Insufficient Spindle Power?

Hi, I just got Nomad 3 last week since then I was testing the machine on aluminum.

So far the result is quite bad as the spindle is not seemingly living up to its capability.
Whenever the load gets relatively high, the internal LED starts flicking and the spindle starts slowing down. Depending on the load, this slow down is enough to stop the spindle completely.

I put a power meter on the Nomad, and I see LED flicking if the total power consumption reaches 100W, and at 120-130W spindles likely to stop.
Nomad 3 suppose to have a 150W spindle and it consumes about 50W at idle with the spindle off. So at least the peak should be somewhere like 200W.

Does anyone see the same issues? i.e. flicking LED light at high loads?

Thanks for help!

What feeds and speeds are you using in what materials and how did you arrive at them?

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I’ve been trying 1/4 3 flutes flat mill, which was unsuccessful at any feed and DOC. I tried down to DOC 0.1mm but even 50mm/min did cause flicking and stopped. (And also too slow)

Today I was trying 1/8 which was p successful and I got meaningful jobs done. I got DOC 0.5mm at 1000mm/min easily.

However, the problem isn’t my feed or so. Either 1/4 or 1/8, the spindle stops if the power consumption reach total 130w.
Again, at idle with spindle off, this machine is drawing about 50w. If we have 150w spindle the total should be close to 200w or so. Then it make sense that I am hitting the max power and it’ll be time to slow down or use smaller tools.

I like to know if this is normal and if I need to give up 1/4 entirely or try out 1 flute

Hello Yusuke, (ăŻă˜ă‚ăŸă—ăŠ)

I have the older Nomad, which has a lower powered spindle.

With that machine and aluminium, anything over 1/8” can make the machine stutter or stall the machine, even 4mm.

I would be surprised if the new Nomad could handle 1/4” on metal - it doesn’t seem that there are enough changes to the machine to handle that load. It would be a pleasant surprise to be wrong there.

As for the wattage, perhaps it refers to mechanical power of the spindle (speed x torque) and not the electrical power supplied?

EDIT: I would recommend you try single flutes if possible.

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@wmoy would need to speak to the specifics (still waiting on my Nomad 3) — but as @Gerry noted, for the previous models we only recommend using tooling larger than 1/8" in softer materials. In theory the larger rotational mass increases inertia and should power through a cut, but in practice that doesn’t seem to work out.

For cutting metal with the Nomad please see the “Material Monday” series:

and definitely consider a single flute endmill such as our:

or

Hi Gerry (こんにづは)

It’s unfortunate then. Nomad 3 suppose to have double the power from the previous one, but seemingly we can’t push the removable rate. I tried the feed and speeds from that youtube video, but that’s all we can do. Cutting 0.75in depth takes like 2 hrs. I guess we are still restricted to thin aluminum or soft material.

Thanks for the reference!

Facing is kind of working with 3 flute. I’ll try 1 flute to see if I can do something meaningful with 1/4 tools.

If you refer to Winston’s MaterialMonday videos that Will linked above, it has feeds and speeds that were established for a Nomad Pro with its 10k RPM limit. With a Nomad3 you can bump RPM up to 24.000RPM, and therefore also multiply the feedrate shown in that video by x2.4. So effectively, you go x2.4 times faster than a Nomad Pro, which means double the MRR, doesn’t it ?

Theoretically, yes, but other factors also comes in. Faster feeds are not stable unfortunately. I was indeed using 24k rpm for 1/8. Maybe I can tune feed in so that the spindle won’t slow down substantially when it touches aluminum.

I have to slow down more than youtube video feeds maybe because I was using uncoated one. Otherwise I can see the internal lighting flicks everytime the tool hits the aluminum.

I’ll try TiN coating tools and add mist supply later this week. But I guess we can only do mostly 2.5D with aluminum. I managed to do 2 sided 3D design with 1/8 tools, but it’s a tiny part.

you may want to go for ZrN coating instead, TiN has mixed reviews


I suspect it’s not that straightforward to calculate the exact effect the Nomad 3 design changes provide.

The old spindle was 70W, the new 130W (x1.8). The old spindle maxed out and 10K RPM, the new at 24K RPM (x2.4).

You can also make things spin faster just by changing the pulleys/gears, but it won’t make it more powerful. So the RPM might not be key here.

I suspect the graph of the differences is not just a simple multiplication, since there are both higher rotation and higher powered motors but at different proportions.

There are several people on this forum who understand this sort of thing more precisely, perhaps most actively @spargeltarzan and @Moded1952 
 maybe they could provide some theoretical input.

I would start with the Nomad speeds and feeds with only 1/8" endmills, and increment either the DOC or the feed speed, but not both, and not doubled. Try 25% per iteration, perhaps? If you must have a bigger endmill, try 4mm and then 5mm rather than 6.35mm.

Welcome Tanaka-san! Looks like you’re going down a similar road to me when I bought my Nomad 883 Pro.

You might find my long adventure pushing the Nomad 883 Pro to its limits to be interesting.

+1. Not a fan of TiN, prefer ZrN or diamond.

Where was the power meter placed? Was this between the Nomad and the wall, or did you manage to connect it to the spindle itself? What style of meter is it? A clamp meter or one of those outlet measuring devices?

What kind of load is it? Are you increasing feed rate, width-of-cut or depth-of-cut? In my experience even with the drastically underpowered 883 Pro, power isn’t the thing that’s likely to cause behaviour like that, it’s torque.

On the Nomad 883 Pro, 6mm or 1/4" endmills worked fairly well for me, as they give you higher surface speed for the same RPM. You have to use a small width-of-cut/stepover though.

Also, don’t run at speeds as slow as 50mm/min. You can play with most of the feeds and speeds numbers but don’t play with feed-per-tooth too much. That, in my experience, is the one that’s most likely to cause problems if set incorrectly. Too high and it stresses the tool and breaks it, too low and you get rubbing. The manufacturer of an endmill should usually provide recommended feed-per-tooth for their particular endmills and it’s best to stick to them.

Also, what was your width of cut in all of these cases? You haven’t mentioned it so I have a feeling you might be doing 100% stepover, which would cause problems like you’re describing.

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Spindle bogging down audibly means that the controller cannot deliver enough current to generate the torque needed to maintain the cut, that can very well happen below maximum power, as @Moded1952 said.

Three-flutes in full slotting (ae = D) have an awful tendency to recut chips: the flimsy chip can’t be properly picked up out of the way before it’s overrun by the next flute. If that happens, you’re essentially cutting everything twice (or thrice) and that is not a recipe to reduce torque. On small machines, single-flute endmills can be helpful because they let you maintain a decently sized chip at low torque, and the large open gullet clears chips away reliably.

Coatings are very beneficial (essentially necessary) for steel. For aluminium, there are possible advantages such as reduced friction, but they are paid for with an increased edge radius, meaning a coated tool prefers a somewhat thicker chip. Especially on a Nomad, that may not be the best bargain. DLC coatings can be made fairly thin, so that’s more likely to help; ZrN, TiCN, TiB2 are more suitable for larger machines that can sustain suitable chip thickness more easily. Most other coatings such as TiN, TiAlN and AlTiN are meant for steel and will make the tool more susceptible to built-up edges because aluminium tends to stick to these coatings.

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I have actually had good results with TiN, but better with ZrN. ZrN tools do seem more readily available then they were a few years ago so unless you are looking to save a slight amount of money suggest ZrN.

Yeah sorry I meant TiCN, TiN is for something hard, but I didn’t know the reason, thanks @spargeltarzan!
I am ordering from McMaster so ZrN seemingly not an option there @PhilG, @Julien.

Once I get 1 flute and coated ones, I’ll try pushing the limits on 1/8 tools as @Gerry suggested.

@Moded1952
Your adventure looks interesting and seemingly I will go down the same path if I’m going to hang on to this machine.
The power meter is just a wall mount type of thing, so it doesn’t have a high sample frequency, but it reasonable enough to see the continuous load.
Did you used 1/4" 1 flute?
I have tried 95% to 10% stepover. 95% stepover was okay for facing with 1/4. But I mostly try adaptive clearing, which at least can do some jobs done.

In that case I wouldn’t rely on it too much. It shouldn’t be too horrible but I also wouldn’t rely on its measurements to determine that there’s something potentially wrong with the Nomad.

Better is to put some kind of current meter between the spindle motor and the Nomad, that’s what I ended up doing.

Yes but I didn’t find much need for it. The big advantage of single-flute endmills is that they’re nearly impossible to clog but with 1/4" tools, there’s plenty of room in the flutes to clear chips anyway, so as long as you have air blast, the higher flute count is more useful than the uncloggability.

My recommendation for high MRR on the Nomad 883 Pro is:

  • Large stepover (say 60%)
  • Safe feed-per-tooth (e.g. 25-30”m for a 1/8" or 3mm tool)
  • Highest surface speed you can get while staying within the manufacturer’s recommendations
  • Start with a conservative depth of cut like 0.05mm
  • Increase the depth of cut until you start getting chatter or the spindle stalls

I do not recommend low WOC, high DOC feeds and speeds on the Nomad 883 Pro. The machine isn’t rigid enough to deal with it. The Nomad 3 might be better but I’d try the more “classic” feeds and speeds first.

And I agree with using a 1/8" tool to start with, particularly a 3mm or 1/8" single-flute endmill. If you can, get one with as short a cutting length as possible/useful. Minimizing the stickout of the tool is really important on the Nomad.

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Call me a noob but full depth of cut with low stepover and high feeds is my new darling configuration. As little as 6% stepover can be used. Fusion 360 3D adaptive paths are fantastic.

So consulting the manufacturer spec sheet I configure feed per tooth and 20k rpm. That’s fixed. (Exception is when feed is just too high. Then I’ll lower rpm along with feed to maintain spec sheet feed per tooth)

Then I pop over to HSMAdvisor to calculate required wattage for different stepover values and shoot for like 40-60w to start with, with a 12% max stepover as a rule of thumb.

If I can’t fit within 60w at 6% stepover at full depth of cut and recommended feed per tooth, the tool is too large for the nomad3 in that material and I choose a smaller tool.

I am not a machinist. Good luck!

(I’d upload a video but I guess they’re disabled on this site)

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Hey guys thanks for all inputs, now I’m handling this machine better.

I added mist system and now things are quite satisfying.

I have no issues using 1/4" 3flute with 1mm DOC, 1mm optimal load at 700-1000mm/min.
I also now use 24k for 1/4" tools, which seemingly helping.
I have to toggle ramping and feed in so that there’s no big kick that’ll stop the spindle right away.
Probably normal counter and pocket operations are not good at all yet tho.
All roughing operations probably need adaptive clearing, but far more stable.

This is like $50 upgrade, but now all roughing are satisfying fast

@Moded1952
Yeah I agree. I never used 1 flute on any machines and I thought that’s for like wood or so. I’m anyway getting one from carbide 3d to see if that’s any good.
I’ll try 1/8 tomorrow if I can push the limit with the mist.

@kvc
Interesting. I stopped using the app for Nomad, but that could be still a good reference.
I didn’t try full depth, but I got to do 5mm doc with 0.5mm optimal load so far.

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