Mixed feelings about svh-320 so far

[Rob]

I took delivery of the beast today and started on my startrite sd300 planar/thicknesser knives at 6:30 pm. Im now sat typing this at nearly 1am and im pretty gutted at the results

I've had no problems lining it all up and getting both angle and parallelism right. They were just fiddly but do-able with patience.  It's the sheer lack of metal coming off the wheel that's driving me insane

I've regraded three times now, I'm doing about 6 passes before I need to reactivate the wheel with the 220 grader.  Im talking aggresive grading such that the wheel stops turning!  The blades can't possibly be carbide, they're HSS I'm certain of it.  Basically the wheel just isn't man enough for the job. All three blades have a nick that's about 1/2mm deep. I'm now 6 hours in and still the 3rd knife to do AND the flippin nick hasn't gone!  What's being ground is my wheel, not the planar knives!

Does this mean I have to shell out even more cash for the black wheel?  Will the black wheel take steel off significantly faster?

I'm not upset with the principle behind the jig, it works, just the time taken so far.  Is there anything else to be done?  Does the black wheel really shift HSS fast?

Could use come good news after tonight's marathon

[Rob]

I've just re-read Ionuts classic experience with the same jig. The way he describes the speed of steel removal but no grading leads me to believe his knives were considerably softer than mine

[Ken S]

Ionut also made the comment that the Tormek wheel has three gradations of coarseness:  When the wheel is dressed with the fine side of the grader; when the wheel is dressed with the coarse side of the grader; and, the most coarse, when the wheel is freshly dressed with the diamond dresser.

I haven't tried it, but, it might help shorten your marathon tomorrow.

Good luck, and keep us posted.

Ken

[Rob]

That's exactly right Ken. You can even go a grade more rough by whizzing the diamond dresser faster than normal over the wheel. Doing it like that leaves a really rough surface. My problem is I'm just not prepared to stop grinding every few minutes and redress the stone. Frankly, that just says not fit for purpose in my view

That's why I'm thinking blackstone. Then you have to layer on another £130 for the wheel. Well I've just spent £109 on the planar jig. I could have bought a controlling interest in my planar manufacturer by now!  The blacstone could be considered a replacement for my regular wheel just a little early so I can probably sell it to myself but to be honest I'm whincing a bit at the cost of "saving money by sharpening my own planar knives".  I won't have broken even till I'm a hundred and sixty three!

[Jeff Farris]

Rob,

Before you give up, or invest in a Blackstone, something in your post gives rise to a question.  If you can easily stall your machine, I think your drive wheel might be slipping. It should take nearly all your strength to stall the stone. Take the honing wheel off and clean the surface of the drive tire with a bit of coarse sand paper, and see if that doesn't give you considerably more torque.

Also, when grading with the coarse side, tip it up so that only the corner is engaged on the grindstone. That makes it easier to bring back a faster cutting surface.

[Rob]

Hi Jeff

I appreciate the thought, really I do. In fact when it got to about 10pm last night I nearly telephoned sharptools as I knew with the time difference you'd be there still. I was getting a bit rung out.

I had already taken the honing wheel off because my SG is about half left and the jig was knocking into the strop right from the off so that had to go early on.   The drive shaft was a bit dodgy at first so I took it right off (mine has the 19mm lock nut and not the new ezylock) to inspect and generally maintain the guts. It was all good.  Remounted and went to work so that wrinkle was ironed out. Once really tight, I must say it was difficult to actually stall the wheel but I was really leaning in it believe me

With respect to the corner of the grader, I've always done that since watching your instructional many years ago.  That meant the only method of really activating the stone was with the diamond dresser.  it cut well after that but literally a few passes in and it was smooth again.  I should add here that regrading did activate the stone and it did then cut again, its just it glazed very quickly whereas truing gave the most performance, exactly as you would expect

Either I'm doing something else wrong or my steel is just too dam hard. Before I started I'd used a sharpie and checked the bevel was cutting right across. I used Ionuts light behind the wheel approach to check parallelism and I double checked with feeler gauges. I'm pretty convinced I had the setup good enough as I was determined not to get tripped up by that. To be honest I was completely taken by surprise when it failed to cut because that's never happened before, even grinding the wings off fingernail gouges in HSS

I will say that I'm eternally grateful to this forum for its intelligent support. Without it I'd feel isolated to say the least

So Jeff, what's your honest opinion on the blackstone. If it works ill make the splash, I'm kind of half pregnant now, no going back so if it works, I guess I'll justify it on the basis that I'd buy one anyway when I replace the SG. But I absolutely positively must be certain it will make the difference.  I would really value your input on it please?  How does it perform speed wise for steel removal, do you need to regrade as often as the SG and does it wear more slowly?

Input gratefully received

Rob

[Jeff Farris]

Knowing now that you're a turner, I will urge you to go with the SB-250 Blackstone...with some minor reservations in regard to planer blades. Let me explain.

The SB-250 will undoubtedly cut faster and resist wear better than the SG-250 when cutting HSS. The minor reservation is that it still isn't "fast" when doing planer blades and you will use the stone grader frequently to keep it cutting. There's no question that it is faster than an SG, but it isn't as fast as some people expect it to be. It's a problem that has been around as long as men have understood abrasives. Given the speed of the wheel and the desire to keep the steel cool, a stone that would really cut fast would leave a very undesirable finish. You will notice an improvement over where you are, but don't expect miracles.

Now, something else caught my attention in your last reply. Having the wheel down under 8 inches in diameter (so that you have to remove the honing wheel) means that your surface feet per minute is down significantly, too.

Switching to silicon-carbide and getting back up to 10" diameter will make that job less arduous, but it still isn't a day at the beach.

[Rob]

Interesting Jeff. I hadn't even thought about stone diameter. I guess the fact my old stone is getting smaller sort of half justifies the blackstone anyway :-). Notice how I'm cunningly selling myself on the idea

I'm glad you put the reality in perspective too because I'd rather have a realistic expectation of its performance.

I finished the third blade this morning after truing the wheel again. One of the up shots of needing to true the wheel whilst in the middle of grinding planar blades is that you can forget the old settings stay the same chestnut. Now you've reground the wheel the knife doesn't even touch it let alone be an accurate mirror of the previous knives depth setting. Because of course so much ceramic has disappeared.  However I've reinstalled the knives already and after jointing and thicknessing a piece of scrap its thickness at the four corners was out by only about 2 thou.  The finish quality was ok but for those nicks that I couldn't go deep enough to grind away. They're a good 1/2mm in and I just can't spare that much time

The good thing I guess about little metal removal is its very difficult to put the blades out of balance!  She's certainly cutting much finer, less noisy, you know that feeling of fresh blades, its a joy

I guess also another plus is with bowl gouges because despite considerable efforts to push the grind across the wheel you do tend to wear a groove down the sweet spot.  The silicon stone should resist that better

Ok. Done.  Sold :-)

I'll probably have another punt at the planar knives when it arrives.  Will let you know. Thanks again or the support

R

[garyls43]

I tried sharpening a set of planer blades for a customer (I own a small sharpening business for which I bought the attatchment) went ahead and bought the blackstone because the standard stone was too slow. I spent another 3 hours and still couldn't get them sharp. The planer blades were flat and grinding the concave edge was just too time consuming to make a profit.

[Rob]

so what did you do in the end if you don't mind me asking?

[garyls43]

I gave the customer his blades back free of charge so he could send them off to be done or buy new ones since they are cheaper to buy new. I no longer do planer blades.

[Rob]

Honest of you...nice one

[Rhino]

Is the wheel mounting hardware generic?  I don't have a lot of experience with machines - that's why I ask.  I wonder if buying a diamond wheel would make life easier.  Are such things available?  Just thinking about this situation.

I got a nick on my 12 inch chef's knife 10 years ago.  It always cut through lobster like butter.  Then I bought a 5 pound lobster and the blade chipped.  I guess a 5 pounder is very different from a two pounder.  Of course, now I have to eat rabbit food to keep an eye on my health so this problem will not come back.

Everytime I use the Tormek (last 5 years), I try to spend as much time on the Chef's knife as possible to grind the knife down, I still don't have it in the shape I want.  It is a long slow process .  A low speed grinder with the Tormek support is certainly on my mind for this winter - just for fun.

[Jeff Farris]

This is pretty off subject from the original post, but since it is here, I'll comment about knife shaping...kitchen knife shaping.

What you've posted, Rhino, leads me to believe you're not getting your stone thoroughly cleaned with the stone grader. I would never contemplate putting a chef's knife on a dry grinder, no matter how badly damaged it was. Reshaping, or even re-tipping a blade should be a matter of minutes with a clean, well graded Tormek SG stone. If you can't get a clean cutting surface from the grader, use the truing tool to open the stone up so that you get an idea of where it can be. That fast cutting action you get right after truing should be achievable (or nearly so) by a properly applied coarse grading. You've got to apply pressure, and you have to tip the grader up so that you're using the corner to rip up the surface of the grindstone. Don't baby it and don't stop until you can feel the grit with your fingers.