1/4" Bevel Edge Chisels

[Ken S]

Kenny,
Do you ever wonder if the invention of the skew chisel was really a botched job given a little spin by the "positive change management"?

I'm glad you are finally making progress.  Your frustrations have proved a learning experience for the forum. Good effort!

Please continue to keep us posted.

Ken

ps Many years ago I saw Duncan Pfyfe's tool chest on display in Williamsburg, Virginia.  It was behind glass, so I couldn't get a good look.  Duncan Pfyfe was probably the equal of any furniture maker in any era.  I would be curious to know how square his chisels are.  (I realize he may have had them sharpened by apprentices and who knows what happened after he died.)

[RobinW]

kennyk - Glad to hear you are making more progress.

I sometimes find that due to the taper between the front and back faces of my firmer chisels they do not always clamp flat, so introducing the inevitable skew. However as you're climbing out of a dark hole you are now equipped to work out any issue.
Fore warned is fore armed.

[RobinW]

kennyk -

KenS has started another topic 'tools for checking grinding wheel to support bar alignment'

I have added a variation using the SVD-110 Tool Rest. I have just used this and was surprised how error was introduced when tightening the usb clamps without any pressure, and likewise when applying different pressures. Small but no doubt annoying!

Assuming you have the SVD-110 Tool Rest, this should help you with alignment.

[kennyk]

The uncorrectable skewing (with a correctly set chisel in the 76) has re-emerged after another truing with the TT-50.  During sharpening, the chisel slipped out of the 76 and gouged the wheel, necessitating a re-truing.  I only managed one chisel before it was time to finish up today, but in order to get a straight edge, I had to skew the chisel considerably. 

So I'm still convinced I have a problem somewhere. I'll need to check what's going on tomorrow. 

regarding the setting using the TT-100, it's not really of much use for most of the chisels I have because they're all far too short to use even the 55mm stop.

[Ken S]

Sorry to leave you hanging, Kenny.  I was called up on grandfather duty helping my granddaughter practice the piano.

The use of the 55mm slot is not at all important.  The idea was to combine a known distance from the grinding wheel to the support bar and a known tool length projection.The 55mm slot is really for turning tools.  The projection length can be whatever works to give you the bevel angle you wish with the support bar distance you choose. The slot or end block is just there to make the distance repeatable without any need to measure.

The idea is repeatability.  Once the two distances are correct for the first tool, any number of tools can be ground the same way without any more measuring or adjusting being necessary. For many of us, myself included, repeatability is no big deal.  Sharpening three of four chisels occasionally does not require speed.  If I had your workload, I would definitely standardize. Incidentally, the correct projection distance for a twenty five degree bevel using the "A" setting with the TTS-100 is approximately 1 3/4" (forty something millimeters).

Using Robin's idea with the SVD-110, you are free to choose any distance you wish from the grinding wheel to the support bar.  I believe it makes sense, especially in your situation with so many chisels and planes to sharpen regularly, to pick a distance and stick with it.  As described in the handbook, you can easily make a wooden "feeler gauge" to return to that distance.  Check out the chisel sharpening you tubes on the Lie-Nielsen.com channel.  They show a simple and effective board with several pre set distances. The board would work just as well setting the tool with the Tormek.

The wooden feeler gauge might be adequate to check for parallel between the grinding wheel and the support bar.  I would suggest using Robin's idea with the SVD-110 as a double check until you either feel confident or not with the wooden feeler gauge.

Hang in there.

Ken 

[kennyk]

I've had a look at the edge of the wheel against the 110. and it's convex, with a high point towards the middle.   I've tried truing it with a number of passes.  I've set the height as per the instructions and run the TT-50 back and forward a few times without adjusting the height.   There is definitely something wrong here because the diamond tip is still  catching the low point at the outer edge after several passes back and forth.  I'm starting to get really fed up with the machine again. At this rate I'm going to need a new wheel very soon.  It's down at 235 already because I can't get it level.

Is the TT-50 meant to rattle?  is there meant to be 0.5mm vertical play in the threaded square bar section that holds the diamond tip?

For the level of performance this machine promised,  the tolerances that I've enountered are shockingly bad, that it is very difficult to get an acceptable result.

I'll be honest. If I'd personally shelled out for this machine, It'd have gone back a long time ago.  I've not got one single chisel to an acceptably straight AND square enough edge that I'd use in my own guitar making workshop.   Even the plane blades are more convex than I'd like.  I'm used to getting far more accurate results with nothing more than Japanese waterstones, or 'Scary Sharp' (3M lapping films on float glass)

The further I get into this to troubleshoot, the more problems I'm experiencing.  With this level of vertical play in the TT-50  I cannot see how it is possible to correct the curve on the stone, as the tip has a tendendency to drop.

[Ken S]

The trouble with the TT-30 dresser came up a couple years ago on the forum. Ionut, one of our very experienced members from Canada and sadly no longer active, suggested placing a zip tie through the compartment which holds the diamond to the threaded rod.  The tie goes through this and around the top of the jig. I did that and have never had a problem with the dresser.  The zip tie has just enough friction to dampen movement but not to prevent being able to move the diamond across the grinding wheel.

I agree, it does seem Mickey Mouse on a sharpening system in this price range.  however, I have not had a problem with it.

This solution was not endorsed by Tormek at the time, and is probably still not accepted. I submit it to you as a quick and inexpensive possibility. A hardware store should stock zip ties.  As a quick temporary fix if you can't locate zip ties, try door bell wire twisted or a plastic twist tie.

Ken

ps If you can't find good zip ties locally, Private Message me and I will mail you some.  Not a fast solution, but they are useful for many things.

[Ken S]

Maybe a tested and known good SE-76, universal support bar and TT-50 overnighted from Sweden to Kenny in Scotland?  That would eliminate his equipment from the trouble equation.

Ken

[kennyk]

I've just received a replacement SE-76 from Brimarc, the UK distributor.  I'm still getting the skew with every  single chisel.

The only way I can correct it is to physically pull the support bar up with my left hand as I work on the chisel in either SE-76 with the other hand.

[Ken S]

I just checked my support bar.  When clamped, it is tight.  I don't detect any play.

I wonder if one of your clamps is not tightening properly.  Try placing the long rail of the support bar in one of your clamps and verify that it is indeed tight.  Then try the other clamp.  Also, make sure the cones which hold the clamping screws are tight.  (Try all four.) Do you have the same problem with the horizontal clamps?

If all these are tight, I think it's time for the rep who travels to Scotland every twelve weeks to quickly reroute his itinerary and visit you.

Ken

[kennyk]

Yes, it is tight.  I'm wondering if it's got a slight downwards bend in it.

[SharpenADullWitt]

Besides the bend possibility, I would check for both bushings to be loose (see the tool diagrams on the Sharptools site), look at the welds of the bar (make sure you see no cracks), and am wondering about the hardening/annealing (not sure proper term) of the bar?

[Ken S]

Kenny,

My two support bars are square when held up against a combination square. if yours isn't square, it's bent.

Ken

ps Maybe Tormek should hire you as a troubleshooter after all this. You certainly have experience with troubleshooting most of the common problems.

[kennyk]

I've got a granite lapping block  http://www.axminster.co.uk/small-granite-surface-plate which is probably as straight as I'm going to get.  when I put the usb up against it, with the legs upright, I'm getting a tapered gap that starts a couple of inches after the micro-adjust leg.  it's a bit tricky to measure but I managed to slip a 4 thou feeler gauge  (think that's about 0.1016mm) under the gap at around 3/4 of the way along.  it's not exact but there is definitely some light.   also it sometimes feels like there's a slight 'rock'  to it. but I was rushing a bit when I did it.
Due to the weld I can't tell if it's got bend in the other axis, as the support doesn't lie down flat on the granite.  Unfortunately I don't have an accurate enough straight edge.  I could use a 12" rule but I suspect its nowhere near accurate enough.

I'm planning to bring the T-7 home tomorrow night and spend most of next week when I am on leave to look at it.     

Did you mean the motor bushings? or something else that I should check?


Sitting down with a nice hot cup of Rooibos tea, (I've had my coffee quota for the day, 2pints of black!) I'm tryin to reason out what could be causing the problem.   The obvious one is user error.
The only other possibilities must now rest with the interfacing between the surface of the grindwheel and the edge to be sharpened.

So that means the areas I need to look at are:

a) bent support bar
b) support bar legs not 90 degrees
c) support bar not in correct alignment with the wheel. (squint)

the thing that I've noticed when I tighten the support legs is the tendency for the non-adjust leg to be pushed away from the screw (as one would expect).  What if the other leg isn't being pushed as far and it's introducing a squint that way?  as the microadjust is the pivot point, any point further away on the other side of the pivot would automatically show the opposite error but larger.  I could be barking up the wrong tree, but I'm now starting to clutch at straws trying to resolve this.

[SharpenADullWitt]

By bushing, I am meaning the sleeve the USB goes into.  (figure if loose at all, it could add more play to any bar issue)
I think if the ones on motor had play, you could see that in the stone when running.