Inventables Community Forum

Outline cut isnt flush for whole depth

Does anyone know what causes this? I am cutting out necks for guitar and when nit goes to cut out the profile of the neck the first couple cits are smooth and in line with each other. Then about 1/4 of the way down it steps. Does it on both sides of the neck and only on the sides. Ive tried a couple different carves with different settings. I orginally followed Chris from Highline guitars settings for when he had a X Carve. The slowed the feedrate down from 100 in/min to 60 in/minute. No real change. All my carves stepped over at the exact same depth.

Thoughts?

a lot of my templates, mdf, tend to do that on the first pass, but not that pronounced. a sharp bit doesn’t do it, but it’s like the cutter drags more on the first pass, perhaps due to the dryer/harder surface of the wood

The bit is pretty new. Only used it on some test cuts of mdf so it shouldnt be that its not sharp enough. but i will try a different bit thats not been used. i wonder if my DOC and my plunge rate are too high. I watched video on youtube of Chris who used to carve with an x carve. he said with his necks he cut outline with feed rate of 150"/MIN. Which seems super fast.

i am far more worried about accuracy than speed. i cut real wood around 70 ipm, with about .06 DOC

I suspect multiple lines in your design.
Zoom in as close as possible and take a look.

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I wouldn’t cut more than about 1/8" deep at a time in maple( assuming that’s maple). I’m still trying to dial in one piece necks myself after installing some upgrades. My first 5 results are less than spectacular.

The depth of cut was set at .06" so not deep at all. Feedrate was 60"/min. I zoomed in as far as I can and no double lines. Trying it now on mdf with 60" feed .08" DOC and plung of 9".

Also, the router shimmys when moving in the X axis. I suspect the eccentric nuts arent tight enough.

The MDF test cut came out better. But still has a small step on the bass side much less pronounced. Treble side is nice and clean.

What upgrades did yo make? Also, what bit are using for cutting outline of neck?

are you using a 1/4" bit or 1/8" bit?

I have a nice aluminum Z axis off ebay. I ordered the Y stiffeners and 9mm belts/pulleys. If I can’t do an accurate neck after all that is attached, I’ll just sell the x carve off. I have two other cnc routers that I bought over the years, a K2-2514, which is nice and I used that for most of my work up to the upgraded xcarve. I can do a neck on an angle. The other router is a shortly lived production called a pcncautomation router and it is OK for things that don’t require precision. I use either a 1/4 straight on neck perimeters on the x carve. I have used a 1/2 straight on bodies. I rarely use a 1/8" bit, unless it’s a small detail. My bits are mostly Freud, CMT, or Whiteside ( I prefer the whiteside).

The saga is in here:

Slowed my feed rate down to 40 with a Whiteside 3/16" 2 flute upcut and the neck cut perfectly. No steps ion the side and face of the head stock is super clean. The router still vibrates a little when traveling in the X direction. Is that a product of the eccentric nuts not being tight enough?

If the wheel can be spun very easily with a finger while it is sitting there, I’d tighten it up. Mine get snugged up and then backed off a bit.

Vibrating or chatter in the X is usually a byproduct of cutting too aggressively for your setup. Aggressiveness can be increased by addressing flexing belts, loose belts, or flex in the z slide assembly. Changing to more robust belts and a more rigid linear slide z effectively eliminated all of my chatter.