CNC "BigBrother" Project

Last update: February 6, 2004
Bigger...Better...Faster...it's the Tim Allen in all of us! The PipeDream is a great machine, but is a little slow for what I really wanted - which is a CNC Router for milling (mostly) wooden signs.

After using the PipeDream for almost a year, I have a pretty good handle on what I want in a machine. This is going to be different for every person, and every application.

The things I like about the PipeDream are:

  • Quick tool change - Router, RotoZip, Dremel, Engraver
  • Large cutting area
  • Relatively easy alignment
  • Great clamping of stock
  • Low cost

    Things I want to improve on the PipeDream:

  • Bigger cutting area (ideally 48"x30" or larger)
  • Faster feed rates using a rolled ball screws and 1/2-10 ACME rod for leadscrews
  • Better access to the Z axis for adjustments
  • Stiffer X axis rails

    Construction Notes

    Controller

    The PipeDream was originally built using a Piker4X controller which I found very reliable. I have even bought several more control boards from John for a couple of other projects I am working on.

    I had hoped to increase the speed by upgrading to a CAMTRONICS 2A Chopper Board with an 18VDC supply. I did not notice much of an improvement in speed with this upgrade. Since I have the controller, I will likely use it on the Big Brother. Originally I had hoped to build the Big Brother with Servo's. I had already bought the box, connnector kit, and DB25 board from CAMTRONICS. I was hoping to use a GECKO system to drive the servos. Now, here is the snag. Start adding up the cost of the servo's, the GECKO controllers, the power supply components etc., and you end up spending many hundreds of dollars. I think I will just stay with steppers for now.

    Z Axis

    The PipeDream uses Thompson linear bearings with a 1/4-20 All-Thread lead screw. This works really well, but is rather slow. It also is very difficult to adjust with the overhang of the gantry unit.

    While looking at the CAD_CAM_EDM_DRO group on Yahoo, I came across Paul Jones name. Paul grinds his own engraving cutters, and now is making full Z axis assemblies for a very reasonable price. I have decided not to reinvent the wheel for the Z axis. I am going to order the Z axis assembly from Paul, which will improve the machine and speed up the assembly process. Check out his web site at: Pauls Site

    Update I just (February 11, 2003) received the Z axis, spindle and engraving cutters from Paul Jones. I would highly recommend purchasing these quality items from Paul! I found the Z axis to be of excellent quality. Very nicely machined, well assembled! The Z axis came with the attachment for the spindle, but it will take a small router like a RotoZip with a little work. The cutters are razor sharp and even cut glass (I would not recommend this...). The spindle will make a wonderfull PCB cutter or engraving head. Drop Paul and email for more info. Tell him I sent you!

    X Axis

    The PipeDream gets its name by the use of 1/2" Black Gas Pipe for its X axis. Roller skate bearings are used to "ride" the pipe to make a linear bearing. This is an excellent idea, and works really well. There are always a few things that could be improved on any design.

    My friend Gerry was kind enough to supply me with two large 54" linear bearings that will be ideal for the X axis. eBay supplied a nice 48" rolled ball screw assembly that will make it quick to move from end to end.

    Y Axis

    The Y axis is going to be shorter than X as it has to fit in my garage up against a wall. We use my shop (garage) to store the car on the really cold days. If I make the router 48x48 it will not allow the car to come in. For this reason, I have cut it down to a 48"x36" machine. The 36" Y axis will have a 1/2-10 acme rod for the lead screw. I will be using the metal lathe to turn down the ends to attach thrust bearings and coupling to the motor.

    Check back soon for more info.