Bits breaking

So I have broken at least 3 1/8’’ bits. I have reached out to inventables ab the problem, they suggested increased feed rate and decreased spindle speed. I tried both, and im still breaking bits on longer carves. It also seems like the collet nut adapter isnt holding the bits real well. Anyone else have this problem??

Did you get the collet from inventables?

yes everything i have is from them

This may be a dumb question but you realize there is a top and bottom to the collet and it will work in only one direction

Feel free to specify what material you carve and feed/RPM/depth per cut data :slight_smile:
So we don’t have to guess :slight_smile:

I’ve broken several bits on the clamps due to the insanity of how the bit lowers for travel (whyyyyyy???) but a 1/8 bit just breaking during a carve is hard to fathom.

Where’d you start? What feeds and speeds are you using now? What material? Depth per pass?

What adapter? Can you get a pic?

yeah i realize that, i had it in correctly. It is snug to begin with, but it ends up loosening during the carving.

Hard maple, 40 in/min, .05in/pass and the dewalt spindle is on 3 speed setting

I dont understand why its happening either, makes no sense to me

I would start by turning the touter down to the number 1 setting. That is 16000 rpms and should be way plenty for hard maple.

How tight are you tightening the bit? It really does not need to be super tight. Just snug

This isn’t normal or something to be expected with a proper adapter/inserted and tightened correctly.
It is possible the damage was done the first time.

If possible, provide up-close pictures of the business end of the 611, with everything in place and another with everything off. Adapter/bit/collet chuck/lock nut.

Are your v-wheels snug? I had them loosen on my z-axis and the spindle lost some stability. I broke a bit before I figured it out. I also had issues when my wasteboard was not level relative to the x and y-axes. Cuts near my G28 position went well but as the gantry moved to the left, the initial cuts were too deep in a single pass. Leveling the wasteboard fixed that issue

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Make sure the the end mill is 1/8 inch and not a little smaller metric size. The collet must hold the end mill tight. slippage in the collet could be the cause of end mill breakage. Speed and feed rates can be tricky. start slow with feed rates and slowly increase them. I have found with my dewalt palm router on my x carve it seems to work well on setting 6 at a feed rate of 80 inches per minute using a 1/8 inch 2 flute carbide end mill in wood or starboard. I only make a pass depth of between .020 and .040 this also helps with machine and tool deflection. Keep in mind there are many different types of 1/8 inch end mills and all CNC machines are not the same. If you are a beginner practice and experiment with scrap material, start with thin slow cut. watch for cutter chatter and tool deflection.A CNC wont complain about making multiple passes . Hope this will help you.

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This is my first post here on the forum and I figured rather than starting a new thread this one fit my problem. Tonight I was carving some hard maple that was a little over 3/4 of an inch and I had two 1/8 inch straight bits break. They both broke in different places. The first one broke in the collet. The second one broke shortly after starting the carve again. They both broke when I was getting deeper into the cut. I had over half of the carve done and they broke about 20 inches away from my home position.

My thoughts:
-Like stated here perhaps it would be my waste board not being level? Is surfacing my waste board the only option?
-My collet (which I thought was seated properly) maybe wasn’t how I thought? Suggestions on a collet if this is the problem.
-I am pushing my feed rate and depth (55 IPM, 12 in/min plunge rate, and .0625 inch depth per pass)? What would be a better rate?

Some of my issues I have noticed in starting carving is some of my cuts have been a little shallower the further I get away from my home position. I am getting some chattering with some of my v-bits. It is almost like the router shakes a little bit while it is cutting. It just doesn’t seem normal to me. It isn’t super smooth. Most of my things have turned out pretty good though so I just figured I was being too picky and expecting too much. I am much more of a woodworker that is diving into this CNC thing. Any help would be appreciated. Thank you!