Making the spoiler-board
Lets make a simple spoiler board that we can use for cutting into when we are cutting a part out and the bit needs to go all the way though the material. This board will also have 1/4-20 hold down clamps on the sides to allow for multiple material sizes to be clamped in place while being milled.
Note:On my board (shown in the pictures) I made the side 1/4-20 clamp hold down holes too close to the work area, the included dimensional drawing has the proper spacings so you would want to use that for your layout.
The pictures below will give you an idea on how we built our spoiler board for the OpenBuilds OX
- Go to your local hardware store and get some 3/4" MDF cut to 17.5" x 29.5" (I had a 4'x8' sheet cut down to 5 of them)
- Study the drawing and mark out all the holes to be added as shown(be sure to get the front and back board to V-Slot mounting holes lined up, they can be a bugger later on.)
- Drill out the holes. (Side holes (hold down's) are drilled to 5/16" front and back holes (board to V-Slot mount) are drilled to 1/4")
- Use a sanding block to knock off any excess and sand smooth
- While at the hardware store be sure to pick up some (hammer in) 1/4-20 x 5/16 threaded tee nuts (10 of them,I messed up and only got 6)
- Also pick up some 1 1/2" x 1/4-20 hex cap bolts(10) and 1/4"ID x 7/8"OD washers (10)
- Hammer the threaded tee nuts in (Tip: you may want to squirt a little glue underneath before the last hit in so they stay in place) (Also very important to make sure they are straight. The slightest angle can make them very hard to thread the hold down screw from the top)
- Flip the board and screw in the hold down clamps tighten them down to help seat everything straight
- (These are prototype clamp plates that will be added to the Part Store once they are available)
- Now to work on the front and back board mounting holes there are 3 in the front and 3 in the back of the board.
- Take a piece of V-Slot and a 15mm low profile screw hold the screw in the track and make a mark about 1/16" above the head of the screw. (This mark will tell us how far down to make the recess for the screw head, while not letting the screw bottom out on the V-Slot track.)
- Make a mark on your recessing bit so you know how deep to go. (Your recessing bit needs to have a big enough diameter to allow for the head of the screw (10mm or 7/16") to go into the recess)
- Recess the front and back holes down to the mark made on the recess bit and then sand the holes smooth
- Put in your 15mm screws and add drop in tee nuts to the bottom (only do a turn or two and make sure they are aligned to fit in the track)
- Install the board to the V-Slot frame (Tip: This is going to take some fiddling and depending on how well you did on lining up your holes to the center of the track its tough to get these in. You may need to ream out the holes a little to allow for some movement to get these right. Also you will need to press down as you tighten the drop in tee nuts to ensure they can turn 90 degrees and catch the inside lip of the track)
- Ok the spoiler board is in!
- Now lets find the maximum cutting area for the machine by moving the gantry's (by hand) to all four corners maximum movement and lowering the bit the spoiler, turning on the router for a sec to make a mark.
- Once you have all four marks set you can connect the marks with a straight edge and a marker. This safe cutting area will let you know where you can set your material for cutting.
- That's it. You're done and ready to hold down some material for cutting
Note:When you are setting up your cuts be sure to remember to stay on the inside of the clamps! you don't want to run into them.