Today I worked on making a set of 6061 aluminum parts! Not sure what their purpose is, but they have a flat top face with radius edges, and some features on the bottom.

Since there is the radius on the top face, the part has to be done in a two-part operation using soft jaws. For the first operation, I did an adaptive clearing using a 1/2" square endmill to remove the bulk of the material, then a contour to clean the sides up, and a boaring operation to locate the part when flipped, and finally a scallop toolpath using a 1/8" ball endmill. I pulled the part out after it finished and noticed there where facets on the walls of the piece. I wasn't expecting this because I've run the same settings on the stainless with excellent results. I played around with the settings a bit and couldn't find the cause of it. Even the simulation had tiny facets on it. I tried using smoothing and adjusting the tolerance in the CAM, but no matter how much I changed them, I couldn't get it removed.

I started on the second operation but only got through a few toolpaths before I ran out of time for the day. Unfortunately, I also broke the drill bit I was using when I had a 0.0625" carbide drill peck down 0.05". Since I was using the Haas minimill which doesn't have a tool height probe, which means I had to use a single tool to do all the visible finishing by itself, because if there were any slight difference in height, it would show up on the finished product. So the finish quality isn't as good as I would have liked, due to the toolpath marks. 

My boss also got me a 3D connexion space mouse for Fusion360, which I had no idea how much of an impact it made until I tried it! It's always been one thing that kind of frustrated me about 3D modeling programs in general, its always tricky to orbit around the design, but with the space mouse, it eliminates that almost completely! 

Finally figured out the issue I had last Friday with the single flute thread milling!

(if you haven't already you can read about the issue in my previous post) 

It turns out the problem was due to the shoulder diameter on the threadmill itself. By default, Fusion360 decides what the width of the shoulder diameter is, regardless of what it should be; however, they do allow you to add the shank and cutting diameter. I looked around for some time, and even went back to the old tool library to see if maybe they had more options to input data into the tool settings, but alas, no. 

I was able to fix the problem in a sort of roundabout way; in Fusion360, there is an option to add custom tools called Form Mill's. The basic idea is you sketch out a 2D half of your endmill, then select the center axis where the form would wrap around to create the tool. Huge thank you to @saundersmachineworks for the video on Form tools, made it super easy, and only took a few minutes to sketch and create the custom tool. Now that I had the custom tool I found the pitch diameter offset by taking the thread size 2mm (2mm-0.4 thread), subtracting the hole size, 1/16", and dividing it in half (for both sides) to get the correct number. I then simulated the toolpath and watched it as it cut through the material, and it ran perfectly! You can see above the two tools in video and drawn out, one on the left sketch pad is the custom form tool, and the one on the right is the tool library input one. 

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. 

Today I worked on cleaning the shop after focusing only on making parts earlier this week. I'm delighted I had the opportunity to organize the tools beforehand as I know where everything is and where everything needs to go!

Not super interesting today, mostly sorting the tools I wasn't able to get to before and setting up new bins for the taps. There are quite a few different kinds of threading tools, some spiral, two, three, and four flute ones, and even some with drills! My boss also got another part for me to work on, which I'll be doing tomorrow, so I'm very excited about that!

Another full day of preparing these parts for shipment!

The last set of parts needed to be threaded (40 holes in all) each was a blind hole, and so I had to go down twice to be sure I hit the acceptable length. An interesting technique I haven't seen or heard of before but is built into the design of the hand taps. There is a hole at the top of most tap holders; its purpose is to slide a gauge pin into a vertical clamp of some sort, which in this case was the old manual CNC mill. You then slide the hand tool into the pin, and it creates a perfectly straight and stable way to hold the tap handle and still rotate and move it up and down. It's difficult to explain, so I'll upload an image of the setup I was using to thread all the holes.

After that, I gave all the parts a bath in soapy water, removing all the dirt and grime from sanding and deburring, then a rinse and spray down. From there, I packaged each part with toilet paper to ensure safe shipment! Since I've spent most of my time working on those parts, the shop has gotten somewhat messy again and will be spending the majority of tomorrow cleaning and reorganizing the tools.  

Today was more deburring, cleaning, and prepping parts for shipment. My boss did the final piece, which is a unique shape requiring three operations to mill it all out and didn't have enough time before it's due to have me do it. 

Removing copper burs is the bane of my existence; this specific piece has over 30 edges on it and ten parts total. Not to mention, copper is very resilient to any sort of tool you throw at it and takes several passes to clean up each edge. If you're not already aware of what a burr is, it's typically melted or pushed away material that the cutter (in this case endmill) didn't slice but simply shoved it to the side. I'll put up an example I found online of a more exaggerated version (before and after).

Part of the design included a section with three thin flat walls that were extended out and open on one end. If you tried machining it without any modifications, you would have a lot of trouble getting an excellent finish and staying in tolerance due to the fragility of the wings. The way he overcame this was to make a temporary wall on the opposite end and fill the pocket with a hard plastic molding material, then you can come in later and remove the partition with better rigidity and structure without the worry of the walls buckling in. The casting material is a Quik-Cast Polyurethane two-part resin and takes only an hour to cure with low shrinkage.

Nothing too exciting today, I finished tapping the set of 101 Copper parts I worked on last week and got those ready for shipment. 

I also programmed the other side of the second set of parts that needed a small corner stepdown and got to do that on the Haas VF2ss. The second operation setup on these parts was pretty easy and only took a couple of minutes to program. Since there were only ten pieces, my boss said just to do each one at a time and put them in diagonally to make each part be in the same spot as before. 

I did the entire operation with a 1/16" square endmill, first to pocket out the soft jaws, then to cut the corners on the part itself. I programmed the corners of the part to cut out a little bit larger than the edge of the part to allow it to sit snug against the side walls. However, after running the program, I accidentally broke the tool when it took the corner at 100% engagement and 29in/min, I then talked with Wayne, and he said that it wasn't necessary as the corners on the parts where rounded. So the 1/16" would already clean the edges properly. I reran it without that pocket and got a lovely finish. 

After that, I did a dry run the copper toolpath to cut through the aluminum soft jaws to prevent things from overloading. When that was complete, I cut the ten parts and got them all within one thou of each other. 

Today I got to machine the 101 copper parts I mentioned previously. Unfortunately, since these are more detailed pieces, I am not able to show the entire piece and have to blur some parts out. But as you can see, they turned out nice!

In preparation for this part, I did some research on milling copper, and for the most part, a lot of people say it's one of the more delicate materials to cut as its got a gummy like consistency and can wad up on your tools. I also read that you want very sharp tools when cutting it to prevent the material from just being pushed rather than sliced through it. I also found that it's super shiny and picks up every little detail; even with the finished product, you can clearly see the path of the tools but can't feel any deviation in the finish. Because of this Wayne had me do a spiral toolpath in the little pocket on a ball endmill, he said if I used a flat or bullnose endmill and cleaned the bottom face unless I had the tools measured correctly, you would see a slight step between the endmills even if you couldn't feel it. I had to use a ball endmill to get the corner radius at the bottom of the pockets.

Overall it wasn't too difficult to program, and the entire machine time for ten parts (each about 1" square) was one and a half hours. I needed to make 20 of these, but the second set required a larger hole size, so instead of reprogramming the whole thing, Wayne just had me run the same program but switched out the drill bit. When I ran the second batch, I remembered a second before the tip of the drill hit the material that I forgot to set the tool height, and thankfully no harm was done. If I let it run, it would have rapid into the stock thinking the drill was shorter. 

After that I de-burred the parts and started threading the holes on one set, I ran out of time though and will have to pick up where I left off on Monday. 

Today I finished up the second batch of larger pieces and got those packaged up. Since these are such small parts, Wayne had me put them in old plastic endmill boxes with a little bit of toilet paper to keep them from getting damaged. I think the issue with the weird height differences for the smaller parts was due to the slight radius in the bottom of the softjaw pockets, which allowed them to be moved around every so slightly, and so getting different measurements if the clamp position was changed. For the larger parts, the tolerance was within 0.0005" of the design, which isn't too bad at all!

The rest of the day, I spent working on the next set of parts using 101 Copper. I am just about finished with the programming for it and cut the soft jaws to hold it in place. I also got to use an edge finder for the first time, which I used to find the back wall of the vice to use as the origin in the CAM setup. The copper will be cut to width when putting it in the vice, so making sure it's perfectly aligned for repeating the process. 

I'm starting to get into a groove at the shop and feeling pretty comfortable with all the Haas mills! I know where all the tools are, how to program and set up one and two operation parts and get them ready to be shipped out! I'm still not as careful as I should be with freshly cut parts and accidentally brushed against the side of the soft jaws when taking them out.

Today I finished up the second operation on the parts I was working on yesterday.

After finding the center of the hole and relocating the G54 to it, I was able to run the second program to finish up the parts. I had a few test pieces that I made before so I could toss these if they didn't turn out any good. It turned out alright, though the surface finish wasn't the greatest, and Wayne noticed the chamfer wasn't entirely centered on the part. As it turns out, I forgot to enter the new G54 home, and so was about six thou off. He also suggested surfacing the top and leave about 0.03" on top to connect the parts; this would allow the tension to be released and make the pieces easier to bend the bow out of it. 

I edited the code and reran it on my main piece, which turned out very nice. Unfortunately, while measuring it, I noticed that it was consistently five thou off on the height, and after discussing it with Wayne, I added that offset to the code to lower it by that amount. However, after putting the parts back in and running it once more, I must have miss measured the first time, and all the parts came in under four thou of the drawing. Since this is on a time limit, he said to use them as is, as the tolerance had to be within ten thou, though he would typically get it closer. I'm not sure how I miss measured it the first time, but I have a sneaking suspicion that the one I referenced wasn't flat against the bottom of the soft jaws. I finished up the rest of the smaller pieces and set up the jaws for the larger parts, which I'll be finishing up tomorrow. 

Overall a bit frustrating with the tolerance mishap, but I'm delighted with how their surface finish!