So just got a new XXL built and almost running. I have been reading the wiki and here for as much as possible before posting and have a few details I can’t find answers to.
I have read many articles about building the additional wasteboard and I want to make the threaded insert option myself. Making the board itself seems straightforward enough with one detail left out. Does it matter to get this threaded waste board perfectly perpendicular ? I would assume you would desire the clamps to hold the piece of stock nice and straight instead of skewed in one direction. Most of the tutorials I have gone through involve machining it from the backside so pockets can be cut for the inserts, all good but then you have to flip it over and attach. I understand when the holes and pockets are cut they will be in perfect alignment to the machine and when you flip it over it has to be put back into the exact same spot or the grid of holes will no longer be perfectly square to the cutting bit. What is the best way to get this done.
Many users of the xxl report the stock wasteboard has a sag towards the middle that they fix with various methods. My unit has more of the peak along the center line of about 1.5mm. The 3 steel runners underneath the stock wasteboard are slightly bowed in the middle. I assume this was done on purpose to counteract the sag of some units. Should I be trying to “fix” this or will tramming an additional wasteboard take care of this?
If indeed the 3 steel runners were made to counteract the sag issue. Is there any documentation to tell which version of the machine I have? I think it would be helpful to know any upgrades or changes made during the production run of my particular machine.
Sorry if these are newb questions. I’m trying to soak up as much info as possible.
Having a straight wasteboard is important because you want to align your stock so the Shapeoko cuts your project straight and aligning using perfectly perpendicular hold down is the best way to achieve that.
I also recommend that you use T nuts instead of threaded inserts because the inserts can come out under pressure from the hold down while the T nut is held from the underside and cannot come through the hole.
I recommended Myers Woodshop design to several people. I use the design and am pleased with the usefulness and versatility it has. Even if you do not use his design it may give you ideas for your own design. The waste board had drilled hiles that use the TEE Nuts to secure clamps. The clamps are relatively low in profile and make your clamping life much easier.
You can get the plans from his web site for free, go to etsy.com and pay a few bucks to reward Myers for his work.
I do not recommend that you use the screw in type nuts. Overtime the stress of tightening the clamps may pull out the thread in type nuts where the TEE Nut type cannot be pulled out.
As to your question about the original waste board the answer is it depends. If you are going to make a supplemental spoil board you will Tram it and thus make your base flat. Personally I did not Tram and/or flatten my factory spoil board. I made the Myers supplemental spoil board and have tram’d it several times. When I made my Myers spoil board I had bought a full sheet of MDF and made 3 total. I still have the other 2 under my machine. I have Tram’d my 1st spoil board a total of 3 times and the next Tram will be with a replacement. I will remove the TEE nuts from the original and put them into the second and third boards respectively. I could just buy new TEE Nuts but I do not go around dropping dollar bills out of my pocket. I still have a few spares in case any are damaged during removal. I have been using the left over scraps from the 4x8 sheet of mdf to make jigs to hold box tops that I vcarve. You will find many uses on your cnc for the left over mdf.
Thanks everyone for the responses. It was the Meyers wasteboard I was looking at doing. Already have 300 T nuts waiting.
Sounds like once it’s installed and trammed the peak in middle will be taken care of. When I mount the new wasteboard what is best way to get the grid of holes nicely aligned with the cutter? Or does it not matter if the additional wasteboard is off by a little in the X or Y position?
Usually folks mount the wasteboard, put the router as low as possible, use a long endmill / increase stickout as needed and machine the board in place.
I think the way to do this is to machine in locator holes on each side of the X axis center then use dowels to pin it. This way I can cut the backside of the wasteboard as I want to include pockets for the t nuts. Sound about right or overthinking this?
This thread might be of value.
I use flanged threaded inserts, pocket milled from the bottom. No way could they pull out. T-nuts would be better if I’m building an overhang on a climbing wall to hang from one hold, but for clamping the m5 threaded inserts I have installed can hold more than enough force. I have 1/4-20 threaded inserts in the layer below my wasteboard to hold it down.
When I created 3 of the Myers spoil boards I clamped them together and drilled a 1/4" hole in each of the four corners. After setting the 1st one on the factory spoil board and got the supplemental spoil board lined up I used a transfer punch to mark the holes. You could also use dowel points. I then removed the supplemental spoil board and drilled the appropriate hole for a brass threaded insert with 1/4"-20 threads. I install the supplemental board with four 1/4"-20 bolts and removed one at a time and used a countersink to ream out the hole so a flat head 1/4-20 bolt would sit below the surface. Just be careful that you have the countersink low enough so during tram-ing you do not hit the steel flat head screws. Since I marked and drilled all 3 of my spoil boards the second and third will only need the countersink done when I install them. During my third tram my original bolts to use in my clamps were 1.25" inches long. As I tram’d the bolts were too long and caused my supplemental spoil board to be uneven. I went back and got 1" 1/4"-20 replacement bolts and that problem was fixed. I made the Myers Woodshop cam clamps and they were 3/4" thick. There was a 1/4" recess for a washer and the bolt head to be below the surface. Because there was 1/2" of the clamp and 3/4" of supplemental spoil board the 1.25" bolts worked until I cut away the supplemental spoil board. So I have two sets of bolts that I use for the L shaped clamps, the big and little cam clamps and swap them out when ever needed. Additionally for the fence I got nylonn 1/4-20 bolts and washers in case I am cutting too close to the fence I will not ruin my router bit should I hit the hold down bolts for the fence. I am using steel bolts for the clamps and L shaped fences. For those that are Metric Centric the Myers Wood shop can be redone quickly for metric holes and hardware.