How to achieve grind angle?

[ByronBlack]

Hi everyone,

I have a rather simple question. Today i've been trying to re-grind all my chisels, they are in a rough state at the moment, and I aim to re-sharpen them according to Mr C's DVD's. However, I have an axminster grinding jig, but for the life of me I can't determine how to setup a repeatable and measureable 25degree grinding angle..

How exactly do you measure 25degree's to the relation of the grinding wheel using one of these jigs? I've tried to use a protractor/sliding bevel, but I don't know what to reference off, I'm probably not seeing the wood for the tree's on this one,

Any help will be gratefully received!

 

[Lord Nibbo]

I'm not sure what jig you got BB, but maybe you could determine the angle the same way as you do with a tormek.

Starting with a chisel you know to be correct, cover the whole face of the ground edge with marking ink (felt tip marker) now offer up the chisel using the jig and rotate the stone, now look at the blade and see if it touches all the ground edge if it dosen't start again with marker ink and readjust the jig, repeat until you remove ink from the whole face, when it does the jig is ready to do any chisel the same angle.

 

[kees]

Hi everyone,

I have a rather simple question. Today i've been trying to re-grind all my chisels, they are in a rough state at the moment, and I aim to re-sharpen them according to Mr C's DVD's. However, I have an axminster grinding jig, but for the life of me I can't determine how to setup a repeatable and measureable 25degree grinding angle..

How exactly do you measure 25degree's to the relation of the grinding wheel using one of these jigs? I've tried to use a protractor/sliding bevel, but I don't know what to reference off, I'm probably not seeing the wood for the tree's on this one,

Any help will be gratefully received!

search for "grimsdale" he's the anarchistic woodworker here.
or old articles of John Brown in GWW. Then you have all the antichrists together.

 

[ByronBlack]

Nibbo - thanks, i'll give that a go, I just need to find a chisel that is 'correct'

Kees - I don't think grimsdales rough stones of wisdom will help me in this particular subject, but thanks anyway.

 

[engineer one]

simple maths mate

where is the centre of the grinding wheel, assuming you can see it, then you can set your grinding support at that point. then mark the wheel there.
now us your cheap wh smith protractor or angled rule, at 25 degrees, then mark the wheel above the centre.

now set your chisel support so that a chisel when pushed against the wheel will meet the wheel at that angle. then make a jig

i would think about cutting a piece of wood to the angle of 25 degrees

sounds more complex than it is.

but you strike the centre line from approx the centre line of the nut holding the grinding wheel on.

paul :wink:

 

[ByronBlack]

Thats excellent paul! Thanks, now that you mention marking the centre of the wheel, i can see how to adjust to the angle, I just couldn't visualize where to reference from.

 

[mr]

Paul I thought you had left us, obviously not - hurrah!

B to the 3 its a question Ive often asked myself, it's kept me away from the the grindy thing.

Paul what do you do if you can't access the centre of the wheel? Where do you measure your angle from so as to hit any given bevel angle.

Kees - 16 posts in and your talking about Mr G and Antichrists? Not to mention John Brown in the same breath? A boy would almost wonder...

Cheers Mike

 

[David C]

Byron,

Why not make a wooden stick with 25 or 23 degrees on the end and use this as a model or template to offer up to the wheel and rest?

In my system of sharpening grinding angle does not need to be precise.

+ or - 2 degrees makes little difference.

I usually go for the "suck it and see" method, grind at approximate angle, note settings, measure actual ground angle with protractor board, adjust settings next time to get closer etc etc

Black felt tip on an existing grinding bevel gives very precise visual feedback after the very first light touch. This can even be done with the wheel static, if the chisel/blade is rubbed from side to side.
best wishes,
David

 

[engineer one]

mr, keeping my counsel i think is the phrase :roll:

as for finding the centre, well actually i think my suggestion is almost
always going to be feasible since i would have thought, and experience suggests that ALL grinders have to allow you to access the drive shaft to
remove and replace the wheel.

sometimes the case may split, but the centre is always through the nut.
even on my old mole hand grinder which now works very well
not that i have had the courage to use it

dc, you are of course right a degree or two make little or no difference, and i agree about making a wooden jig. 8)

paul :wink:

 

[ByronBlack]

David - thanks for the tip. I think i'll try the wooden stick approach first and see how I go, I think if i'm correct from watching your DVD's; you grind the plane blades and chisels primary bevel both at around 23-25 degrees - so in theory, once I have my grinding jig set, I could bolt it down and never have to move it again?

 

[Derek Cohen (Perth Oz)]

Byron

I assume your Axminster is a high speed grinder?

I use a 6" grinder with the Veritas grinder rest, and to aid in getting the angle I want, I use the Tormek Pro AngleMaster.

This helps in keeping the angles repeatable. A hollow grind makes freehand honing much easier.

Regards from Perth

Derek

 

[engineer one]

bb, the only thing about bolting things down is that you have to ensure that
as the chisel gets shorter, you might well have your grind angle changed by the ferrule, or tang of the chisel.

otherwise probably in our mutual lifetimes it won't make too much difference.

paul :wink:

 

[Mike R]

Derek,
Do you have any difficulty anchoring the jig or do you just hold it to the grinder?

Thanks,
Michael

 

[Derek Cohen (Perth Oz)]

Do you have any difficulty anchoring the jig or do you just hold it to the grinder?

Hi Michael

I assume you mean the Tormek jig and not the Veritas grinder rest.

The Tormek AngleMaster is just hand held.

Here is my power grinder (I have a hand powered version as well), which uses a 60 grit Norton white wheel and has a hard felt wheel on the other side.

I have just one picture of the Tormek AngleMaster in use - and I did so incorrectly in the picture. Must update it. Here the jig is applied to the grinder rest. It should be applied to the top of the blade (behind the beve) while the blade is on top of the grinder rest.

There are two downsides to the jig: the first is that it was designed for wheels of 8" and above. It works down to a 6", but if your wheel drops below this size, then it requires a slight modification to the set up screw (evident well you use it). The other downside is that there is not much room to measure with a 6" wheel, which is why I removed the guard. I plan to get an 8" machine in the future, nevertheless, this one works very well.

You do get an angle setter when you purchase the Veritas grinder rest. It is also possible to make one similar (which is the cheap option). But I never found this jig easy to use on a round wheel (I use it instead on the beltsander, which is how I grind flat bevels for BU plane blades).

Regards from Perth

Derek

 

[lurker]

Derek,

The lack of guarding on that grinder will have Scrit spinning in his cyber grave.

 

[ByronBlack]

Thanks for all the advice and pics.. I've managed to create a setup that works and gives repeatability, so today I shall mostly be grinding and sharpening

 

[George_N]

I use a very similar set up to Derek Cohen. I have a very cheap high speed grinder (6") and a Veritas tool rest. The Tormek Angle master jig makes getting repeatable angles very quick and easy.