Re: Problems withVeritas Mk.II Power Sharpening Sy
Lyn J. Mangiameli
>Ah, the frustrations we experience in life. Yesterday I spent almost 4 hours trying to get my usually very reliable Stihl chainsaw to run-all to no avail. Fortunately I already have had so many good experiences with the chainsaw, that I didn't see it as a bad piece of equipment.
If your chisels have ground square, then it is unlikely your problems are due to aligment of the bar or defective platters. Possible, but pretty unlikely. If they haven't, then the most likely cuplrit is that the support bar for the carraige is not parallel to the platters. Your manual will tell you how to check for this and make the adjustment.
For now, lets assume that the machine is adjusted correctly and that you have now defective parts (the most likely scenario given your success sharpening the chisels). Now it becomes a matter of the inherent characteristics of the machine, and/or your technique (which in part can compensate for the machines inherent characteristics.
Others have referred to it in this thread, and I have discussed it at some length in previous threads, any rotating flat platter sharpening system (whether LV or Makita or lapidary laps), when used with a blade that travels along or parallel to a radius, will encouter different rates of abrasive passing across the blade according to how far out from the center a point on the blade is located. The differences are miniscule and basically inconsequential for blades up to 1 inch, have only minor effect up to 2 inches, and have significant effect for blades over 2 inches. Frankly for blades of 2-3/8 inches up to 2-1/2 inches (which, as you know, it the maximum the carriage will deal with), some compensatory technique is required.
First, mark your bevel with a black magic marker so that you have an easy reference to determine your progress. tis works very well if the existing bevel is square, but you may need to supplement this with frequent checks with a square if you are working with an accidentally skewed blade. Use the magic marker between each platter change to confirm you have not strayed, in the course of moving through the gits.
The next most important thing you can do is use both the leading and trailing sides of the platter. This moves the area of faster removal from one side to the other. On a very wide blade, you may still get a slight overgrind on the outsides of the blade, but rarely is this a problem, and a lot of people go to a lot of trouble to put a very minor crown on their blade such as you will achieve automatically.
Third, establish any major geometry changes with a seperate grinder or with very coarse abrasives used on the LVPSS. For major geometry changes, 80 grit is simply not aggressive enough and takes a long time. A platter set up with a 46-60 grit Zirconium abrasive is a good idea if you don't have a seperate grinder (you can get these via the latest catalog from Supergrit). I don't know if this observation is consistent with physics, but I find the more revolutions required for the grinding, the more differential effect I see on wider blades. Thus I go in the direction of starting with very coarse abrasives for geometry changes or to remove nicks, but go through them as quickly as possible.
While these steps require some thoughtful effort the first time you implement them, the quickly become part of your basic techiques and happen quickly and fluidly. I have sharpened and maintained literally hundreds of hand plane blades from a wide variety of manufacturers (not to mention chisels). I haven't found one yet that if it fit in the carriage, wasn't sharpened more quickly, and precisely with the LVPSS than any other method.
A lot has been posted on both models of the LVPSS and you can find some very good threads in the WC archives to help you get the most out of your QPSS.
