Update: Extrusions are drop-shipped directly from 80/20's facility. Please allow 3-5 weeks for delivery once order is placed.
This is my very first CNC blog post, and hopefully it is a good one ;-)
I was chatting with my very first customer in the PwnCNC Users Group about a modification he made to his XXL that looked extremely interesting. Specifically he used 1030 extrusions from 80/20 to make a perfectly flat CNC bed... replacing the MDF bed and cross straps that came with his machine.
His idea was to use (14) of these 1" by 3" extrusions laid out horizontally across the front and rear end plates. Here's a simple image of how these extrusions will be laid out:
This image shows a 1" thick (top-bottom) x 39.5" deep (front-rear) x 42" wide (left-right) bed that perfectly replaces the (2) 3/4" x 19.75" x 42" MDF panels and (3) cross straps that came with your XXL.
So... before we begin, what are the main advantages of making this modification?
1. Perfectly flat surface that beats any solid surface hands down (IMO). Flat surfaces will suffer from the same issue: sagging. The 39.5"x42" surface is just too large for solid surfaces to withstand the pull of gravity over time and use. The included cross straps do help but MDF is notorious for absorbing moister and will degrade over time. These extrusions provide a matrix of t-slot tracks that form a perfectly flat surface with no moister absorption problems and lots of strength across large surfaces such as this.
2. The abundance of t-tracks provide nearly unlimited options when it comes to work-holding. While I will be adding a newly designed PwnCNC Spoil-board (a modified Myers Wasteboard design) to my extrusions bed... you could use this surface as-is with your favorite t-slot accessories.
(14) 39.5" long #1030 extrusions from 80/20
(14) 39.5" 1x3 Aluminum Extrusions
(60) 3390 Flanged Button Head Socket Cap Screws 1/4-20 x .375"
(60) 3204 1/4-20 Slide-in T-Nuts
(30) 3313 1/4-20 Roll-In T-Nuts with Set Screw
I already had a bottle of Loctite which I will be using for that little bit of extra security.
Exciting news: PwnCNC has teamed up with 80/20 to provide a special kit exclusively for PwnCNC customers and Shapeoko 3 owners. Click here to purchase your own kit containing the items used in this article.
1. Hand Drill + 1/4" drill bit for drilling into steel
2. Dremel with metal grinder tip to smooth over any sharp edges
3. Black Spray Paint and some Painters Tape for cleaning up afterwards.
4. 2mm Hex key for securing the Roll-In T-Nuts
5. 5 foot long piece of scrap 2x4 and 1.5" wood screws
6. (optional) 26" 1/4" wooden dowel with a mark half-way down and used to insert center-plugs between extrusions.
7. (not optional) Lots of patience! Definition: the capacity to accept or tolerate delay, trouble, or (more importantly) suffering without getting angry or upset.
Let's get started shall we?
Step 1: Disassembly
You will need to disassemble your CNC machine all the way down to the bones.
Note... The extrusions bed is a major upgrade to your machine and will likely void the warrantee.
Carefully set aside all parts so you can find them later. You'll need all of it (minus the MDF bed panels and cross straps) so don't loose anything!
Step 2: Laying out your new Extrusions Bed
After you've disassembled everything, you'll want to spread out the extrusions with the Shapeoko's end-plates on either side like this:
To make assembly fast and easy I've designed two "plugs". (2) Center plugs will be used to join each extrusion pair together; they make assembly easier and prevent any twisting of the extrusions with continuous use.
(2) End plugs are used on either side of each extrusion pair and act as spacers between the extrusions bed and the two end-plates.
Set two extrusions next to each other and gently hammer tap one center plug to join them together. Insert the first center-plug 26" in using the 26" wooden dowel. Insert the second center-plug and insert 13" in using the half-way mark on your wooden dowel. (Exact placement is not important.)
Note: If you have a Standard or XL Shapeoko, only 1 center plug is required.
Next you'll want to insert the end plug on either side of the joined extrusions pair.
Repeat this until you have all extrusions joined together and laid out on your table.
Step 3: Marking the Holes!
Next we'll need to mark where the (28) 1/4" holes will be drilled into each end plate. Basically there will be 2 holes for each of the (14) extrusions that make up your new Extrusions Bed.
Align the end-plate over the edge of the assembled Extrusions Bed. Ensure it is aligned evenly on either side with a 1.5" end-plate overhang.
Using a pencil or marker, draw on the plate where each t-track opening is. While doing this, be sure nothing moves. The goal is to place a hole on either side of each extrusion.
Step 4: Drilling... so much drilling!
Place the 2x4 on the edge of your workbench and clamp it down on either side.
Place the front end-plate up-side-down on the 2x4 and screw it down using the 6 existing holes and some wood screws.
This will fully secure your plate and provide something to drill into once you've drilled through your end-plate... 28 times!
Next you'll need to add center-marks for all 28 holes. Measure from the edge inwards 5/8" as shown in the picture. Place a dot between the two marks you made earlier. This will be the center point for the 1/4" holes you'll need to drill next.
Tip: I used a center punch and a hammer to add a slight indentation to each center point. This gave me something I could place the tip of my 1/4" drill bit into as I was preparing to drill into the steel plate.
Once you're all marked up... it's time to drill. Grab your drill, 1/4" drill bit, and have at it. (It took me 45min to drill all 28 holes as I took my time, used my patience, and tried to be as steady and accurate as possible.)
Step 5: Grinding the Sharp Edges
Unscrew the end-plate from the scrap 2x4 and flip it over... then drill it back in to hold it.
Using a Dremel with the metal grinding tip, clean up the edges of each hole so they are touch smooth.
Step 6: Repeat!
Go back and repeat steps 4 and 5 for the rear end-plate.
Step 7: Make it Pretty!
Thanks to all of the drilling and grinding you've just done... you may want to repaint your end-plates.
Tape off the parts you don't want to paint with painters tape... and spray the raw parts.
Step 8: Raise the Bed
Using a few 2x4's or scrap lumber... raise your entire Extrusions Bed approximately 6" above your work table.
Ensure your bed is still aligned properly when finished.
Step 9: End-Plate Assembly
Insert (28) #3204 1/4-20 slide in T-Nuts so there are 2 within each extrusion.
Push them so they're just within the t-track.
Align one of the end plates so the 28 newly drilled holes are aligned with the t-nuts.
Grab (28) #3390 Flanged Button Head Socket Cap Screws, add a little Loctite to the threads, and insert them into the end-plate holes and into the t-nut below.
Go one screw at a time and loosely tighten each one down until you have all 28 screws in place.
Odds are high that one or more of your holes may be slightly off from the center of all 28 t-tracks and t-nuts.
Slide the t-nut out of the way and use your 1/4" drill bit to remove the overlapping aluminum. Slide the t-nut back into place and insert your screw.
If the steel hole wasn't too far off, then you should be able to insert the screw but with a slight angle.
Once all 28 screws are in place, tighten every other one till you get to the end... then come back and tighten the others.
Step 10: Repeat That Again!
Repeat step 9 for the other end-plate until both are secured.
Step 11: Flip It Good!
You're ready to re-add your feet and flip it! Don't forget to take time to hug your new creation! You now have a beautifully flat surface for all of your future creations!
Step 12+: Reassemble!
From here on out it's a standard reassembly. Start after the baseframe assembly step as this is where your extrusions bed upgrade is complete!
Next: Spoiled, but Safe
An upcoming blog article will discuss adding an MDF Spoil Board to the top of this Extrusions Bed using the #3313 1/4-20 Roll-In T-Nuts with Set Screw.
The Roll-In T-Nuts mean you do not need access to the ends of the Extrusions Bed in order to get them inserted. 80/20 has a variety of Roll-In T-Nut styles to choose from.
The 80/20 and PwnCNC's Extrusions Bed is a difficult upgrade but totally worth it! Take your time and be patient!
The Extrusions Bed is only a few mm taller than the stock MDF + cross straps which makes it the perfect upgrade without changing too many things.
Ask questions and share your experiences within the PwnCNC Users Group on Facebook!
Hopefully this has been an informative and helpful read... especially if you're interested in doing this upgrade on your own Shapeoko 3 (Standard, XL or XXL) CNC Machine.
Click here to checkout all of the pictures I took during this process.