Over the years we have always wanted to build a industrial grade, solid,  small footprint CNC machine, but due to the cost of components we have always opted to design and build machines that were around the small budget price market.
This market is now swamped with Chinese machines that are not always up to doing what they claim they can do.
So after a lot of consideration, we decided to go for it and invest time and money into a machine that is middle of the road in price.

The D-500 machine is a fast and robust machine which will allow you to cut out and engrave a range of different materials.

We have gone for a compact design that will suit the small business and hobby market where room in their workshop is limited.
In the future we may offer bigger machines, but for now we will be starting off with D-500.

The solid frame is made out of 20mm and 10mm aluminium plates that are finished with bevelled edges, bead blasted and finished oxidisation treatment applied.
(Please note that some plates may have small marks or scratches on them, that can happen when in transit. This does not effect the functionality of the machine)

As you can see in the pictures above, there are no motors sticking out of the machine and all of them are neatly hidden away.

The dimensions of the base are 744mm Wide X 810mm Long and will fit on suitable sized bench.

The machine travel area is 500mm on the X-Axis, 500mm on the Y-Axis and 100mm on the Z-Axis.

The Y-Axis has dual motors and ballscrews with Quad low profile rails.
The X-Axis and Z-axis have Dual low profile rails.

Please see Background information further down this page for more details on the design and build.

To start with we will be offering the machine as a self build kit to keep the price down, but also to keep shipping prices down.
Full build documents will be supplied with step by step instructions on how to correctly bolt it all together and wire it up using custom made cables that are plug and play.

Included in the Kit will be all the plates, ballscrews, rails, stainless steel screws, controller box, 6-Axis controller, wide voltage range Power supply, Switches, Glands, Limit Switches, AMB Spindle with holder and all the custom made cables needed to build a fully working machine.

The base we use on the the machine frame is 25mm MDF that is moisture resistance. Due to weight and shipping most people can choose to supply their own base or we can supply.

The controller box we will be supplying is also our own design and has a dual controller that will allow the machine to be used with Mach3 and GRBL. which mode you want to use can be set using the switch on the front of the controller box.

It also has a controller breakout board which is 6-Axis (GRBL mode) or 5-Axis (Mach3 mode) to allow upgrades in the future and has been design for easy wiring and use.

For more details on the controller click on the link below:
http://www.ukcnc.net/index.php/6-axis-cnc-controller/

Using Closed Loop motors on each Axis not only gives performance and accuracy gains, but allows us to monitor motor alarm conditions and feed these back to the controller. The status of each motor is shown on the front of the controller box using indicators.

The frame has also been designed to allow for a Vac bed system to be installed with outlets on the front and back on the machine for the pipes to exit and attach to your vacuum. This will then allow the workpiece that you are cutting/engraving to be held in place without the use of clamps or screws.

We can supply a plenum grid made out of 25mm MDF if you do not want to mill one out yourself and also the pipe connectors and front vac flange.
Even though this is green moisture resistant MDF, we still recommend putting a couple of coats of varnish over it to seal it in.

On top of the plenum grid we then place a regular bit of 12mm MDF, turn on the vac to hold it in place and skim the top to get the hard layer off. Then we flip it over and glue this in place. Next we skim off the top of that side so the MDF is now porous and air can flow through it.

The way the Vac Bed works is that vacuum cleaner attached to the front flange draws air through the pipes and through the plenum grid.
This then creates a vacuum across the top of the MDF that in turns holds down your work piece.
The MDF also acts as spoil board and can be skimmed down as needed to re-level it. Eventually when it gets too thin you can skim it all the way down and replace it with a new piece.

Of course you do not have to use a vac bed and can just put a piece of 25mm board as your waste bed and screw/clamp your work piece in place.

The spindle holder is for the popular Kress/AMD spindles and can be supplied with a vac boot and brush kit.
With the versatile mounting plate, you can also mount a different spindle if preferred, such as the Chinese water/air cooled variants.

Examples

With all our machines in the past we have supplied videos and pictures of examples that we have cut out on the machine and with the D-500 we intend to do the same and add them as we go along.

Cutting Acrylic

Cutting Feed Rate 1500mm/min
5mm Down Cutter
5mm depth of cut.
AMB/Kress speed 2.5 (approx 10000 RPM)

Video is muted on play, click speaker icon for sound.

Cutting 12mm MDF Hearts

Inside Cut Feed Rate 1000mm/min
3mm single flute Up cutter
6mm depth of cut.
AMB/Kress speed 3 (approx 12000 RPM)

Cutting Feed Rate 2000mm/min
6mm Up Cutter
6mm depth of cut.
AMB/Kress speed 2.5 (approx 10000 RPM)

Video is muted on play, click speaker icon for sound.

Engraving & Cutting 18mm Plywood VW Camper Plaque

Pocketing Feed Rate 2000mm/min
3mm single flute down cutter
0.8mm depth of cut.
AMB/Kress speed 3 (approx 12500 RPM)

Pocketing Clear Feed Rate 2000mm/min
6mm Down Cutter
1.2mm depth of cut.
AMB/Kress speed 2.5 (approx 10000 RPM)

Cutting Feed Rate 2000mm/min
6mm Down Cutter
6mm depth of cut.
AMB/Kress speed 2.5 (approx 10000 RPM)

Video is muted on play, click speaker icon for sound.

Cutting Aluminium

Drilling Feed Rate 1000mm/min
5mm drill bit
6mm depth of cut.
AMB/Kress speed 3 (approx 12500 RPM)

Cutting Feed Rate 300mm/min
4mm up Cutter
1mm depth of cut.
AMB/Kress speed 2.5 (approx 10000 RPM)

Engraving & Cutting 12mm Plywood Coasters

Engraving Feed Rate 2000mm/min
1/2″ V-Cutter
1mm depth of cut.
AMB/Kress speed 4.5 (approx 18000 RPM)

Pocketing & Cutting Feed Rate 2000mm/min
6mm Down Cutter
6mm depth of cut.
AMB/Kress speed 2.5 (approx 10000 RPM)

Video is muted on play, click speaker icon for sound.

Engraving Composite panels

Engraving Feed Rate 2000mm/min
1/2″ V-Cutter
1mm depth of cut.
AMB/Kress speed 3 (approx 12500 RPM)

Cutting Feed Rate 1000mm/min
4mm Down Cutter
3mm depth of cut.
AMB/Kress speed 2.5 (approx 10000 RPM)

Video is muted on play, click speaker icon for sound.

Carving Lions Head Blue Foam

Roughing Cut Feed Rate 6000mm/min
6mm up cutter
12mm depth of cut.
AMB/Kress speed 4.0 (approx 16500 RPM)

Carving Feed Rate 6000mm/min
3mm Ballnose cutter
25mm depth of cut.
Step over 1mm for demonstration. To get rid of fine lines we would usually do a much smaller step over but takes a lot longer to carve!
AMB/Kress speed 4.0 (approx 16500 RPM)

Video is muted on play, click speaker icon for sound.

Levelling the Spoil Board

Feed Rate 6000mm/min
38mm fly cutter
35mm step over
1mm depth of cut.
AMB/Kress speed 4.5 (approx 18000 RPM)

Video is muted on play, click speaker icon for sound.

Background information

We have been designing and building CNC Routing Machines since 2004 and over the years due to the popularity and demand, the linear parts have come down in price and making a CNC machine is now more affordable.
For example back in 2004, using Ballscrews on a machine was an expensive option and hence most low cost machines opted for Trapezoidal Lead Screws. Round rails were always the cheapest option as low profile rails such as Hiwin, again were just so expensive.

The market has been flooded with cheap Chinese CNC machines that sound good, but when you start using them do have limitations and the sellers description is well under what the actual performance and accuracy is.

Frame Construction

So for our next Desktop CNC Router Machine we decided it was time to design a machine that is Rigid, Fast and Accurate, using precision linear components as well as a solid aluminium frame instead of using Aluminium profile.

Below is a picture showing the layout of the 10mm and 20mm Aluminium plates used in the design for the frame and to give you an idea of  the cost, just the raw materials will cost you over £1000. This price would just be for the aluminium sheets and then on top of this you would need to get each plate machined out with holes, pockets, tapped holes and final cut out with bevelled edges.
Then if you like to give the plates a professional finish, you would need to pay for bead blasting of each plate and also oxidisation treatment to protect the plates from erosion which also makes them easy to clean.

Before you know it, you are into thousands of pounds just being spent on the frame before you then start calculating the cost of all the linear parts and motors etc.

You can see why most designs go for Aluminium Profile, but we still prefer a solid frame that cuts down vibration, noise and increases the performance and accuracy.

So with the new machine we have decided to stick by our guns and get a solid foundation in place.
After a lot of back and forth with machining shops we use for other machines, we managed to land a deal that would bring the plate sets down to a reasonable price if we purchased the plates in quantities.

With the design of the machine we wanted to have all the motors within the frame, rather than have them sticking out which not only looks ugly, but also can be a hazard if someone knocks into them. This again adds to the price because the whole frame becomes larger and hence the plates become bigger that have to be machined.

Rails and bearings

Next we looked at moving away from round rails and bearings.
Even though round rails can work well, you still end up with flex if un supported and also the bearings by design can be a little loose, which leads to noise and also slight movements that can get worse under load.

So the next step up is to use Low Profile Rails with Low Profile Carriages. They have tighter tolerances between bearing and rails which improve in every area when it comes to a smooth running machine.
Moving up from round rails to low profile ones, is a big jump in price but the only way to get a machine up to the specification we wanted.

Ballscrews

As usual we have opted for ballscrews all around on the new machine and increased the size to 16mm diameter which reduces the whip caused when being ran at high speeds. Also we have chosen to use a 10mm pitch which will allow rapid moves when needed with out relying too much on high frequency switching from controller pulse trains.
The ball nuts are pre-loaded at the factory and classed as C7 accuracy having 30 microns of backlash over a 1 meter length. With a combination of high quality flanged support bearings on each, the backlash is negligible.

Motors

Motors again are a very important factor to consider when it comes to building a good machine.
Open loop stepper motors are normally used on low cost machines and some commercial machines. These are fine but can cause issues if they start loosing steps due to mechanical stiffness of the machine or load put on each axis.

With Closed loop motors you do not get this problem because they have a built in encoder and intelligent feedback circuit that detects when a pulse has not completed and will play catch up for you automatically in the background to correct this.

The main reason for not using Closed loop motors is the price again, there can be big difference between Open and Closed motors.

For our design we have gone for Closed loop motors all around combined with  the Lovejoy/Oldham flexible style couplers for connecting to each ballscrew.

We have set the PPR of each motor to 1600 which will give a resolution of 0.00625mm. You can change this up to a higher resolution if you want by setting the jumpers on the motor and re-configuring Mach3/GRBL.

On the Z-Axis we have used a pulley/belt connection, using HDT pulleys and HDT belts. These are more expensive than the T type timing belts but the tooth profile is much better fitting and reduces backlash.

The reason we have listed the above points is not to only justify the price and the old saying of “You Get What You Pay For” but also so you can check other machine specs and what to look out for when comparing against ours.

For more details on the CNC 6-Axis controller click on the link below:
http://www.ukcnc.net/index.php/6-axis-cnc-controller/