Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: shopbot CNC version of my cracker holder

  1. #1
    Join Date
    Feb 2008
    Location
    Fort Washington, PA
    Posts
    180

    shopbot CNC version of my cracker holder

    A while back I posted a method of making one of my best selling items at shows, a simple cracker holder. Update, I make them on a Shopbot CNC router now, and thought some might like to see the process.

    Here is the bot. It comes from Shopbot with a 1/2 inch thick aluminum table drilled with 1/4 x 20 holes so you can attach your own table depending on what kind of hold down setups you will be using. I opted to build this T-track table on it because I will be using a lot of product specific jigs and needed lots of options orientation-wise to be able to attach the jigs to the table. So far it has worked out great.

    Here is the bot with the cracker holder hogging-out jig attached to the table ready for a blank.



    Here is a pic of that jig loaded with a blank ready to hog out. That small piece of aluminum angle iron in the bottom right corner of the jig is how I orient the router/bot to the jig when I set up for this job. I'm using a 1/2 inch solid carbide spiral upcut bit for the hogging, and I move the router close to the area of the angle, then nudge the jig till it's touching the inside of that angle. I then tell the bot that that point is zero. The program I wrote assumes that, and it then moves specific distances in the x and y axis to do the hogging. You can't see the bit in this pic because I still have the dust collector shell around the bit. I will remove that for a few pics so you can see the action better.



    I played around and tried lots of methods to actually hog it out, and through trial and error came up with a method that make the cleanest cuts in most kinds of wood without the bit burning any corners or bottom. Method I came up with first goes around and bores a hole at each corner, and then works around the inside of the blank in 5 left and right passes to clean out a layer. The area I am hogging is 7/8 inch deep, and I found that I could do the whole hog out with one 7/8 inch deep cut, but I had to slow the bot down to do that, and it tended to burn some wood like maple and cherry. So I decided to write the program to do the hog in 4 "layers"... 3 hogs each 1/4 inch deep, and then one final 1/8 inch deep final hog. At the speed I set it for this job, it takes about 2 minutes start to finish all four passes.







    Here is the finished rough product ready for the next step, sanding and 1/8 inch roundover all around, then drill the hole in the handle, and finish it with walnut oil. The one on the bot is cherry, the row of holders on the table are already oiled, they came from red oak I milled from a log this past January. It dried fast, was down to 14%MC already, and for this project that's fine to use right off the stickered pile.



    Build it Break it Fix it ...repeat

  2. #2
    Join Date
    Oct 2006
    Location
    ABQ NM
    Posts
    30,020
    Very cool, Dave. Someday, if money and space permit, I'd love to have a CNC setup. Properly used, it seems it could pay for itself many times over.
    When the going gets weird, the weird turn pro. - Hunter S. Thompson
    When the weird get going, they start their own forum. - Vaughn McMillan

    workingwoods.com

  3. #3
    Join Date
    May 2007
    Location
    Kansas City, Missouri
    Posts
    13,452
    Dave, I like the jig and the cam clamps. Will have to consider that when I've got several parts to cut out on mine next time. I built my cnc from scratch. Been collecting parts for a larger one, somewhere around a 4' x 8' table. Figure I'll have about $2000 in it when done, not including software.

    Thanks for posting, great info.
    Darren

    To a small child, the perfect granddad is unafraid of big dogs and fierce storms but absolutely terrified of the word “boo.” – Robert Brault

  4. #4
    Join Date
    Feb 2008
    Location
    Fort Washington, PA
    Posts
    180
    I made those cams from osage orange because it's so strong and tough, and they work great. They are only 1/8 inch out of round so they put a tremendous force on the blank. They speed things up because they are quick to use but yet they hold as tight as anything else. Because they put so much force on that blank though, I had to redo the stop behind the blank. Originally it was just glued and screwed, but the cams had so much force it kept pushing that stop to where it started to move. I then dadoed it into the base and glued and screwed, and so far it hasn't moved.
    Build it Break it Fix it ...repeat

  5. #5
    Join Date
    Feb 2007
    Location
    Catalunya
    Posts
    4,632
    Excuse my ignorance, but what is a cracker holder?

    A device to hold crackers (fireworks)?
    A device to hold nut crackers?

    Thanks
    Best regards,
    Toni

    __________________________________________________ __________________________________________________ _________________
    web site:http://www.toniciuraneta.com
    I also dream of a shop with north light where my hands can be busy, my soul rest and my mind wander...

  6. #6
    Join Date
    Dec 2006
    Location
    Lakeport NY and/or the nearest hotel
    Posts
    5,533
    Toni,
    It is a special tray to serve Crackers as a side dish to go with Soup or cheese at the dinner table.

    quick google search found an example here:
    http://www.flickr.com/photos/calvary...7594121784059/
    -Ned

  7. #7
    Join Date
    Feb 2007
    Location
    Catalunya
    Posts
    4,632
    Thanks a lot Ned.

    I should have known that, but I got lost wondering, and my mind took the wrong direction.
    Best regards,
    Toni

    __________________________________________________ __________________________________________________ _________________
    web site:http://www.toniciuraneta.com
    I also dream of a shop with north light where my hands can be busy, my soul rest and my mind wander...

  8. #8
    Join Date
    Nov 2006
    Location
    Constantine, MI
    Posts
    7,891
    Quote Originally Posted by Frank Townend View Post
    Gee and I thought they were shoes for safe crackers.
    Whip holders for Floridian cattle herders.
    Host of the 2017 Family Woodworking Gathering - Sunken Wood

    “We all die. The goal isn't to live forever; the goal is to create something that will.” - Chuck Palahniuk
    www.wrworkshop.com

  9. #9
    Join Date
    Dec 2006
    Location
    Lakeport NY and/or the nearest hotel
    Posts
    5,533
    Quote Originally Posted by Rennie Heuer View Post
    Whip holders for Floridian cattle herders.
    *tweeeeeet* you alMost owed me a new keyboard and monitor there Rennie...
    -Ned

  10. #10
    Join Date
    Feb 2008
    Location
    Cedar Park, TX
    Posts
    320
    That isn't the model Rockler is selling now, is it? Seems larger than I imagined their's to be. Maybe one of these days.
    Jerry

    http://www.sawdustersplace.com

    "If politics wasn't built on careful deception it wouldn't need its own word and techniques. It would just be called honesty, education, and leadership."
    Bob "Phydeaux" Stewart one day on Woodnet

Similar Threads

  1. Owning the ShopBot
    By Carol Reed in forum New Systems and Builds
    Replies: 4
    Last Post: 02-19-2015, 09:49 PM
  2. Replies: 5
    Last Post: 07-03-2013, 07:13 PM
  3. sketchup free version ? pro version?
    By keith Boutselis in forum Designs, Plans and Sketches
    Replies: 34
    Last Post: 11-28-2012, 02:26 AM
  4. My Nut Cracker
    By Paul Douglass in forum Lathe Project Showcase
    Replies: 12
    Last Post: 01-31-2011, 07:33 PM
  5. making my cracker holder
    By Dave Kauffman in forum General Woodworking Q&A
    Replies: 7
    Last Post: 03-02-2008, 05:43 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •