Share Your Speeds & Feeds Bits and Wood Carving Info

Nope. Still experimenting. I had the grain follow the side of the bass and it was SO cool… until it crashed. There is no real way to finish it now. I do like the contour toolpath better than the raster for organic shapes. If was cutting something very geometrical like nested rounded over squares, I would probably go raster.

I went to a furniture store the other day and they had carved fish on the wall for $50. They looked like they were painted by a child. Now I am obsessed with carving fish.

Good stuff guys, can you throw in some links for the bits you are using? Another information overload subject there.

Here is a link to the 1/4" ball nose I use. I don’t know where I got my 1/8" - probably from precisebits.com.

1 Like

I have been purchasing my bits from China on Ebay. Most ball nose and fish tail bits are less than $10 including shipping.
So far I have been very pleased with the quality of the bits, the shipping takes about 2-3 weeks so that is a downside, but the price is the selling point for me.

Thanks for all the good info guys. I never thought there would be so much to carving a piece of wood with one of these machines. I’m still trying to compile information and put a bit shopping list together and trying to get something going.

Please keep it coming.

1 Like

I have attached a basic Feed and Speed calculator I found (Excel format). It allows you to enter your feed rate (celll D4) and it will calculate the RPM required to produce various chip loads.

The spreadsheet also shows the recommended chip size for various materials with 4 different size bit diameters.

I added a column to show the Dewalt Speed setting necessary to achieve the desired RPM. If the required RPM exceeds the 27,000 RPM limit of the 611 it will display “To Fast”. If the required RPM is below the minimum speed of 16,200 it will display “To Slow”. Otherwise it will display the speed setting between 1 and 6 (i.e. 2.5 is halfway between 2 and 3)

The first thing I noticed is that if these calculations are correct, I have been running my RPM’s way to high.

For example if cutting hardwood with a .125 inch bit the recommended chip size is between .003 and .005
To achieve that chip size with a two flute cutter moving at 100 inches per minute the RPM should be 16,667 or a setting of about 1.5 on the Dewalt 611.

For MDF with a Feedrate of 125 inches per minute and a .125 cutter the Dewalt should be set at 1

Please let me know if anyone finds an error with the calculations, they look pretty straight forward but wow these numbers are very different from what I have been using.

CNC Speed Calculator.xlsx (14.0 KB)

14 Likes

Thanks for posting this. I feel like I’m still guessing a lot with feeds and speeds. Hopefully this helps. I may be doing some carving later. I will use the chart and see what kind of results I get.

@Allen Massey - above where you say, change the bit and try not to move the router… Mine is set to lock the motors when it is stopped… It would be very difficult for me to move the router during bit changes. The setting in grbl is $1=255

Thanks Erik, Mine locks also, but when applying torque with a wrench to loosen the collet it is easy to overcome the holding power of the motors if I am not careful.

Cutting some pine this morning with a 4 flute 1/4" endmill, I slowed the Dewalt down to about 2.5 and it is cutting much better, I am running at 70 IPM and I am getting nice clean cuts. Thanks Allen.

Do you have the nema 17 motors or the 23s? With the 23s locked I am in no danger of moving it while I am changing bits. It is solid.

I am still using the nema 17’s. It may be time to upgrade.

I’ve noticed it is always time to upgrade something :slight_smile:

3 Likes

Wow, that speeds calc is great but I’m a bit scared to try 300inch/min for hardwood with a 1/4" cutter! That sounds super fast - I wouldn’t think the motors or belts could cope with that? I’ve been using 40inch/min and the router set on 5 so far, so I should probably push that up a bit.

I agree that 300ipm is to fast. So what I try to do is use a smaller bit or if possible a bit with 1 or 2 flutes.

But yes, I was running my 611 way to fast for the feedrates, Lowering the speed helps a lot. I have also been increasing my feedrates to between 90 and 120 ipm (up to 140 on soft woods and MDF)

I was very surprised by the number the calculations were providing but they seem correct, The only “non calculated” number is the chip load and those seem very consistent with the values most bit manufacturers recommend.

I would like to find a source of chip load values for 1/16 and 1/32 bits but so far I have not seen any published numbers for bits that small.

1 Like

little late to the game, but this is my first time looking into some best practices for the Dewalt 611 feed & speeds. I’ve been running at the recommended settings all this time, so jumping from 28ipm to something like 90ipm sounds crazy! Also to slow down from 4.5 to 2.5.

The one thing I don’t see is, what is the best depth per pass?

It depends on the bit and the material you are cutting. I cut primarily wood, for example:

If I am using a 0.25" endmill and I am cutting a hardwood like oak, cherry or hard maple, I usually cut at a depth of 0.05" and a speed of somewhere between 60 ipm and 120 ipm…it all depends on what I am making…do I need super smooth cuts? I go slower…If it is simply a roughing pass and I will clean up with another bit, I go faster.

I run my roughing passes in pine at 140 ipm.

Keep in mind, I have done the X-Axis stiffening mod with a 3/16" steel bar and my machine is very well dialed in and is working great.

5 Likes

As you cut more wood you will get a feel for what works best for your machine. As a general rule of thumb you always want to keep your depth of cut to about half the diameter of the bit you are using. But that is just a good starting point, as Erik says there are lots of other variables like how perfect do you want the finish and the type of wood you are cutting. But in most cases if you start with DOC of about half a diameter you will be in the right ballpark.

As for the RPM of the Dewalt, I have found that keeping it around 1 or 2 gives me good results. It also keeps the bit from overheating, keeps the wood from burning and will extend the life of the router. But if you think you get better results with a higher RPM, it is your machine.

2 Likes

Forgot I started this thread a while back. It would be nice to see pictures of finished jobs with the exact cutting info so others could try to copy and get a good feel for what the machine can do. It’s also amazing some of the finish work folks do and that’s another beast in its own. Great group of folks here and as always thanks for any help that will get Newbies up and running.

just did an oak plywood cutout at 70ipm (machine wasn’t moving as fast as the superman speed I was expecting in my head) and .05dps at #2 on the Dewalt 611.

Would post a photo but the machine didn’t go over the exact same place twice when cutting so the edges are stair stepped, but was a clean cut! (guess back to the belts, pulleys, and wheels game of tweaking…)

1 Like

hello.

I am new here. I have a makita router fitted on 1000mm x carve.

Is there a way of increasing the cutting speed using easel on standard plywood? I tried changing all settings of material for the machine to cut deeper/faster, but cannot figure out how. Ive also tried setting it up to cut ABS plastic on plywood to no avail. Im cutting using 6mm 2 straight flute, and Im pretty sure the router can handle deeper cuts than easel is set for.

If the above has been answered, sorry for this, as said I am new here.