MashingMetal
Ultra Member
I am just going down the VFD route with my lathe set up. It really isn’t hard and the benefits just to tweak the speed to avoid harmonics and get a little more top end for carbide and small parts are worth it.
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METAL LATHE SMOKE, RPM LOSS, NEW LATHE MOTOR?
- Thread starter MooseMeat
- Start date
Tom Kitta
Ultra Member
Just measure the shaft size. If it is indeed metric you would need to modify the pulley by enlarging it a bit to fit imperial.
Don't be shocked if BB quotes something out of this world for the motor - I just seen King 12 x 36 motor as over 700 list.
Getting metric motor new is a non issue - plenty of places will ship to your door for about the same price as imperial motor of the same size.
BaronJ
Ultra Member
That means that the motor is a capacitor start & run, no centrifugal switch inside. The likelihood of the motor being recoverable is low.
Wiring up a VFD is easy !
Only three wires and only two of them will be powered. I am assuming USA 110v-neutral-110v plus earth. 220 volts across two wires. The live wires will go to the L and N on the VFD, the earth connection will go to the earth terminal. That leaves only three wires plus earth to be connected to the motor. It won't matter which way they are connected, because if the motor runs in reverse just swap any two wires. Don't forget the earth terminal. This one should be connected to the main earth system.
The rest is just setting up and should be done carefully in conjunction with the handbook.
WARNING: Do not use the existing forward and reverse switches on the machine only the ones on the VFD. The stop switch should be wired before the VFD, to ensure that power is completely removed when stopped.
Buy a motor suitably rated for use with a VFD, some are not !
MooseMeat
Super User
I think this is the route I will go, now the motor hunt is on, just missed a suitable one in FB marketplace here, however I don't mind buying new, not interested in inheriting someone else's problems; I have 220 in my little shop.
thank you...
MooseMeat
Super User
lots of encouragement here, thank you
Don't feel like you MUST use a VFD rated motor. You really don't. All of mine are and I like the additional rpm range this gives me. But if you use the gearing that is already built into your lathe, you need not worry about using the VFD to adjust your speed plus or minus 25% that's +/- 15 Hz and if you keep the power levels down +/- 20 Hz is not unreasonable. Just keep an eye on motor and bearing temperatures. But ya, if you want to push that, then by all means get a VFD rated motor. They typically come in turn down ratings of 10:1, 20:1 and even 1000:1. 10 & 20:1 motors are not usually outrageously priced.
If you have a nearby pump vendor, they will often have new and unused take-off vfd rated motors.
Personally, I favour the idea of using a VFD to fine-tune the RPM and/or adjust rpm as you turn a part down to smaller circumferences to keep surface feet up. Or as someone else said, fine tune rpm to avoid vibration etc.
As others have said, for basic settings, it really isn't rocket science and we do have a few members that dream about VFDs while on vacation.... Lots of help available if you are patient.
One piece of advice from me is to look for a VFD that supports sectorless vector control mode. It's amazing what this mode will do to the smoothness of a motor. It uses its own internal measurements of back emf and current flow to figure out where the motor is without physical sensors and adjust the controls to give real-time feedback to the output.
You may not use this feature initially, but someday you will be glad to have it available.
If you have a nearby pump vendor, they will often have new and unused take-off vfd rated motors.
Personally, I favour the idea of using a VFD to fine-tune the RPM and/or adjust rpm as you turn a part down to smaller circumferences to keep surface feet up. Or as someone else said, fine tune rpm to avoid vibration etc.
As others have said, for basic settings, it really isn't rocket science and we do have a few members that dream about VFDs while on vacation.... Lots of help available if you are patient.
One piece of advice from me is to look for a VFD that supports sectorless vector control mode. It's amazing what this mode will do to the smoothness of a motor. It uses its own internal measurements of back emf and current flow to figure out where the motor is without physical sensors and adjust the controls to give real-time feedback to the output.
You may not use this feature initially, but someday you will be glad to have it available.
MooseMeat
Super User
I'll do some research tonight on those VFD's, from looking they're not too expensive and it sure beats even trying to figure out the stock wiring as I had to pull the contractors out and clean them and it took me three days to trace 1 wrongly placed wire from the photos I took before hand. The easy route would just be to swap out the motor for the same, but as I mentioned before, no guts no glory.
cheers....
The opposite of that is to figure out how to use or modify the existing controls to integrate the VFD. That's definitely the guts route, but the glory part might be visible from the Pacific to the Atlantic...
MooseMeat
Super User
I do like the vfd route, and I see some vfd's have a removable face with an extension cord tucked in behind it. A fella could extend that cord if needed and mount the controls in place of the old buttons
It's very easy to mount a SPDT switch for fwd/off/rev and a potentiometer for speed control in a box and mount it on the lathe. Also easier to use than membrane switches on a little keypad.
slow-poke
Ultra Member
Interesting comment, I have found his videos and instructions first rate. I'm quite impressed with his teaching skills. IMHO he often takes a somewhat complicated or generally unknown topic and explains it in a way that less knowledgeable people can understand. I would give him a 10/10. I wonder what people don't like?Some folks don't like Clough42 but I converted my mill to 3-phase motor and VFD based on his videos. I bought the same VFD as he used and it was really straightforward.
Clough42
Welcome to the Clough42 shop. We get up to all kinds of nonsense in here: manual and CNC machining, 3D printing, toolmaking, electronics, PCB design, CAD, and sometimes even frickin' lasers! All sponsorships are clearly disclosed. We do not accept promotions for mobile games or VPN apps. As...www.youtube.com
I like those extension controls, but I really don't know why. I've never used that feature and my higher quality VFDs don't even have that. I don't think easy access to programming is all that useful unless the VFD is buried in a hard to get at cabinet.
As @David says, the most important controls are fwd/rev, a speed pot, and I'd add jog. You can get fancy with other stuff, but the basic setup is where the magic is and you don't need the fancy stuff after you have it running.
No idea. I also think he's a good teacher.
+1 on the VFD, not the most inexpensive route but is an excellent way to go. One of the great features of the VFD is the soft start, you can set the run up time from 1 to 10 seconds depending on the VFD manufacturer.
If your machine has a drum switch just use it for fwd/n/rev. The VFD should have connections labelled as Comm/Fwd/Rev and as these are control signals you can use small gauge wire like CAT5 network cable.
My Allen/Bradley drum switch connections are as follows:
Contact 1 - Reverse
Contact 3 - Common
Contact 4 - Forward
You would be wise to meter your switch to be sure of the connections.
If your machine has a drum switch just use it for fwd/n/rev. The VFD should have connections labelled as Comm/Fwd/Rev and as these are control signals you can use small gauge wire like CAT5 network cable.
My Allen/Bradley drum switch connections are as follows:
Contact 1 - Reverse
Contact 3 - Common
Contact 4 - Forward
You would be wise to meter your switch to be sure of the connections.
As almost everyone knows, I don't generally like YouTube. But Clough42's videos are some of the few I will watch but only if they are relevant to my interests. Not all of them are. But he gets a pass from me and that isn't easy to do.
BaronJ
Ultra Member
Be very careful if you go down this route ! There should not be any switching between the VFD and the motor. Use the VFD to do the forward and reverse functions , also the speed control and braking. The supplied handbook will give you all the information that you need.
That's, why it's called the guts route.
Your cautions all apply regardless of which route you choose.
Hahahaha! That's rich! Even the better models have manuals that are difficult to understand. In my opinion, that is one of the reasons why so many people are scared of VFDs. They are written by foreign engineers and translated by AI or someone who doesn't really speak English.
It would be so much better if they had a basic hookup & basic programming chapter right up front. It isn't rocket science, but they sure do try to make it seem that way.
The other problem we seem to encounter frequently is the open box scenario. Someone was in there before us and messed up the programming. Worse, the return to factory reset doesn't always work the way it should either. I had two like that.
I'm not trying to scare anybody here, but that's why this forum is such a great resource. Often WAAAY better than the manual.
My version of what you said is "Don't let the manual scare you"! Followed by "Don't be afraid to ask questions here!"
BaronJ
Ultra Member
Hi Guys,
Yes I've seen some of those chinglish handbooks/manuals ! Some look like they have been written by a tame monkey.
I'm particularly busy at the moment but I was thinking about doing a drawing explaining the connections. But as far as setting up any particular VFD, no I could only generalise.
Just a quick one, there are some very good low priced VFD's out of China. The Ecogoo is one and there are several others. The Ecogoo is quite well thought of and sold under various other names by the same manufacturer.
Yes I've seen some of those chinglish handbooks/manuals ! Some look like they have been written by a tame monkey.
I'm particularly busy at the moment but I was thinking about doing a drawing explaining the connections. But as far as setting up any particular VFD, no I could only generalise.
Just a quick one, there are some very good low priced VFD's out of China. The Ecogoo is one and there are several others. The Ecogoo is quite well thought of and sold under various other names by the same manufacturer.
MooseMeat
Super User
perfect, thanks