Newbie question: riding the bevel but not cutting

[sploo]

Very new turner here - just starting practice cuts of beads and coves on spindle work.

My first "proper" piece was to make a round bumper to protect a wall from a door handle. Essentially nothing more than a Cadburys Chocolate Button, but about 65mm in diameter, and finally parted off to be just under 10mm thick. I was using ash.

I was cutting the curve using the same technique as for a bead, but I found two problems:

1. With the tool rest parallel to the stock, the gouge obviously ends up overhanging the rest as you get near the button centre, which felt unnatural
2. I could cut the corner, but as it flattens out towards the centre of the button I found I kept riding the bevel, and being unable to find the cutting edge. Obviously I could twist the tool to force a cut, but then I'm not going to get a smooth curve from edge to centre.

I did try putting the rest across the face (like bowl turning) but wasn't sure if that was a good idea. I attempted a pull cut across the face, which worked (albeit not the best finish)... until I tried to traverse the steeper rounded edge, and caught the wing of my 3/8" spindle gouge (fortunately no serious consequences).

Any advice on the "proper" technique of how to tackle such a shape would be gratefully received!

 

[CHJ]

Place your tool rest along the face of the button as you would for bowl turning, at roughly the angle of your curve.
As you proceed with the cut be prepared to roll the tool in your hand to maintain edge contact, job to explain but as you move your arms or body the angle of attack of the cutting edge can change dependant upon how you are swinging, so it may need a twist component in the tool shaft to offset the arc the tool point is traveling through.

Practice it with the lathe stationary on a positive curved surface, Large bead or bowl outer bottom, and take note of cutting edge contact.

Of course make sure your tool has a sharp edge to the primary bevel and you have not formed a small micro bevel on the cutting edge, this although sharp will give the symptom of a blunt edge that will suddenly dive into the wood when you get it to cut.

 

[sploo]

Place your tool rest along the face of the button as you would for bowl turning, at roughly the angle of your curve.
As you proceed with the cut be prepared to roll the tool in your hand to maintain edge contact, job to explain but as you move your arms or body the angle of attack of the cutting edge can change dependant upon how you are swinging, so it may need a twist component in the tool shaft to offset the arc the tool point is traveling through.

Practice it with the lathe stationary on a positive curved surface, Large bead or bowl outer bottom, and take note of cutting edge contact.

Of course make sure your tool has a sharp edge to the primary bevel and you have not formed a small micro bevel on the cutting edge, this although sharp will give the symptom of a blunt edge that will suddenly dive into the wood when you get it to cut.

Thanks Chas. I guess it's just practice practice practice!

My "button" mostly had a flat face with rounded edges (deliberately), but I guess that doesn't really change the tool rest position. I assume what I should be doing in that instance is effectively a push cut across the face of the button?

Fortunately the tool was definitely sharp. I used the ProEdge Angle Set (45 degrees) to set the tool (a Crown 3/8" spindle gouge) in the standard Fingernail Profile Kit, and with a bit of black marker pen on the bevel to check my cutting I'm pretty happy it's grinding something very close to the original tool shape (and hitting the whole bevel. Whether or not I should be changing the grind I don't know, but for the moment at least I haven't changed it, and the sharpening was a breeze. So far I am pretty impressed with the ProEdge.

Changing subject slightly; I've ended up with two of Crown's 3/8" bowl gouges. Would it make sense to maintain the original grind on one, and try a deep fingernail on the other?

 

[CHJ]

Forget the deep fingernail at the moment, as a new turner a steeper 55 0r 60 degree nose will be of more practical use to you allowing better bevel support in the bottom of bowls as you can have the tool handle and shaft nearer to 90 degrees to the surface you are cutting.

If you try to follow through with your 45 degree gouge from rim to centre, dependant upon the bowl depth the shaft may well foul the rim and lift the bevel out of heel contact with the wood, leading to chatter or worst case dig in, a steeper nose grind of 55-60 degree will allow you to approach more straight on without fouling the rim.

Does need a little change in handling pressure in as much as you apply more sideways drive to the shaft as opposed to pushing in line with the shaft.

If you try both nose angles you will find the spot on the inner curve of bowls where you find it easier to change between gouges.

 

[dickm]

I'm confused (happens a lot these days) but is the OP using a SPINDLE gouge for this? That's what the post seems to say and if so isn't that the problem?

 

[sploo]

I'm confused (happens a lot these days) but is the OP using a SPINDLE gouge for this? That's what the post seems to say and if so isn't that the problem?

Yes - I haven't used the bowl gouge yet as I'm spending some time trying to learn some spindle techniques first. I suppose that doing a button (even something only 65mm in diameter) is arguably like the bottom of a shallow bowl or platter - though the grain was parallel to the bedways.

I probably confused the issue by asking about fingernail grinds on a bowl gouge!

 

[CHJ]

I'm confused (happens a lot these days) but is the OP using a SPINDLE gouge for this? That's what the post seems to say and if so isn't that the problem?

Spindle gouge, as long as it's a modern concept of a round steel shaft, as opposed to a continental gouge, there should be little difference, many of the earlier Bowl gouges had a shallow flute before the move to the various deep flute forms and their promotion as being/providing better cutting profiles.

It will of course affect the presentation angles but for the purpose sploo was using it as long as he achieves the bevel nose contact at the optimum angle to the work piece it should still cut.

 

[sploo]

I got some wood from a local recycling place - cheap pine posts, that have turned out to be pretty nice looking wood underneath.

Roughing is going pretty well, and I'm just about getting the hang of a finishing (shear?) cut with the roughing gouge. It's really nice to start to get the "feel" of using small movements to control the cut in order to end up with a (reasonably) consistent cylinder, that's also got a pretty smooth finish.

I had a go at the cove & bead cutting exercise from Keith Rowley's book. The results aren't that consistent, but look OK, and I rounded the end off (like another button):

After sanding, sealing, and waxing:

It's not going to win any awards, but I'm certainly seeing the benefit of how relaxing makes the cuts better.

I've also learned that turning is a process by where you transform wood into hamster bedding...

 

[Stiggy]

One question - what height do you have your rest at in relation to the centre, and what height is your cutting edge in relation to your centre?

 

[sploo]

One question - what height do you have your rest at in relation to the centre, and what height is your cutting edge in relation to your centre?

For the original attempt at the button, I can't remember; tool rest probably a bit below centre, cutting edge all over the place as I was trying to make it work!

 

[Stiggy]

Well sounds like you're in the right area then!

 

[sploo]

Well sounds like you're in the right area then!

I'm making some progress. I've just (about) finished a pair of simple kitchen roll holders - nothing fancy, just a spindle with a gentle cove near the top, and a tenon on the bottom to fit into a round base. The round base was my first attempt at cross grain turning (and the first time I've used a screw chuck and my bowl gouge).

I still occasionally "fall off" the cutting edge and back onto the bevel, but it was very satisfying being able to get some full length push cuts all the way across the face of the bases (with a gentle curve, created from slowly changing the bevel angle from the waist). I also used the lathe's ability to rotate the headstock by 45 degrees, as it was easier to work on the face that way.

The only screw up was that I drilled a hole in each base for the spindle tenon, but in doing one I wound the headstock back too far - loosening the morse taper for the chuck, and ended up cutting a slightly oversize hole. That was sorted by using epoxy - but it's ironic that I'd managed to size the tenons correctly on the lathe (for which I have little experience) but failed to cut a hole with a forstner bit :wink:

Finally - it was also nice that both finished pieces are very similar. My early attempts at shaping were "artistic" rather than accurate. I'm still very slow, but at least I'm starting to get the gouge to go where I want it!