Bit slippage issue

I’ve had an off and on issue with my bit slipping or shall I say being pulled from the collet/router.

For detail: I’m using shapeoko pro xxl, with carbide 3d router.
This issue occurs when I do roughing passes using a 1/4" End mill in hard maple at a depth per pass of .125 and speed of 80. I understand it’s hard maple, but surely this machine can cut through it. any suggestions? Anyone else do 3d carves through hard maple? may I ask what your feeds/speeds are?

I had this issue around Christmas when I did my 1st couple of 3d carves, and after posting it in the Facebook groups ruled out several factors. I’ve tried multiple bits, I’ve tried multiple collets, I’ve tried multiple routers (carbide 3d even sent me a new router). I’ve cleaned the router nut and collet and shaft of any debris. I purchased eclair precision collets, as well as precision collets from skyone cnc.

I don’t know what else to do, but i need to figure it out as I and wasting a lot of really good and expensive wood

Here is a hardness scale of wood.

You can see that just plain maple is 1450 on the Janka Scale. That is pretty hard. Since you are doing roughing there is likely a lot of vibration. That vibration may be causing your collet nut to loosen letting the router bit loose.

You might try to lower your feed rate to help eliminate the vibration. If it is not vibration then you have a defective collet nut and/or collet. The has collets at reasonable prices to replace your original one. Be sure you clean out your router shaft cavity and your collet and collet nut. Any lubricant even your skin oil can cause the collet to slip. I use brake cleaner. Just be sure if you do clean your collet it is clean and dry before reassembly.

The Makita and C3D router use the same collets.

Here are some examples of collets

Standard Collet for Makita Routers; RT700C, RT0700CX3, RT0701C, RP0900K, 3621, 3621A

Elaire Product Number Size Manufacturer Number Price
MRP-1181 3 mm MRP-1181 $24.50 Add to Cart
MRP-1250 1/8" N/A $24.50 Add to Cart
MRP-1575 4 mm N/A $24.50 Add to Cart
MRP-1875 3/16" N/A $24.50 Add to Cart
MRP-2362 6 mm N/A $24.50 Add to Cart
MRP-2500 1/4" 763637-1 $21.50 Add to Cart
MRP-3150 8 mm N/A $24.50 Add to Cart
MRP-SET Collet Set 1/8",3/16",1/4" N/A $63.50 Add to Cart
MRP-SETM Collet Set 4 mm, 6mm, 8mm N/A $63.50 Add to Cart

How are you tightening the collet?

We recommend only using the button to hand-tighten so that things will stay in place and then fully tightening w/ a good quality pair of wrenches (for the Standard Carbide Compact Router 13mm low profile and 22mm stubby).

The community has the following notes on Carbide Compact Router/Makita RT0700/0700 shaft and collet/nut wrench sizes:

13mm — note that this must be low profile.

  • Bicycle cone wrenches work as well such as the 13mm Park Tool PT-09 Shop Cone Wrench
  • Asahi low profile 11/13mm wrench
  • McMaster-Carr Tight-Clearance Open-End Wrench with Black Finish, 13 mm Size, 4" Overall Length (sourced from Martin as of mid-2020)

22mm — a stubby wrench is well-suited for this, and handier due to the low torque requirements

You’ve mentioned it but regular cleaning of the router nut and collet helped me a lot with this issue.

I never realised fine dust accumulation in this area was such an issue till recently but now i take the nut off and clean the collet at every tool change. Tool slip is no longer an issue for me and i dont have to tighten the nut so much either.


I solved my problem in hard maple with the exact same machine and router by inserting my cutters all the way in and then backing it out about a tiny bit. Don’t make them reach unless you have to.


Regardless of the machine that’s too fast and too deep for hard maple.
Everything would likely be much happier somewhere in the range of 1600mm to 1800mm feedrate and a 2mm to 2.5mm DOC. As Will mentioned a good wrench is essential. I use a Sunex (bought on Amazon) 7/8" combination wrench that’s approx 5.5" long.

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