New lathe is possessed

[RaisedByWolves]

The dc drives do have feedback- both current and voltage at least on the KB units I've used

KDB drives are the ****!

OP, your board should have accell, decell, and torque pots that can be adjusted to suit your needs.

If or how that would be labeled on your board is anyone's guess.

These are the pots on a 7x14 lathe drive I just bought. No idea what the IR references, nor min max for that matter but these are those.


If you want to play around with them and see if you can improve things, make a witness mark where they are pointing boefor making any changes so you can go back to zero if you get things out of whack. Also, resist the urge to turn the motor speed all the way to max as you could overspeed, and grenade the motor doing this.

 

[markba633csi]

His Vevor unit doesn't have any adjustments- that's one of the things he had mentioned in his first post
IR is the current compensation and adjusts the motor power for constant rpm with varying loads
It's the one adjustment that I consider essential for any dc drive

 

[RaisedByWolves]

His Vevor unit doesn't have any adjustments- that's one of the things he had mentioned in his first post
IR is the current compensation and adjusts the motor power for constant rpm with varying loads
It's the one adjustment that I consider essential for any dc drive

I looked at his pics and couldn’t tell if it had pots or not.

The pic I posted was of a vevor unit I bought the guts out of.

Yeah, I played around with it a bit last night. Speed pots were way off optimal. Got the low set much more realistically and turned up the high to only 70% or so from the 30% it came at.

Then I messed with ir and had this figured to be equal to torque?

I got it to greatly increase my low end torque without surging and kind of thought this is what op needed to do and is the reason for returning to this.

Not sure his pics tell the whole tale unless they just throw anything in a given unit.


ETA: just looked at his pics again, totally different board.

Nicer looking lathe though, could his settings be electronically set?

That is how the custom crafter units I have are setup, just push buttons and set values.

Kinda nice actually.

 

[Iconoscope]

Hello! First post but I feel like I'm going to spend a *lot* of time here.
I picked up a new direct from Vevor 7x16 800w lathe. It's listed as a direct drive lathe and sure enough the brushless motor is mounted directly on the spindle, no belts or gears connecting the motor to anything.
I've contacted the company and it sounds like the techs that normally work on this machine are all on vacation or something, but basically they don't have any parts in stock to send me for replacements or any troubleshooting help, they can't even send me a service guide or a wiring diagram for the controller board.

Here are the problems

1. Speed control knob: it's maxing out at 2500 RPM at about 1/4 turn of the knob and the whole rest of the swing of the knob does nothing.
2. E-stop electromechanical switch: The machine also takes a long time to turn off once the e-stop has been pressed or the chuck guard is lifted and the safety switch engages. I'm not sure if that's normal on these machines because of the huge capacitors on the board or if they're supposed to shut off right away.
3. Forward Reverse switch: Lastly when the switch is on the "0" setting between Forward and Reverse the machine will not turn on. Not sure if this is supposed to be an "idle" kind of thing or if the machine is actually supposed to turn off here, again no familiarity with these mini-lathes.

Tested so far:
The potentiometer for the speed controller- It is listed as a 4K7 pot, and testing it with a multimeter accurately shows 4.7K Ohms at the full swing of the dial and the resistance is smooth through the range when the knob is turned.

I checked the electromagnetic on/off switch with built in e-stop, I'm getting 120v at the mains and at the send once the switch is closed. The switch seems to be working fine as far as I can tell with the meter but it's 30 bucks to replace it and from what I've been reading they are notorious for going bad. I might bypass the switch and wire the machine directly from the main just to rule this component out.

I know nothing about this board other than I don't want to accidentally touch those caps. I've checked it front and back for bad solder joints or any obvious signs of bad components but other than swapping the board out I am not sure what else to check for. I don't see any adjustments anywhere on this board and am guessing it's all in firmware/software.

I'm at a loss and I really would love to get this machine working properly to start producing some parts. I have included some attachments in the event that it might help and hopefully the video works, but I am at a loss here and really hope someone might be able to shed some light on what I might do to get it going. Thank you in advance for any help and honestly if you've read this far I feel like I already owe you a beer.

I have the same machine with the same problems. Be sure to unplug the machine from AC power before doing anything! This is my modifications and work arounds so far: Place a 10K resistor in series with the top side of the speed control potentiometer (the top side has a constant 5vdc applied from the control board). This limits the maximum speed of the machine and makes the control a bit less wild. The machine will still race at power on but settles down quickly.
2nd: The machine continues to run for about 2 full seconds after power off as there is no electronic braking mechanism installed. So....use the "forward-0-reverse" switch to quickly stop the motor, just set it to "0" and the motor stops quickly while it simultaneously turns off power. It is my guess that the system was miswired from the factory, but I need to investigate this further!
3rd: The shield and its interlock serve no useful purpose. The shield is over the lathe chuck where no one is ever cutting anything! You can safely remove this aberration. Take off the back and remove all the interlock components then short the two wires that went to the microswitch. Place a piece of tape over the hole where the interlock rod was removed so that swarf won't get into the electronics.
Anyone else have any hints about this silly control system?

 

[Dirtmover]

...I've contacted the company and it sounds like the techs that normally work on this machine are all on vacation or something, but basically they don't have any parts in stock to send me for replacements or any troubleshooting help, they can't even send me a service guide or a wiring diagram for the controller board...

This is a pretty typical response from Vevor. I purchased and ultrasonic cleaner from them recently and had a couple of issues with it. This is what I got from them:

Dear Customer,

Thank you for contacting us.

We are contacting the production department for you, please wait patiently for 1 to 3 working days, and we will reply you as soon as possible.
Sorry for the inconvenience caused.

Then 3 days later:

Dear customer,

We sincerely apologize for any inconvenience caused. We regret to inform you that, due to the unavailability of a prototype at the moment, our technical team is unable to promptly verify your issue and provide an accurate response. However, we have already reported the fault for further investigation and to ensure the resolution of similar issues in the future.

In consideration of this situation, we would like to offer you compensation in the form of 52CAD. We kindly request your cooperation in considering the option of purchasing the corresponding parts locally for repair or seeking assistance from a local technician.
Thank you for your understanding and patience.

So basically you're on your own!

 

[Iconoscope]

Very few Chinese made machine tools are ready to use from the factory. Modifications usually are easy enough to correct deficiencies and the result can be a fine piece of equipment. But the motor control system on the Vevor 716G is a lost cause!

 

[verbotenwhisky]

Very few Chinese made machine tools are ready to use from the factory. Modifications usually are easy enough to correct deficiencies and the result can be a fine piece of equipment. But the motor control system on the Vevor 716G is a lost cause!

That is the best I have heard anyone voice the thought on Chinese machines.

 

[CraigH]

I would request (perhaps demand) an RMA. Is this Vevor agency in the USA?

I had a Grizzly that would not turn off with any degree of reliability - sent it bad.

 

[Schatten]

My respect to those here,

I bought a 600mm Vevor machine on Ali-express, which I kept with appropriate compensation, I sold it after informing the buyer about the defects. After that I bought the MX-S716G. If I find this forum first, I will definitely not buy. Since I found it mechanically fine, I kept it with $260 (price 883$) compensation. The agreement was reached after more than 10 exchanges of letters, I threatened them with the EU review body. Rewiring the electrical wiring is easy, the On/Off switch must be connected directly from the spindle protection switch. The wire of the direction changer that goes to the On/Off switch must be thrown away, For me, this wire is red. After that, there is normal mode,no need to mess with the direction switch to work properly. Switching sequence Green button, main spindle stop , display lights up or shows the revolution. Unfortunately, it also rotates at 126/minute by default, there is no 0 position. I installed a spare switch which interrupts or closes the input wire of the direction changer (R - L switch). This is how I exclude immediate spindle rotation after switching on. I am currently building the digital threading (automatic feed), so the end of the spindle is bare. Sorry, the comment was a bit long. Regards, Imre from Hungary

 

[Schatten]

Hello! First post but I feel like I'm going to spend a *lot* of time here.
I picked up a new direct from Vevor 7x16 800w lathe. It's listed as a direct drive lathe and sure enough the brushless motor is mounted directly on the spindle, no belts or gears connecting the motor to anything.
I've contacted the company and it sounds like the techs that normally work on this machine are all on vacation or something, but basically they don't have any parts in stock to send me for replacements or any troubleshooting help, they can't even send me a service guide or a wiring diagram for the controller board.

Here are the problems

1. Speed control knob: it's maxing out at 2500 RPM at about 1/4 turn of the knob and the whole rest of the swing of the knob does nothing.
2. E-stop electromechanical switch: The machine also takes a long time to turn off once the e-stop has been pressed or the chuck guard is lifted and the safety switch engages. I'm not sure if that's normal on these machines because of the huge capacitors on the board or if they're supposed to shut off right away.
3. Forward Reverse switch: Lastly when the switch is on the "0" setting between Forward and Reverse the machine will not turn on. Not sure if this is supposed to be an "idle" kind of thing or if the machine is actually supposed to turn off here, again no familiarity with these mini-lathes.

Tested so far:
The potentiometer for the speed controller- It is listed as a 4K7 pot, and testing it with a multimeter accurately shows 4.7K Ohms at the full swing of the dial and the resistance is smooth through the range when the knob is turned.

I checked the electromagnetic on/off switch with built in e-stop, I'm getting 120v at the mains and at the send once the switch is closed. The switch seems to be working fine as far as I can tell with the meter but it's 30 bucks to replace it and from what I've been reading they are notorious for going bad. I might bypass the switch and wire the machine directly from the main just to rule this component out.

I know nothing about this board other than I don't want to accidentally touch those caps. I've checked it front and back for bad solder joints or any obvious signs of bad components but other than swapping the board out I am not sure what else to check for. I don't see any adjustments anywhere on this board and am guessing it's all in firmware/software.

I'm at a loss and I really would love to get this machine working properly to start producing some parts. I have included some attachments in the event that it might help and hopefully the video works, but I am at a loss here and really hope someone might be able to shed some light on what I might do to get it going. Thank you in advance for any help and honestly if you've read this far I feel like I already owe you a beer.