Beginner: Spindle and bowl gouge grinding angles question.

[Stevekir]

Returning beginner here. I have set myself up with a lathe (Axminster AH-1218VS) and some bits including their £93 set of tools in a wood case. After practicing beads and coves on softwood, the spindle gouge seems blunt and I need to sharpen it. I have a Creusen 6" electric  grinder with two wheels: grey, rough; and white, smoother. I will of course be using the white one. I had read that these two gouges are normally ground with a different curve on the wings by using the Woodcut etc. jigs.

I have accurately measured the angle of the spindle which is 30 degrees, to my surprise both at the tip and at the wings (unlike the bowl gouge whch as different angles for the tip and the wings). (Please see attachment for my understanding of the definition of grinding angle.)

The spindle gouge seems to have been sharpened by simply rotating the tool about its axis, without any change in its 90 degree angle to the wheel from left to right, so producing a ground surface which is part of a cone (like on a roughing gouge). It was rotated (about its axis) sufficiently far clockwise and anti-clockwise to produce sharp wings (unlike a roughing gouge of course). It seemed to work alright.

The bowl gouge has a different angle at the wings, so must have been ground on a Woodcut etc. jig. However, as I will be sticking to spindle turning for some time, re-grinding the spindle gouge as it is would save me the cost of a Woodcut jig for some time.

Question 1: Why has the spindle gouge been ground with the same angle from wing to wing? All my reading indicates this is unusual.

Question 2: Would re-grinding it as it is be OK?

Grateful for any help.

[GBF]

Where do you live there must be a pro turner near you for a bit of advise

Regards George

[Stevekir]

I looked for one in a list (outdated) of turners offering tuition but some have retired and others are a night-bed-and-breakfast away which adds to the cost of the £150 or so fee.

I have been trying to find a woodturning show like the one near Warwick about 20 years ago, which seems to have closed, and there does not seem to be one within reach of me. I live close to Ludlow.

[Stevekir]

I have just discovered http://www.shropshire-woodturners.org.uk/ who are 47 minutes away from me. I will contact them (although they meet in the evenings).

[Bryan Milham]

Steve,

To expand upon Georges answer, a nearby club with a member who will help you would probably be easier than a Professional. They are not all as helpful or free with their time and advice as George.

Stratford upon Avon Club might be closest. Look at the AWGB Website http://www.awgb.co.uk/club-map/for a list of clubs.

But to answer your questions,

Question 1: Why has the spindle gouge been ground with the same angle from wing to wing? All my reading indicates this is unusual.
No it shouldent and yes it is unusual.

Question 2: Would re-grinding it as it is be OK?
Yes it would.

As advice, Grind the gouge upside down, so you are grinding the wings, to achieve the fingernail shape you want, then turn it right way around and grind the bevel to meet the shape you've created.

Going back to my first statement, a local amateur with a grinding jig would help you perfect the shape, practice will teach you to maintain it.

[Mark Hancock]

You could consider the Hereford club http://herefordshire-woodturners.org.uk/

Regarding the grinds on your tools bear in mind when you purchase tools they don't necessarily have a suitable grind on them to start with. Tool manufacturers are just that, tool manufacturers; generally they are not turners. Grinds can be very individual with regard to angles, bevel etc. and are also dependant on how you turn and what you turn. You just need to work out what is suitable for you.

[George Watkins]

I am probably a bit too far away from you in Leicestershire? but hopefully one of the clubs can help

[Stevekir]

I have made myself a spindle/bowl gouge grinding jig for producing the required fingernail shape (with "wings"). The angle turned out to be smaller than I intended - 22 degrees but I will correct that - but I can now turn beads and coves without catches or other gross incidents. Although about 80% as smooth as I would like, practice will improve that.

I have discovered a long-established and active woodturning club in Hereford, only 34 minutes away, and joined it. The Secretary has offered to give me tuition at his home and I will take him up on it in a couple of weeks.

I have noticed the huge amount of fine shavings produced by using a roughing gouge on the usual 2" x 2" square turning blank, tossed a long way away from the lathe (I am still using softwood for practicing but now have some hardwood blanks). As I have an electric planer, I am using that now to produce an octagonal cross section, several blanks in a batch, which is quick and the subsequent roughing produces much fewer shavings and is also quick.

Does anyone else do that?

[fuzzyturns]

Well, it sounds like you're moving in the right direction.

I have noticed the huge amount of fine shavings produced by using a roughing gouge on the usual 2" x 2" square turning blank, tossed a long way away from the lathe (I am still using softwood for practicing but now have some hardwood blanks). As I have an electric planer, I am using that now to produce an octagonal cross section, several blanks in a batch, which is quick and the subsequent roughing produces much fewer shavings and is also quick.

Does anyone else do that?

If you have a huge amount of fine shavings from the roughing gouge, then that probably means you haven't quite got to the stage yet where the roughing gouge is used in full flow. For a 2x2 (in my opinion) it's not worth doing anything, it goes on the lathe, between centres and in less than a minute it's round. In softwood, and with a sharp gouge, it's probably more like 10 seconds (on a foot long piece), but that does require a bit of practice.

Don't try and do that yourself right away. Do what feels comfortable and safe. As you gain experience, you will go faster (both in terms of RPM on the spindle as well as usage of the tools). Don't force it, take your time. You need to walk before you can run.

[seventhdevil]

i too am wondering why anyone would make a blank octagonal unless it is too large when square to fit on the lathe.

i've just been turning 8" squares 24" long to round and it only take a couple of minutes with the roughing gouge which is easily less time than you would spend on the planer in my opinion.

fuzzy's right though, you don't want to run before you can walk.

[Lazurus]

Some good advice on this thread, I use the sorby fingernail jig on a slow grinder and find it easy to reproduce my swept back grinds every time, its easy to set up and use and can be picked up cheap on Fleabay.

[Schurchy]

Like Lazurus, I too bought and use the Sorby fingernail jig and would recommend it. TIP - To make the process quicker and repeatable, I drilled blind holes into a piece of scrap hard wood to the depth needed to set the length of projection of the gouge from the jig.

[Lazurus]

Now that's a good idea.....

[Stevekir]

Thanks folks. All very helpful.

I can now reveal my home made fingernail grinding jig (jig.jpg attached). I got details from Marius Hornberger at:

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

Mine is made entirely from scrap except for the metal items and works well. Saved me up to £130. The free plans he offers can't be found but I created them by blowing up part of one of the early frames in his video.

Attached are three pictures of the jig and my spindle gouge after sharpening. Its grinding angle turned out to be about 25 degrees which I think is quite small although I have read that a relatively small angle is good for beads, and (especially) coves where it helps to avoid getting its wings caught in wood. It seems to suit me as I practice beads and coves.

EDIT: Notice the bluing on the tool. I have a wide 6" white grinding disc, bought 20 years ago. Videos of people grinding turning tools show them grinding for several seconds but not apparently getting bluing. Is bluing to be avoided with HSS, and if so, how. I press very lightly.

[fuzzyturns]

That looks like a decent jig. Better than my first, self-made one, at any rate.
the white grinding disc is OK, but you are probably running it on a fast grinder, in which case you really need to use a light touch. Ideally you'd have a container with water nearby and cool the gouge tip in that before it starts changing colour.

Also:

• 25 degrees is OK for a spindle gouge, but I wouldn't recommend it for a beginner, as it can be very aggressive. I'd more inclined to recommend 40 degrees or even more.
  
• Grind the heel off. Otherwise you'll end up with ripple features in your covers, if they are wider than your gouge is thick
• Resharpen when you feel it has lost its razor edge. Most beginners leave it far too long before they resharpen (and don't ask how I know that)