Wobblycogs Workshop

Author: Doozer

  • Wyvery – Power Transfer and Gantry Design – Day 12

    Wyvery – Power Transfer and Gantry Design – Day 12

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    Doozer
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    I’ve been doing quite a bit of reading of build logs in the last week and a some tinkering in sketchup to try and improve the design. One of the things that I constantly read people being advised to do is beef up the connection between the gantry and the x-axis ball screw. It’s very…

  • Wyvern – Information – Day 11

    Wyvern – Information – Day 11

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    I’ve been adding a bit to the design over the last day or two but I’ve been struggling a little with the diagrams provided by Chai (linearmotionbearings2008 on eBay). They look like scans of scans of badly taken photos and are only just readable if you squint. I thought, therefore, I’d try and track down…

  • Wyvern – Bolt Positioning – Day 10

    Wyvern – Bolt Positioning – Day 10

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    Now that I’ve redesigned the frame it’s time to start adding bolts to the drawing to find out whether I can actually hold everything together. It might seem a little superfluous to add every single bolt but there’s a couple of good reasons to do it.

  • Wyvern – Frame Redesign – Day 9

    Wyvern – Frame Redesign – Day 9

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    No matter how much I tried to convince myself otherwise I just wasn’t happy with the design of the frame. Having the legs on the inside of the frame just felt an accident waiting to happen so I bit the bullet and reworked the frame to give it a more conventional design.

  • Wyvern – Mounting Plates – Day 8

    Wyvern – Mounting Plates – Day 8

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    I was reading this build thread yesterday realised I was trying to rush this project and that something was going to go wrong if I didn’t slow down, do a bit more homework and spend longer on the design. I really wanted to get this done in the time I have off but it looks like that…

  • Wyvern – Mounting Plates – Day 7

    Wyvern – Mounting Plates – Day 7

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    Doozer
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    After much dithering I decided to go with the 2510 screws and some powerful nema 34 steppers. I’ve not picked the motors and drivers yet but looking at what’s been recommended to me by others I can clearly get something that will work in a 34 package so it’s time to press on with the…

  • Wyvern – Ball Screws – Day 6

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    In an effort to keep the screw length down I moved things around in the design and did a stack of calculations for different screw and motor sizes and then did a bit of pricing up. This spanned a couple of days and a lot of discussions with people that know far more about CNC…

  • Wyvern – Ball Screws – Day 5

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    So it turns out that 1500mm is a magic length for home made CNC machines, who could have guessed. My new super long 1800mm design is going to cause me some problems and I have to decide whether it’s worth pressing on with this design or dropping back down to 1500mm.

  • Wyvern – Frame Design – Day 4

    Wyvern – Frame Design – Day 4

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    Doozer
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    After chatting with some of the guys on the MYCNCUK forum it seems steel is a lot cheaper than I thought it was. In fact 50x50x4 mild steel box section can be had for almost the same price as and equivalent piece of PAR pine. When you consider what goes into steel construction compared to wood production…

  • Wyvern – Frame Design – Day 3

    Wyvern – Frame Design – Day 3

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    Doozer
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    Having realized that SBR20 rails are 45mm wide I scrapped the 80x40x4 box section in favour of 50x50x4 – should have checked that before designing the thing I suppose. I then plugged the figures into the gantry stiffness calculator and, if I understand it correctly, I should be getting a maximum deflection of about 50μm with a…

  • Wyvern – Frame Design – Day 2

    Wyvern – Frame Design – Day 2

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    Doozer
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    So there was quite a break between day one and two of this CNC build which was probably a mistake but nowt I can do about that now. After much debate my better half has convinced me to try building the CNC as my Christmas project. I’m planning on trying to get the mechanical side…

  • Wyvern – Home Made CNC – Day 1

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    After several seconds of hard thought I’ve come up with a name for the machine the “Doozer V1”. My nick name is Doozer and I can’t think of a better (imaginary) creature to name the machine after than one that spends it’s days building things. After tiring myself out thinking up a name I didn’t…

  • Wyvern – My First CNC

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    For years now I have wanted to build a CNC machine. I don’t know why they have just captured my imagination and stuck there. I think it might be the mix of skills required that appeals, woodwork, metalwork, electronics and software. I’m fortunate that I have a good understanding of the software side of things…

  • Building a Power Supply – Part 2

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    Doozer
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    In the previous part I discussed most of the major components in the power supply. In this part I wrap up the discussion by talking about the smoothing capacitor and other components that will be needed.

  • Building a Power Supply – Part 1

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    Doozer
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    In the previous part of this series I looked at the calculations needed to determine the current and voltage the stepper power supply should be built to provide. In this part I start to discuss the components that the power supply is built from. From the previous part we know that we need to provide…