Thread: Fitting a VFD/VSD to Waldown Buffing Machine

The motor will almost certainly be wired as Y and will need to be converted to ∆ to retain full power.

The Waldown may be different but inside most grinders and buffers there is next to no room to work and perform the conversion.
The two GMF grinders that run alternately from one VFD that I converted were particularly difficult.
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The VFD you linked to shouldbe OK although it may not last as long as a full industrial strength unit.
Things to watch out for;
Make sure you get to see the manual before you buy - some are nearly undecipherable.
Getting help from the forum for VFD programming for an unknown VFD will not be as easy as for a VFD that other folks are familiar with.
A VFD on a grinder has to be able to stop under what is known as "coast to stop" conditions - make sure it has this capability.
If it is "decelerated to stop" the wheels can come off - DANGER WILL ROBINSON"
Grinders have high rotational interia so the cannot have their speeds changed too quickly so always set their accelerations and decelerations to slow.

The VFD will almost certainly not be an Vector type VFD that means irrespective of its power rating, below 50Hz the motor will not deliver full power.
This is not that big a deal on a buffer or grinder where 50Hz is usually the lowest speed and if anything, especially for buffing you want to go to higher speeds. However I often find myself grinding, using a wire wheel, or sanding with these grinders at around 35-40Hz. It doesn't make a lot of difference but psychologically I find I can hold things closer by hand without staining my pants when the wheels are not going as fast as usual. My grinder setup uses a non-vector drive VFD and I have not found this to be a problem but I do plan on upgrading the VFD to a Vector drive some time sometime. A vector drive VFD will be much more versatile into the future if you decide to swap them around onto other machines.

I have been slowly upgrading all the non vector drive Huanyang VFDs in my shed for Vector Drive Powtrans which I have been buying direct from the Factory in China. If this interests you then do a search for Powtran on these forums.

Great information, Bob - many thanks.

I have found your post started back in May 2017 ("VFD install summaries") and will read through that post in detail over the next few days. As some have mentioned, the whole VFD scenario is somewhat daunting to non-electrical chaps but the potential opportunities and benefits will keep me moving forward with my proposal/intention to adapt several 415v machines.

Your suggestion to utilise a brand/type of drive that is familiar to forum members, and to stick with that brand if intending to adapt several machines makes perfect sense. Still not sure of the distinction between Vector/Non-Vector drives but will try to continue my online education in these matters. Very interesting read on the braking and speed-change options & requirements. Again, your alert in regard to the need for bench grinders etc to be able to "coast to stop" makes perfect sense once you explained the rationale.

Accordingly, I'm ready to order a Powtran vector VFD for the Waldown grinder I mentioned above. Before I do that I will take a few photos of the grinder in question, including some images of the internal wiring setup if I can capture it, and will post them here for your consideration & comment if that's OK. Will the Powtran people be OK with shipping one unit only, or is it more economical to purchase a few? All going well I may seek your further indulgence with contact details for Powtran in due course.

It will be my hope & intention to keep the machines in their original motor configurations and just mount the VFD via a custom bracket, assuming that this will work with the existing wiring setup and switches etc. Hopefully, if I can get one unit installed, programmed and operating smoothly the next one will be somewhat easier. As a matter of interest I have attached a couple of images below of my Waldown pedestal drill which has a VSD fitted by the previous owner. I will try to upload a few images of the grinder/buffing units shortly.

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Thanks for taking the time to comment, advise and offer expertise in these matters, Bob.

Before you do anything I would make sure the Waldown can be converted
If it's wired as 415V ∆ you have to get the motor rewound.
If its wired as 415V Y it will have to be converted and it sounds you had better get someone to do that and there may not be enough room to do it.

G'day Bob.

I have observed your advice and taken the Waldown grinder/buffer to the local motor-rewind guy for assessment. He reiterated your concerns re the potential difficulty in adapting the wiring configuration to suit the VFD modification, but said it should pose no significant problem once he accesses the motor internals. He will make the necessary changes and leave a cable outside the motor for connection to the new controller.

20180820_080854.jpg 20180820_080906.jpg

That being the case, I will now be in the market for something like a Powtrans Vector Drive to suit the Waldown machine above. I did a Google search for Powtrans but only came up with links via Alibaba or Made-In-China - no direct factory info. Any suggestions?

Originally Posted by Hardenfast

G'day Bob.

I have observed your advice and taken the Waldown grinder/buffer to the local motor-rewind guy for assessment. He reiterated your concerns re the potential difficulty in adapting the wiring configuration to suit the VFD modification, but said it should pose no significant problem once he accesses the motor internals. He will make the necessary changes and leave a cable outside the motor for connection to the new controller.

20180820_080854.jpg 20180820_080906.jpg

That being the case, I will now be in the market for something like a Powtrans Vector Drive to suit the Waldown machine above. I did a Google search for Powtrans but only came up with links via Alibaba or Made-In-China - no direct factory info. Any suggestions?

Do a search for Powtran (not Powtrans) on the forum and there are posts showing how to order direct from the factory - it's a tad messy but it works.
For your application I would recommend a PI160 0R7G1 Thats a 1HP Model.