Threading

Welcome to another uccs machine shop video, today we will learn how to tap to make a threaded hole -On your drawing find the correct thread size for your holes -In the machine shop room there is a white chart by the doors separating the rooms, this chart shows threads and the appropriate size holes for to make the threads -Find your thread size on the chart and right next to it is the correct drill bit size -Get the correct drill bit - once you are zeroed on your block Find the best center drill for your size drill bit and load it into your machine - Find the correct position of your holes and plunge into the metal using the lever don’t forget to use oil -Plunge far enough that the center drill makes a dome shape, this will help guide the drill bit into place -Insert the correct drill bit into the keyless chuck and install in the mill like a collet -Make sure the spindle is up all the way and lower the table until the drill bit is above the surface you are working on -Grab the thin aluminum foil from your box and take note of the thickness -With the foil between your surface and the drill bit slowly raise the table while moving the foil back and forth. Continue until there is slight pressure moving the foil around, set that point to zero then raise the table to the thickness of your foil. -Set your “z” to zero once again on your machine, note every machine is different and you should ask your TA where yours is -Look at your paper for reference on how deep the hole is. Use your calipers to find that correct distance and move the spindle stop to the correct position. This allows you to drop the spindle compared to raising the bed -Once you do that you’re ready to drill, make sure to use oil and plunge then retract a little at a time. This allows the cut metal to escape, which has many benefits. Please note that this was sped up -Go until the stop doesn’t let you go any further -Now you are ready to tap, insert the tap guide into the machine -When you are in the correct position grab the correct tap and t-shape tap wrench, assemble and place between the tap guide and hole like so -The correct process to threading is two turns forward and one turn back, this enables you to clean out the cuts and remove the excess material -When threading metal make sure to use oil. Follow the two turns forward, one turn back process. Take this part slow and keep appropriate pressure with the drop spindle, once again note that this part of the video was sped up -You will know you hit the end when there is resistance while turning, do not try to tighten it past this point, that will cause the tap to break. -Retract the tap while still keeping it straight up and down with the pressure from the spindle -Now you have a threaded hole, thanks for watching