Spindle Speed Control

Hi,

I bought my cnc router on ebay and it was in a bit of a state and had no information with it.

I have the machine up and running but I cant seem to control the spindle speed.

The spindle and vfd look to be chinese types and both have no markings on them at all so I have no idea on their ratings!

The spindle always runs at about 22k rpm (as shown on the display of the vfd - it does fluctuate alot between 20k and 23k) and in mach 3 I have no feedback as to the current speed and no matter what I try to set it at it always runs at the same speed.

I have read a number of posts regarding the setup of vfds/spindles/mach 3 but I must confess I dont really get it...:hopelessness:

Here is a pic of the current general wiring...

Attachment 9037

Thanks,

Jim

ibetalltheseeditswillbeannoyinglee

Ah I see, that makes sense, thanks for explaining it m_c - I will test tonight! :star:

I notice in mach 3 there is a field in which you enter the spindle speed you would like and another field which displays the actual speed. In my setup the actual field stays on "0" and has a yellow flashing "led" next to it. Am I right in assuming I would need some sort of sensor on the spindle to monitor the spindle speed and then display the result in mach 3? If so is this easy to setup?

Thanks,
Jim

remember to set the spindle pulley values.

Don't worry about a sensor, just check the speed with a chronograph when you set it up.

Ok, I have just checked the voltages from the spindle 3 board to the vfd and readings increase by roughly 1 volt per 1000 rpm (set the spindle to 1000 = 1v, 2000 = 2v ..... 9000 = 9v, 10000 = 10v). Everything over 10000 the spindle board just spits out 10v, and at 10v the vfd displays a speed of roughly 22000. This explains why I thought I had no control, I never tried to take the speed lower than 10000 so the it always ran at the same speed.

So I guess the issue would be with the config in mach 3 (motor tuning?)? I have just checked the mach 3 setup manual and I'm not sure it's in English! Even if I could get my head round it will i will still be stuck as I have no information on the vfd/spindle and therefore have no idea on the correct values to enter?

Am I stuck cutting everything at 22000?

Ic2 - thanks for the pulley tip, I was wondering why mach 3 kept moaning when I tried setting lower values! As for measuring the speed I do not have any tools to do that.... I only have the display of the vfd.

Jim

what are the min and max values in the spindle pulleys

Hi Jim
If you post some pictures of your VFD it may be possible to identify it and source manual for it.

Kn8

The min was 20000 and max was 24000. I changed this to min 0 and max 22000 so could test different values.

Quote:

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Originally Posted by Kn8

Hi Jim
If you post some pictures of your VFD it may be possible to identify it and source manual for it.

Kn8

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Thanks Kn8, here are some pics of the vfd and spindle.

Attachment 9042
Attachment 9043
Attachment 9044
Attachment 9045

Edit:
Just found the front cover for the vfd in a box of bits! It doesn't have a model number but it does say "240v 1.5Kw".
I've had this thing for over a year and never spotted it, what a spanner!:witless:

Jim

That looks like a Huanyang Inverter I have sent you a PM.

Kn8