I’m close to setting up my own VFD. I was really concerned about blindly hooking it up to my Acorn. I never thought about using a voltage source other than trying Acorn. Thanks for the video, you may have saved me a new Acorn!
Thank you so much for this info! All of the info here is exactly what I needed to get over my pcturn retrofit hurdle. Finding a compatible VFD for the factory motor at a reasonable price can be a hassle. Going this route, I should be able to get both a motor upgrade and the VFD for under $300... And that's a big win.
Thank you Marty! OK. Let me begin :-) I already asked you similar question but I can`t remember the related video. So I`ll take freedom to ask it again. I am planning to convert an older lathe to Acorn + DMM DYN4 + DMM servo motors + VFD + encoder. This lathe has multi-speed gear box and I am not sure how to use it (related with torque). You told me to use three speed. OK. But, how to use them with Acorn? ( I am aware that there are three buttons on spindle control on monitor). So, I beg you to make a video (if you can) and explain this in detail. And I am sorry to all of you if my English is not good because it is not my native language but I think that you understood me.
Whether or not to ground both ends of the shielding is a constant cause of controversy. Some manufacturers say you must, some say you mustn't, some say you should, some say you shouldn't. There is no universal "right" answer - it depends on the installation and in most cases it really doesn't matter. I've done a lot of EMC testing of drives and complete installations and I can tell you that in some cases it helps and in other cases it doesn't. What I CAN tell you is that anyone who says it MUST be one or the other is wrong. For the purposes of this kind of application, it almost certainly doesn't matter, so just do whatever is most convenient.
Murray Edington That’s good information, I usually go with shield grounds on one side only, closest to the source unless the wiring diagram or schematics indicate otherwise.
You ground one side only or you will be creating a ground loop (thats really bad) The trick is to run separate ground wires to a common Chassis ground. The Same terminal the ground lead on the power cord goes to. Do not daisy chain the shield wires. Be careful were you run the ground wires do not run them parallel to each other or near something like a VFD. Or they could pick up the interference and make the shielding interfere with the wire your trying to protect. Its best to shield only low output control wires NOT power wires if you shield power wires it could amplifie the interference. Component location and wire routing is by far the best way to protect electronics, shielding should be used sparingly only were there is no choice. Do not run neatly bundled wires in parallel this sets up fields of interference
You are trying to teach a whole room full of grannies how to suck eggs. What do you think is "really bad" about it? Last time I looked we were talking about connecting an industrial motor to a VFD, not connecting up a high end audio preamp. To get into the detail, the stray capacitance between the motor windings and its chassis massively outweighs that of the cable so any return current from the motor would otherwise have to come back along the protective earth connection rather than back up the motor cable assembly - that's simply a different EMC earth loop, as there are most likely other ground paths between them already. However, if you go back and read the intro and the Belden reference you might understand there is no right or wrong. Some VFD manufacturers recommend one, some the other. If you aren't EMC qualifying an installation, you would never know the difference and each installation is different. It's all rather academic anyway as 99% of installations have the motor and VFD mounted on heavily grounded / interconnected chasses and almost none of the hobby installations even bother with EMC filters on the input to the VFD.
Murray edington I see why Marty chose a short polite answer. I respect your opinion but I am 100% sure you dont know what your talking about , Your wrong on so many points. I wish you the best of luck. Have a good life.
Hey did you find this motor had enough power? It's the perfect size but the stock motor on my compact 5 is rated for 800 watts (later edition). I don't want to downgrade as far as power or torque goes, but I really want a vfd because I don't want to mess with transmission/ drive belt speeds. I'm not sure the motor runs at 800 watts continuous but it's the stated output.
The original motor was a single speed single phase motor. The owner wanted variable speed control of the motor. By all means use the motor you have. If you have the DC motor, you will need a controller such as the KB Electronics KBIC-120 with the SI-5 signal isolator to connecto to Centroid Acorn
I’m close to setting up my own VFD. I was really concerned about blindly hooking it up to my Acorn. I never thought about using a voltage source other than trying Acorn. Thanks for the video, you may have saved me a new Acorn!
Ask for help on the Centroid CNC Acorn forum. Post a link to your manual. Use a relay board on the 6 Acorn outputs.
Thank you sir! Is the Acorn forum on the Centronics site?
Yes, centroidcncforum.com/viewforum.php?f=60
Thank you so much for this info!
All of the info here is exactly what I needed to get over my pcturn retrofit hurdle. Finding a compatible VFD for the factory motor at a reasonable price can be a hassle. Going this route, I should be able to get both a motor upgrade and the VFD for under $300... And that's a big win.
Still need to test the performance on the lathe....soon....still prototyping what needs to be done to fully convert one of these machines.
Where did you buy the pulley from? Looking for one with a 11mm bore is proving more difficult than I thought!
Thank you Marty!
OK. Let me begin :-)
I already asked you similar question but I can`t remember the related video. So I`ll take freedom to ask it again.
I am planning to convert an older lathe to Acorn + DMM DYN4 + DMM servo motors + VFD + encoder.
This lathe has multi-speed gear box and I am not sure how to use it (related with torque). You told me to use three speed. OK. But, how to use them with Acorn? ( I am aware that there are three buttons on spindle control on monitor).
So, I beg you to make a video (if you can) and explain this in detail.
And I am sorry to all of you if my English is not good because it is not my native language but I think that you understood me.
Really informative video thanks for making it
Whether or not to ground both ends of the shielding is a constant cause of controversy. Some manufacturers say you must, some say you mustn't, some say you should, some say you shouldn't. There is no universal "right" answer - it depends on the installation and in most cases it really doesn't matter.
I've done a lot of EMC testing of drives and complete installations and I can tell you that in some cases it helps and in other cases it doesn't.
What I CAN tell you is that anyone who says it MUST be one or the other is wrong. For the purposes of this kind of application, it almost certainly doesn't matter, so just do whatever is most convenient.
Thanks Murray. I do my best. At the end of the day, you do what is best for you.
Murray Edington That’s good information, I usually go with shield grounds on one side only, closest to the source unless the wiring diagram or schematics indicate otherwise.
You ground one side only or you will be creating a ground loop (thats really bad) The trick is to run separate ground wires to a common Chassis ground. The Same terminal the ground lead on the power cord goes to. Do not daisy chain the shield wires.
Be careful were you run the ground wires do not run them parallel to each other or near something like a VFD. Or they could pick up the interference and make the shielding interfere with the wire your trying to protect.
Its best to shield only low output control wires NOT power wires if you shield power wires it could amplifie the interference.
Component location and wire routing is by far the best way to protect electronics, shielding should be used sparingly only were there is no choice.
Do not run neatly bundled wires in parallel this sets up fields of interference
You are trying to teach a whole room full of grannies how to suck eggs. What do you think is "really bad" about it? Last time I looked we were talking about connecting an industrial motor to a VFD, not connecting up a high end audio preamp.
To get into the detail, the stray capacitance between the motor windings and its chassis massively outweighs that of the cable so any return current from the motor would otherwise have to come back along the protective earth connection rather than back up the motor cable assembly - that's simply a different EMC earth loop, as there are most likely other ground paths between them already. However, if you go back and read the intro and the Belden reference you might understand there is no right or wrong. Some VFD manufacturers recommend one, some the other. If you aren't EMC qualifying an installation, you would never know the difference and each installation is different.
It's all rather academic anyway as 99% of installations have the motor and VFD mounted on heavily grounded / interconnected chasses and almost none of the hobby installations even bother with EMC filters on the input to the VFD.
Murray edington
I see why Marty chose a short polite answer.
I respect your opinion but I am 100% sure you dont know what your talking about , Your wrong on so many points.
I wish you the best of luck.
Have a good life.
Hey did you find this motor had enough power? It's the perfect size but the stock motor on my compact 5 is rated for 800 watts (later edition). I don't want to downgrade as far as power or torque goes, but I really want a vfd because I don't want to mess with transmission/ drive belt speeds. I'm not sure the motor runs at 800 watts continuous but it's the stated output.
800 watts is over one HP. You must have the DC motor. My client hat the 120vac motors
Hi Marty, do you recall which version of the GS1 this is?
Version? Depends on your spindle motor horsepower and you want single phase input. If less than 1HP you can use the 120VAC single phase input
Hi, why did you decide to put in a new motor ? My original motor still works fine is there any reason to swap in a new one?
The original motor was a single speed single phase motor. The owner wanted variable speed control of the motor. By all means use the motor you have. If you have the DC motor, you will need a controller such as the KB Electronics KBIC-120 with the SI-5 signal isolator to connecto to Centroid Acorn