[jcarpenter2]

This is for steven6282 as it seems there is a bit of confusion, if there isnt, just ignore this message.
Houses in the US are wired with 220 single phase.
Outlets in your house are 110 single phase.
Large appliances in your home (i.e. - dryer) use 220 single phase.
110 is a single leg (generally black) of 110 voltage, along with a neutral (white) and a ground (green).
220 is two legs (generally black and red) of 110 voltage along with a neutral (white) and a ground (green) (total of 4 wires)(look at your dryer plug - it should be four pronged)
old school 220 used two legs of 110 and a ground (some old dryer outlets have three prongs).
220 three phase (three legs of 110 voltage - red, black, blue, but the colors may very) is normally ran for large commercial types of equipment to meet specific applications.
A VFD creates three phase electricity for smaller applications that require variable frequencies (like a spindle).
A VFD that has an input of 110 single phase can be used for a spindle that is under 1hp, anything over that and it is doubtful you will get the full max capabilities of the spindles.
A VFD that has an input of 220 single phase is a much better option as it will produce more amperage in order to drive a larger spindle.
The VFDs i have seen only require three wire inputs, two 110 legs and one ground (the neutral is not used). The VFD will generate three legs of 110 voltage and of course dont forget the ground (total of 4 wires). Also, most VFDs will accept three phase, but that does not affect most users as we generally work with single phase.

Hopefully this is a bit helpful.

[Eldon_Joh]

for circuit board milling i would go with an er-11 spindle as they are likely to have smaller bearings, and the smaller bearings will run with less friction at high rpms.

Some of the spindles mentioned in this thread are cheap enough I would consider running them faster than 24K rpm, but it may be difficult to find a vfd that will deliver more than 400hz.

The 12,000 rpm spindles are likely 4 pole motors, the rpm limit is really a frequency limit (and possibly bearing limitations) not a voltage limit. a 600hz inverter would deliver 18,000 rpm, or 36,000 rpm on a 2 pole motor


with regard to steppers, they are magnetic springs, they lag behind the commanded position at an angle that is proportional to torque (when below half the maximum torque) much longer explanation here: Stepper Motor Accuracy | Applied Motion

[steven6282]

Nevermind about this, found my answer I'm pretty sure. Found one website that specifies the diameter of ER11 as like .7" and ER16 at around 1.3". So an ER16 nut shouldn't fit on an ER11 spindle. Although, I don't know why a little adapter could not be made (I know it could potentially cause more runout but the main appeal to a bigger collet is for rough passes where runout isn't as big of an impact).



Question about the ER11 vs ER16. I saw this today while looking at stuff:

ER16A Collet 0 8KW 1 5KW 2 2KW 3KW 4KW Water Cooled Air Cooled CNC Spindle Motor | eBay

Does anyone know if that would fit on a spindle that comes with an ER11? I can't seem to find anywhere with specific specifications on these spindles and their collets. But ER11 and ER16 seem really similar, they both support the same smallest size, ER16 just supports up to 3mm larger.

The only advantage I really see to having an ER11 is if it is smaller diameter than ER16, it would be easier to make deep cuts.

[ger21]

No, they're not interchangeable. The bigger the collet, the larger tools it's capable of holding.

[jcarpenter2]

I would dare say not they wont fit. Here is a pic that shows more detailed information.

[jcarpenter2]

I am curious though. I have a 1.5kw water cooled spindle with an er11 collet. Is it possible to replace the shank in order to accept the er16 collet or will I need to replace the whole spindle if I want to upgrade?

[ger21]

No, the spindle is one piece, with the taper ground into the end. You can't just replace the collet.

[mactec54]

Ok, I'm just getting more confused on VFDs and their voltages lol. There is so much differing information out there. I just had a spindle seller tell me I could run a 220v spindle on a 110v VFD with no problems.... I did some more research and found some other forums that suggest the same thing. Some even say that 110v VFDs are really outputting 220v 3 phase power anyway, they are just serving as a step up converter. In another place I read that there are a very few true 110v spindles. Seems to me all this makes for a huge mess lol. If there really are very few 110v spindles and some 110v VFDs output 220v, it's a recipe for disaster! Plug a 110v spindle into a 220v output VFD and the magic smoke would probably come out in short order haha.

It seems to be difficult to find some clear, reliable, concurrent information on this stuff. I don't have hundreds of dollars to throw around trying out various stuff for myself unfortunately. My newest concern is the collet size. The majority of the 1.5kw spindles come with ER11 collets. I have seen a few that come with ER16. I don't know if I will really need ER16 or not, but I need to figure it out before I invest nearly 400 dollars on a spindle setup. I've seen some places say that you can replace the collet holder on the spindle to upgrade it to an ER16, but others say the holders are not replaceable on the spindles. I don't know which of these are true. It would be nice to have the option though... The 65mm diameter 1.5kw I pointed out earlier is ER11, there is a nearly identical model that is 80mm diameter with an ER16 from the same seller.

Yes don't mess with the 110v rated spindles, this is a not a normal built spindle

Nothing confusing about it, a VFD built to run on 120v input has a dubbler built into, ( step up transformer ) the VFD, the power in the VFD then turns into 220v and has a 220v output for the spindle, you will draw twice the Amps on your 120v circuit, so make sure your 120v circuit is up to the task

No you can not upgrade the collet size if it is ER11 then that is what you have, If you have a ER16 you could have the same range of collets sizes that the ER11 uses, and larger sizes up to it's max

[mactec54]

I am curious though. I have a 1.5kw water cooled spindle with an er11 collet. Is it possible to replace the shank in order to accept the er16 collet or will I need to replace the whole spindle if I want to upgrade?

The shank/shaft runs right through the motor, the Bearings run on this shaft, and can not be changed, if you need a ER16 then you will have to buy a spindle for that size

[steven6282]

Can anyone give me any real use examples of ER11 max size vs ER16 max size? Like I said, I know bigger ER16 bits would make roughing faster since you can do fewer rough passes, but I don't know how much faster it would really be. Are there other advantages to ER16 that I'm not considering? Like does it provide better support when cutting harder materials or anything?

I'm just having trouble deciding because everything has it's own set of advantages and disadvantages lol.

.8kw 110v would be easiest for set up in my current place, but it's ridiculous to pay the same amount or more for a .8kw spindle as a 1.5kw.
.8kw 220v would give me an upgrade path if I got say a 2.2kw VFD, but again paying just as much for a .8kw as for a 1.5kw, and has the inconvenience of having to run a 220v extension cord from a pre-existing outlet.
1.5kw 110v easy to set up, but potential power supply issues with 15 amp limitations on standard 110v lines.
1.5kw 220v extension cord annoyance again, but if I did go this route I'd have to decide between ER11 and ER16. ER16 is slightly more expensive (about 20 dollars more).

Right now I'm leaning toward the 1.5kw 220v model just because it would cost the same as a .8kw setup and give me the possibility of a future upgrade to a 2.2kw spindle (I'd get a 2.2kw VFD for it initially). The convenience of being able to just plug a 110v .8kw unit in anywhere is appealing though. However with that route if I wanted to upgrade that later on I'd have to buy another VFD as well since no US home is going to be wired to handle the amp load of a 2.2kw on 110v....

Just can't make up my mind on it, so that is why I'm trying to see if there is a good reason to go for the ER16. It's only available on the 1.5kw units making my choice a little easier :P

[jcarpenter2]

I think you need to determine what you plan on cutting (I saw you mentioned pcb's) which obviously doesn't take much of a spindle. You also mentioned some aluminum which you would want something beefier like a 1.5. Also what size bed are you building? A 1.5 can be gotten in the 65mm diameter whereas a 2.2 is going to be an 80mm diameter, I say this because it takes up some of your space on the bed if you go with a larger spindle. I would think for pcb's and aluminum once in a blue moon you could get by with a .8k with a 110v, however, if your intent is to cut aluminum more often then definitely move up to the 1.5 with 220v. If you plan on having a large bed, then a larger spindle makes sense because your projects will be much larger and a small spindle at slow speeds will take forever.

[steven6282]

My millable area will be around 30" x 30".. probably a little over actually but I'm being conservative. I don't know if that is considered a large bed or not. But it's large enough to do the projects I want to do, the largest of which is guitar related stuff. Right now I don't know how often I'll end up doing aluminum. It will only be occasionally initially but as I play with the machine and figure out things to do with it, it could potentially increase.

[ger21]

I would say that at some point you'll wish that you had an ER20 collet,so that you can use 1/2" tooling.

[hanermo]

Agree with ger21 on everything.

Re: precision.
Your real resolution will be about 1/4 of the typical 10-microstep resolution you have.

If you have 10 microsteps; thus at 0.005 mm, your actual resolution will be about 0.02 mm.

Everything flexes and has slop- more so on alu stuff,
and lightweight stuff,
and undersized screws,
and undersized rails,
and floppy frames,
and sloppy screw mounts (all of them imo, imee).

If you want 0.01 mm resolution and repeatability, this is easy to achieve.
Basically;
Go 1 size up in screws, mounts, frames, rails, double machine mass and rigidity.

If you want 0.005 mm resolution and repeatability, this is easy to achieve.
Basically;
Go 1 size up in screws, mounts, frames, rails, double machine mass and rigidity.

If you want 0.001 mm resolution and repeatability, this is still easy to achieve.
Basically;
Go 1 size up in screws, mounts, frames, rails, double machine mass and rigidity.
Use rigid screw mounts, that you build, or spend a lot of money on.
Use servos.

In all cases, the 4:1 rule applies.
So, to get 0.001 mm resolution, you need about 0.00025 mm steps size, with servos.

Example:
I use 0.2 microns, or 0.0002 mm step size,
with industrial ac brushless servos,
and 32 mm thick screws (and sufficiently rigid rails (35 mm)
and rigid structures (20-40 mm thick steel plates).

I get 1 micron or less incremental movement, ie resolution.

Add:
Steppers CAN be used for 1 micron resolution.
But they will be quite slow in movement, although very accurate.

Steppers have small dynamic range.
This means you can either get accuracy, power, or speed, but pick only 2.
Acceleration is usually good enough with good drivers.

Add:
I would aim for 0.0025 mm microstep size for approx 0.01 mm real world resolution.
The one thing you *dont* need in PCB stuff is speed.

[kmin]

Can anyone give me any real use examples of ER11 max size vs ER16 max size? Like I said, I know bigger ER16 bits would make roughing faster since you can do fewer rough passes, but I don't know how much faster it would really be. Are there other advantages to ER16 that I'm not considering? Like does it provide better support when cutting harder materials or anything?

I'm just having trouble deciding because everything has it's own set of advantages and disadvantages lol.

.8kw 110v would be easiest for set up in my current place, but it's ridiculous to pay the same amount or more for a .8kw spindle as a 1.5kw.
.8kw 220v would give me an upgrade path if I got say a 2.2kw VFD, but again paying just as much for a .8kw as for a 1.5kw, and has the inconvenience of having to run a 220v extension cord from a pre-existing outlet.
1.5kw 110v easy to set up, but potential power supply issues with 15 amp limitations on standard 110v lines.
1.5kw 220v extension cord annoyance again, but if I did go this route I'd have to decide between ER11 and ER16. ER16 is slightly more expensive (about 20 dollars more).

Right now I'm leaning toward the 1.5kw 220v model just because it would cost the same as a .8kw setup and give me the possibility of a future upgrade to a 2.2kw spindle (I'd get a 2.2kw VFD for it initially). The convenience of being able to just plug a 110v .8kw unit in anywhere is appealing though. However with that route if I wanted to upgrade that later on I'd have to buy another VFD as well since no US home is going to be wired to handle the amp load of a 2.2kw on 110v....

Just can't make up my mind on it, so that is why I'm trying to see if there is a good reason to go for the ER16. It's only available on the 1.5kw units making my choice a little easier :P

There is a very good reason to choose ER16: If you are looking for cutting bits from Ebay for example, you have much more availability for ER16. Many times I lost a "good deal" or "hard to find" cutter because the cutter was slightly bigger that could be fitted to my ER11 collet. You can save that 20$ difference in one bit easily.