Official Luthiers Forum!

Hi Guys,

I need to purchase a VFD for my spindle and the guy at Driveswarehouse is trying to steer me to a higher priced VFD and I wanted to get your opinion on this.

Apparently they have two products, a constant torque and a non constant torque drive:

Constant torque: http://www.driveswarehouse.com/Drives/A ... 022SF.html

Non: http://www.driveswarehouse.com/Drives/A ... 2NFU1.html

The price difference is about $85 which isn't a ton but the costs of these things are just getting out of hand!

My spindle is a 2kW air cooled Teknomotor. I'll be cutting mostly wood with a smidge of Al and plastic from time to time.

Are most of you going with the cheaper one or a constant torque version?

Is constant torque much better or is it just going to burn out my motor at low speed? It's an air cooled spindle so I imagine full torque at low speed isn't going to be too good for it.

Any advice would be greatly appreciated as I'd like to order today if at all possible - I'll be gone for the rest of the week and this way it will be waiting when I return.

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

For what it's worth, the Delta VFD-B that I use is listed as a constant torque drive, and it works very well. It's the only drive I've ever used, so I can't really make a comparison, but it works well even at lower speeds. It is possible to lower the rpms to the point where the spindle will stall, but even at these lower rpms, the shaft mounted fan keeps the motor cool enough from what I've seen.

Dave

Thanks Dave.

I ended up going with the constant torque version per just about everyone's recommendation - U.S. importer for Tekno and two VFD suppliers.

The tekno guy really recommended adding a line reactor which is another $100 but I decided to go without for now. Drives Warehouse has free shipping so there's no benefit to buying it now. I'll add it later if I feel motivated. I hear a lot of people going without one with no problems.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Andy, what would be the purpose of the line reactor you mentioned?
Thanks
Nelson

http://en.wikipedia.org/wiki/Line_reactor

Apparently it makes your VFD and Spindle last longer.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Andy, can you update the link to that VFD? It's not working, and I'm re-thinking my purchase. It hasn't arrived yet, so I could send it back if I want to.

Thanks.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Don, The links are updated.

I ended up going with the Constant Torque version per the recommendation of the guy at Teknomotor and the Drive Warehouse guy. Having no prior experience with either, I don't know if it's performing better than the other.

I do know that either one of the Hitachi's is going to perform better than the Hungyang that arrived non-functioning.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com