[David_Nolan]

Hi,

I'm uprgrading my cnc spindle and am having a little trouble getting the seller of the spindle I want to respond to my queries. I think it's just to do with covid. I'm buying my spindle on amazon and it is a 1.5kw water cooled spindle. Everything seems fine except in the technical specifications it says 8000-24000rpm and I want one that can go from 0-24000. I'm using a vfd to drive it so I figure it will go down to lower rpms...

However I am unsure why it can't go lower, I orignally thought it was because of overheating but it shouldn't be if its water cooled in my opinion. My uses rarely run past an hour run time so I don't think it will be an issue but I do need the lower rpms for some applications that I have in mind. So I'm just checking if anyone knows why this seller is capping the spindles at 8000rpm. I checked the other spindles which are the same brand i think and the 2.2Kw variant is 0-24,000 This confused me because I figured that this capping was most likely to prevent overheating. I will link the spindle below, Please advise.

https://www.amazon.co.uk/VEVOR-Spind...4343001&sr=8-2

Cheers,

- David.

[ger21]

They have very little torque at low rpm's, and if you stall them, they will burn up almost instantly.

[David_Nolan]

So is it impossible to use flycutters or large diameter surface finishers with a spindle like this? and what about the ones that are rated for 0-24,000 do they have the same problem?

[Jim Dawson]

If you want to spend the $$$$ you can get spindles that will run 0-24,000 RPM, but you are not going to find them on Amazon. I have one that will do it, 12KW I think. (not for sale) Several thousand $ new.

In order to get a useful range that you want, you need to get into the heavy industrial stuff.

As Gerry said, if you try to do this with the small spindles you will instantly fry them.

If you really need the lower speed ranges, then separate the motor and spindle and use a belt drive so you can change speed ranges.

[David_Nolan]

To be honest, I was considering doing that, seperating them and using a belt drive, My concern is will this damage the spindle, I mean its not designed to drive a belt. I can't imagine why it would but then agin I'm not very experienced and would prefer to know beforehand if it has potential issues?

[Jim Dawson]

I don't see a problem driving a belt system. The bearings in the spindle are more than robust enough to handle the radial loading from the belt drive.

[mactec54]

Hi,

I'm uprgrading my cnc spindle and am having a little trouble getting the seller of the spindle I want to respond to my queries. I think it's just to do with covid. I'm buying my spindle on amazon and it is a 1.5kw water cooled spindle. Everything seems fine except in the technical specifications it says 8000-24000rpm and I want one that can go from 0-24000. I'm using a vfd to drive it so I figure it will go down to lower rpms...

However I am unsure why it can't go lower, I orignally thought it was because of overheating but it shouldn't be if its water cooled in my opinion. My uses rarely run past an hour run time so I don't think it will be an issue but I do need the lower rpms for some applications that I have in mind. So I'm just checking if anyone knows why this seller is capping the spindles at 8000rpm. I checked the other spindles which are the same brand i think and the 2.2Kw variant is 0-24,000 This confused me because I figured that this capping was most likely to prevent overheating. I will link the spindle below, Please advise.

https://www.amazon.co.uk/VEVOR-Spind...4343001&sr=8-2

Cheers,

- David.

He is capping the spindle at 8,000 RPM because this saves them a replacement, the first time the user starts it at 500RPM and wonder why it smokes, you would request a new spindle because it has just failed, as the spindle slows down the current draw goes up until it fails or faults out

You and 10,000 others would like a spindle like that, there is no such spindle in this 24,000 RPM range that can be used below 3000RPM and that is only with one manufacture the regular 24,000RPM spindle has a minimum speed of 6,000RPM for a water cooled

If you fail to set the VFD Drive Parameters correct for the spindle you are using ,the same thing can happen also total failure

[mactec54]

To be honest, I was considering doing that, seperating them and using a belt drive, My concern is will this damage the spindle, I mean its not designed to drive a belt. I can't imagine why it would but then agin I'm not very experienced and would prefer to know beforehand if it has potential issues?

Some others are using these spindle with a belt drive to get lower RPM