Need to save my hearing - Spindle time

price was quite reasonable so it’ll arrive in a few days :slight_smile:

thanks for the heads up @gmack

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I have a 1” with a 1/4” shank.

They do not plunge well. With an hdz it’s not an issue. But a belt drive z will loose steps undoes you ramp slowly.

I actually stopped using them to rough out material because I can run a 1/“4 bit sooo much faster that it doesn’t really save me any time especially when I have to do a bit change to get into smaller areas.

What speeds do you use?

I’ll have to see what the 1/2" one can do… it looks very different from my 1" surfacing bit i the pictures (my surfacing bit plunges like a brick so yeah not too useful)

I’m Camping for the night. I’ll look up my speeds when I get home tomorrow and post them.

They call them A plunge bit but the cutters do not come together in the tip. There is a ledge ground into the steel that can be plowed through wood but takes some force.

I have an XXL with a Chinese 2.2KW water-cooled spindle with ER20 collets. I have built a new Z-axis for it because the stock one was woefully inadequate. (nursed the stock Z-axis along so I could cut the parts for the new Z.)

The new Z-axis if fantastic! I no-longer worry about tool paths that need to raise and lower the bit repeatedly. I upgraded the steppers on Z and X to ones with more torque. Definitely recommended… I ordered linear rails for the X-axis too. Should be another big step forward in reliability like the Z-axis has been. (after I ordered them I saw Shapeoko have gone down this path for the pro model too.) I find the ER20 very useful. A lot of my tooling is half inch. It just feels more solid to me. I recently printed a drag-knife for cutting cardboard using my Shapeoko; the 1/2" shaft butting against the shoulder of the ER20 collet is study enough for cutting even quite thick cardboard. It would not have been remotely possible with a smaller collet.

The other upgrade I heartily recommend is a small 3d printed fan attached to the spindle. It blasts a hurricane of air down the cutter into the trench the cutter has just made. It blows the swarf out so well. It’s made my machine much more reliable, especially when I use down-cut or compression bits.


so got to try my new 1/2" Amana cutter today. That is a beast.

For 3D roughing I started at 2mm DOC with 50ipm feedrate… but basically dialed it up in Carbide motion to 150% without blinking


That fan doesn’t just blow apart under jet engine like RPM?

I totally thought it would, but it’s been going strong for months now. It was a careful tight press fit over the collet nut. I used a vice to squeeze it on. So it’s not flopping around. Also, the ring around the outside helps keep it in one piece (and direct the airflow like winglets on airplane wings) It’s also a safety measure. I figured something would one-day catch on exposed fan blades. I suspect also stops it from whirring badly. I should drop a copy up on thingiverse in case anyone is interested. I used petG plastic at 100% infill.

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That’s awesome, I’m more and more amazed at 3d printing. I just got my printer a few months ago and it’s been a blast learning just how much it can really do.

I imagine with a dust sucker of some sort it must really work well. Almost like ram air into the vacuum. Would love the STL.


I was facing an end grain board i’d glued up from birch ply strips today using a 22.3mm 2 flute cutter. I had a 1.5mm depth but was driving it at 5000mm/min (197 ipm) I heard no drop in rotational speed in the 2.2kw spindle… I think the torque of the 2.2kw spindle means that something else is always the limiting factor in your speeds and feeds. For me, after doing a slightly over the top upgrade for my Z axis, the weakest link is the v-wheels on the X axis and the torque of the X stepper. Things go wrong on that axis if i push too hard. So that’s why I bought linear rails and a high-torque stepper… have to wait till the lull after the holidays to install them. Too busy at the moment!
I reckon you can push your feedrate higher. For a facing cut you might as well keep going faster until you get missed steps and then back off your feed rate about 30%. That should give you a calibration. It works flexibly too. If you double the depth of cut you half the feed rate. Lessening tool engagement is the other option. (as with adaptive clearing strategies - I use fusion 360 for my toolpaths.

I keep finding uses for it.
I just uploaded the fan to thingiverse. The fusion 360 file is there so you can modify it directly (if you have f360) Also an STL.
Mine fit snugly over my er20 large collet nut.
The fan is thin enough that it doesn’t get in the way of the spanner flats on the nut.

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I think you’re absolutely right about that, and suspect that @LiamN would agree!

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I have yet to even slow down my 2.2kW spindle and that includes things like sending it into a cut at 1,200RPM edge finder speed instead of 18,000RPM, I just got big chips and an unexpected sound :wink:

The cutting forces and resulting frame deflection and vibration you’d be likely to see getting anywhere near full power on these spindles are rather beyond what the Shapeoko was designed for.

I have made mine stop once, I ran a 2" surfacing bit into hard maple at 8k rpm instead of 18k, its a 7 cutter bit and i was cutting 0.125" off of a slab with it, to its credit it made it a good 12" before it quit cutting and starting slipping belts

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Did the spindle slow/stop, or did the machine’s belts slip? What DOC, WOC and feed rate (IPM)?

The spindle got really slow. Then the belts slip or should is say lost steps because I’m not sure if it was belts or stepper motor.

It was the initial cut so it was a full with 2” wide cut at 1/8” deep at 140 ipm.

I hit estop rather quickly.

Wow - 35 cu-in/mi! :star_struck:. What spindle, machine, and feed direction?

2.2kw spindle. And it’s an xxl with steel belts and I run left to right on all my surfacing passes.

Stock V-Wheels with HDZ and constant torque (most Chinese) spindle?