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Forum topic by Karda posted 01-29-2017 05:59 PM 728 views 0 times favorited 17 replies Add to Favorites Watch
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Karda

1289 posts in 702 days


01-29-2017 05:59 PM

Hi, I made strop wheels for my grinder, the motor is slow, I think a washer motor. My problem is that when I srop with the leather wheel it dulls the blade rather than sharpen it. the leather wheel is the rough back of a leather belt, I also use one made of cereal box same results. However when I hand strop with the same leather it works well. What am I doing wrong


17 replies so far

View Bill White's profile

Bill White

5072 posts in 4109 days


#1 posted 01-29-2017 07:36 PM

You’re “dubbing” the edge. Strops are for the final refining of the edge, not sharpening. Very light touch on the wheeled strop.
Bill

-- bill@magraphics.us

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Lazyman

2528 posts in 1536 days


#2 posted 01-29-2017 07:46 PM

I’m still honing my sharpening skills (pun intended) but from what I have read, you should match the bevel exactly on the strop to avoid rounding over the edge. When you do this with a few strokes on a stationary strop it may be less of a problem than when you do a few hundred feet against a moving strop wheel.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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Karda

1289 posts in 702 days


#3 posted 01-29-2017 08:31 PM

ok, sharpening was the wrong term. But when I touch the sharp knife to the wheel it dulls it rather than strop it

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Lazyman

2528 posts in 1536 days


#4 posted 01-30-2017 02:16 AM

If you have the strop wheel mounted on your grinder, which direction are you stropping. This might be obvious, but the strop should run backwards from the way you normally grind the bevel on a grinding wheel.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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Karda

1289 posts in 702 days


#5 posted 01-30-2017 02:32 AM

the the wheel rotates forward soit rotstes away from the cutting edge

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hairy

2767 posts in 3681 days


#6 posted 01-30-2017 11:54 AM

I think speed might also be a factor. What is the rpm of the motor?

I use a Tomz sharpener that runs at 33 rpm. http://lumberjocks.com/reviews/3198

-- My reality check bounced...

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Lazyman

2528 posts in 1536 days


#7 posted 01-30-2017 03:07 PM



the the wheel rotates forward soit rotstes away from the cutting edge

- Karda

Then the only thing that makes sense to me is that you are not keeping the bevel perfectly aligned with the wheel and must be rolling over (dubbing) the edge. Try looking at your edge under magnification before and after stropping. That might give your more insight into what is going wrong.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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Karda

1289 posts in 702 days


#8 posted 01-30-2017 04:28 PM

the plate is not clear but the highest number is 1140 so I am assuming that is RPMs

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mpounders

890 posts in 3044 days


#9 posted 01-30-2017 04:33 PM

“Slow” is a relative term. 1725 rpm is slow compared to a grinder that may run at 3000 rpm, but both are a little fast for stropping. I used a pulley on my motor shaft and a larger one on a shaft holding my stropping wheel to step the speed down to about 600 rpm. I also place my finger on the blade, back behind the edge, to help hold it flat and to judge when the temperature is getting too hot. Faster can mess up faster as well as sharpen faster, but I bet with a little practice you will get the hang of it. Just hold the bevel flat against the wheel. Many people will use a Sharpie marker to blacken the edge on both sides. Then when you hold it to the wheel, you can see if you are not holding it flat enough by how it wears the marker off. When you take the blade off the wheel, make sure that the compound is smeared on the blade all the way to the cutting edge. When you are holding it to the wheel and you see compound curling up over the edge, you may be holding it a little too stepp and need to flatten the angle a bit.

-- Mike P., Arkansas, http://mikepounders.weebly.com

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mpounders

890 posts in 3044 days


#10 posted 01-30-2017 04:51 PM

Here is a good video by Allen Goodman. He starts with hand stropping, but about halfway through he uses a reversible drill and shows the process for power stropping.

-- Mike P., Arkansas, http://mikepounders.weebly.com

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Karda

1289 posts in 702 days


#11 posted 01-30-2017 04:57 PM

ok, my motor wheel is 3” and the arbor is 2”. I don’t know if I can i ncrease the arbor size, it is shrouded. do you have any ideea what size wheel or wheels I would need thanks Mike

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ClaudeF

773 posts in 1856 days


#12 posted 01-30-2017 05:58 PM

To slow down the honing wheels, the pulley on the motor needs to be smaller than the pulley on the honing wheel arbor. Your measurements indicate you are making the honing wheel go faster than if it was mounted directly on the motor. If the motor is at 1140 RPM, your honing wheel is rotating at 1710 RPM.

As to the size of pulleys you need, it depends on the speed you want to end up with. The ratio of drive wheel diameter to driven wheel diameter is your speed multiplier: 2 inch drive pulley and 4 inch driven pulley will be 1/2 of the motor speed. 2 inch drive pulley and 6 inch driven pulley will be 1/3 of the motor speed and so forth.

Claude

-- https://www.etsy.com/shop/ClaudesWoodcarving

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Karda

1289 posts in 702 days


#13 posted 01-30-2017 06:05 PM

I I would want stropping speed, you are a better judge of that than I am. I can’t change the driven wheel size because of the shroud over the wheel, I might be able to go 3” but I won’t know until I take it appart

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mpounders

890 posts in 3044 days


#14 posted 01-30-2017 07:01 PM

The slower, the better! If your rpm is correct and you do have a 3 inch pulley on the motor, then a 6 inch pulley on the arbor shaft would cut it down to around 550 rpm, which is fine. My factory made Burke has a 1 inch pulley on the 1725 rpm motor shaft and a 3 inch pulley on the arbor, which means it runs about 575 rpm.

-- Mike P., Arkansas, http://mikepounders.weebly.com

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Karda

1289 posts in 702 days


#15 posted 01-30-2017 09:14 PM

what would happen if I put the 3” 0n the arbor and a 1 or 2 inch on the motor

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