Thread: Current breed of eBay VFD's for lathe upgrade

Vector drive is looking attractive but have to drop a fare bit more cash to get it though. Looking at Chinese options around the $250 mark, or for an extra $50 to $100 can get more of a name brand like Omron or an Invertek as John mentions above. I don't know much about the Invertek's but appears you would get good support and warranty on either Invertek or Omron, plus the manuals for both of these are excellent. The manuals for the Chinese brands I have seen are a joke and I am finding eBay sellers are either quoting wrong model numbers or wrong capacities on some of their listings - as they don't match the specs in the manuals (e.g. selling a .75kW drive as a 1.5kW). eBay is looking like a bit of a mine field so I may be end up going with a more trusted source and spend the $300 and hopefully only spend once vs the $130 non vector Chinese drive that maybe I'll find inadequate at low speeds but maybe not. Originally was hoping to do the upgrade for under $400, but starting to look like stretching my budget if I don't find a decent used motor and have to buy new.

Originally Posted by Oddy

Vector drive is looking attractive but have to drop a fare bit more cash to get it though. Looking at Chinese options around the $250 mark, or for an extra $50 to $100 can get more of a name brand like Omron or an Invertek as John mentions above. I don't know much about the Invertek's but appears you would get good support and warranty on either Invertek or Omron, plus the manuals for both of these are excellent. The manuals for the Chinese brands I have seen are a joke and I am finding eBay sellers are either quoting wrong model numbers or wrong capacities on some of their listings - as they don't match the specs in the manuals (e.g. selling a .75kW drive as a 1.5kW). eBay is looking like a bit of a mine field so I may be end up going with a more trusted source and spend the $300 and hopefully only spend once vs the $130 non vector Chinese drive that maybe I'll find inadequate at low speeds but maybe not.

If you double the motor power you won't have any problem with power at the spindle. It's not really advisable to use low speeds with a vector drive for an extended period anyway, as the motor may over heat. If this is what you want to do then additional cooling is advisable.

This $172 unit is interesting
1 5KW 2HP 7A 220VAC Single Phase Variable Frequency Drive Inverter VSD VFD | eBay
It claims to "Support Open loop vector control"
Also claims to have an "Independent cooling channel design:Prevents dust and corrosive gas damaging the circuit board, and slows down the aging speed of circuit board".
If I was a little more flush I would buy one to test.
Has anyone found a manual for these?

Good find there Bob. I missed that one because it didn't have "vector" in the title and was otherwise on the expensive side for the run of the mill drives. I found the same listing on the eBay Australia site and got the manual from the supplier. Supplier was quite responsive, with adequate English and at first glance the manual looks ok, so will take a proper look at it over the next day or so. Will PM it to you Bob.

Thanks for the manual Oddy.

Based on the manual I'd say this looks like a decent budget level unit.
It is limited to 300Hz but that's heaps for WW machinery.
The manual says something about using it to controls several motors but not under Vector drive control.

Well I have ordered one of these KCLY drives. Picked up a 1.1kW motor today. Will report back on how the VFD goes when its all hooked up and tested.
Just need to find someone to bore out my step pulley for me to fit the new motor shaft.

Oddy

Check to see you if there is have enough metal to enable you bore the existing 5/8 hole larger and the allen key slot. I know that when I convert my Woodfast Cobra the stepped pulley did not have enough meat to machine out and be safe. This was checked by 3 qualified Fitter & Turners . I ended up fitting a CMG 3 phase motor with 5/8 shaft. no problems. Good luck with your conversion.

Originally Posted by chucky

Oddy

Check to see you if there is have enough metal to enable you bore the existing 5/8 hole larger and the allen key slot. I know that when I convert my Woodfast Cobra the stepped pulley did not have enough meat to machine out and be safe. This was checked by 3 qualified Fitter & Turners . I ended up fitting a CMG 3 phase motor with 5/8 shaft. no problems. Good luck with your conversion.

I went ahead and had the pulley bored out (thanks Andre over on the metalwork forums).
On the old motor there was no key in use - just 2 grub screws, one of which screwed into the key slot. The key would only extend into step 3 and step 2 of the pully on both old and new motor, with step 1 (the smallest) furthest onto the shaft and beyond the key slot. Steps 5 and 4 are hollowed out (or cast) well beyond the shaft diameter. There is still plenty of meat on the 2nd and 3rd steps for a key but I may just go with the grub screws as it is currently.
There is not a lot of meat left on the pulley first step - about 6 or 7mm around the diameter. I'm not sure of what the sheer strength of this would be. While I don't see it as a danger I guess it would be possible for a high torque load running off that step to shear that step off from the larger body of the pulley that is locked to the motor shaft. All I believe that would happen if this were to occur I think would be that that disk would be trapped between the motor frame and the larger portion of pulley and would just slip on the motor shaft.
To avoid this happening though I am considering using locktite on the pulley so that the smallest step will not have a tendency to slip on the shaft and shear from the larger pulley steps. Also with the VFD I might be able to avoid using this step at all.

My 1.5Hp motor is adequate for everything I throw at it other than coring of very large blanks. An extra 1/2 to 1 HP would be better for coring very large blanks. If not coring to that diameter, 1.5HP should do everything if the VFD is adequate.

eg, this 20in (50kg) blank was within the capacity of the 1.5HP motor and variable speed drive that came on my Woodfast.

20in blank on C100X.jpg

Originally Posted by Oddy

There is not a lot of meat left on the pulley first step - about 6 or 7mm around the diameter. I'm not sure of what the sheer strength of this would be. While I don't see it as a danger I guess it would be possible for a high torque load running off that step to shear that step off from the larger body of the pulley that is locked to the motor shaft. All I believe that would happen if this were to occur I think would be that that disk would be trapped between the motor frame and the larger portion of pulley and would just slip on the motor shaft.
To avoid this happening though I am considering using locktite on the pulley so that the smallest step will not have a tendency to slip on the shaft and shear from the larger pulley steps. Also with the VFD I might be able to avoid using this step at all.

When you say first step I assume you mean the smallest pulley?
If so then you won't need to use it at all.
The ration between the smallest and next biggest pulley is unlikely to be more more than a factor of 2 and their can easily be achieved with the VFD.

I have 6 step pulleys on WW lathe and in 4 years have yet to move the belt off the 3rd pulley position - not that I am a regular turner.

Well the KCLY drive turned out to be a dud. I can't complain about the ebay vendor (superistore), they were very responsive and attempted to help troubleshoot. We concluded that the unit is likely defective and I have now returned it for a refund (will wait and see how that goes). The vendor also offered to send a replacement free of charge and still provide a refund if the second unit did not work either.
I declined the offer and have decided to go with a brand I have some faith in. So in the end wasted a bunch of time and ended up going back to original instinct.
The unit I ordered was the 1.5kW model and I was trying to drive a 1.1kW motor. The unit refused to autotune for vector drive and was unable to drive the motor at all when it was wired in Delta mode - always giving overcurrent alarms. Wired in star it was able to drive the motor up to 17Hz but always tripped out on over current when I went above 17 Hz. I have another VFD for my dust extractor that I tried on the motor with no problems and currents looked normal. I spent a lot of time exhausting all the relevant settings in the KCLY drive with no luck. So my conclusion is this device is extremely cheap for a vector drive for good reason. It was a gamble and it didn't pay off so 1 strike and you are out in this case. Lesson learnt.

Originally Posted by Oddy

. . . It was a gamble and it didn't pay off so 1 strike and you are out in this case. Lesson learnt.

And thanks to their forum we have all learned something useful.