My build and questions

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22 May 2014 00:10 #47173 by andypugh
Replied by andypugh on topic My build and questions

When I go to load linuxcnc and as the splash screen is loading the spindle will spin up for about a second and then stop.


This is probably due to the startup state of whatever pin the motor is controlled by. Unfortunately this might be out of the control of LinuxCNC.

You might want to check if any other pins have a better behaviour during startup.

The correct and safest solution is a "charge pump" which disables everything until there is an oscillating signal on a pin. This means that nothing can be energised until the software is completely in control, and will shut things down if the computer freezes for any reason.

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22 May 2014 05:24 #47179 by yoshimitsuspeed
So back to the drawing board. I was wondering how my RC motor would hold up. I have read of a lot of people using these in lighter duty applications.
I hoped since I had bigger bearings supporting above and below the motor that the motor bearings would have very little load but it was too much.

One thing I liked about the RC motors is that I had a huge RPM range. I don't know for sure but I am guessing 1000 RPM to about 30000 RPM.

Now I need to figure out what is next. Had this motor lasted a few hundred hours I would probably consider staying with a similar design for now but I don't think it's worth wasting my time.

Of course I am on a very tight budget but I also don't want to need to upgrade again in the near future.
This motor with the 300W 36v inverter produced enough power that I could live with it but more would definitely be better.
I am sort of torn between something cheaper like this.
www.ebay.com/itm/CNC-400W-Brushless-Spin...&hash=item46205ca006

And something a good bit more expensive like
www.ebay.com/itm/CNC-2-2KW-Spindle-Motor...&hash=item41803918c4


I don't think my little CNC really needs more than about 1.5 KW but the main seller is the ER20 collet and the much greaer tool availability it gets me.

Do you guys know much about either of these options? Is there anything I am missing that either setup needs on top of those kits?
Any idea on how both would interact with linuxcnc?

One of the biggest concerns for me is the RPM limitation. I would think the smaller spindle would spin faster but most I have seen are limited to about 12k RPM.
On the other hand the big spindle only goes down to 8000 RPM and only up to 24000.

I hope to machine a lot of aluminum as well as some smaller steel projects with this machine.
Should I just get it over with and step up to the 2.2kw setup or should I be happy with the .4kw setup?
I would also rather stay all 110v but I have a 220 outlet near the machine so that wouldn't be the end of the world.

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22 May 2014 07:06 #47180 by andypugh
Replied by andypugh on topic My build and questions

I don't think my little CNC really needs more than about 1.5 KW but the main seller is the ER20 collet and the much greaer tool availability it gets me.


ER11 will only hold tools up to 7mm / 5/16"
ER20 goes up to 13mm / 13/16"

zero-divide.net/?page=fswizard
Seems to suggest that you would use 10,000 rpm with a 13mm carbide tool in aluminium.

Way outside my experience, my mill tops out at 1000rpm and has one gear that tops-out at 47rpm.

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22 May 2014 10:46 #47185 by yoshimitsuspeed
Thanks for the input. For the RPM and the bigger spindle I went with the 2.2 KW with the VFD.
I hope buying the cheap Chinese version doesn't come back to bite me. I read some mixed reviews on the VFDs in particular.
This week I will be working on cleaning up the wiring and modules, making some sort of box to keep all the electronics clean and cool and reinforcing some parts on the machine that I only tacked together.

I killed the motor trying to cut a 1/2" thick piece of aluminum. I was only taking 1mm cuts. The spindle had a little chatter but I was very impressed how easily the machine pushed through the material. I think with a decent spindle this machine should meet the vast majority of my needs.

I mounted my dial gauge to the spindle and after making a couple adjustments to the gantry rails got a flatness and parallel of +- .1mm across the whole table. Pretty good for a hand built machine I'd say. Good enough for me for now.

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04 Jun 2014 13:02 #47669 by yoshimitsuspeed
I will be setting up my HY 2.2 KW spindle and VFD tomorrow.
I got it hooked up to 220 already and it powers up.
I finally after a good bit of searching was able to confirm how the spindle should be wired.
I am going to go through the setup part of the manual very carefully tomorrow but I am wondering if anyone has any input, warnings or suggestions for me.
I am a little worried about letting the magic smoke out of something.

I am also wondering what you guys use to calculate feeds and speeds for mystery cutters?

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04 Jun 2014 18:39 #47673 by andypugh
Replied by andypugh on topic My build and questions

I am going to go through the setup part of the manual very carefully tomorrow but I am wondering if anyone has any input, warnings or suggestions for me.
I am a little worried about letting the magic smoke out of something.

How are you connecting the VFD to LinuxCNC?

I am also wondering what you guys use to calculate feeds and speeds for mystery cutters?

I have found the fswizard web site that I linked to earlier to be useful.

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05 Jun 2014 00:10 #47682 by yoshimitsuspeed
You know, I just kinda assumed it would be no problem but now you have me worried lol.

I have the C-10 breakout board along with this kit.
www.automationtechnologiesinc.com/produc...6v9-7a425oz-inkl4030

I assume I can wire one of the extra outputs to run it right?

I would assume I can run it off of port 14, 16 or 17.
www.kelinginc.net/c10.pdf

I'll need to go out to the shop to look up at what the VFD needs to see.

If anyone has any more input it would be greatly appreciated.


I saw fswizard when you posted it and was wondering. I only took a quick look at it but assumed I needed the manufacturers info to calculate.
I guess it has it's own parameters that it starts at but gives you the ability to change them if you want is that right?

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05 Jun 2014 01:37 #47684 by andypugh
Replied by andypugh on topic My build and questions

You know, I just kinda assumed it would be no problem but now you have me worried lol.
I have the C-10 breakout board


The VFD probably expects to see a potentiometer or a variable voltage as the speed input. The Parallel port can only manage digital outputs.

If the VFD manual says that it is happy with PWM then you should be OK, but otherwise you will need some sort of circuit to convert PWM to analogue voltage.
For example, this (horribly expensive) breakout board has a 0-10V output www.automationtechnologiesinc.com/produc...out-boards/kl-db25rs
Mesa do a much cheaper board: store.mesanet.com/index.php?route=produc...spinx&product_id=205

However, you can convert PWM to voltage with just a resistor and capacitor to make a simple filter circuit. But unless the VFD says that it is happy with PWM (or step/dir) then you will need _something_

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05 Jun 2014 03:01 #47685 by yoshimitsuspeed
Looks like my breakout board doesn't even do PWM which it looks like the mesa board would need to recieve.
From what I can tell it looks like I need a spindle control board that will convert a stepper signal or a new breakout board. due to having well exceeded my budget already I will probably just control it manually for now.

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05 Jun 2014 04:44 #47690 by yoshimitsuspeed
So this how to says to set the pd144 (rated motor revolution) to 1440.


This one says 3000
www.cnczone.com/forums/diy-cnc-router-ta...settings-manual.html

The manual says its the rated RPM which is 24000.
If I'm not mistaken this just changes how the VFD displays the rpm right? It won't mess anything up if I change the value will it?
I set it to the 1440 in the first vid but at max frequency it only shows 1200 RPM but I can't figure out if that's actual or if it just thinks that i what it is because the scale is off

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