Thread: Sharpening jig

I think you will just have to play with it . I use a "trugrind jig " and it didn't come with much information .With the trugrind , the bit sticking out the front of the jig is a constant and you vary the angle of the leg and the distance the pivot point is from the grinder .I just ground a freehand angle to about what looked right then adjusted the jig to match it .I then ,over time , adjusted the jig to produce a grind that I liked . I recall it took me the best part of a day to get near what I wanted for all my tools .
Ted

I suggest you watch Doug Thompson's video.

Sharpening - Thompson Tools

Originally Posted by Fumbler

T
Problem is, I have the booklet with the settings ie a, b, c etc, but it doesn't give dimensions etc for distances from the lathe etc.

Do you mean the distance from the grinding wheel? I also use a TrueGrind jig, and as TurnerTed advised the chisel sticking out in front of the jig is a constant and the a,b,c, just adjust the angle (as does the distance from the pivot point to the grinder). The Truegrind instructions are to have the chisel protruding 50mm from the front of the jig and this works fine for me whether I am sharpening bowl gouges, parting tools, detail gouges, skews etc. A small timber stop set 50mm from the edge of the stand makes it quick to set up your chisels for grinding. If you would like a copy of the TrueGrind instruction sheet and set up, just PM me. The best advice I have had for sharpening is "sharpen gently and frequently".

Cheers, Gary H

Thanks. I was using 50mm, and in between waiting for a response, I did just as Ted suggested. I first eyeballed it then put marks on the jig and the foot rest. I also made notes of which tool gets which settings so can repeat with each tool.

i will have a look at the attachments and see if any clearer. Thank you.

You have almost a direct copy of the Oneway Wolverine sharpening jig.
Go to the Oneway site and download the Wolverine/varigrind manual and you will find all the settings you need.

ONEWAY Manufacturing

The distance, therefore grind angle, is a deeply personal thing.

I'm not sure what others use, but I like some of my spindle gouges slightly more obtuse, but my skew ground with a curved sweep and flatter sides.

Took me a little to settle into the right depth to set it though!

Having made a few DIY gouge sharpening jigs and purchased a few (4 at latest count), I think the critical factor is the length of the leg to the fulcrum. That is the one factor that you can't change. Everything else is a variable that you set to get the grind you want. If you are using the instructions from a commercial jig make sure the above distance is the same as yours.

Fumbler, what is the distance from the toe to the fulcrum on your jig?

The other factor that might have some influence is the distance from the fulcrum to the front of the jig where you start measuring your tool protrusion. The fulcrum on yours looks to be closer to the front of the jig than either the tru-grind or vari-grind, but I might be misjudging that.

If you measure that distance on yours someone can tell you if it is the same as either of the above jigs, which someone on the forum is likely to own.

Originally Posted by NeilS

If you measure that distance on yours someone can tell you if it is the same as either of the above jigs, which someone on the forum is likely to own.

I measured the relevant components on my Tru-grind.

Fulcrum to toe approx 145mm
Fulcrum to front of jig 50mm
fulcrum to bottom of V holder 25mm

All the best.

Originally Posted by NeilS

I measured the relevant components on my Tru-grind.

Fulcrum to toe approx 145mm 194mm
Fulcrum to front of jig 50mm 48mm
fulcrum to bottom of V holder 25mm 23mm

All the best.

Ok, I have put my measurements in bold

OK, the last two are not significantly different to the Tru-grind, but perhaps significantly different from the Vari-grind to make a difference.

However, the 194mm for your fulcrum to toe (194mm) length doesn't match either the Tru-grind or the Vari-grind, which is 168mm (6-5/8").

http://azwoodturners.org/pages/tips/...erSetupJig.pdf

So, your jig is not a replica of either and their instructions will not be helpful.

If it was mine and I was finding it hard to know where to start I would make up another leg the same length as the Tru-grind and use their instructions. But, I wouldn't be making any more of them for others or Woodcut might be paying you a visit...

https://www.woodcut-tools.com/upload...t_trugrind.pdf

I don’t plan on doing anything other than using myself. I downloaded the plans from here

https://www.youtube.com/watch?v=sfmIv0iXjis

Originally Posted by NeilS

I would make up another leg the same length as the Tru-grind and use their instructions.

Fumbler, one further dimension to take into account is the height from your slide to the centre of your grinding wheel. Someone (who knows what he is talking about) pointed out to me that the YouTube video clip you are basing your jig on omitted to provide that detail and did not point out the importance of that dimension.

Each manufacturer provides a measurement for the height that the wheel centre needs to be above the base board (or bench top) to match their particular jig. For Woodcut's Tru-Grind it is 6" to 6-1/2" and for Vari-Grind from OneWay (using their Wolverine slide) it is 6-1/4" to 6-1/2'. As you can see they are quite tight tolerances.

There are also additional height adjustments that need to be made for anyone with a 6" wheel (or significantly worn down 8" wheel).

The above dimensions have take into account the final height of the slide pocket above the grinder base board (or bench top). If the pocket on your slide has a different height from the base board than those supplied by the manufacturers then your results are going to be different, even if your tool holding part of the jig matches theirs. You will need to take that dimension into account and adjust for it.

The downloadable Woodcut manual provides good instructions on setting up the jig to reproduce your preferred grind (or someone else’s) from a gouge that is already ground to that profile. Woodcut also make a sampler that you can use to do this for two standard grinds (it's not made from cutting steel, so just a jig setter).

CWS Store - Woodcut Tru- Grind Profiler

Of course, it is cheaper to borrow a gouge from a very experience turner and replicate that. You might also get some invaluable advice along with that.

Glenn Lucas sells cards with the setting numbers for all of the well known jigs to reproduce his preferred grinds. Not a bad place to start if you are not sure where to begin. When you have turned as many bowls as Glenn has you will be ready to start adjusting the grinds to better suit yourself...

Sharpening Charts – Glenn Lucas Master Woodturner

All the best and, as always...