Spindle Advice (3 Phase ATC upgrade)

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I have recently had 3 phase power added to the workshop, so want to take the opportunity to upgrade my Plug&Pray Avid CNC 3HP spindle setup. I’m not sure of the pro’s and cons of some of the spindle options though.

(Please note: A US-supplied option like the SC30 is not an option - the US$ is just too strong, and postage to Australia daft, so I’m stuck with a Chinese import).

I’m planning to convert to a 3P VFD, and a water-cooled ATC spindle. I don’t actually want the complexity of a full ATC function at the moment, but like the idea of having a bunch of tool-holders with tools installed that I can change quickly and easily with the press of a hissing button. (Maybe one day @subnoize will have his little beast in production and I’ll be in the queue for the next upgrade)

Water-cooled to cut down on the noise.

I’ll get a Powtran VFD - I have one on my bandsaw, and another on my cyclone, so I’m vaguely familiar with them, they’re reasonably priced (as opposed to cheap junk), and are still going strong after several years’ use.

I’m an enthusiastic hobbyist, so this is not a production environment. I churn out things like workshop/kitchen cabinets and butcher some Australian hardwoods. I’ll get to a bit of 3D carving in the next decade or two at current rates of progress!

So, questions:

  • ISO25 vs BT30 vs other. The ISO25’s seem quite a bit cheaper, and I’m not going to need to hold anything bigger than half an inch…
  • Spindles seem to be offered as 400 or 800Hz - How does the frequency affect things (380V 400Hz vs 380V 800Hz)?
    *Jianken seem to have a reasonable reputation, but have a bewildering range of spindles. I was thinking of around 4-5HP (or 3.2-4ish kW). Their JGL-100 or 110 range looks like it might be a good starting point to chat to them?

Does anyone have experience of any other ATC spindles? Or other suggestions/things I should think about?

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I am sorry, I wouldn’t know what to tell you. I know people who buy those spindles off ebay and just toss them after they start acting up. A good spindle should last you 10 years of daily use if you treat them right. These el’cheapos last like 2 years or less even if you baby them.

I’ve been told by people who buy those things that it evens out in the end but that should be treated as what it is, “rumor and opinion.”

But, something to think about before you jump; ATC is way more expensive than the spindle.

Case in point, you can buy 5 ISO30 tool holders off Amazon for about $120. They are balanced but the runout is pretty bad. Your tools will wear quicker and the vibration will wear out the bearings sooner in your ATC but if you are cutting wood nobody will ever notice on the quality. The runout is smaller than the accuracy of the machine so you know…

So, to just have 10 tools available for the machine you are looking at $240 and we haven’t even added a single tool to those holders.

If you want to cut aluminum, plastics, composites and foam then the tool holders start at $150 each. In that case you are looking at $1,500 for 10 of them before you purchase a single tool.

Once you have your setup running you will realize the crazy idea you had to just move tools between holders is a complete pain in the butt! You will need to recalculate the offsets each time and one day you will forget and wreck your machine.

I woke up one day and realized that I have more money in ISO30 holders than I do in spindles and CNC machines combined. Forget the cost of the tools stuck in those holders.

If you are having a hard time justifying the cost of the ATC spindle, the price of the tooling will be overwhelming.

Then there is the added complexity. AvidCNC’s basic design is just uncomplicated and fun. There isn’t a lot to go wrong with it.

Add that dern Mach4 tool table to the mix and things that AvidCNC did for simplicity go right out the window. Next thing you know you will be making checklist that would scare the hell out of 747 pilots and death clutching that e-stop every time you hit cycle start.

My best advice is this; ATC is for hobbyist with lots of cash and businesses wanting to save cash.

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Thanks SN

The price of ISO30’s is one of the reasons I thought of going for ISO25’s. I’ve seen some testing and reviews of these, and they came out pretty well.

I guess many of the branded spindles are also actually made in China - trick would be to find them direct from China.

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Interesting, I always thought they included the metal for the tool holder for free. The cost is the tolerances they are machined at, not what they are machined out of.

https://www.multicamtooling.com/tool-holder-iso-25-er25/

I would not assume that. Tooling to make low runout milling equipment is on the technology export ban list for China.

So, here are the cheapest I would go for in the ISO30 size, they have better runout than the link you posted at 0.001" and they cost less to boot;

https://www.amazon.com/gp/product/B07W5CQX4R?th=1

This one is a bit more expensive but is claiming to be AT3 and full runout 0 ≤ .008μ (aka 0.0003")

https://www.amazon.com/gp/product/B08LGTPJMW

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As somebody pointed out to me that iso25 claims to be 0.002mm which is simply not possible at that price point. That would be 0.00008" which we all know isn’t anywhere near the truth.