Author Topic: Chinese spindle performance at low speed  (Read 6257 times)

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Offline BrightCNC

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Chinese spindle performance at low speed
« on: May 06, 2015, 07:37:12 AM »
Hi everyone. First post here.
I am looking to use a 2.2kW Chinese spindle and a Haunyang drive package for a new machine capable of milling steel. Wondering what the torque performance  is like at around 3000rpm. Can't seem to find any data on these things.
Has anyone cut steel successfully with this type of motor?

Offline ger21

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Re: Chinese spindle performance at low speed
« Reply #1 on: May 06, 2015, 09:23:33 AM »
If it's an 18,000 or 24,000 rpm spindle, it probably won't have much torque at all.
Those spindles are not designed for cutting steel, and if they don't burn up at 3000 rpm, the bearings probably won't last very long.
Gerry

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Offline geh7552

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Re: Chinese spindle performance at low speed
« Reply #2 on: January 22, 2016, 03:50:36 PM »
Motor bearing aren't the problem and nether is burning up a motor. All VFD's only operate in V/F mode... that volts/hertz mode. This means the voltage going to the motor from the VFD decreases as the output frequency decreases. This also decrease motor torque by the square of the voltage. So motor torque takes a nose dive and at low rpm the motor simply stalls. Industrial quality VFD's have the option to operate in "vector mode" that prevents motor stall at low rpms. But now you are talking about a $1500, 3 hp drive.

The only way to operate at low speeds is use a pulley or gear reducer system to keep the motor rpm in the high ranges.

Haunyang drives are as about as low quality junk as you can get. None are UL or CE listed. They are watered down copycats of the old Toshiba G3 VFD's from the early 1980's except Haunyang uses sub quality components.      
« Last Edit: January 22, 2016, 03:53:42 PM by geh7552 »

Offline BrightCNC

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Re: Chinese spindle performance at low speed
« Reply #3 on: January 22, 2016, 08:24:25 PM »
Hi geh7552,
thanks for that bit of knowledge and a response to a forgotten post! .I have not yet purchase motor for this project but an earlier motor/drive package used in a wood router (so mostly run flat out) has now clocked up over 300 hours and still OK. How could one quantify the quality of these vs something more upmarket.
Not sure UL or CE is of concern in home build as the whole machine would never qualify anyway.
So, how to determine less junky? BTW the drive IS electrically noisy and screened motor cable was the only solution for a reliable machine.
As my sample size is only 1, maybe others with failed drives or motors may wish to also comment on Huanyang and suggest some alternatives.

Offline geh7552

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Re: Chinese spindle performance at low speed
« Reply #4 on: January 26, 2016, 12:43:41 PM »
UL or CE is a safety rating which means the VFD has to meet specific standards. If you get a year of service out of a Haunyang VFD consider yourself lucky. Most Chinese Ebayers list a 2 year warranty sales gimmick.... Good luck getting a warranty replacement from China. They are very RF noisy because they lack circuity found in higher quality drives to prevent or reduce RF interference. Automation Direct sells a nice 3hp VFD for a reasonable price. Unless you are cutting thick material with heavy cuts and fast travel chances are 3hp (2.2kw) is overkill. Typically general wood working cnc a 1hp or 1.5hp is more than enough.

Anytime a VFD is used it requires shielded motor cable... and only shield grounding at the drive end. People use 3 wire SJO extension cord type cable from a big box store and wonder why their cnc machine goes crazy when the drive is turned on.