There's a lot to make. And what needs to be made would take a really long time, if they had to be made manually. So I'm always looking for force multipliers that will make the jobs faster or easier, or both. In the Lowell Makes machine shop, that force multiplier is the Tormach!
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| Hyperdrive frame on the Tormach CNC mill |
The Tormach CNC mill is a computer-controlled machine that carves parts from blocks of metal. To produce a part, I have to design and model the part in 3D. Then I create a CAM program to tell the Tormach how fast and deep to cut, what tooling to use, and what paths to take. All that takes hours before any IRL metal is cut.
The latest part I worked on is the frame for the main drive train of the Falcon, which I dubbed the Hyperdrive (haha). Here's the design.
Here are just two CAM operations that make the frame.
The frame is too wide for the Tormach's reach, so I had to create two setups that each worked on half of the frame. I had to move the plate over to do this and somehow keep the plate aligned. The short side of the frame was aligned using the back, stationary jaw on the Tormach but the long side still needed a common starting point between the two setups. The trick was to machine an edge into the first half of the frame as part of the first setup, then use that edge as the origin for the second setup.
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| Surface used as origin of second CAM setup |
After many changes, our machine shop captain blessed my CAM programs. I got started making the real frame. I spent the first day just setting up the stock on the machine.
First, I had to adjust my CAM setup until all the operations fit inside the Tormach's milling envelope. It can realistically mill inside a 14" x 6.5" area, but that also includes the diameter of the tool used, so effectively it's 13.7" x 6.2" using a 3/8" diameter tool. It was easy to tell when it fit because the machine refused to continue if it didn't. Next, I had to mount the stock metal. This was the hardest part of the setup.
Because of the Tormach's dimensional constraints, I had to slim the design of the frame by almost an inch and reduced the size of the pulley mounting holes to reduce the length. The final frame dimensions became 5.5" wide x ~25.5" long. I also milled down the stock from 7" wide to just under 6 inches. It was quicker to do that on the manual mill.
The last part of the setup was securing and supporting the stock material. The center of the milling area was secured by a vice on the machine, but metal stuck out from both ends. If I tried to machine it like that, the metal would start to vibrate whenever the tool danced over the ends. I needed to jack up the ends to increase the material's stiffness.
Instead of ordering machinist jacks and waiting, I took our machine shop captain's advice and made jacks out of some spare aluminum blocks and a few bolts. Then I used those jacks to hold up the ends of the stock.
All that was the first day.
I then spent the next two days running the first CAM program, moving the stock, resetting the X origin, and running the second program. And cleaning. The sheer volume of aluminum flakes was enough to fill half of a 30 gallon trash bag. That takes a while to vacuum up.
The final result came out great! I had a few mishaps that removed some "extra" material from the surface of the frame, but nothing that would ruin the part. And now it has some character.
I would have never been able to do something this intricate manually. I could've made something, probably rectangular shaped, that worked but didn't look as good and probably weighed more. And I think it would have taken at least as long. Now, thanks to the Tormach, it's ART.
Oh, and multiplying my machining skills is not the only advantage of using the Tormach. Once a program is proofed (i.e., pretty sure you won't ruin the machine, the part, or your tool), I can do other things while a job is running. For example, I can prepare the stock for the next CAM job while the current one is running. But I'm always listening for the high-pitch whine of the tool happily cutting through material.
The frame was too complicated to leave unattended. But while I worked on the CAM program for the frame, I used the Tormach to make 14 bearing cups that will mount and weld to the frame and 4 tensioner blocks that will also mount to the frame and will allow me to tighten the belts around the pulleys.
The bearing cups were a particular win. Making those on a lathe would have taken me days. With the Tormach, I was able to bang those out in 2 hours.
I now have all the pieces to put together the Hyperdrive, and it's thanks to the force of the Tormach!
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