Machinist's test indicator holder for Petsfang

thingiverse

This is a test indicator holder that attaches to Dave Petsel's PetsFang-v2 fan shroud. I'm a hobby machinist who needed a bracket to hang a test indicator from my printer. I wanted to use a DTI to assist with tramming and mechanical adjustment along different axes, as well as a poor man's CMM! Note that this is for a dial **test** indicator (DTI) and not for a simple dial indicator. A dial indicator uses a plunger, while a test indicator uses a lever arm. The advantage of using a DTI over a dial indicator is that you can get the point into confined spaces. This includes areas like directly under the hot end close to the nozzle. This support bracket is just the beginning. It's intended to be used with an articulating arm, similar to the Interrapid holder. I'm also working on creating a printed version of that holder, but I'm not yet satisfied with its rigidity. A decent DTI, holder, and precision reference square can cost considerably more than most printers. However, if you have access to machinist's tools, you can create your own setup for less money. If you're interested in acquiring these tools, a decent DTI can be found for as low as $30 USD. However, the quality of the indicator is directly related to its price. For this application, I recommend using a 0.01 mm resolution indicator (or 0.001" or 0.0005" resolution if you use Imperial tooling). Anything finer is far too sensitive for 3d printing. SPI makes a cheaper version of the Interrapid holder for about $40, but again, you get what you pay for. I think I'll eventually get the printed part to work well enough (though it will likely be bulkier and more difficult to use). I tram my bed perpendicular to Z using the indicator directly on my glass bed, and used a 1" thick precision granite square laying flat on the bed to verify that X and Y truly moved orthogonally. Within about +/- 0.0015" over 9", it's not stellar, but sufficient for printed parts. Precision granite is extremely expensive, but a normal machinist's square should be sufficient (though it will be difficult to sweep the narrow blade). As printed, this holder bracket is an intentionally tight fit into the touch probe bracket on the Petsfang. I've added some stiffening along the edge which obscures the screws on the left side of the shroud, so you'll have to fully assemble and adjust the Petsfang before adding this bracket.