How deep can you go...And How ?

[Glossopguy]

Hi guys

I'm getting along nicely now but I'm hitting the same problem from the very first project. That's turning inside the bowl. I seem able to comfortably gouge out 50% deep of the Diameter of the bowl. after that point the gouge judders badly on the outside edge and refuses to cut smoothly. I've tried many different tools but seem to hit this 50% ratio
I'm trying to turn a cup from a 6"x 4" dia blank of what could be Sycamore. I'm down to 1.5 " deep on a 3" hole and now the trouble starts. The sides are parallel to the blank diameter and the bottom is Flat. So before it jumps from the chuck (again- this isn't the first time) I thought I'd ask you advice.

How can I get this 3.5 diameter hole 5"deep ?

 

[RichardG]

I’m a new turner and struggle with the same issue. What helped me was stopping the lathe, getting a decent light and then manually pushing the gouge down the side and then round the bottom watching exactly how the bevel was rubbing on the wood. I discovered that I couldn’t maintain the 45 degree gouge bevel rubbing all the way round. Changing the bevel angle to 50 degrees and cutting the heel off made a big difference and solved my problem but if I went much deeper then I’d need a higher gouge angle, perhaps 65 degrees, or use a scraper.

 

[Steliz]

Are positioning the rest inside the bowl to support the tool?

 

[Alpha-Dave]

Tool overhang should be minimal. 1” to 2” is all I use on bowl turning. Hollowing for vases is much more, but that is medium-to-advanced work.

You need to cut on-centre or slightly-above as the gouge arcs through the cut.

Your gouge needs to be sharp. You need to be careful not to sharpen to a ‘wavy’ edge; this is likely to catch.

Use the largest gouge you can; mass really helps.

Holding the gouge far from the fulcrum helps, as does moving from the knees so you don’t bend over or bend backwards while cutting.

Ride the bevel; always. Apart from when not, but be sure you are making a choice there, not just letting it happen.

You should be able to control the depth-of-cut by a combination of: the sharpend-angle of the gouge; the height of the tool rest; the distance of the tool rest to the work surface; how the gouge is rotated (think clock-face on the end of the handle); and the pressure you apply as you move over the tool rest. Some of these are easy to pre-set, others you have to vary as you move through the cut.

Literally listening to the wood as it is cut will tell you a lot once you recognise the sounds; some noises that are higher pitched are caused by chattering, which happens before some forms of catch; you will become adept at recognising these and pulling back.

The clubs are starting up soon; near you are Teesside Woodturners, and Wear Valley Woodturners.

Get a couple of lessons from a pro; close to Barnard Castle I recommend Andrew Hall (registered professional turner). I started out with Andrew.

Well worth £15 is Keith Rowley’s book:Amazon.co.uk

 

[Phil Pascoe]

For bowls, goblets etc. it doesn't hurt especially when trying to remove wood quickly to drill a witness hole on centre first - drill it maybe 1/4" under the finish depth. It saves having to stop to check the depth and it also gives a starting point for the gouge. You can buy morse taper drill bits cheaply enough (UKDrills are discontinuing imperial sizes) - they save getting a chuck out.

 

[Heavygate]

For bowls, goblets etc. it doesn't hurt especially when trying to remove wood quickly to drill a witness hole on centre first - drill it maybe 1/4" under the finish depth. It saves having to stop to check the depth and it also gives a starting point for the gouge. You can buy morse taper drill bits cheaply enough (UKDrills are discontinuing imperial sizes) - they save getting a chuck out.

 

[Adam Pinson]

I try to leave as much mass towards the centre as i can whilst shaping towards the rim, keeps things more solid, less vibration, sharp tools are a must.

 

[Owd Jockey]

I think all of the comments above will help over come your depth issue. Personally I try and keep the tool rest as close to the wood as possible. I have made a number of tool rests in various shapes that allow me to do specific work. With the right bowl gouge you can begin a cut close to the lip of the bowl and ride the bevel in an arc shape down to the centre, but you will need to position and shift your body to accommodate this. Do not try and start a cut right on the lip edge as you will get a catch ( I still do it myself). Also invest in a round carbide cutter for the walls. Finally, just keep on and persevere, its a steep learning curve but we all get there in the end. Improve on this and you can progress to deep hollow forms.