CNC Router Pattern Making

Discussion in 'Pattern making' started by oldironfarmer, Apr 24, 2018.

  1. oldironfarmer

    oldironfarmer Silver Banner Member

    HT-1 posted he needed someone to route out a plaque pattern. How hard can that be? So he sent me the model and I converted it to gcode for my router. 857,000 lines. 8 hours route time. Part of that is my fault for being a novice at CAM. Here it is in progress.

    Roughing out


    Roughing about finished


    Cut from 1-1/8" black walnut.

    Next stage


    And cleaned up ready for a lot of sanding.


    This is the lapel pin the plaque represents, Command at Sea, worn by ship's commander.

    Mark's castings and Tobho Mott like this.
  2. Tobho Mott

    Tobho Mott Silver Banner Member

    Looks great to me, can't wait to see what HT1 does with it!

  3. crazybillybob

    crazybillybob Silver Banner Member

    That's some beautiful wood (I'm a sucker for Black Walnut). Very nice work on the tool paths! Great job.

  4. oldironfarmer

    oldironfarmer Silver Banner Member

    It is black walnut. Thanks for the comments, the good stuff is all in the software.

    I'm eager to see it cast as well.
  5. Jason

    Jason Silver Banner Member

    Body filler will make those lines go away easier than sanding.
  6. Jammer

    Jammer Moderator Staff Member Banner Member

    Which CAM program are you using? I've been looking at Mesh CAM but haven't pulled the trigger.
  7. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    That looks very nice and walnut is a thing of beauty. Ever use urethane modeling board? Once you do you'll never use anything else for master patterns. It's a bit pricey but machines, sands, and finishes like a dream and dimensionally stable forever.

  8. oldironfarmer

    oldironfarmer Silver Banner Member

    I'm sure HT-1 will have a clean solution. Not knowing whether he was going to use an edge tool I didn't sand any. A little sanding would have cleaned it up a lot, then a little filler would slick it up.

    I'm using Fusion360 for CAD and CAM. It's free if you use it to earn less than $100,000 per year. I've been around AutoCAD for many years (not an operator) and it was 2D expanded to 3D. Fusion360 is also from AutoDesk. It had a steep learning curve fro me but I now know enough to do the simple stuff I want. The CAM function is very broad and I'm just scratching the surface of it, but it does have a CNC Router subset. It's also good for CNC plasma and laser applications as well as 3D milling and turning. Price is right.

    Never heard of modeling board. Sounds a lot like a controlled substance. Are you sure I should try it?
  9. Jason

    Jason Silver Banner Member

    We use vectric cut3d for toolpaths and mach3. They play nice together are cheap and easy. Cut2d would have worked well on this.
  10. oldironfarmer

    oldironfarmer Silver Banner Member

    I also use Mach3 to drive my router. I wonder how many CAM programs there are? It must be north of 100. I had never heard of cut3d or Mesh CAM.
  11. Seeing a pattern like that makes me want to create something similar and appropriate for my workshop:

    Kaos-logo.jpg Kaos.jpg
  12. crazybillybob

    crazybillybob Silver Banner Member

    There are a ton of CAM packages out there if you count all the free / opensource ones.
    The Various one from Vectric (they have 7 costing from $149(us) to $1995(us))

    These are probably the top 4. Fusion360 and HSMworks are Pro tools for machine shops the Vectric Aspire would be the pro tool for sign making. There's a new tool coming out about every week because every company/group that has a CAD package is working to add CAM to keep up with the 600Lb Gorillas that are Autodesk, Solidworks and Rhino(ok Rhino might only be a 400Lb gorrila).

    I learned CAD on AutoCAD a long time ago so the Fusion360 path felt right. With that said I have tried out the Vetric Vcrave Desktop and am seriously considering buying a seat for signs and 2D -2.5D molds as it's got a very easy to use interface for setting up machining ops.

  13. HT1

    HT1 Silver Banner Member

    since I cannot get to this for sometime... I'm swamped with work for several weeks I'l just highlight. the thinnest sections are 3/16... Which I just dont trust to consistently fill with holes in the pattern, I will put something under the whole thing... to give it a tough more thickness... perhaps 1/16 bass... or 2 sheets of paperboard... Cereal box ;-)

    I'll hand carve just a little more relief into the anchor and the star. the whole thing will get shellac and a smoothing with steel wool, if that wont give a good enough finish... sandable sealer... will ruin the beutiful walnut... but will give a great finish for a pattern.

    I was really surprised by 8 Hour of routing time... I probably could have hand manufactured the pattern in about three times that

    Thanks again it's beautiful
    V/r HT1
  14. Some clear epoxy before sanding will soak in and stabilize the hairy wood fibres before sanding, a few more epoxy coats between sanding would preserve the wood finish and give a smooth surface. The only problem is the 24 hours between coats due to curing, a warm oven will fix that and give a much harder durable surface.
  15. oldironfarmer

    oldironfarmer Silver Banner Member

    I think I may know you, your picture seems to ring a bell...

    Thanks for that information. I don't know how guys handle learning two CAD programs. I know I sure don't want to try to pick up anything other than Fusion360 until I have to change to something else. My brain just does not work well enough to switch between software packages. I have enough trouble with one computer on Windows 8, one on Windows 10, one on Vista, and my Mach 3 running on XP. I do know I like Windows 10 best.

    I'm just glad you'll be able to use it.

    Interesting, I would have guessed a warm oven would want to warp the pattern.
    Mark's castings likes this.
  16. Hmmm probably true..... My experience is with moisture resistant MDF which I rough machine then paint with the epoxy several times as it gets soaked into the fibres quickly and then after curing I finish machine to exact size. As a general rule (Ahrrenius Law) every 10 degree C increase (18 deg F) will double any chemical reaction speed, including epoxies. So even a 20 deg C or 36 deg F increase over ambient will cut cure time to 1/4 of what it was before. You would have to judge for yourself how much warmth the wood can safely take and even a bowl of water in the oven to prevent drying of the wood couldn't hurt. Too hot will cause outgassing and bubbles. If you do get bubbles by accident then a flame from a lighter will instantly pop them if the resin is not already cured.

    Of course a dedicated oven not for food use would be a good idea as epoxies have Bisphenol A which is an endocrine disruptor in males (female hormone) and you would not want to be growing certain secondary sexual features as an accident.
    Last edited: Apr 28, 2018
  17. Petee716

    Petee716 Silver Banner Member

    What would be an example of a suitable epoxy?

  18. I use a boat builders fibreglass epoxy made by Nuplex which is bisphenol A based and mixes in 5:1 ratio and cures water clear but ages yellow over a year or so. Bisphenol A and Bisphenol F are the least viscous of the epoxies and pretty much what you'll find in fibreglass epoxy resins. It's got a 24 hour cure but can be accelerated at the expense of strength (like 5 minute epoxy). As a general rule, the closer you get to 1:1 mix of the component ratio the more additives an epoxy resin has in it, so with 5:1 ratio is close to the pure epoxy chemicals.

    It's like a clear lacquer when painting on wood or MDF and because it's liquid for 24 hours (edit:it's a runny liquid for an hour) it has a good chance to soak in (MDF is like a sponge and sucks it up in seconds). It will generate heat when a small volume is cast so I save wood and aluminium sawdust from the bandsaw to mix in to dilute the resin without reducing strength.
    Last edited: Apr 30, 2018
  19. HT1

    HT1 Silver Banner Member

    It came out wonderfully I couldnt be happier , I'll Polish it up and post finished Pics when It is ready to sale ... If anyone is interested in doing soome work for me I have another hot project need to be able to do a Piece about 6x12 inches

    V/r HT1

    oldironfarmer and Tobho Mott like this.
  20. HT1

    HT1 Silver Banner Member

    And here it is all shiny many many thanks V/r HT1
    FDFE2344-47AE-472E-8DC2-A3495C0C3207.jpeg FDFE2344-47AE-472E-8DC2-A3495C0C3207.jpeg
    Last edited by a moderator: Jul 12, 2018

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