OpenBuilds OX DIY CNC router from Ooznest

posted in: CNC, CNC Router, ooznest | 0

This is the build log of the OpenBuilds OX CNC router from Ooznest. Having already built a Hot Wire CNC foam cutter I got the bug to build a CNC router.   I’ve used the TB6560 4 axis controller controller with Mach3 and LinuxCNC that I use on the Hot wire foam cutter.

After a lot of research I decided to buy the OX mechanical kit from Ooznest, the 500mm x 750mm which can be upgraded if you need it bigger.  I did considered building one from scratch using MDF and skate board bearing.  But wanted something I could get up and running fairly quick.   Total build time was probably about 10 hours over a few days.

The Ooznest Kit

I’ve read some very good reports about the kit and wasn’t disappointed when it arrived.  The packaging is second to none with items very clearly labelled and boxed into to major assemblies.  I also purchased the router mounting kit at the same time for the Katsu 107148G trim router from Amazon which is a Makita RTX0700CX clone at half the price.  Since found out the router is 65mm diameter and the mounting plate is 71mm.  So I had to buy a new one the cirrect size.

The manual supplied is superb and nice and glossy!  The kit is based on the OpenBuilds OX design by Mark Carew with some modifications to improve the rigidity of the machine.  Mark has the build videos on OpenBuilds in the previous link which are very good.

Costs

The kit isn’t cheap but I’m very pleased with it.  You can use Mach3, UCCNC, LinuxCNC or Arduino based kits. Here is my review of free CNC software

I now use LinuxCNC exclusively on this machine, and my CNC foam cutter . My article on how to use LinuxCNC here.  Mach3 is very good but will cost you $175 where as LinuxCNC is free.  If you want to use USB from a laptop or Desktop machine then an Arduino  RAMPS based kit is probably the most cost effective way.

Ooznest OX CNC router configured for Mach3

As you can see the build of the OX CNC router is almost complete.  Next step was to get the limit switches and the emergency stop installed and wired up.

OX CNC router running

I’ve used a 4 port RJ-45 socket to connect my steppers and limit switches.  Only 4 of the 8 wires in the Cat5e cable are used so I can use the two for the switches. The switches are wired in series as I have done on my CNC hot wire cutter to pin 11.

CNC OX router from openbuilds stepper motor wiring

This allows me to swap back to my hot wire machine just by plugging in in the Cat5e cables back into the towers and run up a different config in Mach3.

The small 5 port ribbon connector on the controller I used to connect all the switches in series.  As I used RJ45 LAN cables with 8 wires I was able to use the 2 of the 4 spares to get the inputs back to the controller board.

Its wired up as above and you can download a copy here Limits diagram

Mach3 is clever enough to know which axis the input relates to.   This confused me a bit a first but if you follow this setup it works fine.  When you press REF ALL HOME each axis should home, its quite satisfying to watch it all work.

When the switches are wired up go to the Mach3 diagnostic screen and test that each switch lights up all LEDs as screenshot shown below

cnc Mach3 4 axis config

Here’s how I fitted my limit switches.

Emergency Stop

I’ve wired the E-stop with a Cat5e cable back to the controller. Which has a RJ-45 socket installed and connected to the E-stop on the TB6560.  The joypad works via a plugin on the Mach3 website http://www.machsupport.com/software/plugins/ and can be configured to move all axis and buttons set to a function of you choice.  Works really well.

Router Set-up

I’ve opted for the Ooznest router mount which didn’t fit the Katsu router, my fault should have checked. I did try adding some packing but it wasn’t ideal so I purchased another from eBay 

The build is almost complete the OX CNC router works and I have the home limit switches installed. Took some figuring out as I use the 2 spare wires in the RJ45 cables to send the signals back to the TB6560 driver board.

All the switches are wired in series which may sound strange but works well as Mach3 figures out which axis is moving.  Makes the wiring a bit simpler.  So all I need is a ground and pin 10 on the TB6560.  I’ve also made a probe touch plate  which uses pin 12.

Y Axis with two NEMA 23 stepper motors

The Y axis uses two steppers so both have to work together. One way this can be achieved is by joining the step wires and reversing the direction wire on one motor.  But then you force all the current through one driver, which may exceed the limits.

A much better way is to wire them to their own driver and slave the axis in the controller software. Both Mach3 and LinuxCNC can do this.

For Mach3 set the option “Home Slave with Master Axis” on the Settings screen. 

For LinuxCNC we do it is a slightly different way by setting the pins as below

linuxcnc stepconf parallel port

Here’s the full setup for LinuxCNC  here

The part below was the first test of the OX just using a piece of depron foam.  Used SketchUp with the phlatboyz extension Sketckucam and it works really well.

Then I made some mounts for the dremel which cam out well and holds it very securely.

Using the OX router with LinuxCNC

If you want to go the LinuxCNC route then I have an article on setting this up and a video showing all the steps. Using a desktop machine with a parallel port.  Still a viable option even thought the parallel port is not fitted to PC’s anymore.  PCI parallel ports adapter cards are still readlily available and older desktops with the port can be picked up very cheaply.

CNC Router Software

When you start looking in to CNC you see the term CAD and CAM used quite a lot and you probably know what CAD means but CAM for me wasn’t something I quite understood.

So when you have built you machine you’ll probably want it to make something.  So how do you go about it?   You need to send G-codes to you machine so that interface board will convert these in to electrical pluses.   These pluses then the move stepper in either direction and hence move the router.  There are many different G-codes each one has a specific task.  For example the G-code G0 X5 Y6 Z-.5  will move the axis to 5 mm in the X  and to 6 mm in the Y and the Z down  to .5, assuming the machine is working in millimetres.  You don’t need to learn these codes but its useful to know a few of the more common ones.  CAM software  takes your design and coverts it in to G-code that’s sent to your machine.

There is quite a lot of CAM software some free and others costing a small amount to very expensive.  As a hobbyist I try where possible to us free software but in all my CNC endeavours I’ve spent a significant amount of money on software.  Luckily for me the CNC router I’ve built makes us of free software with very good results.  With my CNC hot wire cutter I’ve had to purchase CAM software.

SketchuCam or Fusion 360

My first tests cuts were done with Sketchup and the SketchuCam plugin from the PhlatBoyz and its produces some good results.  But like any software you need to spend time learning it.  There are some great videos here

I did find a few limitations when I was designing a brushless in-runner motor mount for my DeHavilland Mosquito and have started learning Fusion 360.  I had a small crash with the Mosquito caused by the in runner motor coming loose, so I decided to use my new OX CNC to make new and better mounts.  A good opportunity to lean Fusion 360.

Fusion 360 is free to use for students and hobbyist, I think you just need to re-register every year.  Its a very impressive program but has a steep learning curve.  I watched this series by Lars Christensen How to learn Fusion 360 CAM.  Its aimed at high end milling machines but the principles apply and Lars is very good.  Also another clever guy is Martin Barfoed  he’s built an OX CNC and now uses Fusion 360 and has made some good Fusion 360 Videos

Fusion 360 can also be used for 3D printing.  I used it to build several part for my RC airplanes and tri-copters.  I lost the spinner from my Focke-Wulf 190A and couldn’t get hold of a new one so I set about making a new one with Fusion.  It took me a few attempts but it worked out really well.  Now if I loose it again I just print another.  Here’s the link to the post 3D printed propeller spinner using Fusion 360

My recommendation would be start with Sketchup and the SketchuCam plugin and then move on to Fusion if you need to.

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