Another Newbie Question - Spindles

2424 Views 27 Replies 7 Participants Last post by MikeSibley, Aug 16, 2020

MikeSibley

Discussion Starter · Aug 13, 2020

First, I want to thank everyone. You have been very kind and generous with your knowledge. So, from John and David's advice I'm trying to build my second machine first and am relying on information that y'all give me to avoid the mistakes or issues that you have had.

I've studied sizes, brands, China vs US, software, etc.

Looking for a little update. Ive decided on a 2.2 KW and VFD spindle when I get my machine. Beyond the air-cooled or water-cooled option, I've noticed a lot of discrepancy in spindles and their uses. If you simply do a Goober search, of course Amazon comes up with about the first 50 items. On their pages, all seem to be Chinese (wording is not what US English is in the description) and some say that they will not run less than some particular speed, others say good for engraving, not milling. I believe that buying on Amazon just might be a crap shoot even they all say 220 Volt, 2.2 KW.

But, when you look at the machine suppliers' pages, the cost of a spindle is 5-10 times the cost of those on Amazon. How does one decide which Chinese import at either site is worthy?

I noticed that John uses air cooled, David's build showed liquid cooled. Is that a differential in the climate between Michigan and Louisiana? I'm near the Gulf Coast where the humidity and temperature are usually about the same, 95 degrees and 95% humidity! My workshop is in my garage and I have an air conditioner, but it is still hot and humid in the Spring through Fall. By the way, we only have two seasons down here, Tolerable and Incredibly Intolerable! Our Spring and Fall seasons are usually about 45 minutes long each.

Back on the water versus air cooled. From my reading, people say that air cooled spindles have fans and it blows more dust around the shop. Also, some say liquid cooled are quieter, but I can certainly see if something went wrong with a liquid cooled machine, wow, what a mess especially if using antifreeze. Also liquid cooled machines might have more things that can break. And with any machine, if you use it, it will break.

Everybody has a budget so before diving off into mine, I want to make the best decisions that I can with the advice of you good folks who have been there and done that.

I get verbose sometimes, but I'm at a break from my work and thought I would reach out.

Thank you to everyone! You have been so helpful. I appreciate it!

Mike

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ger21

· #2 · Aug 14, 2020

Here's the reply I posted at CNC Zone.

You'll find that most spindles are either 300Hz or 400Hz, with 300Hz being 18,000 rpm spindles, and 400Hz being 24,000 rpm spindles. These spindles are 3 phase motors, with the 3 phase voltage at high frequencies generated by the VFD.

Sticking with 2.2Kw chinese spindles, you can break them down into round, or square bodied.

Starting with the round bodied, there are two varieties, water cooled or air cooled. Both are about $200 for the spindle only.

All of these cheap spindles have limited power at lower rpm. So most should not be run below 6000-8000 rpm. The air cooled spindles have small, ineffiecient fans, so they can get hotter at low speeds than water cooled, and can not be run at low speeds as long as a water cooled. But it depends on the loads it's seeing.

My preference is the air cooled, which eliminates the hassles of water cooling.

At $200 (or less), these should be considered disposable. They won't last forever, but many people get 5 or more years out of them. And while most claim to have a 1 year warranty, don't count on it.
Because these are so cheap, quality control can be all over the map.

While I've never seen one in person, the square Chinese spindles are basically round spindles in a square extrusion. These are all air cooled, and have a larger fan than the round air cooled spindles. The larger fan makes them louder, but they'll also run cooler. These tend to cost a bit more, usually in the $300-$400 range.

The only "expensive" Chinese spindles I'm aware of are from UGRA CNC.
These spindles have much better quality control, are individually tested, and have a warranty and support you can count on. For some, that's worth the additional cost. For others, it's not.
I believe the spindle that AVID CNC sells is the same as the spindles from UGRA CNC.

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MikeSibley

Discussion Starter · #3 · Aug 14, 2020

Wow, thanks for the primer on spindles. I am doing my best to learn, so that clears up a lot. I just couldn't understand the 300-400 dollar spindles (with VFD) versus one that costs $1,000+. But as you say, they are almost disposable at the price point, so the question begs as to whether a little more quality control is worth over double the cost. I want to purchase good, but not overpay for it.

This will be my first machine, so I'm trying to do as much research as I can.

Gerry, thank you very much!

difalkner

· #4 · Aug 14, 2020

If you want to splurge a little, Mike, get a Hitachi VFD. They produce far less electrical noise than the Huanyang and have much larger internal components. Plus, you can call Drives Warehouse in Dallas and talk to the guys who are very knowledgeable on setting these up, great support (that's also where I bough ours).

There are a lot of folks who have used the Huanyang for years without issues, though. I just preferred to get the better VFD for ours.

David

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RainMan 2.0

· #5 · Aug 14, 2020

difalkner said:
If you want to splurge a little, Mike, get a Hitachi VFD. They produce far less electrical noise than the Huanyang and have much larger internal components. Plus, you can call Drives Warehouse in Dallas and talk to the guys who are very knowledgeable on setting these up, great support (that's also where I bough ours).

There are a lot of folks who have used the Huanyang for years without issues, though. I just preferred to get the better VFD for ours.

David

David , from memory you are liquid cooled I believe . Don’t you have an issue with a bearing in your Chinese spindle acting up ?
I wonder how much of a challenge they are to replace.

difalkner

· #6 · Aug 14, 2020

RainMan 2.0 said:
David , from memory you are liquid cooled I believe . Don’t you have an issue with a bearing in your Chinese spindle acting up ?
I wonder how much of a challenge they are to replace.

Yes, it's a water cooled spindle, Rick. There is a bearing that occasionally makes a little noise and has for a year. So I bought a second spindle thinking that I would make the change and then repair the first one with new bearings. However, since buying the second spindle the bearing noise went into hiding and only rears its ugly head once in a while.

I've read about changing bearings and have watched a couple of videos but I'll dive into that a little deeper when it's actually time to replace the bearings.

David

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MikeSibley

Discussion Starter · #7 · Aug 14, 2020

difalkner said:
If you want to splurge a little, Mike, get a Hitachi VFD. They produce far less electrical noise than the Huanyang and have much larger internal components. Plus, you can call Drives Warehouse in Dallas and talk to the guys who are very knowledgeable on setting these up, great support (that's also where I bough ours).

There are a lot of folks who have used the Huanyang for years without issues, though. I just preferred to get the better VFD for ours.

David

Okay, now David is introducing me to new variables! Since you have been in a career involving this type of electrical components previously, I'm interested. The VFD drives the spindle by basically converting single phase power to three phase (is that correct?) so the better quality of VFD could reduce electrical noise which I am assuming creates a more stable, smooth running motor in the spindle. From the electromagnetic properties of a motor, three phase is more true than using other single phase units. Now I am getting outside my expertise. Induction, magnetic fields, current and waveforms are stretching into the boundary of my knowledge base.

Does the electrical noise affect the RPM of the motor only or does it potentially transfer into the drive systems, ie: stepper motors or whatever control systems for the x,y and z axis placement?

Now I've got an idea, you guys that have accumulated all this knowledge should band together and write a book, even in PDF format, so folks like me can learn! You could sell it to us newbies and we'd not pester you guys to death!

I like to know the ins and outs and what makes a gizmo work versus just knowing that I can connect two pieces of equipment together and they will work!

As a kid, way before they had internet and google, I'd take things apart to find out how they worked and the put them back together. I admit that I destroyed a few things, but I learned! Sometimes I'd get in real trouble over destroying Mom's kitchen gizmo.

Curious minds want to know!

THANKS! I really appreciate it.:smile:

PS - I put my Avitar to match up with all my questions!

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difalkner

· #8 · Aug 14, 2020 (Edited)

MikeSibley said:
Does the electrical noise affect the RPM of the motor only or does it potentially transfer into the drive systems, ie: stepper motors or whatever control systems for the x,y and z axis placement?

Now I've got an idea, you guys that have accumulated all this knowledge should band together and write a book, even in PDF format, so folks like me can learn! You could sell it to us newbies and we'd not pester you guys to death!

Electrical noise doesn't directly affect the spindle rpm but can interfere with anything electrical in your enclosure and system. It can cause lost steps, weird hiccups in operation that just pop up and go away, or can even cause consistent issues with steppers and proximity sensors.

One of our members @Gaffboat wrote a book on CNC and I think it's available on Amazon.

David

Edit - here's the book on Amazon - Guide to CNC Sign Making

MEBCWD

· #9 · Aug 14, 2020

Looks like Gerry covered everything well.

The only thing I would say is the higher end spindles do have better quality bearings and most will be backed by the company making them.

The problem with a lot of the Chinese spindles is they are knock offs of other Chinese spindles so they are made with even cheaper components. If you do go the Chinese route, check the reviews to make sure they won't be your next headache.

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ger21

· #10 · Aug 14, 2020

Does the electrical noise affect the RPM of the motor only or does it potentially transfer into the drive systems, ie: stepper motors or whatever control systems for the x,y and z axis placement?

Electrical noise will have zero affect on RPM, but can affect many other electronic components.

All VFD's can generate a lot of electrical noise, so using proper shielded wire and proper grounding methods is very important.

Fwiw, in the hobby CNC world, the ratio of people using Chinese Huanyang VFD's to high end VFD's like the Hitachi is probably 100:1. Mainly, because you can buy 3 Huanyang VFD's for the price of 1 Hitachi.

A Hitachi is certainly more robust, and is likely to be much less prone to failure from user error, which is what kills most Chinese VFD's.

My Huanyang came with a faulty output that was the default output for starting and stopping the spindle. But there are 5 outputs, and 99% of people only use 1 of them, so it only took a minute to move the wire and change two settings to get it working.

If you do buy Chinese, be sure to get a Genuine Huanyang VFD. There are a fair amount of knockoff Huanyang spindles that are lower quality.

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MikeSibley

Discussion Starter · #11 · Aug 14, 2020

I don't know what I'd do without you folks advice, I'd probably have some knockoff of a knockoff running backwards, continuing out the shop door into my wife's car or something! I'm one who loves to know the little details and your help is immeasurable!

让买家特别提防与中国人打交道！

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difalkner

· #12 · Aug 14, 2020

MikeSibley said:
让买家特别提防与中国人打交道！

LOL! Especially if seeds some with it! :grin:

David

MikeSibley

Discussion Starter · #13 · Aug 14, 2020

I thought a little Chinese would be fun!

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MikeSibley

Discussion Starter · #14 · Aug 14, 2020

So, what is the difference between a variable torque and constant torque VFD?? Is one more suited to CNC versus the other? I noticed that constant torque is more expensive.

ger21

· #15 · Aug 14, 2020

You won't be able to get constant torque from a spindle. You need a special motor for that.
So you don't need a constant torque VFD.
You just need one that can output 400Hz.

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MikeSibley

Discussion Starter · #16 · Aug 14, 2020

Thank you Gerry. I know I am a pest, but this is the only way I can learn details, maybe I can repay the favor sometime.

MikeSibley

Discussion Starter · #17 · Aug 15, 2020 (Edited)

Okay folks, here's my plan.

First, I would sincerely like to thank the members of this forum, especially John, David, Gerry and all the others who have helped me and provided information to set my thought process straight. My first thought was to get something like an Axiom that was stronger than a standard hobby machine, but after getting all the information I have changed and am ordering the following machine on Monday.

Avid Pro 4x4 kit. It can be upgraded later if I need larger.
Avid (80/20) stand for the machine.
Avid NEMA 34 Control System
Avid Spindle and VFD (I can upgrade to Hitachi later if the electrical noise is an issue)
Spindle mount
Mach 4
Touchplate
Limit Switches

Software: Aspire.

Please review the list above and if you have a strong opinion otherwise, please let me know either by post or PM, hopefully before Monday.

An issue that I see is that there is no dust shoe for the machine. I have seen some of you have a dust shoe, so I'm assuming that you have purchased one from another vendor and modified it? UPDATE: I found the dust shoe on the site, had to look for it.

I have a dedicated 80 amp 240 subpanel with a 30 amp single phase 240 and two 120 20 amp circuits. Is there likelihood that noise from the 240 affect the 120 circuits? I can run a separate 120, but it's all coming from the same source, the sub-panel.

Did you guys make your own spoil board for the machine using t-tracks and MDF or some other method? I'm thinking I need to buy some t-tracks for clamps, etc. Don't know about a vacuum hold down, that might have to wait unless the cost is comparable to purchasing all those t-tracks.

I need to do this right the first time, as my Chief Financial Officer (my wife) is saying ok get it, but do it right the first time. She doesn't want me to keep "having" to get more stuff. I know about bits, but I consider that an expendable commodity even though they are pricey. I'll get a few at first until I get the hang of using the machine and add accordingly.

Again, thank you VERY much for your help.

Mike

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ger21

· #18 · Aug 15, 2020

A lot of people buy these dust shoes.
https://www.kentcnc.net/nc

If you can afford, it, nothing wrong with buying everything from Avid. Everything is deigned top work together, and everything will be supported by them.

You shouldn't have any noise issues. Avid has sold thousands of these systems, so they should have it figured out. And really, the only noise issues I've ever heard about is noise triggering limit switches.
As I mentioned before, proper wiring and grounding should eliminate noise issues.

How you do your spoilboard is a matter of personal preference. Some people just screw their parts down to the spoilboard. Some use T tracks and clamps. I use T nuts and cam clamps against a fence, but will have some type of vacuum on my next machine.
No one method works great for every application, so depending on the work you're doing, you may need to use different hold down methods.
Vacuum excels at sheet goods, but a good vacuum system can be pricey, loud, and generates a lot of heat.

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MikeSibley

Discussion Starter · #19 · Aug 15, 2020

Thank you sir!

honesttjohn

· #20 · Aug 15, 2020

You will not be disappointed buying the kit from Avid. Just download and print the manual (skip the Nema 23 part). The instructions are quite good, with all parts illustrated. Everything does fit and work when done. Avid's support is better than most and, of course, you have a bonus in having us in your corner too. I don't know how much different Mach 4 is from Mach 3.

For the bed I bought 3/4" T-track from 80/20 and use clamps from Rockler. I have every intention of putting 1" material between the tracks, making a grid and having a "semi" permanent bed. Right now I just use 1/8 whatever on the T-track and clamp the whole thing down. If I ever get the bed the way I want it I'll still use the 1/8" (or whatever else is available) and save the bed. There's plenty of z height and spoilboard backing stuff is cheap.

Congrats!!! But make sure the CFO understands there may some "accessories" to acquire too.

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