Lee Valley Power sharpener

Re: Lee Valley Power sharpener

Lyn J. Mangiameli

>Taking your question in order:

"So when you are shapening a knicked plane iron at a 25deg bevel, do you perform the task on a rough grit, like 120,...."

Unless it is a very minor knick, it is best to drop back to a very coarse abrasive and blast away the necessary steel as quickly as possible. I'd say a 60 or 80 grit paper is not too coarse for this purpose. You will find that going to this coarseness will make the task much quicker, cut much cooler, and give much longer abrasive life.

"...then change the setting to 30deg and start grinding a micro bevel on higher grits. Or do you just keep working with the original jig setting at say 25deg and count on the automatic 1 deg microbevel that comes with the different thickness disc?"

In most instances, your secondary "micro" bevel needn't be much more than a degree or so different than your primary bevel. So determine what primary angle is suitable for your task and then just count on the changes in abrasive size and platter thickness to achieve the secondary bevel. What some don't realize is that just going from the coarser abrasives to the finer ones, even using the same platter thickness, actually will privide a small change in bevel angle as the coarse disks are much thicker than the later fine disks.

So, assuming you are content with a 25 degree primary bevel, just rely on the paper and platter changes to achieve your secondary bevel.

"Is it necessary to work your way through the whole array of grits."

It's not necessary, but it is definitely more efficient in time and abrasive life. Since you have constant jigging and the platter changes are so easy to make, by all means go through the array of grits when you are making significant changes in angle or needing to remove knicks.

" Any advice on grit sequence if starting with a chipped iron vs if your just touching up a dull iron. "

As above, I suggest going with a very coarse grit to make any geometry changes (i.e., a different bevel angle) or to remove steel to get past a knick or pit. LV doesn't sell them, but for making major geometry changes (say changing the primary bevel angle 5 degrees) I really think using a 46-55 grit paper is a good place to start. At a minimum, use a 60 grit paper.

For small geometry changes or small nicks, I suggest starting with 60 or 80 grit abrasives.

For renewing a dull edge that does not require a geometry change, start with no more than a 20 micron abrasive, then go quickly to your finer sizes.

For maintaining or refining an already sharp edge, use 9, 5 and .5 (or .3) micron abrasives. For final smoothing, I sharpen often, but usually only need to maintain the edge with the .5 micron abrasive.

By the way, LV doesn't include ready made disks in these small micron sizes, so just get their PSA microfine papers and apply them to a spare disk (assuming you have one), and then trim around the edge with a knife.

Feel free to get back to me here or via email if you think I might be of any further help with using the LVPSS.

Thanks Lynn

Robin Frierson

>My local friend, Fred Kingston, loves the machine and I am looking forward to trying it out. Thanks for the tips. Robin

Re: Lee Valley Power sharpener

Don Thompson, Cutler Ridge, South of Miami FL

>Lynn wrote:

What some don't realize is that just going from the coarser abrasives to the finer ones, even using the same platter thickness, actually will privide a small change in bevel angle as the coarse disks are much thicker than the later fine disks.

Are they of continuously narrowing thickness as one proceeds from the coarsest to finest grit? If so, would this not provide multiple bevels?

Re: Lee Valley Power sharpener

Lyn J. Mangiameli

>Since the changes in bevel angle are very small, whether you have multiple bevels will depend on three things: how much difference there is between your initial and final abrasive for the same platter thickness; how big the steps are between grit sizes; and whether you spend the time and abrasive life to bring the entire surface down to the bevel angle provided by each abrasive grit.

So, if you have to establish the initial geometry with a very coarse abrasive, which will make for a greater combined platter/abrasive thickness, you will have a greater change between your initial bevel angle and the final bevel angle (for a given platter thickness) done with a fine (thinner) abrasive).

If you go through more and smaller abrasive steps, you are more apt to erase the previous bevel angle and establish the new one across the entire face. It all depends on whether you want to spend the slight extra time and abrasive life to achieve this.

Keep in mind that these bevel angle changes are very slight (in fractions of a degree) and all in the direction you would want (from lower to higher angle).

My personal approach, in the interests of shortest sharpening time (which also makes for cooler sharpening) and longest abrasive life, it to regularly drop to a grit size that will quickly allow for removal of all the steel required to remove the dull or knicked edge, then quickly go up in small grit steps, each time remaining at a given grit level only long enough to achieve removal of the scratch pattern from the previous grit. This does result in the final sharpened blade of a visible series of steps of different scratch pattern going down the bevel face. Again, those steps represent only the faintest fraction of a degree difference in actual bevel angle. Again, I do this in the interests of speed, reduced heat, and abrasive life, but it has no meaningful functional effect on blade performance.

I must admit, there are some chisels where I like the bevel to have a bright even polish across its entire face. I do this just for aesthetics and it is easily achieved by just spending the extra time on each grit step to establish that grit's bevel angle across the entire face.

Either way is equally functional, but just like a deliberate micro bevel, the choice is most commonly made based on ease and quickness of sharpening.

Re: Lee Valley Power sharpener

NickB

>I recently acquired the Mk II system, and first let me say it is the cat's a**. The blade holder is easy to set up, and platter changes are very fast.

I've sharpened almost all of the blades in my shop since I got it, and (at least for this first round), started with the coarse disk that is included with the machine, and worked up through the grits. Per the comment above, you can tell that you will get slightly different bevel angles as you change grits, but the difference is a small fraction of a degree (I'm not looking at it now, but my impression is that about 1" in tool height change = 10 degrees change in bevel angle).

I've only gone down to the 40 micron paper when resharpening blades (I've not made any big nicks yet), and I suspect that will be a good starting place for most resharpening (unless you need to touch up a blade that is still pretty sharp).

Enjoy!

Nick

ps. Not affiliated with LV, but a very satisfied customer