What I’ve learned after using the CNC for a year.
Tie your project down. I have found that if the project you are working on moves you destroy your work. Not good. Also you may also break the bit. Sometimes I use two methods to hold things down. I hate to waste wood so sometimes I cut fairly close to the edge. More than once I have cut my holddown off. Before I start the cut I look at my drawing on the computer and determine at what measurement I should put the holddowns so they don’t get cut off.
I use the painter tape and super glue combination when I have loose items in the middle of the work piece. If it is an expensive piece of wood and I don’t want to take chances I also hold down the edges. I’ve also used Woodworkers tape, but found it harder to get off my work.
I use the machine bed when doing setup. After replacing the slats because I couldn’t go any lower with my surfacing I put some serious thought into what is happening. Seems like when I was doing the material surface I had to measure the material depth and then cut just a little deeper for it to cut all the way through the material. Each time it left a small little grove. After a while I had a lot of those little grooves. So much so that the painters tape wouldn’t stick anymore. Using the machine bed I still measure the material but since the bed doesn’t change I don’t have to keep checking the Z axis.
I have put two ¼” dados in a slat on the left side vertically and a horizontal dado in each slat. I cut those with the machine. Then I have some little 1 ¼ inch by 2 inch pieces of ¼ inch plywood that I put in the slots for aligning my work piece. Since the machine cut it I know it’s square. By having those slots and ¼ inch pieces in the slots I can just place my piece down and my x and y are always at the same place. This saves me always having to adjust the x and y which saves me time. If I have a larger piece that I need the full bed I adjust the x and y, but don’t have to worry about the z since I’m using the machine bed. Be sure to remove the ¼ inch pieces before you start cutting. They can get in the way and it’s not pretty.
It seems that sometimes the T track just isn’t quite in the right place. To solve that, when I made new slats for the machine I drilled holes in each slat between the holes that hold the slats to the base. I placed a 6mm tap in each hole. With the taps I got the driver for them that puts them in at the right distance and keeps the mdf from puckering up around the hole. I then take a 6mm hex bit in my 12v Bosch drill set on tension 4 to drive them in till they touch the base of the machine. The tension 4 is working so it doesn’t raise the slat at that position.
That brings me to using the allen wrench to tighten the hold downs. I hate that. I put a 5mm hex bit in my drill and again use tension 4 and away I go tightening things down. This is so much faster than messing with the allen wrench. To loosen you have to increase the setting on the drill. Just be sure to set it back.
Carbide sells a set of bolts that has about 6 different lengths of hex screws. That is well worth it.
I make most of my own hold downs. I cut them on the machine. I usually use oak and I have two different lengths. About 4 inches and 6 inches. With them I put a notch on both ends. That allows me to hold things down and also horizontally. I then put either a ½” or ¾” block on the end away from the material. That seems to work really well.
Bits: My favorite bits are ⅛ inch. I have found that a compression or a downcut bit really works well for cutting plywood. I find that the downcut is best for ¼ inch stock and compression for ½ and ¾”. Another reason I like the ⅛ inch bits is because if you are using a compression bit or a downcut bit when doing ½ inch and thicker material individual pieces are held in place by the sawdust. Pretty cool.
As I think of more things I will post to the forum. If you have any questions feel free to contact me.
Douglas