With the pulley change to bump max RPM to 12,000 and my ER16 collet (up from ER11), I can hit ~1200SFM with a 3/8" insert mill…which I’m currently installing in the machine. I am already being pretty sporty with my pulley ratio, not sure how much past 12krpm the pulley diameter or spindle bearings will be happy with.
Something is definitely going to happen.
By chance, is your er16 shank from little machine shop? No need for one currently, just curious.
https://littlemachineshop.com/products/product_view.php?ProductID=5189&category=
No @peteseyeview , for reference, the model number is C8-ER16A-100L but seems unavailable based on first few pages of Google results. It’s honestly a pretty goofy design having such a large collet with tiny shank, so not super surprised it’s not widely available. I spent a couple hours today stress testing the machine, so far so good! I have ran a 3/8" insert mill in 6061 in a facing operation; 12,000RPM, .050" step over, 24IPM, no more than .010" DOC. Definitely the loudest the machine has been but overall super successful; machine wants to chomp.
After that result, full of (over)confidence, I tried an 1/8" drill in 6061…which stalled out the spindle after a few revs and alarmed out the machine. It seemed like it was close to working; it’s possible after I upgrade the power supply from stock, drilling will be in the cards. Realistically, helical boring is the right way to make holes and pockets on a machine like this.
Finally, after all this messing around need to do an actual project for the wife…while stress testing the machine. Here’s a video:
I am pondering tonight; I assumed running larger diameter, non-single but odd flute number tooling would reduce the noise level but it has not. Noise is my limiting factor on material removal rates now. It is also not a resonance as far as I can tell.
Somewhere on the list of my next dozen Nomad projects is figure out where all the noise is coming from, fix it and then send feedrates through the roof!
Thanks! I’ve been turnin’ and burnin’ parts for an old SO3 rebuild, and haven’t gotten the chance to explore yet.
Quick update! My life got crazy for a bit, just getting back into using my Nomad this past weekend!
Noise levels remain the limiting factor to using the additional power. Running at hooligan feeds and speeds, I’m measuring 90-95Db, per wikipedia is louder than a lawn mower but not as loud as a tractor with noise peaks in the 400Hz range. Really need hearing protection as is to use the extra power.
I’ve redesigned the actual spindle to use a larger diameter ER11 collet shaft (+56% stiffer), larger diameter, angular contact bearings and a threaded mechanical preload. Parts are completing fabrication this weekend and I hope to have some test results within about a week. I am hopeful this will reduce the noise although I do expect there are factors contributing here.
I realize the subject of this thread is somewhat misleading, this started as a spindle motor modification but like any good project I’ve now totally gone off the rails. New spindle arrived and I finally got it assembled late last night after some spur of the moment design changes to add a port to the side for through spindle air blast for chip management and cooling.
I have really been liking the power upgrade to the machine but cutting harder with the Nomad means more noise. Disclaimer: I genuinely think the Nomad is an awesome machine, the fact I can accurately cut aluminum on my desktop is hilarious. I just want to see how far I can push this platform since the machine is built like a tank.
More tests to come!
Continuing to be a nerd and replying to myself. Am pretty astounded with the results so far; have been cutting aluminum at .040" step over, .040" DOC, 12,000RPM and 40 inches per minutes with the 102-Z 1/8" 2 flute end mill using the motor and spindle cartridge upgrade. (I think I can finally call it an upgrade now.) Machine can seriously haul for a desktop mill and just sounds mean, night and day difference. Freaking love this machine. Spindle has not stalled out yet and the chip load is getting pretty aggressive for an 1/8" end mill so instead of pushing it faster, I’ll swap in 3/16" and 1/4" tooling this week when I have more time to play.
Hi Tony et.al.-
I hope that you’re all safe and using the current ‘lockdown’, like I’m doing, in the garage with your Nomad.
I like your mod a lot and would like to implement it - anything that improves precision CNC of aluminium milling is of interest to me.
(Winston Moy -with his great YouTube postings - helped me upgrade my G-Code from MeshCAM to Fusion360 (adaptive clearing).)
If your mod can further improve the performance and precision of the Nomad 883 milling in aluminium that would be fantastic.
I’d like to know if you think your 125W Spindle Modification can be applied to the ‘Classic’ first generation Nomad 883, and if so do you think that there it is applicable to the original belt driven mill.
Thanks much.
-Peter
Been tinkering with my own motor upgrade… the spindle upgrade is something I will have to do as well. Are you maintaining the same precision as before the upgrades?
@ScoobyDoo Surface finishes are way better with the new spindle, especially facing. I have not checked (haven’t had a reason to) see how this has impacted machines ability to hold size but a more rigid spindle cartridge will only help on that front!
Wait, this seems to have goen pretty unnoticed: you managed to get an insert mill into the Nomad!?
Have you tried the insert mill with the new spindle?
How loud does the machine get when you’re running it that hard? Is it still at ~75dB like in your earlier test (9,600RPM, 12.8 in/min, .040 step over, and a DOC that ramped to .040")?
Ha, yes! I ran a 2 flute 3/8" diameter insert mill on my Nomad in aluminum and it was also super noisy but didn’t stall. Based on those results, I suspected the common theory; that the small diameter tooling was vibrating was probably not correct. Also, even I know when to draw the line, 3/8" tooling doesn’t make a ton of sense on a desktop machine. 
I went back to ER11 collet for new machine for a few design reasons so I can no longer fit 3/8" tooling; honestly, without a tool changer, running that large of tools would just be inconvenient for me.
When running 40" a minute, .040" DOC, .040" stepover at 12krpm, it was 89 dB, so definitely getting loud again but this is approx 5x the material removal rates (MRR) recommended for the stock machine which is a huge time saver. I’m really happy with current capability of the machine so this is totally sufficient for now. I will likely run at half those rates in aluminum going forward, more than twice the stock machine but you can’t hear it in the next room.
Fair enough on the 3/8" tooling.
That spindle upgrade sounds really interesting. Do you think you’ll publish the designs or sell them or something?
I’m interested in it because of the noise reduction but I also have an enclosure for my Nomad already so maybe I could get it to stay quiet even with the higher material removal rates.
Also, have you tried going for a higher axial DOC with reduced radial DOC and higher feed rate (HSM-like)? I’m curious if the mods you’ve made can make it go deeper. It’d be great to be able to use the entire tool.
Actually…yes to potentially selling them. A small handful of people have asked about them on Instagram so I am currently working on a ‘production design’ that removes requirement for internal spindle forced air blast to keep the bearings clean and goes to a sealed angular contact bearing design. Keeping this at a reasonable consumer price point is really hard due to sealed bearing costs in this form factor but I’m working on it over lots of coffee this morning and making good progress.
I do think the spindle cartridge has been the best upgrade I have done to the machine; the extra power was pointless at first due to noise. Now with the new cartridge, 125 watt spindle motor is awesome!
Nice! Make sure to keep the thread up to date. I’m sure there are some lurkers who are interested as well.
No clue how feasible it is but internally cooled cutting tools are pretty common around here and it’d be cool to pump air through the tool, for cooling but also chip evacuation.
Haha, I also thought about that! Thru coolant/air carbide tooling, even at these small diameters will sit you back $200-250 an endmill, at least the Sandvik ones.
To do that, you’d seal the cartridge which is the new design but you’d also need to cross drill and have long axial centerline drill the spindle shaft, which is tricky because it’s hardened steel and would sacrifice some stiffness. (Maybe EDM instead?) After that, you’d have to replace all your collets to more expensive sealed ones or not use thru coolant tools and use a jet collet instead. You’d probably spend $400 to get restricted air flow vs just standard air blast.
That said, definitely possible.
Really!? Here I can get a 3mm diameter, 4-flute, ZrN-coated, solid-carbide endmill with internal cooling for ~$60 and that’s from the local, more expensive seller. If I order from Germany they’re about $48.
That’s a lot more than I’m willing to pay for it unfortunately.
Sounds like I need to stop paying aerospace prices… 
Yeah, add 5x the cost just so you can get a a Certificate of Conformity, that’s the aerospace industry! Waay back in time, like early 90’s I worked for a small aircraft repair station. I remember going to pick up hardware from the local distributor and thinking,”Holy moly, $80 for 3 bolts?!”. Nothing special about the bolts, just standard NAS hardware, but the paperwork was the clincher. I’m not sure how that relates to tooling, but I’m sure there’s a premium there too. Funny🤪
I don’t own a Nomad, but your upgrade makes me want one, very cool indeed!
Dan
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