Hardcore Aluminum milling on an S3

With that adaptive finish, who needs a contour finish???

Well…technically…adaptive is almost always never a finishing strategy due to the model tessellation that’s mostly effected by tolerance and smoothing values. Basically adaptive can make really clean straight lines but is fated to leave rough lines on curves.

Even the most ridgid machine needs a toolpath with constant pressure for finishing and contour achieves that.

What’s impressive is the 200ipm at a 0.0017 chipload after thinning at only a 3.35 lbf machine force


Side by side comparison, the golden standard

Shapeoko VS Datron Neo surface finish. We’re good on the straights…but can we compete in the corners?


Single flute for finishing? What does " Limiting factor is not being able to put the power down in manual vfd input mode" mean?

@Vince.Fab already seen you use couple of different routers, spindles, vfds. Any idea how much you spent on them so far? I’m only asking because jgl makes really good spindles which cost somewhere around $1500 to $2000. Seems like a lot at first but considering that you get a ATC 2.2kw er16 40K rpm it seems like a really good deal. If I were to guess I’d say you spent close to this much so far?

I have a full quote for three JGL spindles but even the cheapest comes out to $1750. Also there is a big weight difference between these and the other spindles. It would be silly to buy one of those yet still run V wheels imo.

I have three spindles

0.8kw 24krpm 65mm 110v with sk15 ATC
1.5kw 24krpm 80mm 110v
1.2kw 60krpm 62mm 220v

Both 110 spindles use the same VFD and the 60k is just unbelievable. All in all I only have $1500 in these spent over a good amount of time (cnc work paid for them). While combined they come close to the same amount of money, using one would not be good data. Those are far out of the price range with these machines and would upset the balance imo.

If I can get the 60k going like it should, its a far better option for the masses.

I’m not a VFD expert and in manual controller mode I cant seem to get it to output more than 1.75amps. When switching to PID plus feedback it will output much much more and is set at a 4.5amp max. However because I need a 10v converter for my input, haven’t wired it into the board yet.

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There’s been so much conversation about the linear rails that I completely forgot you’re still using wheels on the Y axis. I’ve seen them and common 80mm Chinese spindle side by side and theyre huge indeed. Would love to add atc to one of my machines (obviously not under grbl anymore) and trying to get as much info as possible. Have you ended up using chiller for the 60k spindle or just a large radiator?

Yeah atc plus grbl is a little too much work for me but semi automated with a one button touch is cool, the sk15 can hold er16 I believe. Currently I haven’t run long enough to heat 4 gallons up without exchanger but it will go on soon.

Either way, it’s nice to have multiple spindles. If I can’t get the vfd working right in the 60k I’ll throw the 24k back on.

Got some fun stuff in the pipeline

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I’m going to have to agree WRT ATC and GRBL. I made some progress with my ATC changer, and it certainly makes manual changes easy, but GRBL really doesn’t have the infrastructure available to support tool changing, and none of the gcode senders really do either. I started adding ATC support into CNCjs, and made some progress, but the whole thing was turning into a giant mess. In the end, I think it’s going to be less work (and cheaper) to switch to something like LinuxCNC which has built-in ATC support.

GRBL is cool, but it just isn’t flexible or expandable enough to support tool changers in a sane way. That’s not to say that it can’t be done, but the end result is going to end up being a hack, and it’s not really going to be something that I’m going to want to live with.

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When I checked in May, shipping for Jianken’s apparently awesome spindles was ~$500 to California. Have you checked on that?

IMO intended spindle use really needs to be considered when deciding what to buy. Most woodworkers and plasticworkers would likely be better off with a spindle that support’s 1/2" shanks (ER20) rather than one with a smaller collet that runs at speeds much higher than 24 kRPM. Most cutters for wood are only rated for 18-27kRPM operation. Also lower speeds are less demanding on cumulative runout and balance, so the detrimental effects of adding ATC are somewhat mitigated.

There are cutters available for the higher speeds in aluminum (to 100 kRPM) so the higher speeds can be productive. But, the higher speeds are more demanding on cumulative runout and balance, so the detrimental effects of adding ATC needs to be considered and may add significant expense.

Cutters for harder metals are typically rated for speeds lower than 24 kRPM. Here’s a Chinese spindle designed for hard metals.

Note that almost all Chinese spindles (except some Jiankens) are constant torque types, so they only provide the rated power at their maximum speeds..

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I did not check how much the shipping was so that’s a great info to have although from what I see in your post that’s not a quote from the company itself but the Alibaba’s estimate? Anyways, in regard to your lengthy post (which is very informative) I asked about that particular company in this thread because I have no plans on cutting wood anytime soon. I’m trying to get better at cutting aluminium and thats all I’m interested in.

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Sorry - I get carried away sometimes! But, I suspect that there are some thread viewers that do cut other things (including @Vince.Fab) . It looks like those Jianken ATC spindles are available with ISO20 collets up to 40 kRPM. They should be awesome for aluminum with high quality high speed tool holders and tools! A 1/2" endmill at 40 kRPM could increase the MRR of a 1/4" endmill at 60 kRPM by 1/3 without increasing cutting forces (the limiting factor on Shapeokos). :slightly_smiling_face:

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I don’t really know for sure, but it seems to me that you should be able to use the manual controls on the VFD to run the motor at whatever speed you set it too. Even without any feedback (PID, etc.) the VFD should source whatever current is necessary to maintain that speed under loads that don’t exceed the maximum for that speed. Maybe someone like @Julien could validate that? :thinking:

where did you settle on your acceleration & rapid settings? I’m playing around with mine at the moment - I’ve got steel belts to fit but still running standard belts at this point.

I’ve had no issue jogging with 25,000mm/min rapids which is around your 1000IPM, and accels are at 27,000mm/min2 which is a little under your 1200IPM.

Interested to see where you ended up, I might go back to about 80% and run some heavy jobs, see where that takes me. What did you settle on for your HDZ as far as accels and rapids?

@gmack, @Vince.Fab

On my VFD there is a setting where you have to set the maximum Hz the VFD outputs when it is in manual mode (i.e when you use the potentiometer on the VFD to set the speed). Perhaps this is the issue?

This setting was by default set to 100 on mine and I had to change it to 400. What type/brand is your VFD?

I have the 1000hz version of this and spent the whole day cobbling up a much bigger wired vfd cable to take that out of the equation.

Still only seeing a max 2amp draw at max speed when trying to stop by hand.

Mostly I let the steel cores because I don’t have to adjust steps for calibration, just throw on. Set tension and go.

Also usually I’ll run maxes at 50% just because it starts to move scary fast and I like an extra tq cushion. I know Winston is running torture tests on his hdz, I just doubled


I think you’d be better off trying to get it to work properly in open-loop (no “feedback” of any type) manual control mode before complicating things with remote control.

I found the final spindles speed vs. Fusion command to deviate too much when connecting the C3d board to my Omron vfd. I can imagine that this deviation would be amplified pretty heavily with your spindle that is 60k Compared to my 24krpm, and in addition using the converter to bump 0-5V up to 0-10V which I don’t believe helps on deviation either, however I might be wrong.

If you experience too much deviation here and want better accuracy, I would buy the cheapest arduino board you can find and connect your C3d PWM signal to an input here. And a DAC module similar to the one below to wire your output to the VFD from.

I did this on mine, and made a linearization table in the arduino on every 1k rpm, this to ensure spindle speed is according to G-code throughout the whole range of the spindle speed.
This way coolant, dust collection etc. can easily be controlled also.
I will gladly share this code or help with the setup.

I don’t believe the issues you are experiencing with power limitation on your VFD will change if you hook it up to the C3d board. I have earlier used CNCzone forum and user mactec54 for vfd questions, he is knowledgeable and very very helpful.

I don’t mean to interrupt you tread here, but I didn’t manage to post in the “Best vfd thread” and I feel the information is relevant, to you and most of the users adding a vfd to their Shapeoko.
If there are any further questions to this I can make a new thread with pictures and better explenations.



How much off are the rpms? I’m using xpro v4 controller to send 10v pwm signal to the HY vfd and I’m always off by 200rpm which in my experience isn’t that big of a deal. Anything higher than that I’d honestly be concerned.