I recently received a gift of a 3d printer from my son.The "no cost" way to level the bed, which is required to get good prints, is to use a sheet of paper inserted under the print head extruder nozzle. You adjust the bed one corner at a time by trapping the sheet of paper between the nozzle and the bed until it has a "small amount" of friction when you pull out the paper. You repeat for each corner until they all feel about the same.Because reasonably inexpensive printers can print at about 0.1 MM accuracy this method is OK but not great.I found a 3d printed bracket to mount this Neoteck dial indicator on the print head of my printer. My first test was to use the "sheet of paper" method to level the bed then verify the accuracy using the Neoteck dial indicator. The result showed that the "sheet of paper" method was in some cases off by 0.05 MM which amounts to 50% of the accuracy of the printer itself.The method is to insert the Neoteck into the bracket then push it on the print head with a friction fit. You then can use a g-code file to position the head to each corner and make an exact adjustment. You can also move the head manually to accomplish the same thing. Usually 2 passes to adjust and reverify each corner is required to get the bed almost perfectly level.I have also discovered that the bed leveling can change from one print job to the next even if the jobs were printed back to back without turning off the printer. Bed leveling can also change by small amounts based on the bed heating and probably air circulation in the room. Bed heating is needed to make the very first few layers stick.I have seen what happens when the bed is not level even if just a very small amount. The first layer may not stick on some points or you get some "strings" on the first few layers if the design needs to move the print head in certain ways.The Neoteck device looks and feels durable and comes with a very nice fitted case. It is very simple to use and you barely need the small instruction manual. The accuracy appears to be very good. And all for about $25.So the bottom line is this fairly cheap solution has raised the print quality and the number of occasional "do overs" when you see the first few layer passes don't print correctly.If you are still trying to level without a digital gauge and have random print problems this could help solve your problem if it is related to bed leveling.If you you want to give it a try search your favorite 3d pattern site for "Bed Leveling Bracket" and "Neoteck".