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Thread: Lap Sharp sharpening tips and media

  1. #16
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    It was the too high speed of Veritas that made me buy the Lap Sharp. If you do the backs of blades some other way, Veritas has some better engineered features compare to Lap Sharp. That is the reason I still keep it while trying to decide between the two.

    If Lee Valley changed the design to slow down the Veritas speed, it would be my choice.

  2. #17
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    generally after I tire of re-shaping a carving tool with oil stones and try once more to very lightly just touch the tool to the Mark II, just for a moment, and...blued again, dammit.
    I have blued my share of tools on the MK II power sharpening system.

    One thing I have learned is to dip the tool into water before hitting the platter. The water helps to keep the temp down as it boils away. It doesn't give much more time on the platter, but it gives a good visual indicator of the tool heating before you get the color indicators we all despise.

    Another part of the learning is the finer grits may do more to cause heat than to remove metal. My smaller tools are not worked on the coarsest grit. They also do not get the finest grit. They are usually worked on the second or third grit (220-500?) and finished using oilstones and a strop.

    Also as someone else suggested, keeping toward the center of the disk effectively is the same as slowing the rotation. Just be careful not to run into the mounting bolt. DAMHIKT!

    jtk
    Last edited by Jim Koepke; 12-14-2015 at 12:32 PM. Reason: added last sentence
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  3. #18
    Quote Originally Posted by Frank Martin View Post
    It was the too high speed of Veritas that made me buy the Lap Sharp. If you do the backs of blades some other way, Veritas has some better engineered features compare to Lap Sharp. That is the reason I still keep it while trying to decide between the two.

    If Lee Valley changed the design to slow down the Veritas speed, it would be my choice.
    If the Veritas has a universal motor - instead of an induction motor - you can put a simple router speed control on it. Ask LV what kind of motor is in their product.

    Mike
    Go into the world and do well. But more importantly, go into the world and do good.

  4. #19
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    Quote Originally Posted by Mike Henderson View Post
    If the Veritas has a universal motor - instead of an induction motor - you can put a simple router speed control on it. Ask LV what kind of motor is in their product.

    Mike
    Mike, there are some posts on this above and does not look like there is an easy way to slow it down.

    By the way, I never had bluing issues with the MKII.

  5. #20
    The Veritas is most certainly using an induction motor, I can tell this based on its size, weight, and sound. There's a chance it uses a DC motor but they'd probably slap on a speed controller if this were the case. If it were a uni motor it would sound more like a corded drill.

    I suspect it uses a belt and pulley to get the speed to 650. I did the numbers a few weeks ago on what sized pulleys you'd need for a 4 pole to make a slow speed disc sander. I found out that to stay above the minimum bend radius for v-belts, one of the pulleys ends up being kind of massive. My guess is that this pulley sits below the platen and is the largest that would fit.
    Last edited by Trevor Goodwin; 12-14-2015 at 4:33 PM.

  6. #21
    Quote Originally Posted by Trevor Goodwin View Post
    The Veritas is most certainly using an induction motor, I can tell this based on its size, weight, and sound. There's a chance it uses a DC motor but they'd probably slap on a speed controller if this were the case. If it were a uni motor it would sound more like a corded drill.

    I suspect it uses a belt and pulley to get the speed to 650. I did the numbers a few weeks ago on what sized pulleys you'd need for a 4 pole to make a slow speed disc sander. I found out that to stay above the minimum bend radius for v-belts, one of the pulleys ends up being kind of massive. My guess is that this pulley sits below the platen and is the largest that would fit.
    If it's an induction motor it wouldn't take much to get it to 650 RPM. Most of the induction motors we use are two pole motors and run about 3450 RPM fully loaded. A few motors we use are 4 pole motors and run at 1725 RPM. But you can get motors with more poles and slower RPMs. For example, a 6 pole motor would run about 1150 RPM and an 8 pole motor about 863 RPM. It would be very easy (not a lot of difference in the pulley sizes) to take an 863 RPM motor to 650.

    [Here's some discussion on motor speeds verses poles. It's for synchronous motors and Induction motors slip so their RPM is a bit less. For example, a synchronous 2 pole motor on 60 Hz would run 3600 RPM but a regular induction motor is rated at 3450 RPM.]

    The motor is probably not a capacitor start motor with a centrifugal switch so you can probably use a VFD on it if you wish. It could be a small VFD. If you choose a VFD with 3 phase output, you need to multiply the VA of the motor by square root of 3 for the size of the VFD. But in small motors like that, you can purchase a single phase output VFD.

    But make sure it's an induction motor before you buy a VFD. If it's a universal motor you can easily control it with a router control device. And a router control device will not work for an induction motor.

    Mike

    [If there's room, you might be able to change one of the pulleys to make it run slower.]
    Last edited by Mike Henderson; 12-14-2015 at 5:22 PM.
    Go into the world and do well. But more importantly, go into the world and do good.

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