Tried out my new toy *LINK*

Oh no...

Scott Burr in Ben Lomond CA

>Yet another good review... I get one in a heartbeat if it would help in sharpening all the cutters for a 45. Scott, I see a lot of sharpening in my future

Question about clamp

Jonathan Ronnow, Sweden

>Boy am I jealous... I still sharpen my jap. chisels with the veritas guide. I found out that by clamping the chisel in the guide loosely and then holding it, just as you would when sharpening, against a flat piece of melamine chipboard lets me see if its skewed. If the edge doesnt sit flat against the melamine whilst the roller does, then its off.

How short chisels can be sharpened without the clamp being cut by the platter? Mine have 60mm long blades, what when they are worn down to say 40mm, like the mini-chisels? Not that that will happen during my nearest years, but still....

Jonathan

Re: Question about clamp

Lyn J. Mangiameli

>Truth be told, one of my sharpening carriages has acquired a bit of a forward bevel on its lower surface as a result of sharpening a couple of tool at very low angles. It doesn't detract from the strength or function of the carriage at all. Thing is, I think that was from doing back bevels with the required extremely long blade extensions. I don't recall a problem with short tools, but will try to refresh my memory over this weekend and report back. If presentation angles of the tool to the platter need to be extremely steep for some reason (say short tool and unusually high bevel angle), then you can easily avoid any chance of the chisel digging into the platter by simply moving to the other side and sharpening on the trailing side (i.e., the platter moving away from the edge). Overall, the QPSS works very well with a very wide range fo tools and angles.

Re: Tried out my new toy

Lyn J. Mangiameli

>I'm pleased as Punch that your experiences with the QPSS have been as positive as mine. I think it transforms ones approach to tool usage, with one now regularly maintaining (and reaping the benefits of) a highly refined edge, and tending to use choose tools that allow for very quick and easy blade removal and replacement. I'll bet you eventually experiment with an additional platter that has a very fine grit abrasive (be it "paper" or honing compound) that will allow you to leave behind the waterstone step for final honing.

I must admit, I take a slight selfish delight in your validation of my concerns with its use for working the backs of blades. I think there may be an inexpensive carriage system that could be used to insure that blade backs would be held parallel to the disk (but would require the front and back of the tool to be coplanar). I've passed the idea on to Rob, but of course it is competing for attention with a thousand of their own projects they have in the works.

Re: Tried out my new toy

Sean Evoy

>Lyn (or any other user of the system),

One of things that has stopped me from buying the sharpener is that, according to the reviews I've read, the tool holder seems to be limited to plane blades 2 1/2 inches wide. Unfortunately, this means it won't hold my #8 blade. Have you tried using the holder with wider blades?

Re: Tried out my new toy

Mick Foley

>Hey all,

I've had the MkII for a couple of months, my experiences have not been quite as good as most of the other posts for two reasons:

1. On very wide (2+") plane blades, I don't seem to get even grinding, one side is ground more than the other. I suspect that I have the tool rest slightly out of alignment and I need to realign.

2. I have not had good luck getting the finest grit disks onto the platter without bubbles. Pricking the bubbles does not seem to help because as soon as I sharpen a blade steel filings (from the blade) get into the bubble area and I end up with a slightly higher area. This leads to a bumpy ride on the finest grit and I suspect a less than ideal edge. I've gone through about five of the fine disks trying to get this right without luck.

I have not been able to spend as much time in the shop as I would like (heel spurs), so I have not had much time to fiddle with this. As I noted in #1, I think I can solve the wide blade issue, but does anyone have any suggestions for the problem I am having with bubbles?

Thanks!

Mick

bubbles... Lyn?

Jonathan Ronnow, Sweden

>I think Lyn wrote about that, it can be avoided if you spray water on the disk so the abrasive sheet "floats", and then press it in place with a roller. By working the water out you�ll also get a flat, tight bond. Like applying stickers and sun film to vehicles and glass panels.

Did I get it right Lyn?

Jonthan

Re: bubbles... Lyn?

Lyn J. Mangiameli

>Yep, exactly.

Other thing that helps, wet or dry, is to fold the disk like a taco and begin applying from the center hole out. You can also, again wet or dry, use a veneer/laminate roller to roll out radially from the center.

Re: Tried out my new toy

Lyn J. Mangiameli

>Alignment is more critical for wide blades (as it is whether you use a holder or not for sharpening), but there is another factor at work here.

The one area in which the design of the QPSS is inherently compromised is that it applies a straight blade along a radial line out from the center to the edge of a spinning flat platter. This, unavoidably, means that the abrasive is moving past the blade at different rates depending on where along the radial line the point of contact is measured. Simply, for the same RPM, the outside of the platter is moving more abrasive past the blade edge on the outside of the platter, than the inside of the platter. (Compare this to, say, the Tormek, where the same amount of abrasive moves past the blade edge, regardless of where along the blade it is measured).

On narrow blades, up to about 1 inch (i.e., most chisels), the difference in rate (i.e, feet of abrasive per second past the contact point) is insignificant. As you get wider, the differences in rate of removal do become significant. The more revolutions of the platter required, the more these differences in rate of removal add up, and become significant.

There are several approaches to minimize this. One is to try to limit the time the blade is in contact with the platter, which means to err on the side of starting with coarser grits and moving up the range rapidly by sharpening only the area needed to establish the effect of the finer grit. Second is to use more of the outside of the platter where the overall speed (f/s) is greater. Third is to apply slightly more pressure to the inside of the blade to compensate for the difference in removal rates (i.e., greater pressure enhances removal in that area and thus counterbalances the differences in removal rate). Fourth, and the technique I most employ, is to switch between the leading and trailing sides of the platter. Thus you move the opposite side of the blade to the faster outside portion of the platter. This balances the removal rates and leads to a more consistent edge. This ofen will result in a very slight crown to the blade, with the two ends being ever so slightly ground back more than the center of the blade. In my experience, this is actually a feature rather than a draw back.

A great way to measure to what extent difference is occuring (and is meaningful) and to note your progress in compensating for it, is to always mark your edge with a black magic marker. Then you have a clearly visible indicator of what portion of the blade edge has been altered in this sharpening, and the effect of your compensations.

Seriously, given the efficiency of the sharpening and the ease with which the blade can be moved from the leading to trailing side of the platter, these adjustments for wide blades pose no chore, and are easily integrated into one's sharpening technique.

Re: Tried out my new toy

Lyn J. Mangiameli

>Nope, it won't hold a #8. See my comments below for why that wide of a blade doesn't make for a perfect match to the QPSS anyway. I must admit, I like my #8 a lot and actually use it quite a bit, however, the time spent working with that blade compared to all the other blades I maintain makes it, for me, an inconsequential factor in the decision about having a QPSS.

LV should have a very nice solution to maintaining the #8 blade come Fall, and perhaps even an enhanced solution a season or two after that.

BTW, one of the things I really appreciate about Shapton Pro stones is that they are wide enough to use along their long axis for a #8 blade.

Re: Tried out my new toy

Paul M in San Diego

>I'll bet you eventually experiment with an additional platter that has a very fine grit abrasive (be it "paper" or honing compound) that will allow you to leave behind the waterstone step for final honing.

Hi Lyn,

Per your recommendation, I bought a 2nd 3mm platter and some honing compound. The 4mm platter has the 80 grit and 100um papers. The 1st 3mm has 40um and 20um. The 2nd 3mm platter has two 9um papers, and when one wears out it will be charged with honing compound. But until it wears out, I'll need to use the waterstones for a final honing.

-- Paul M.

Re: bubbles... Lyn?

Paul M in San Diego

>The taco method is what I used. I just used my fingertips to press out the width of the flat section at the bottom, while the other hand was holding up the edges. This worked pretty well, with only a couple of very small bubbles.

Re: Tried out my new toy

Paul M in San Diego

>Fourth, and the technique I most employ, is to switch between the leading and trailing sides of the platter. Thus you move the opposite side of the blade to the faster outside portion of the platter. This balances the removal rates and leads to a more consistent edge.

Another wonderful tip from Lyn. I haven't gotten to plane blades on this sharpener yet, but I'll keep that one in mind!