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Don

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About Don

  • Birthday 08/20/1962

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  • Gender
    Male
  • Location
    Genoa, Ohio
  • Interests
    woodworking, model ship building, target shooting and reloading

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  1. As far as I know there are no programs that will give you a 100% conversion without some manual touch up. I found it was easier to scan what you want insert the scan directly into CAD, scale it, and trace over the underlay. On bulkheads and frames etc you only have to trace half and mirror the other side. This way you can correct any errors in the original. Don
  2. Doug, Speeds and feeds for milling whether manual or CNC can be tricky. It depends on many factors material, bit size, spindle speed, feed rate and the bit type (carbide, HSS, number of flutes) whether drill, end mill etc. and chip clearance. Check out some speed and feed calculators online to give you some ideas. The the short answer for the slower rpm is you can use HSS bits to cut hard material such as stainless or tool steel. If you switch to a carbide bit you can increase your spindle speed and feed rate without burning up the bit and get a good finish. In our hobby work we usually work with softer materials such as wood, brass, plastic etc. so the slower speeds aren't as important. You also have to keep in mind many of these calculators may assume you are using a coolant which you will not be using. A easy visual of this is using a hand router. Move the router to fast it starts tearing out and leaves a rough surface, to fast and you burn the wood and bit. Keep in mind we are doing this for a hobby to have fun. In the end you will probably use the higher end of the spindle speed with some carbide bits and adjust you feed rate to match. Don
  3. Doug, EMC2 and Linux are open source software, you should be able to upgrade to a newer version without any cost. I am not real familiar with either thou but I am sure an Internet search would give you all the info needed. I use mach3 for my control software which is windows based and very popular with hobby and small shops. The important thing about both programs is they are based on old hardware platforms specifically the 25 pin parallel port. An old computer with the parallel port on board is an advantage. If you use a newer computer with no parallel port you will need to convert the USB signal to pulse signal for the 25 pin parallel port that goes to the stepper drivers. The timing of these signals is what allows you to control direction and speed in all directions at the same time. You would think that it would as easy as using an USB to parallel converter but it's not. You need special converter or a separate breakout board (such as smooth stepper). Also just sticking in a parallel card in the computer is a hit and miss, I don't know about the new Linux platforms but the new Windows OS do not support parallel ports the way the old OS did. Whether you have an box that plugs directly into an USB or an Ethernet port all of the stuff I just mentioned is built into the box. From that hardware, whether in a separate box or built into a computer, this is what you connect your stepper cables to. You do not need a new processor to run these programs. I use an old Pentium 4 with Windows XP that is over 10 years old. Will I have to eventually upgrade, yes but not until this computer dies. The main reason is that I would have to buy a USB motion control breakout box and reload and setup up the software. Yes you can use a CNC machine manually. There are a number of ways: handles on the stepper shaft,. keyboard, joystick, and a pendant (MPG (manual pulse generator)). A pendant is the easiest. All the axis, speeds, steps etc. can be controlled by this hand held unit. What also is important is the spindle speed. Getting something up to 10000 rpm is nice especially since you will be using smaller cutters. I should say I don't own the Sherline I have a Taig CNC mill, but all these hobby type CNC machine are all basically the same. They use steppers, stepper drivers, control software (almost alway EMC2 or mach3), and a PC. You also need software to draw you part and software to generate g-code. Note Fusion is free for non commercial use. I am by no means an expert. My son has his own small engineering and CNC manufacturing business, so when he needs the extra help I operate one of the large mills (these are not hobby mill but the principle is the same) so this gives me some practice at what not to do. If I get in trouble I just find him that's the nice thing about being free help, but I have learned a lot by helping and watching him trouble shot. Don
  4. Joe Generally what they mean by CNC ready is that the machines are ready to attach the stepper motors. In short the brackets are attached to the machine and you need the stepper motors mounted to be able to use the machine in any mode. The handles attach to the shaft on the back of the stepper, then you would be able to rotate the shaft as if in manual mode. To run in CNC mode you need to attach the steppers to drivers then this controller box is attached to a computer with the controller software (the most common is probably Mach3). This is how almost all hobby CNC mills are controlled. Some setups use servo motors and ball screws but this setup is not as common for hobby use because of expense, but there are some out there. Servo motors are used in commercial machines because they provide position feedback (the machine always knows where it's at) stepper motors do not. The easiest way to use a CNC mill in manual mode is to have the machine able to function in CNC mode. Then use a pendent to move the axis and use the controller software as a digital readout. This way you have a fully functional machine in both modes. I will try to get some pictures of my Taig setup (the setup is similar no matter what brand machine you use) this weekend. It is partially tore down as I am designing an enclosure for it. It is easier to explain if you have something to look at. Take a a look at this build log he uses a Taig setup very similar to mine. He has a great log and this will give you a very good idea of what can be done with a good hobby CNC mill. Hopefully this link works if not just do a search http://Western River Steamboat Heroine by ggrieco - Scale 1:24 - 1838 as she appeared before hitting a snag in the Red River. - Build Logs for SCRATCH SHIP MODEL PROJECTS - Nautical Research Guild's Model Ship World Don
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