[Jim Dawson]

I don't think that a 2.2 KW VFD would work well with a 5.5 KW motor, the 2.2 KW VFD would barely output enough power to run that motor unloaded. You would be better to run it with the proper sized VFD if you have 3 phase power available.

If you only have single phase available, then you would need a VFD that is rated for single phase input at 5.5KW or about a 10KW VFD that will run on single phase. Another option would be a 10KW rotary phase converter.

[pikolo]

I don't think that a 2.2 KW VFD would work well with a 5.5 KW motor, the 2.2 KW VFD would barely output enough power to run that motor unloaded. You would be better to run it with the proper sized VFD if you have 3 phase power available.

If you only have single phase available, then you would need a VFD that is rated for single phase input at 5.5KW or about a 10KW VFD that will run on single phase. Another option would be a 10KW rotary phase converter.

thanks for your answere! Yes in my workshop i have a single phase power and i dont know if the line can hold so much power i will have to test it...well i now have to dismount everything so as to clean this machine cause deadly kitten is making fun out of me hahaha

[hfjbuis]

If the tailstock is to low, you could shim it using aluminum foil. If it very low, shim it using epoxy. Oil the top half so it can be loosened again. You will probably don't be able to ajust it for turning small tapers.

If you just need to scrape a few 0.01 mm on planes that don't slide, use a small diamond disk (dremel) and "scrape" it by hand (don.t use the dremel, just the disk). I did the same for adjusted the head stock of both my lathes. It will take a few hours, but who cares.

[pikolo]

Very interesting!! The biggest problem i think is the cross slide that is very stiff in one place and normal to another...what did you use as a surface plate and straight edge? My lathe has a worn bed 0.08mm from what i measured

If the tailstock is to low, you could shim it using aluminum foil. If it very low, shim it using epoxy. Oil the top half so it can be loosened again. You will probably don't be able to ajust it for turning small tapers.

If you just need to scrape a few 0.01 mm on planes that don't slide, use a small diamond disk (dremel) and "scrape" it by hand (don.t use the dremel, just the disk). I did the same for adjusted the head stock of both my lathes. It will take a few hours, but who cares.

[hfjbuis]

The headstock of my lathe (s) were not aligned. The are bolted to a trapezoide bed. To align the headstock, i had to scrape the trapezoidal bottom of the head stock. It took me about 4 hours to get the alignment within 0.01 mm measured over 100 mm distance. So I hadn't to remove a lot of material and uses a dremel diamond grinding disk. To decide where to grind, i made the bottom of the tailstock black using a pental pen and grinded only the high spots.
The second problem was to carriage of both lathes. I could rock the edges about 0.03 mm. So i grinded the other 3 sides the same way as the headstock until it was flat. After the carriage was done, I polished the bottom using the dremel, polish brush and polish paste. I am sure scraping would be better but I haven't a scraper or large straight surface to check. For my hobby use, I am very satisfied with the result.

If you can measure the worn of the bed, than maybe you can use this measurement to straighten the bed. Even if you don't get it a 100 %, even a bit better will be worth a try.

Here in the Netherlands there are some companies that will straighten the bed. This will cost a lot more than a new Chinese lathe (both my lathes are Chinese).

When I need a straight surface, I use the mill table or the bed (unused part) of the lathe.

[pikolo]

I will try to do the same as you did using the minj lathe bed!hooe it works...evebtually i will need the tools but till then i have to try it...many conglatulations on you success!!

The headstock of my lathe (s) were not aligned. The are bolted to a trapezoide bed. To align the headstock, i had to scrape the trapezoidal bottom of the head stock. It took me about 4 hours to get the alignment within 0.01 mm measured over 100 mm distance. So I hadn't to remove a lot of material and uses a dremel diamond grinding disk. To decide where to grind, i made the bottom of the tailstock black using a pental pen and grinded only the high spots.
The second problem was to carriage of both lathes. I could rock the edges about 0.03 mm. So i grinded the other 3 sides the same way as the headstock until it was flat. After the carriage was done, I polished the bottom using the dremel, polish brush and polish paste. I am sure scraping would be better but I haven't a scraper or large straight surface to check. For my hobby use, I am very satisfied with the result.

If you can measure the worn of the bed, than maybe you can use this measurement to straighten the bed. Even if you don't get it a 100 %, even a bit better will be worth a try.

Here in the Netherlands there are some companies that will straighten the bed. This will cost a lot more than a new Chinese lathe (both my lathes are Chinese).

When I need a straight surface, I use the mill table or the bed (unused part) of the lathe.

[arizonavideo]

I cant tell if your lathe has a hydraulic pump on it or not. If so it will have a lot of drag on it and the smaller 2.2K VFD might be a problem.

I have been running my 3 phase lathe on a VFD for some time and it works fine.

For the price I would get a 5K VFD or the 3.2K from China and it will work fine. I have a 2.2K a 3.2K and a 5.5K. The 5.5K is almost twice the size of the 2.2 or 3.2K units. The 3.2K is the same size as the 2.2K but the heat sink is larger.

All the AC motors have good efficiency so what to look at is power in and power out and start up current. 3.2K power output is good enough for most work so that leaves startup current. This is where a VFD is so good. You just ramp up the motor so start up is really easy and has low peak current.

Most VFD's will also give you more current for a short time before faulting.

With the low start up current and knowing that you can only do a 3K cut you lathe will work fine with most VFD's. I would grab a 3.2K and it will be fine for $149.

My only problem with the China drives is the noisy fans. I just replaced the 5.5K unit with a much slower fan and its SOOOO much quieter. I like it this way. I can get all the peak power I need and I never need continuous 5.5K of power so it does not over heat.

I have a new fan for the 3.2K too, the stock fan is really whinny.

BTW it looks lie a really nice Lathe. Cant wait to see the finished product.

[pikolo]

I cant tell if your lathe has a hydraulic pump on it or not. If so it will have a lot of drag on it and the smaller 2.2K VFD might be a problem.

I have been running my 3 phase lathe on a VFD for some time and it works fine.

For the price I would get a 5K VFD or the 3.2K from China and it will work fine. I have a 2.2K a 3.2K and a 5.5K. The 5.5K is almost twice the size of the 2.2 or 3.2K units. The 3.2K is the same size as the 2.2K but the heat sink is larger.

All the AC motors have good efficiency so what to look at is power in and power out and start up current. 3.2K power output is good enough for most work so that leaves startup current. This is where a VFD is so good. You just ramp up the motor so start up is really easy and has low peak current.

Most VFD's will also give you more current for a short time before faulting.

With the low start up current and knowing that you can only do a 3K cut you lathe will work fine with most VFD's. I would grab a 3.2K and it will be fine for $149.

My only problem with the China drives is the noisy fans. I just replaced the 5.5K unit with a much slower fan and its SOOOO much quieter. I like it this way. I can get all the peak power I need and I never need continuous 5.5K of power so it does not over heat.

I have a new fan for the 3.2K too, the stock fan is really whinny.

BTW it looks lie a really nice Lathe. Cant wait to see the finished product.

Hi there!It doesnt have a pump on it ....with the motors and the vfds i am a little bit confused i will try to read it better maybe i am missing something..i really like te procedure too...i will definately keep you informed!!

[pikolo]

hello! Some days ago i went to tha jank jard so as to buy cheap metal...there was a lathe there the one shown in the picture and the guy told me that he would give it ot me for 400 euros...
so would you buy it ? is it worth it trying to clean it and make it work? Is the price good for what it is?thanks alot for your time .

Progress so far

[__Britt]

Disclaimer: I am not a machine restoration expert; nor do I play one on TV.

However, some things do come to mind:

First, if you aren't already subscribed to Kieth Rucker's YouTube channel; you should check it out. Amongst other things, he does machine rebuilding. Ox Tools is another good one, too...
https://www.youtube.com/user/ksruckerowwm
https://www.youtube.com/user/oxtoolco

If you don't already have it, get some high-spot bluing compound.

Supposedly, float glass is really flat; and sometimes you can find granite tile that's very flat also (although, when you are talking about one that's tile-sized; a proper granite surface plate isn't that expensive). Take three pieces and compare them against each other with the bluing compound - the only contact surface that can be common between three pieces like that is a flat plane. Not only can you use this principal to verify the plate's flatness; but you can also make them more flat by putting lapping compound on them and alternately rubbing them against each other (1 against 2, 1 against 3, and then 2 against 3). It is labor intensive; but it does work. Come to think of it; I might even get a small gear motor (like perhaps a windshield wiper motor off of a truck, er, lorry) to do the rubbing for me.

[pikolo]

Yeap totaly agree with you with everything said...but isnt my chineese lathe bed more accurate than float glass or granite tile?

Disclaimer: I am not a machine restoration expert; nor do I play one on TV.

However, some things do come to mind:

First, if you aren't already subscribed to Kieth Rucker's YouTube channel; you should check it out. Amongst other things, he does machine rebuilding. Ox Tools is another good one, too...
https://www.youtube.com/user/ksruckerowwm
https://www.youtube.com/user/oxtoolco

If you don't already have it, get some high-spot bluing compound.

Supposedly, float glass is really flat; and sometimes you can find granite tile that's very flat also (although, when you are talking about one that's tile-sized; a proper granite surface plate isn't that expensive). Take three pieces and compare them against each other with the bluing compound - the only contact surface that can be common between three pieces like that is a flat plane. Not only can you use this principal to verify the plate's flatness; but you can also make them more flat by putting lapping compound on them and alternately rubbing them against each other (1 against 2, 1 against 3, and then 2 against 3). It is labor intensive; but it does work. Come to think of it; I might even get a small gear motor (like perhaps a windshield wiper motor off of a truck, er, lorry) to do the rubbing for me.

[RCaffin]

It is beginning to look very nice now.

Cheers
Roger

[pikolo]

Thanks alot! I really like it too!Much time spent on thia oroject and it is not done yet...if i find a way i will scrape the parts needed to become better!

It is beginning to look very nice now.

Cheers
Roger

[__Britt]

but isnt my chineese lathe bed more accurate than float glass or granite tile?

Depends on how much it's been used; and how good it was leaving the factory. It could be... however, if you are cross-checking them all against each other, you will know for sure. Of course, out-of-the-box, nothing from the home improvement center is going to beat a proper metrology-grade reference surface...

The glass & tile was only suggested because they are cheap; not because they are optimum for the application.

[pikolo]

Hi there!I have tried and found glass beforre but was not flat at all...maybe we dont have float glass where i live..i will post back the results as soon as i read the machine reconditioning and scraping book

Depends on how much it's been used; and how good it was leaving the factory. It could be... however, if you are cross-checking them all against each other, you will know for sure. Of course, out-of-the-box, nothing from the home improvement center is going to beat a proper metrology-grade reference surface...

The glass & tile was only suggested because they are cheap; not because they are optimum for the application.

[RCaffin]

Ah well, what you buy for windows is NOT float glass. I am not sure what it is called, but it wobbles everywhere.
I have what I think is one piece of float glass, but I cannot see how I could use it to check the bed on my lathe, There are two ridges there. What really matters is how well the saddle rides on the bigger of those two ridges.

Cheers
Roger

[pikolo]

Yes i have the one for windows haha....it is bent all over!I will upload a video so as to see the current problems of the lathe!

Ah well, what you buy for windows is NOT float glass. I am not sure what it is called, but it wobbles everywhere.
I have what I think is one piece of float glass, but I cannot see how I could use it to check the bed on my lathe, There are two ridges there. What really matters is how well the saddle rides on the bigger of those two ridges.

Cheers
Roger

[__Britt]

The idea is supposed to be that you use it as a reference surface to blue the bed against... basically as a substitute for a granite or cast-iron straight-edge. I figure that it would need a backing support frame to keep it from flexing; and you would definitely need to do the three pieces test/correction to get it spot-on... and watch out for thermal effects that could curve the surface.

Again; this is just what I've read elsewhere; not from personal experience... and it's not suggested as good or easy or expedient in a commercial setting... just cheap.

[pikolo]

Hi there!So i have bought alla the electronic parts for an electronic leadscrew...Fist of all i would like to ask...is there a way to make threads if you attach a servo o the kathe feed screw?Remeber this kathe does not have a leadscrew..only a feedscrew...i will also post pictures to tell me of there is a simple way to attach the sensor to the spindle

[hfjbuis]

Hi there!So i have bought alla the electronic parts for an electronic leadscrew...Fist of all i would like to ask...is there a way to make threads if you attach a servo o the kathe feed screw?Remeber this kathe does not have a leadscrew..only a feedscrew...i will also post pictures to tell me of there is a simple way to attach the sensor to the spindle

A lead screw is a bit more accurate than a feed screw. Due to the bronze nut, it is also more fragile. So it is still usable for threading.
On the picture below is the setup for the spindle sync (threading) sensors. Basically you only need one spindle sync pulse. If your spindle drive is low on torque (like mine), you can benefit from extra speed synchronization pulses. If your controller support this (I use GRBL) you could add a speed synchronization pulse sensor and some magnets on the spindle. I have added 8 magnets on my spindle. If you do, make sure the index magnet is located in the mid of the speed synchronization magnets.
If your controller supports it, you could also use an encoder some how coupled (1:1) to the spindle.
I glued the magnets on a aluminum bus that is screwed on the back of the spindle. Just to start, you could also tape the spindle sync pulse magnet to the spindle.

I use NJK-5001C NPN NO sensors, the 5V version.