I will start by saying, I know I’m pushing the limits but I am not sure I understand why this is happening so trying to learn about it.
Settings:
Makita Router on setting 3.5
100 IN/Minute or 42.3 MM/Second or 2540MM/Minute
Oak Wood
.2 IN DOC
1/4" downcut endmill (Have got same results with upcut, but video is with downcut)
Now onto what’s happening, the x axis just stops at 100mm when it hits the wood, like it just can’t push through it at that speed maybe?
I have tried the following:
Less DOC, this works and will cut just fine
Manual control to make sure the plunge wasn’t the issue
I tightened the belt on x, but too tight and it doesn’t even move, so I met it half way so it can move freely and easily. I also noted that the shorter side of the belt gets much tighter than the longer side of the belt on the x axis.
Based upon the last line, I set the core in the middle of the x axis and tried making the pass there same result.
I raised the amps on the x motor in .05 increments from .68 (default) to .95 and same results.
I checked the grub screws, and they are tight and there is no movement on the pulley when the stops happen.
Thoughts, or is this just outside of the stepper motors capabilities? The machine isn’t flexing, the LR4 is handling it without issue, it’s just like it locks the stepper motor.
The video is showing me trying to make a 100MM pass manual control at .2" DOC. it just stops moving after about 1/8" into the material
Im no expert on feeds and speeds. Still very much learning myself. But, I observed what looks like some smoke in that video. What’s the status of the bit? Is it dull? Will it do this same thing in the Y direction?
You are correct, there smoke, but it’s more coming from it not having enough force to go through. I tried two bits, the upcut bit had the same issue and it is almost new.
Good chance that bit is dull. But thats probably way too fast for oak. Its hitting it and bouncing back some.
I need to look and see what RPM that you are running at that setting, but I am guessing way too high. When you slow down enough for it to make the cut how are your chips looking? Are you making actual chips or are you making dust?
The chip is what pulls the heat away from the bit and keeps it cool. Turning too many RPMs will cause you to make more dust than chips, and dust cant pull the heat away so you end up smoking the bit and dulling it FAST.
I would slow your feed rate WAY down. By half. Get you several GOOD cuts under your belt. Learn more about the other settings and getting your RPMs right for good clean chips and good clean cuts. Then You can slowly start dialing up the speed a little.
Fast is great, but it does no good if you cant complete the cut accurately and cleanly. Only thing you are doing fast that way is adding to the scrap pile
As you dial-in maximizing overall MRR for your current setup, are you using temperature stickers / FLIR to help monitor how much more/less current to give the X Stepper so they’re operating ~45C, no more than 50C? Or, did you print with some high temp material?
Obviously, I’m not going to suggest trying untested higher torque 92oz Nema 17 on the X Stepper until other variables using stock build have been explored first
I know for sure I need to slow down, but I saw the LR4 tests that were doing 50mm/s in hardwoods and was wondering if this means something is not setup right with mine.
I think that a) it wasn’t really hardwood that Doug used, he was unsure which wood it was, but I am not sure and b) I am using a 2-flute so I can basically go double the speed.
I always used 5 at the beginning which was too fast also, but it might work. The Sorotec App is pretty good to give you a guildeline, they are Germany’s biggest retailer for CNC stuff.
I also have done a bunch of cutting into white oak, which is pretty hard. Biggest thing I have noticed is that the wood is much harder than MDF/particle board/pine, and should be treated differently. I was using a 2 flute upcut bit, 10,000 rpm, 2mm depth of cut, and only going around 8-10mm/s, which is 480mm/min or 18in/min. I was just about on the limit it felt like, because the router was definitely sounding like it was struggling. I think if I increased the rpm to maybe setting 3-4 on the router, I could probably go faster, but need to test.
I was also pretty amazed watching that video, it was cutting through that wood like butter. I believe he mentioned it was Alder wood, and to me it looked similar to Poplar. I have never cut Alder before, but for poplar I have noticed it is super soft and cuts very smoothly, which explains how he is able to go so fast.
I can really only recommend using this as a guideline for your cuts. Back in the LR3 days their suggestions where really on the higher side, now they are good to cut. But it’s still incredibly high!!
Yea, just for everyone’s info, I am getting 40 IN/Min or 1016/MM/Min or 16.9 MM/second in this same oak with the 1/4 on setting 3 of the makita, it was at .15" DOC cutting flawlessly
Edit to add, this post was me not understanding why it’s stopping instead of just cutting poorly which I’m used to on pushing the limits.
I think the take away from the replies is, router speed and bit sharpness.
I was doing more than that in Plywood, I dont remember anyone making cuts in oak. Maybe @Tokoloshe
But him and I differ in opinion for RPM on your router though
I my videos I was running a much slower RPM with a single flute bit and throwing real good chips. But I am not just starting out. So I might have been running different settings on my control board than you are running as well.
That smoke from the bit tells me its shot. That can make a BIG difference in making a cut vs not as well.
