This is great, another CNC made of wood that makes aluminium chips!
Clamping force needs to be much more than with wood.
I prefer using single flute especially at the kind of RPM you're running. The chips get evacuated more and this helps keeps the temperature lower so the alu sticks less on the cutter.
This is when I cut alu that I find my rpm controller to be the most useful.
Jeremy
http://www.diycncdesign.com/
Rewired machine and added cable carriers
When machining smaller pieces, there was no need for cable management; the wires all stayed out of the way without tending to them. Lately I’ve been working on making a chest of drawers that uses the full working envelope of the machine. This drove the need for cable carriers, drag chains, energy chains, or e-chains, as I’ve seen them called. I ordered a few different styles and sizes to see what I liked. The smallest size for the Z axis (15 mm by 40 mm) cannot be opened so the wires must be fed through from the end. This is not a problem due to the short length. For the gantry, I chose a 25 mm by 50 mm fully enclosed style that can be opened on either side to lay in the cables. On the long axis I used an open style 25 mm by 57 mm cable chain that can also be opened from either side. These cable carriers have extra room to add coolant lines, air lines, and additional wires for future upgrades.
Some research on cable carriers showed that special wire or cable type is required when used in a constantly flexing application like inside the cable chain. The way the wire strands are wound is important and the jacket material must have properties for flex, abrasion resistance, and optionally oil resistance. I ordered some cables from Igus and rewired all the stepper motors, the router power cable, and added wiring for homing switches.
Researched and purchased a few styles of home/limit switches to try out
When I originally built the machine, I had ordered optical switches to test out as homing/limit switches. After realizing the added complexity of needing a lower voltage power supply and something to interrupt the beam at the limits, I decided to go back and start with a simple setup using mechanical switches. I ordered two common styles found online, the microswitch with roller actuator, and the adjustable-arm switch with a roller actuator.
The size of the adjustable-arm switch came as a surprise to me. I was envisioning it being much smaller. I should have read the spec! The price was right for both options, so I will try them out and see how easy they are to mount and which one gives better results. The large adjustable arm switches would be the easiest to mount and setup, but I think I would prefer the smaller switches for a cleaner look, so I decided to try those first.
I wired up one switch on each axis to use for automatic homing, since it is starting to get annoying to have the re-home the machine every so often. I can add other others later for limit functionality if desired, but for now the soft limits in LinuxCNC are sufficient. A fourth switch should also be added to the other side of the long axis to be able to square up the gantry if needed. In the following picture the Z-axis and gantry axis switches can be seen.
I wired each switch to a separate input on the Gecko G540 to enable simultaneous homing of each axis. After setting up the inputs for the homing signals in LinuxCNC, I tested it out. What a joy to have the machine home itself at the click of a button!
I intend to test the repeatability of these homing switches and perhaps compare them to the other styles eventually.
Jeremy
http://www.diycncdesign.com/
Plans update:
After working for a long time on updating my machine design and making improvements for strength and ease of building, I have finally completed making a set of plans so that others can build a machine like the one in this thread. I am offering them for sale through a website I put together for my DIY CNC related projects (see signature below).
I used Fusion 360 to create a fully dimension-ed set of drawings for every part of the machine (other than components that would be purchased). I also wrote up an instruction manual with some guidelines and tips for the build and am including a Bill of Materials (BOM).
Based on my experience building and operating the machine that is documented in this thread, I made some improvements to strengthen the Z axis, and to make the machine much easier to build. The updated machine is what is described in the set of plans.
I will be building the updated machine per the plans, to ensure there are no issues, but I’ll start a new thread for that build.
Current machine updates:
Since my last update I added a compressed air nozzle and coolant mister to my machine. I bought a cheap kit off of aliexpress to test out. So far I’ve only used it for compressed air, but I'm happy with the way it works. It has allowed me to almost double the speed that I run the laser for engravings, since the smoke is kept out of the beam. I also installed a relay in the air line between the regulator and the CNC machine. This will allow the software to turn it the air on and off at the right time automatically. I haven't connected it yet; it is on my to-do list.
Not sure if I mentioned it before, but I tested out a Mesa 7i76e Ethernet FPGA card, to take over the step generation duty from the PC. This gets around the latency/jitter limitations that are inherent in sending the step signals over a parallel port. I’m using LinuxCNC as control software, so I had to make some configuration updates to run the Mesa card. With this new configuration, the machine is able to run over 1000 inches per minute. I haven’t tested the upper limit yet, but 1000 ipm is more than enough for a machine this size.
Last edited by jpvonoy; 02-09-2019 at 12:17 PM. Reason: Spelling error
Jeremy
http://www.diycncdesign.com/
At the website the plans are 70 sheets of PDF. Have you considered a price for the Fusion 360 file?
Steve.
I couldn't find anyone else offering similar models for sale. I did see some CNC machine models being sold just for the CG renderings (not complete design files) for between $50 and $400. I also found that if I wanted to hire someone to recreate the model based on my drawings, it would be a few thousand dollars. My gut feeling is to offer the files of the model for $250, and that seems low to me, yet at the same time I feel like not many people would be willing to pay that much for it. Steve, or anyone else here, is $250 too much? What would you say is a reasonable price?
On the other hand, am I shortchanging myself at that price and giving away my intellectual property? I will have to license the file(s) for personal use only.
Jeremy
http://www.diycncdesign.com/
Have a look and see what other plans are available for the designs offered and what prices they are asking. View any available forums/support resources to see what activity they have - this might give indications on popularity (or problems; no problems could mean either no problems or no sales).
Selling stuff can be either sell lots for a small profit and make some money or sell one for a lot of money and don't get any. It depends.
Sweet machine!
Is there an ETA for the detailed design book (as opposed to the Intro ebook or the plans)? I may well want the plans at some point, but first I need to work my way through the various options and considerations. (The intro is already very good, but needs a bit more detail - good advertising!)
Thanks for the feedback and showing your interest in the detailed design book! I put that project on the back burner so I could make the set of plans. I've also been monitoring interest in the detailed design book to determine if I should put the time and energy into it. Realistically, I don't expect to have it completed anytime soon, but the more interest I get, the higher the priority I will give it. As a very rough estimate I currently see it being completed in the 4th quarter of this year.
Thanks fretman_2! It's always nice to hear some positive feedback!
I appreciate your feedback. I'll continue looking and evaluating. I'll have to start somewhere and just adjust pricing as I go based on demand or feedback.
Jeremy
http://www.diycncdesign.com/
How about some video??
There are some on its blog page. https://www.diycncdesign.com/blog/
Best of luck Jeremy! This is a solid build, I'm being partial here as there are a lot of similarity with my machine.
Thanks. I had recorded some video of using the cnc router and laser to make a chest of drawers for my daughter's nursery. Unfortunately, my phone died before I downloaded all the videos so I lost it all. In a couple months I'll be making a second identical chest of drawers, so I'll take some more video of that and share it here.
Jeremy
http://www.diycncdesign.com/
Nice machine man!
I think the $250 is reasonable and acceptable for the home hobbyist. My thought is there are a couple different types of customers; those who intend to build an entire machine verbatim, those that want to use it as a starting point and those who only want to leverage certain parts of it. I am somewhere between the first and second as I already have some parts not identical to what you have used. As HE1957 mentioned, the price will dictate how many you will ever sell. You could look into some kind of copyright or patent, although that is only so good.
Steve.
Thank you Steve! This is excellent feedback. It really helps to hear the opinions of others to help me make good decisions.
I will clean up my Fusion file and make it available for sale on my website. I've also had other inquiries for the files this week. I will offer it at $250 and see how it goes.
For anyone that provided or provides feedback here on my pricing or product offerings, I'll provide a discount in appreciation of your honest feedback which is so valuable to me. Send me a private message if you're interested.
Jeremy
http://www.diycncdesign.com/