Grinding distances

[Democritus]

Hi Guys

I’ve acquired a OneWay type sharpening system , with the ‘swinging’ gouge clamp thingummy.
Can any explain how I calculate the distance the pivot slide needs to be out for different bevel angles? Mike Waldt recently put a video on YouTube where he showed the use of bits of wood to set distances for each of his gouges, but he didn’t say how he worked out the lengths needed.
Any help gratefully received.
D.

 

[Phil Pascoe]

Trial and error, I suspect.

 

[Orraloon]

I dont use the Oneway but sharpening any chisel on a wheel is trial and error. Offer the bevel up to the wheel(switched off) and adjust rests/jig to get the whole bevel on the wheel. Then turn on and just a quick touch of bevel on wheel. Check the mark ground goes all the way up the bevel to the edge. Repeat until you get that then you are ready to grind. Also at that point you can note those settings for next time.
Regards
John

 

[Richard_C]

I don't use one way, but a similar homemade device.

As John says, trial and error. Even if you could calculate, wheels wear and diameters vary. Another way to check is to use a marker (sharpie or similar) on the existing bevel, turn wheel by hand and see what wears off.

Oneway (Oneway.ca) have downloadable manuals which might help. Keep scrolling down, after lathes, accessories, chucks you get to other stuff.

 

[Jonzjob]

I have the One Way system and Orraloon is correct.

First to get as close as possible by eye with the wheel switched off. Then I flick the switch on/off so the wheel isn't at full speed and touch the gouge to it and see where the new bright patch is.

I am not a fan of the shaft distance locking lever on it, but then just loosen the clamp and you should only need to move the shaft a very small amount, re lock and try again.

It takes a hell of a lot longer to explain than to do, but with a bit of practice it's very quick. I also have the One Way True Grind OBC wheel. It cuts quickly and cool and stays the same diameter. Expensive, but worth it.

 

[Sandyn]

Pythagoras or try looking on-line. You can find calculators for most things

 

[D_W]

Take something that's already set at a certain angle and get the wheel to scratch right in the middle of the bevel and record the distance. I went to school for mathematics and I'm all for hobby calculations of things, but this is the case (just like the discussion in the HT side about effect of skewing a plane on effective cutting angle, just make a triangle, turn it and measure the angles), I think making a projection stick with markings on it from a couple of trials will be better than referring to literature and knowing specific numbers.

 

[Terry - Somerset]

Use a felt tip to colour the bevel - it will be immediately clear whether the angle is right.

IMHO + or - a degree is really unimportant - the main thing is a consistent bevel angle to develop familiarity.

I have a Sorby jig - I am not sure how the One-Way works but the gouge can be consistently clamped in the same position to get the same bevel angle by fixing a small block to the the worktop the required distance from the edge.

 

[Jacob]

Easy enough to visualise 30º. If practice needed pinch a school child's 30/60 protractor and stare at it for some time.
The only other angle you need is something close to slightly less than 30º

 

[Richard_C]

A further development here. I needed a new door handle set, and with it came the square bar that goes through the latch. That gave me a spare square bar. So I set the rest to be right for my scraper, sharpened it and then ground one end of the square bar to the same angle. That gives me something to set it by next time. Bar has 2 ends, so will grind the other end to match my spindle gouge and see how I go. A way to test settings without grinding bits off the tools.