How to get the angle...

[beer is good]

I have embarked on a campaign to restore some old chisels and planes I have inherited. Having considered all the various methods promoted (Tormek, scary sharp etc). I have got a 6" bench grinder, a couple of waterstones, the Veritas honing guide and a CarbaTec tool rest. I have started using the Alox wheel on the grinder

What I am stuck on is getting the chisel at the right angle on the bench grinder to grind the 25 degree bevel.

What is a quick way to set this bevel angle? Any recommendations on books?

[Skew ChiDAMN!!]

Many woodturners use a grinding jig (http://www.cws.au.com/shop/item/sabre-grinding-jig) to get their bevels about right. (There's a whole slew of different brands out there.)

They don't have preset angles because as the grinding wheel wears away the angle changes anyway. But if you already have a chisel ground to 25°, it's easy enough to use it as a template to set the table.

Just colour the bevel with a black marker and place it on the table, pressed against the wheel... while it's turned off. Turn the wheel by hand a few turns and then check where the "scrape marks" are... they should be in the centre of the bevel. If not, adjust the angle slightly, reapply the marker and test again.

Not perfect, but with persistence it'll get you close enough to move on to a whetstone.

(Always remembering that the angle will change as the wheel wears... but that should be a matter of days or weeks, not minutes. :; )

[msiemsen]

I have a stick with the angle cut on the end that I keep by the grinder to use as a gauge for setting the tool rest to wheel angle.
Mike

[rsser]

I think there's real benefit in standardising your bevel angles if you've got a lot to do.

Just make up a wood block guide of the type in the bottom right picture here (http://www.leevalley.com/US/wood/page.aspx?p=32973&cat=1,43072,45938) with the common angles you want to grind.

Which angles is a matter of application.

25* with a 5* secondary bevel for softwoods perhaps; add 5* for hardwoods. Steeper with mortice chisels.

The bible on sharpening is Lee's Complete Guide to Sharpening. Highly recommended.

[STAR]

I think there's real benefit in standardising your bevel angles if you've got a lot to do.

Just make up a wood block guide of the type in the bottom right picture here (http://www.leevalley.com/US/wood/page.aspx?p=32973&cat=1,43072,45938) with the common angles you want to grind.

Which angles is a matter of application.

25* with a 5* secondary bevel for softwoods perhaps; add 5* for hardwoods. Steeper with mortice chisels.

The bible on sharpening is Lee's Complete Guide to Sharpening. Highly recommended.

-------------------------

Ern's direction to the Veritas grinding Jig is interesting. I received one for Christmas. I found it did what I wanted an overcame some grinding set ups very well.

But I do not think that I was completely happy with the special angle jig that came with it. It appeared hit or miss to me. I have the white wheel and various protractors and a Kell brass angle checker.

However, what I did because i have some 4mm white perspec on hand , cut some into the width of the stone and about 150 mm long. I then grabbed a chisel that I had that was about 25 degrees to set the Veritas grinding jig in place then just transferred the perspec to the jig and ground back the angle to 25 degrees.

I did a few, now all I have to do is to check with this rather then the bit iffy angle jig supplied. When I transferred the chisel over to the Veritas MK 11 honing guide it matched up with the 25 degree gave it a few wipes on the water stones and then reset the micro bevel to finish off.

So, by making your own guides , as someone had said works well. Sure in time the wheel will get smaller and you will have to rejig your 25 degrees, but the number I do, it will not Be next week that I have to worry about it. Providing it allows me to put a micro bevel on the Veritas honing jig, close enough is good enough for me as the result is still razor sharp.

I give this caveat, that I am still learning this sharpening thing but I am way past being a beginner. in sharpening at least.

Pete

[rsser]

Yeah, it's a limited guide and works best when you get your platform as close as poss to the wheel.

Years ago when Carba-tec used to sell one of the two std cheap replacement platforms they provided a photocopied sheet with templates for various tools and angles.

You could use spray adhesive to stick it to a piece of card and then cut the templates out with scissors.

[rsser]

To add re making your own, and I'm not quite clear on Pete's method so apologies if this is duplicating ...

You will need a method of measuring the bevel angle. In the pic is a Veritas jigger.

Find a chisel that has the angle you want (there must be one!), use Skew's method of setting the platform angle, and then make a template by laying a bit of card on the table that extends past the wheel circumference. With a pencil mark that arc on the card and cut it out. The card should be about 125 x 25mm.

You now have a guide for that angle.

Yes, as noted the wheel will reduce in diam as it wears so make another guide or estimate the variation and adjust accordingly.

Hope this helps.

[derekcohen]

The template idea is on the right track, but flawed as it is.

I made similar templates for 25- and 30 degrees by grinding into wood.

Blades of different thicknesses require slightly different settings for the same bevel angle.

The answer is to set the template on top of the blade when setting up for grinding.

http://www.inthewoodshop.com/WoodworkTechniques/AngleSettingJigForDryGrinder_html_m10e41ef0.jpg

Article: http://www.inthewoodshop.com/WoodworkTechniques/AngleSettingJigForDryGrinder.html

Regards from Perth

Derek

[beer is good]

Thanks guys for your help and suggestions. I am about to hit the shed and have a go (Saturday 3.30pm). :?

Ern, I have ordered the book you suggested. $14.80 plus freight from Amazon, $59 from Carba Tec. So I also ordered a book about hand planes as well. Both books landed here for $53. That should really upset Gerry Harvey!!

[rsser]

Hope so!

BiG, the Lee book is a gem and at that price an excellent investment.

Derek, thanks for that post. V. hepful.

Are you still buying SG wheels from overseas? (Or is the Blue Max one of that breed?)

[rsser]

Just to add, I got the Veritas angle checker (as per post #4 above) to work by aligning the very heel of the bevel with the grind wheel, with the platform as close as possible to the wheel face.

[derekcohen]

Hi Ern

I use the angle checker on my 8" dry grinder. I purposely sited the rests so that this can fit below the guards.

Regards from Perth

Derek