Installing a VFD on a Lagun FTV-3

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mspetersen
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Joined: Sun Jan 13, 2013 12:26 pm

Installing a VFD on a Lagun FTV-3

Post by mspetersen »

Looking to add a VFD to my Lagun FTV-3 in place of its current variable speed drive. Do I need to replace the original drive pulleys or can I leave them in place and use them with the VFD?
Mark Petersen

12" x 36" Logan Lathe
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Steggy
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Re: Installing a VFD on a Lagun FTV-3

Post by Steggy »

mspetersen wrote:Looking to add a VFD to my Lagun FTV-3 in place of its current variable speed drive. Do I need to replace the original drive pulleys or can I leave them in place and use them with the VFD?
Let's see some picture of the stock drive.
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Hopefuldave
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Re: Installing a VFD on a Lagun FTV-3

Post by Hopefuldave »

You can, and it's worth keeping the variable drive as unlike the VFD it will give a torque multiplication at low speeds, VFDs often give reduced HP at low speeds (HP is torque x RPM) as torque is the result of motor current. With the variable belt drive you can gear down the VFD powered motor running at full speed (so full power) to get maximum torque when you need to push a 2" drill through an inch of steel...

Dave H. (the other one)
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mspetersen
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Joined: Sun Jan 13, 2013 12:26 pm

Re: Installing a VFD on a Lagun FTV-3

Post by mspetersen »

Thanks. Still have to figure out why the thing won't go max speed. Best I can run is 2951 RPM when the dial says 4000. I know the dial isn't 100% accurate but that still seems like a long way off.

Also, looking for a good set of manuals for it so I know how the head is supposed to go together. Not sure someone wasn't into it before I was. I took several pictures, but who's to say they were correct?

Images here: https://flic.kr/p/RUGuvi and https://flic.kr/p/RUGupg
Mark Petersen

12" x 36" Logan Lathe
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rudd
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Re: Installing a VFD on a Lagun FTV-3

Post by rudd »

I could not find an FTV-3 right off, but I found a manual for a FTV-2. Look at the top of page 7 about the requirement to run the thing through the full speed range twice a day to avoid "pulley freeze". This might be related to your problem.

http://www.bbssystem.com/manuals/Lagun_FTV-2_Manual.pdf

courtesy of Metal Illness - link: http://www.bbssystem.com/
mspetersen
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Re: Installing a VFD on a Lagun FTV-3

Post by mspetersen »

Turns out the problem was in the stallion of an after market Power Drawbar. Must have been messed up at some point and some crews stripped out. One of the previous owners added a 1/2" ring of metal around the opening to attached the Power Drawbar too. Trouble is it interfered with the Speed control. When i replaced the bully and bearings I remounted the power drawbar and got rid of the extra metal. I know have the full range of speeds.

Now that its repaired I wonder what speed the bearings are good for? If i installed a VFD, how fast could I run it then?
Mark Petersen

12" x 36" Logan Lathe
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