So I need to put my new lowrider to work and have a lot of large cuts in 5/8" cedar. (80 pieces 92" long)
I would like to cut these at a good rate obviously as there is a lot of cutting, but I was wondering if anyone has any recommendations on the speed/depth of cuts with a 1/4" bit the lowrider could handle. I just did a few test cuts and the machine is running great but I don’t know this machines limits yet. Any input would be appreicated!
Thanks,
Chris
It’s not clear cedar, so it will hit knots occasionally as well btw.
Why 1/4" bit? If you are slotting an 1/8" is faster.
If you have a lot to cut I suggest starting with the Basics page suggestions and increasing depth on each cut, then you will find what your machine can handle (machine size, bit sharpness, bit type, spindle, wood dryness).
It’s not very often that I use bits that large so my problem is breaking the bits if I move too fast, that shouldn’t be a problem for you. I would think you would be safe trying to start at 4mm d.o.c. and 15mm/s. If it sounds like it is bogging the router slow it down, if not I would continue to increase speed until it begins to bog down or cut quality degrades. I dont know what the fastest stabil feed rate is but I run my MPCNC up to 25mm/s, at that speed if I feel like it can handle more I increase the d.o.c. It wont take long to get a feel for your machine
I increase depth before speed. Even multiple of material thickness, one less pass is way faster than 5mm/s faster moving. 8-15mm/s is my comfort zone. A single flute upcut can really hog out some material.
The router isn’t even being loaded at this at all. My concern is missing steps. It’s a big long arch, and I’ve made a jig board to load 5 planks
on it to cut at a time side by side. Missing steps could really mess that up.
Ryan, when you say 15 mm/s is your comfort zone, is that the issue you are referring to, or about how the bit cuts our router being loaded?
Thank you for the feedback guys! I will start with 4mm depth and 15mm/s speed but I would like to understand why you choose these numbers and learn more about it all, so greatly appreciated.
Thanks,
Chris
New to terminology. By Slotting you mean doing a parts cut from estlcam to cut a shape out of a board? If so, then yes. I was using 1/4" because I thought it could cut deeper and faster than a 1/8 on the machine. What speed/depth would you recommend for a 1/8" bit to make it faster than a 1/4?
Issue?
You are removing 4x times the material with a 1/4 vs 1/8. that means 4X the load on the gantry, meaning you theoretically can cut 4x faster with an 1/8"… realistically 2x but deeper is faster than faster.
What I meant by issue, is when you say your comfort zone is 15 mm/s and not faster, your primary concern is the load on the gantry, not the router/bit ability.
How deep would you feel comfortable cutting with a 1/8" upcut end mill?
I have video up showing the the entire flute length, but that is not slotting, with slotting you need to be able to get the chips out.
We are not going to be giving you numbers. You have not told us anything about any of your equipment and even then it would not help, every build is different.
Start at 10mm/s, and increase your depth to get as few even sized passes as possible, from there increase your speed until something goes wrong or it just sounds bad.
You can go super fast and push it to the bleeding edge, then hit a knot and break something…or your bit will get dull and break. I play it safe, I have work to get done and breaks waste more time than a few extra mm/s.
If it is a simple profile and there are a lot to make, I find it it faster to create a template then use a router and flush cut bit to run through parts. Sometimes I can have a couple parts cut in the time it takes to get the cnc set up.
Thanks again for the feedback. I only have 2 flute 1/8 end mills. They cut horribly for cedar. Parts are great while others are brutal depending on grain.
Slow down the rpm, and they should work. Basically half the rpm of a single flute.
A single flute is slightly better because of a larger flute means easy chip evacuation.
I had slowed the RPM to the lowest setting and it was still making powder at 15 mm/s. I’ve got a set of single flute bits coming today, we’ll see how those go. Thanks!
I did some tests by hand to feel forces. With the 1/8 single or double flute end mills I have I had to push hard even with very thin depths. Obviously not great. With the 4 flute 1/4 there was virtually no resistance even through knots and deep cuts. I did some 6.5mm deep cuts at 15mm/s without issue. I kind of want to see how far I can push it on a few tests to see when steps skip. I would want to make sure I’m not on the edge. The 4 flute 1/4 made really nice cuts too.
Need to find some better 1/8 end mills I guess.
