the big questions, am I close enough, or can I fine tune this more?
I have been using my burly MPCNC to cut scales for my folding knife, se pic below for an idea, roughly 33c103 mm. before my more recent end stop mod, I would check the squareness with the skew calculator or any other test and I appeared to be accurate within what I could measure with my cheap digital calipers. I redesigned endstops to bolt to the tubing, much like the primo build and just ran my first test. I drilled 4 holes at the corners of a 100 x 100 mm square. sr image below for my measurements from the inside and outsides of each hole.
I learned in R&D, 1 hr in the library can save 3 days in the lab. you guys are my library. before I mess with any settings, I was hoping to get the experts opinions.
right now I mill the pockets on the underside of the scales and cut the profile. I would love to be able to flip the scales over and mill features into the show face. chamfer the edges, recesses for the screws, ect.
ANY other suggestions for improving performance? should I run this square test three times and compare those results? in the past, I had to oversize the pocket clip screw holes to makeup for some sort of skew, as well as oversizing the exterior and grinding to match the titanium liners.
I’ve been waiting to answer, since all I have to offer is the same advice that has been posted on the forum before.
Check to be absolutely sure there is no play in the Z axis. Any play will result in sloppiness in your cutting.
Surface your spoilboard to make sure it is parallel to the XY plane of your machine.
Tram your router. Use a tramming arm to make sure the router is perfectly vertical. If you find it out of alignment, you need to use shims to adjust the router. You must surface your spoilboard before you tram the router.
Using a piece of paper the size of your working area and a pen mount on your machine, home your machine and then draw a big rectangle. You only need to draw the corners of the rectangle. Then home the machine again and draw the same figure. The lines should overlap. If not, you have a mechanical issue to be solved.
Using the rectangle in the previous item, measure the diagonals. If they are not the same, adjust the stops until they are close.
Fine adjustment to the diagonals can be done using M666. Note you have to execute an M500 after the M666 to lock in the setting. When I have everything setup, I scribe the position of my endstop stops on the tubing. This helps if a stop gets moved or broken.
Using the speeds you normally use for your stock, cut one of your scales out of foam. Use a fixture and cut both sides. You should see the kinds of precision you are looking for.
Cut one of your scales out of scrap. If your foam version aligned okay but your wood version did not, look at 1) speeds and feeds, 2) need for a finishing pass, 3) sharpness of the bit, and 4) possible mechanical issue.
thanks. I have already been cutting knife scales on this machine, operationally, I am comfortable. as far as tuning, today I repeated the same squares cuts offsetting them from each other. basically, cut a square. home the machine, move to 10,10, zero the x and y and cut again. repeat. my diagonals are either right on or within 0.4 mm of each other. I think it’s time to move on. thanks
