Feeds and Speeds testing my LR2

Is there any interest in creating a feeds and speeds test topic? There’s probably some use in using a standard test set but this comes up so often and could serve as a limits of possibilities for all the various forms of our LR2’s.

I finally did just this myself for my on own LR2 v2. It’s a 48" x 30" top, with the gantry running across the 48" length.

After early crashes and failed things I’ve settled into a conservative but nearly 100% success rate feed and speed of 8mm/sec 4mm doc, for both 1/8" and 1/4" bits. I do full depth finishing passes at 10mm/ sec.

So here is where the testing comes in. Brave pants on. Shop grade 1/2" spf plywood as the victim, full face shield and safety glasses on :nerd_face:. Dewalt 611 run at 11! (just kidding but it was max speed), 1/8" carbide single flute upcut bit of Amazonian quality.

Test 1 try more depth and slightly faster fed rates. 10mm/sec feeds, 20mm/sec finishing passes at full depth.

Quite impressed with the quick finish pass, and nothing broken, 8mm doc even came off in good shape. I was expecting danger, none found.

Test 2, definitely break things time. Increasing feedrates all the way up to fswizard craziness. Double check face shield is down.

Things got a bit funky in the pockets but still amazingly no crash and burn. Oddly on my control #4 I distinctly noticed the most burning smell of all of them, and they all performed pretty well. Dimensions were not all that different looking at a ruler, calipers will confirm.

All the pockets had a bit of this


This was the fswizard run, and was the worst, surprisingly none were perfect and all had this slight rounding on the NE corner.

The circles all had some consistent bite into them where the cutting started on each pass.


Again this is fswizard showing it the most.

The pocket bottoms were all really good across both tests. Squares circles are 40mm.

Takeaway for me are that I can definitely cut deeper and a bit faster with no real loss in current cut quality. I can also safely speed up the feed on my already full depth finishing passes.

7 Likes

I love test cuts!!!

Some caliper numbers. It seems I’m more off on the intended dimensions on my x axis than I am on my y axis. Maybe not a surprise as my x is 48" across, vs 30". After all the talk about calibration elsewhere in the plane building threads it makes me think I can adjust my setup a bit to get closer to the true sizes.

I had expected to have more variance in the depths as I have always felt that I was cutting a little deeper then intended. Now with the super touch plate I should be more consistent with the start heights so I think that’s improved the depths.

I would cut your finishing pass speed in half, maybe give it a little more or less to cut.

Looks like maybe a belt is a tiny bit too loose.

Something to try for sure. I’m taking a 0.5mm finishing pass on all these and the 20mm/ sec seems quick to watch. I pretty much always do 0.5mm.

You can hide a lot of mistakes with a proper finishing pass. It is a great place to perfect things. You can rip through a giant job, then come back for one or even two finishing passes and correct most mistakes.

At the same time, make sure you are not just chasing zero’s. I love test cuts, but anything under 0.5mm and I am very happy but that is the sort of tolerances I design for. So don’t bother chasing zero’s if ± 2mm is fine for you. If you enjoy dialing it in…I bet you can get it a little better.

1 Like

Thanks for the feedback. I’m not building planes so yep it’s been fabulous as it is. I’ll play around and see if i can at least even out the difference between the x and y. Hadn’t thought of second finishing passes on perimeters, but I had on the bottoms of my pockets.