I was in a bit of a rush the other day and didn't have time to write up what I did. I got a new part to work on from my boss and one of the things he wanted me to try thread milling for the tapped holes.
I thought it would be a relatively easy toolpath to program after watching a few videos's on it. However, I very quickly ran into an issue when making the tool itself. Unfortunately, there isn't a lot of information online about actually creating the tool, only some of the settings that set the offsets. I played around with the tool settings a bit and input the data I got online from this threadmill, and finished setting up the toolpath and everything seemed fine until I simulated it and saw it only cut into the material and left a very light trace where the tool barely touched the material. I spent a very frustrating two hours on it trying to problem solve but with no avail. I thought it might have to do with the tool diameter offset but I played around with that and didn't get any results.
My boss then pointed out that the shaft of the cutter might be rubbing against the walls of the hole and thinking it's cutting it when it's not. I played it through and had it show color differences so I could see if the tool was rubbing or not. Turns out it was and I tried again to change the settings around with the threadmill but got similar results. I found that Fusion doesn't allow you to dimension the stickout of the teeth on the endmill. It's very difficult to describe the issue, but if it works I'll go into more detail and visual examples. At this point, I ran out of time and had to leave it for the weekend.
I saw my brother (@bladesofbelaq) who is also a machinist and asked him about the issue I was having and we discussed it for a while. He then realized that the issue might not be with Fusion, but rather the tool itself, not being the right size for these threads. He pointed out that the threads are only going to be cut with the sharp edge of the threadmill and never with the stickout of the teeth.