CNC
Silver Dust
I just finished heat sink #3 for the HB2, which is the forth one I have machined counting the initial test block. I wondered how much aluminum I was removing from each 4x4x1 block.
I don’t have a full size un-machined block left but I do have the scrap end which is nearly a full block. It measures 4 x 3 11/16 x 1 which is 4 x 3.6875 x 1 or 15.75 cubic inches.
I have a postage scale that measures to 0.1 ounce. That is going to determine my overall accuracy. The undersized solid block weighed 23.2 ounces. Doing the math to figure what a cubic inch of aluminum weighs and bringing it back up to the 16 cubic inch start block ( 4 x 4 x 1), my figures say the start block should weigh 25.2 ounces.
The fully machined heat sink weighs 14.4 ounces, a 10.8 ounce loss. That is 43% machined away!
Pushing the fun with math a bit further, when I finish my 5th block, I will have made 54 ounces or 3.375 pounds of aluminum flakes.
I bet Gloria thinks about half of that has already tracked into the house, Oops!
A Boring Weekend
I had a good weekend in the shop. I bored out some axle caps for use on a Harley motorcycle. I didn’t create them, but the owner updated his ride to a new machine and the caps would not fit the new bike. All I had to do was use the Lathemaster and bore the stainless steel caps to the correct I.D. Each was a different size.
Next I set up another HB2 heat sink on the Taig CNC and let it run for four hours. That got the motor side done on one blank. Then on Sunday I did the other side (another 3 hours) and I have a full heat sink complete. That’s three so far counting the test one. I actually have 3 and ½ finished at the moment, heading for five.
While the Taig was running and buzzing happily away over in the corner, I used the Wonderful little Proxxon PD400 to make 16 identical aluminum leg extensions for mount the HB2 heat sinks to the machine frame. I am going a lot fancier than the stock motor mounts.
The legs are ½ inch round aluminum 6061-T6 bar stock I cut to about 1.750 inches. I faced both ends to exact length; spot drilled both ends, drilled #24 holes for tapping, tapped both ends 10-24, and then chamfered the tapped holes. Repeat 16 times. Of course I had an assembly line type process for each step. The tapping was the most work.
I also did some computer work and filled a couple of orders and questions from the store. In all it kept me out of the bars this weekend! (As if I ever go to such places 🙂 )
Thankful
The HB2 heat sinks are milling just fine now. It just takes a lot of time. More time than it is worth to put them into production by milling alone. This is why prototypes cost so much. They prove the product but there are much cheaper ways to make things in quantity. That’s the challenge of home shop machining. I can make just about anything I can imagine, but not necessarily the using the most efficient and least expensive process.
Milling something from a billet of aluminum is no where as efficient as starting with a casting with most of the unnecessary metal not present. I don’t see enough of a market for these HB2 heat sinks. Heck, I haven’t even tested them yet. I do have one on the HB2 machine and sure does LOOK cool. Ha!
The mighty little Taig Micro-mill is working like a champ. It sets there running constantly for three to four hours just singing along. The little end mills and light cuts are just right for this machine. It shows fancy (expensive) screws and ball nuts are not required on small machines. The very light mist cooling keeps things cool, just a huge amount of slightly damp aluminum chips to sweep and vac away.
HB2 Brain Box
Bare Bones Asus Computer
I went into NewEgg and did a search for bare bones computers. That is a good start to build up an inexpensive computer. A bare bones computer usually includes the case, power supply and general purpose mother board. That’s an Asus bare bones case you see in the picture. The flat screen I already own.
I picked one that could use one of the dual processor AMD processors. Dual processors (on one chip) are the only way to go. I chose an AMD 64 Athalon X2 5000+ processor. The speed is 2.6 GHz. This is a faster processor than I have in my office computer I am using to write this post. It is also a bunch cheaper than I paid for my 4400+ a few years ago.
Inside the case. Note air intake on side panel.
Besides the case and the AMD processor, I also purchased 2 Gig of RAM. The mother board only holds two sticks and 2 Gig is more than plenty for a workshop CNC computer. The last Item I purchased was a CD (lightscribe) drive. I did not install a floppy. (What’s a floppy?)
I had a 60Gig hard drive, so no purchase there. I also had a copy of Windows XP Pro from a decommissioned computer I threw away. The sound and video is built in and are working just fine with Mach3.
Total out of pocket cost for what you see here is $270.00, not too shabby.
Let me tell ya, this little package runs faster and better than my office system. But it is not a super computer. The only cooling fans are on the processor heat sink and the power supply. Heat is NOT a problem. All fans are running on low speed… Continue reading
HB2 Stepper Heat Sinks in the Rough
HB2 Stepper heat-sinks CNC rough milled
These are the four spacer/heat-sinks I am milling for the HB2 router. All four heat-sinks are rough milled on both sides. I flipped two so both sides could be seen.
Total run time so far is about 1.5 hours each. So with setup and clean up and taking pictures, this is about a full days milling work.
I also spent as few extra hours in the morning with RhinoCad making some last minute adjustments for the final runs. Mostly to make sure I don’t get any of the early versions mixed in with the final edits. I was also to reduce some of the run time through better tuning.
The fin cutting is going to take about 4 hours per side, so there is at least four full days of work left to do.