Machinist Apprentice | Shipping Parts & Programming 101 Copper | Day 22

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.

Machinist Apprentice | Finishing up the Parts | Day 21

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!

Machinist Apprentice | Finishing First Operation and Cutting Soft Jaws | Day 20

Today I got to finish up the rest of the parts on the first operation. There are two sizes of these parts and did all the first operation in one go before cutting the soft jaws since the location was a known one and easy to set the stock in place. 

My boss also solved the issue I had yesterday, where there would be a small cap on top of the part that should have been cut off when facing the material but wasn't. Wayne thinks it might be due to the released tension in the stainless stock, and rerunning the facing operation, that seemed to solve it. Each part I loaded ended up with the same small cap on top and had to rerun the first toolpath on each one. 

After making enough of the first operation parts, we moved over to the soft jaws. For that, Wayne had me put a 1/32" parallel to separate the two jaws, to give it some clamping force when the parts are in. I then faced the aluminum and located the center for the soft jaw milling operation. It came out a bit rough, and after consulting my boss, he reran the program after deburring the edges. From there, the parts fit in pretty nicely, though there was a slight radius in the crevises of the pockets which I didn't see on the used endmill I loaded. Thankfully it doesn't look like it will be an issue as the fillet on the part matches the radius on the inside pocket. From there, Wayne put a 1/16" pin in the locating hole, and I used a dial indicator to find the center to set the G54. I ran out of time for the day and will finish the final operation tomorrow!

In between runs, I started programming the other parts, which will be made in copper. I unfortunately, I won't be able to share any images of the elements themselves as they are proprietary, but I'll do what I can to share pieces of it. It's got a lot of nifty corners and crevices, which were a bit of a pain to figure out how to do because of interior radiuses done in metric.

Machinist Apprentice | My first Operation on the Haas Minimill | Day 19

Today I got to run the milling operation on the Haas minimill that I programmed last week!

I loaded the new soft jaws into the vice and faced it. I then used a couple of parallels to space the two apart so I could cut a groove down the center to fit the raw 1/4" stock in the middle. From there, I loaded all the tools and found the center to set as my G54 (work origin). While loading the endmills (each bit has to be manually measured in using a height gauge block), I accidentally sent the z-axis crashing down on the material, breaking the 1/16" ball endmill and leaving a small fragment in the stainless stock. Thankfully there was no lasting damage, but it made me jump when it happened and left me a bit on edge for a while after. 

After loading and setting the tool heights, I started the operation. Everything went according to plan and got through all the toolpaths without a hitch. I did set the peck-drilling process to take 0.0004" by accident, and so that took quite a bit longer than intended. Once the first operation was complete, I loosened the vice only to see the part practically spring out at me due to the released tension in the material. Right away you could see it didn't look the best, it has significant facets which the contouring toolpath should have cleared up, and you can see the top face somehow has a little cap on top of it from what I am guessing is a tool height issue. 

I edited the toolpaths to correct these issues by changing the tolerance and added smoothing (allows the toolpath to roll around instead of point to point), which I posted the code again and set the machine running. I also re-measured the tool height offsets on each of the tools to ensure everything was correctly aligned; this time, it ran much better and had an excellent surface finish (I forgot to take a photo). However, there was still a small cap on top, not as tall as it was before, but even noticeable, and I'll have to do some digging to figure that out. 


Home Workspace | New Vice Fixture | Pocket NC

My boss gave me the day off for independence day so I thought I'd write about my new Vice Fixture from @pocket_nc!

After talking a bit with a few different people about my old clamp system, I designed a couple of months ago; they pointed out a few flaws. The main flaw with it is the rigidity of the design, the only point of contact with the stock is the lower half maybe 1/2" in total, and the rest is free-floating; this causes vibrations to go through the stock and leaves imperfect surface finish quality. 

I talked with my boss about it and mentioned @pocket_nc had a circular stock fixture to hold round rods of material with an ER-40 collet. It's got sufficient clamping force to hold it securely in the vice and provides much more rigidity. I was convinced that it was worth it very quickly, especially since I didn't have to do as much work calculating where the stock was in the machine. My boss also mentioned that you could take 3" round stock and put it on a lathe to cut one end down to 1" (the largest diameter the clamp can hold). With a piece of circular stock cut down to 1" on one end means you can pretty much mill out whatever size part you like on the machine with relatively stable work-holding.

It came in on Tuesday, and I was dismayed to find the tool to tighten the fixture, not in the package. I contacted Pocket NC, and they responded within an hour, apologizing for the mistake, and shipped a new one right away. The next day I received it, not even 24 hours after I got the package. I love the people at @pocket_nc; they are always super friendly and have fantastic customer support!