Basic speed problems on a new VEVOR MX-7x14lathe

[riversidedan]

have the same lathe someone told me might have something to do with pods on the circut board,,,,,,just a suggestion,,,,,,

 

[Smithdoor]

Hello,
I have a good friend who has a brand new VEVOR MX-7x14 lathe. When he turns the speed all the way up he gets 2250 RPM. But if he sets it for 1000 RPM and tries to take a light cut, the machine slows down to almost nothing. A couple of questions, if I may.
1. What type of motor is used in this lathe? Brushed or Brushless? Does the motor operate with any feedback to the controller?
2. How does the controller adjust the speed? Is it voltage, PWM or something else?

I am a retired electrical engineer. I would appreciate any thoughts about this problem.

Thanks!

The pots/ adjustable resistor on the board may have a dead spot.
Use a small screw driver and move the adjustment back and forth on both min and max pots. Leave in different spot and see fixs the problem .

Dave

 

[riversidedan]

Examination of literature for their 7x14 on the Vevor web store shows that the lathe doesn't have a high/low transmission. This suggests that the 500 Watt motor is brushless. My experience with the 500W brushless motor on my mini mill (also sans transmission) has shown that it it has good torque at low RPMs, so it is possible that the controller in your friend's lathe is either defective or is incorrectly adjusted so it can't maintain torque under load.

sorry to say that motor is not b/l if so the lathe would be more expensive , in fact that stock brushed motor imo is garbage
and craps out when parting even at a low speed with soft materials which is why i was playing around with that pod thing,,,,other than that its a decent machine for the price and if yur a cheap skate like me,,,,,,,

 

[mbemy]

After a small tweek to IR with no noticeable improvement. Started takeing cuts and useing the speed dial to adjust underload for a very underwelming performance untill I let the smoke out of the motor. So here is a picture of the ZYT-338 220V 120W 2500RPM DC motor. I'm thinking the best option is a VFD on a BLDC motor.

 

[dabear3428]

After a small tweek to IR with no noticeable improvement. Started takeing cuts and useing the speed dial to adjust underload for a very underwelming performance untill I let the smoke out of the motor. So here is a picture of the ZYT-338 220V 120W 2500RPM DC motor.View attachment 488673 I'm thinking the best option is a VFD on a BLDC motor.

do you mean speed controller on a BLDC or a VFD on an AC motor?

 

[mbemy]

do you mean speed controller on a BLDC or a VFD on an AC motor?

I was thinking of a VFD on a BLDC. But after some research I ended up going for a "1100w Brushless Servo Motor with Controler" $225AUD after GST. I'm now considering poly v pulleys rather than the existing. (

) Mine is single speed.

I could have got the 750W Servo Motor combo for around $176 but why bother it is the effort/time that is the real cost here. The 1100W is just a bit longer. Feel like i'm over capitalising though, ****** at the seller though he had already given me a %10 refund due to claiming a 100mm chuck.

 

[riversidedan]

The pots/ adjustable resistor on the board may have a dead spot.
Use a small screw driver and move the adjustment back and forth on both min and max pots. Leave in different spot and see fixs the problem .

Dave

ive tried that when taking a deep cut or parting the motor speeds up then slows down afterwords

 

[dabear3428]

I was thinking of a VFD on a BLDC. But after some research I ended up going for a "1100w Brushless Servo Motor with Controler" $225AUD after GST. I'm now considering poly v pulleys rather than the existing. (

) Mine is single speed.

I could have got the 750W Servo Motor combo for around $176 but why bother it is the effort/time that is the real cost here. The 1100W is just a bit longer. Feel like i'm over capitalising though, ****** at the seller though he had already given me a %10 refund due to claiming a 100mm chuck.

my 9x24 MX-600A has a 1100watt brushless motor and it it plenty on my lathe, it should work well for you, and yea i'm with you if you are going to put in the effort you might as well go big. you very rarely see anyone say "i wish i had gotten a smaller or less powerful one".