SO3: Issues with the second pass off alignment by a half inch

Thanks for the help and suggestions. I’m about 20 solid cuts into CNC and figured out the speeds were just way too much! I’m dialed back a lot while tighten up belts. Everything now looks good again and runs great.

Again thanks for the advice!

Scott Jacobs

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You’ve had good experience at .04" (~1mm)? I’ve tried that with hardwood (at 7500 RPM and about 68 IPM) and… well, it doesn’t fail but it sure sounds like it’s chattering and vibrating something awful. I’m still quite new to CNC so I don’t really know how to trust my ears yet. I know that .3 sounds perfect but is slow, .5mm sometimes sounds chattery, but only a little and seems find. 1mm sound scary. Not sure how to make that call.

1mm stepdown with that Starboard plastic is perfect.

The sharpness and cutting angle of the cutters and the specific wood in question may make a difference.

Yeah, I was assuming these feeds and speeds were for the “standard” Nomad .135" flat endmill since that’s what most people start with and I use 90% of the time… but I probably shouldn’t have since this is a shapeoko thread…

@CopperTopWoodShop said that roughing was fine so I left it alone and simply reduced the depth to ensure quality.

I’m still quite new to CNC so I don’t really know how to trust my ears yet.

AWESOME COMMENT!

When I teach feeds and speeds I do a class on sound and feel, how to detect chatter. Eventually I have students able to dive for a pause or E-Stop by sound or touching a mill within seconds. I comes with practice, so keep it up! That is a very good skill to develop!

75IPM @ 0.04" depth (0.125" end mill, 2 flutes) on the Nomad is definitely doable in hardwood… depending on your definition of hardwood and certainly only for hogging (severe roughing). You’re correct, it’s “right on the edge” with things like Poplar and Red Oak - FOUND NEAR ME.

I must admit that I forgot that I run with coated end mills and that causes a gain of 5-10 IPM over uncoated. Sorry about that!

At 0.04" depth (0.125" end mill, 2 flutes, uncoated), something around 35-50 IPM is much safer for roughing hardwoods on the Nomad.

Feeds and speeds for wood taken off the internet are extremely dangerous as wood density, hardness and knot concentration and other factors vary widely across the US and the world. Yes, specific woods generally fall into “bands” but not knowing a source and testing it can be quite a surprise.

Quercus Alba - American Oak from the NE - is very different to machine than Quercus Laevis- American Oak from the SE and Quercus Robur from Europe. American Oak from Oklahoma is different than Tennessee.

Red Oak is softer than many other Oaks. It’s common in Home Depot and Lowe’s in the US.

They taste different too! I teach Whisky tasting and, yes, the cask wood is noticeable (Quercus Alba is often associated with Bourbon; Quercus Alba and Quercus Robur are often associated with Scotch). :smiling_imp:

Yellow Pine is a hardware, not a common, easy to cut pine. I’ve seen this cause a tool breakage more than one. It’s only pine…

Always run a few experiments when getting in a new stock of wood. I recommend cutting chevrons (so one gets linear and curves) with at least 1-2" for each side of the chevron.

mark

Everything has been going great. I tightened everything up and did some adjustments. I slowed everything down. .4 depth at 50 speed. Plunge I use 20. Seems to have improved everything! I stayed at 75 for the finish pass which works great.

I’m going to start another thread about using the Shapeoko for engraving blank plates for going away gifts. Not sure what bit or depth to go with. Also should I use the Carbide 2D for this?