-gram gadget in place for a long time, except if you want to displace it intentionally. For sure, there are many simple ways to permanently attach a 20grams gadget to your extruder, if you want to install it for one time and leave it there.