Beginner, speeds and feeds

Hey everyone , so we got our new machine last week , all set up and ready to go but feeling overwhelmed with the speeds and feeds. I understand that you need to calculate the speeds and feeds by using a formula and knowing the chip load for each bit and type of material/wood. I have looked up my bit and was wondering how fast the machine/ Makita router can go and if the suggested chip load are for a more industrial machine.
Thanks

Hi Nicole - don’t sweat it. You don’t need a formula. The general guidance is set your depth of cut to 50% the bit’s diameter, your router at 1-2 on the dial, and feed rates to 40-60ipm. That will work for 85% of the materials and bits. You can go faster and deeper with larger bits, but slower with smaller.

I have found the machine is super unforgiving and will snap a bit before it falters. Big difference from the X-carve and the belt drive.

Ed (@EdwoodCrafting) and I are developing a speeds and feeds app that should be out in beta “soon”. We just need to clean up the UI and stop adding new features!

-Tom

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Thank you I had it up to 130 ipm and my dial set to 3 and the plunge at 50 for 1/2 inch baltic birch and my bit was the 1/4 inch down cut Amama 46054-K 3 flute , maybe i need to lower it.

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So 0.25 DOC for a 0.25 diameter bit is pushing the limits; especially at 130ipm. I’d recommend 0.125 DOC at 100 ipm and 12000 RPM - that should be fine. If it works, play around from there. A 2 flute or 1 flute would be much better though.

-Tom

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We are planning to have the app give very basic general suggestions on one level and switch to much more detailed information. The OneFinity is a beast and will snap a bit before any damage can happen. The rigidity of the OF is very strong so it will allow for prosumer types of speeds and is very forgiving. So with the OF, I think it’s mostly figuring out the best settings for your bit and material to give the best finish in the least time.

I do have my first version of the CNC Explorer on my site if you want to take a look at that before we can get our new APP released.
https://www.edwoodcrafting.com/estore/CNC-Explorer-Full-Excel-Application-p275044785

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my doc was set at .125 at 130 ipm with a plunge of 50 @ 17000 rpms

Ah, OK - I guess I mis-read your note. Your DOC seems reasonable; RPMs are high, but not too bad. Feed rate is reasonable, but a little aggressive. Hope this helps.

-Tom

I think quite a few people are confused about how running the machine slower than recommend is a bad thing. When you have too slow surface travel the bit does not take enough chips to cool the bit and creates heat. This will dull and wear the bits out faster. Its better to run the machine at the proper speed based on what you have your router speed set to.

I recommend watching both of these videos to better understand feeds and speeds. I would also using a chart like this one to determine the exact feed rate for the chosen rpm.

http://informatyksiedlce.pl/_PROJECTS/feedrate_calc/index.php?lang=en&feedrate=ipm&chipload=in%2Fflute&settings=Save

The makita’s max usable rpm is around 18950 Just past 3. The slower sweet spot rpm is around 12000rpm. around 1.5
For a 1/4 2flute bit
18950rpm you can run 341ipm 120plunge .25doc
if you use 12000rpm you should run 216ipm 108plunge .25doc
For 1/8 bits and smaller 50% bit diameter. doc

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wow thank you so much this has helped. I am going to watch the video I am just cutting baltic birch plywood and mdf right now but plan on getting some hardwoods next week to engrave and cut. For hardwoods do you run at a slower ipm.

The example I listed above was for hardwood. (.009 chipload) For plywood it would be closer to 400ipm at 18950 or 264ipm at 12000rpm. (.011 chipload). These are settings for a 2 flute bit. If you use a 1 flute bit it would be half these speeds. 3 flute bits and 4 flute bits run faster. Just check the charts and set the speeds accordingly. I have been running my machine this way for around 3 months everyday no problems so I don’t see why anyone needs to baby it.

Something here got me thinking about this subject and just wanted to make a point.There is only either a correct or incorrect way to run these machines. Thinking that you need to start out slower as a beginner or a new machine owner is bad advice. Finding the proper speeds for your setup will not be too far off from factory recommendations because the only weak variable is the performance of the router and the quality of the bits. Based on these factors will be the determining factor for how much to adjust those settings. For the makita it means running the machine to spec for whatever your best router rpm is.

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I really appreciate the help, I know I will eventually get there and understand my machine and how to properly us it. Knowing the sounds and how fast i can go with it but at least a starting point and knowing how fast other people go, gives me reassurance . Thank you

I am really trying to push the limits of the makita to see what it actually will take and I can tell you from early observations that it really only has the power to reach the minimum capable chiploads for most applications. Anything over 400ipm and the router body starts to heat up. Same thing if you use a big bit like a surfacing bit 1inch over 250ipm it really heats up. I think the announcement of the larger spindle will be a game changer when it comes to what this machine is actually capable of.

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I was cutting on pine today and my whole machine was shaking when i was cutting. I used three different bits and the first was a dish bit and it was hot after does that mean i need to go faster. The second was a v bit which did great and the third was the bit 1/4 inch downcut the machine shook and skipped . Was i going too slow or my rpms wasn’t fast enough. I feel so defeated

@cyberreefguru . I am a Vectric user and when I set up a tool I try to achieve the chipload Vectric calculates in the tool description area. Do you have any indication as to how accurate Vectric is in this calculation???

Dave

Hi Dave - I have no idea where Vectric is getting their information from or what sort of recommendations they are making (I’ve only used the SW in passing since I don’t have a windows computer). However, the chip load formula is very straight forward:

Chip Load = Feed Rate (inches per minute) / (RPM x number of flutes)

As you can see, if you select a feed rate, spindle speed, and endmill, the chip falls out. Alternatively, some manufacturers give you a chip for various materials and bits, so you can then compute an appropriate feed rate or spindle speed.

-Tom

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Tom,

Vectric makes the chip load calculation when you enter the bit into the tool database. I am surprised the DOC plays no part in that calculation.

Dave

Yep, I was too. Especially since my experience tells me DOC is far more important to a successful cut than any of the other parameters. My take away is chip load is an indicator of an optimal cut, not a successful cut :exploding_head:

The DOC in most charts is set for 100% tool diameter. To adjust this for deeper or shallower cuts it looks like this.
reduce rpm* 20-25% - for depth = 2x tool diameter
reduce rpm* 40-50% - for depth = 3x tool diameter

@nsampson a dish bit is very large and can only run around 12000 rpm without major vibrations. Usually when major vibrations show up its because the speed of the spindle is too fast for the bit.
A good way to tell this is to run the rpms up until it starts vibrating then run the rpms down till its running very smooth. At this point note were you are at in rpms and adjust your ipm accordingly. Also make sure when the router starts to vibrate that it does not lower the rpms on its own. I had to tape down my speed dial from it moving and creating bad cutting vibrations.

As a newbie I keep coming back to this post for guidance. You suggest a feed rate of 40-60ipm will work most of the time, but as I continue reading here and researching I’m seeing some say they use much higher rates, in the 100s and 200s.

I’m using Easel and by default feed rate is set to 40. Am I safe to continue in the 40-60 range? I’m mostly cutting MDF or pine.