Moisture Resistant and Sacrifical CNC Wasteboard

00:04 I attempted to install the waste board while the machine was on the upright sand.  I used hot glue to hold the t nuts in place but eventually gave up with that plan and placed the stand idea on ice.

00:29 The waste board is 12mm moisture resistant MDF and has a partial torsion box made using 18mm MDF glued on the underside.  My idea is the three boxes will add additional rigidity between the now thicker aluminium profiles.  By also using 12mm MDF it should mean I am able to pull the waste board flat against the aluminium frame.

00:52 I am using flanged machine screws to do this.  I later added large washers infill the counter suck holes.

01:04 I am using a technique I picked up from David Attenborough having replaced the twig with a packing strap and the termites with tee nuts.

01:20 On top of this I will add 4 aluminium tee slots and three pieces of 18 MDF which I will level with the machine itself.  That will be the sacrificial waste board which will be easy to make and replace.

01:46 Before that, I check (what is in facts) the sub waste board, with an engineer’s straight edge and a torch to check for gaps.  It looks pretty good.

01.57 I finally check the cutting capacity which is 780mm along the x axis and 600mm along to the y axis.

02:15 I cut the tee slot track on the table saw and then make the section to go between them using scrap 18mm MDF.  The brown block is wax which I use to lubricate the blade.

02:35 I will be rebating 5mm in on either side of the sacrificial waste boards, which will overlap the edge of the tee track.  The difference is height between the track and MDF is also 5mm, and will give me plenty of material to self level over time.

02:58These were quite easy to make on the table saw but could also be made on the machine themselves.

03:10 The Tee slot track is squared against the front of the machine, and screwed into the sub board.

03:35 I will be securing the sacrificial waste board to the sub board using M5 machine screws fastened into wood inserts beneath.

03:44 But before I did this, I levelled the spindle router along the x and y axis by adjusting the C beam linear actuator.  The x was particularly simple and all I used was an engineers square, but the entire gantry is tilting back going along the y.

04:05 I measured the distance between my square and the X Carriage Extrusion using my vernier callipers.

04:20 I took some exceptionally thin washers that I found during my swivel chair hack and padded out the back.

04:45 I scored the MDF for the sacrificial wasetboard using a marking gauge, and drilled the holes with which to secure it down.  I made sure to countersink the MDF, so the heads of the machine screws would lie well flat of the surface.

05:01 I transferred the holes through the wasteboard to the sub board – and used the inserts from the original wasteboard which I also countersunk using a forstner bit.

05:17 Once everything was secured I performed my first cutting job to level the sacrificial wasteboard.  The bit I used was a 19mm straight flute with the feed rate set at 3000 mm / minute.

05:45 I am really impressed by this and suspect I could have well increased the feed rate.

05:56 Once done I checked the level again using an engineers straight edge and a torch.

06:01 While this might not be how I would build a CNC machine from scratch, if yours happens to be underperforming I highly recommend these improvements.

  • A new reinforced polyurethane timing belt
  • Thicker aluminium profile for the base
  • Secured the x axis profile with bolts
  • Upgrading the z axis with a C Beam linear actuator
  • Fitted a more powerful spindle
  • Replacing the wasteboard

All of which amounted to turning a machine from something barely capable of hitting the spot, to a work horse.

List of Parts for Upgrade

Part Dimensions Quantity
Polyurethane Timing Belt T2.5 5meters
Aluminium Pulleys T2.5-16T 3
Aluminium Profile 20x40x1500 2
Aluminium Profile 20x4x10002 2
L Bracket Double 8
Tee Slot Nuts M5 32 for L Brackets

20 For Sub-Board

C Beam Linear Actuator Kit / 1
Router Spindle Mount 71.0mm inner radius 1
90 Degree Corner Brackets Single 4
Allen Machine Screws M5 x 10mm 32 for L Brackets
Low Profile Machine Screws M5 x 20mm 25 of which 4 are cut shorter for mounting spindle & 18 are used for holding wasteboard.
Flanged Machine Screws M5 x 10mm 20 for Sub-Board
Washers M5 32 for L Brackets
Washers M6 x 18mm 20 for Sub-Board
Washers M5 x 15mm 18 for Waste Board

2 thoughts on “Moisture Resistant and Sacrifical CNC Wasteboard

    • Hi – yes it is a 6mm wide belt and no I didn’t have to replace the smooth idlers. I can’t recall the supplier but it was on Ebay and I searched T2.5 steel reinforced belt.

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