big trouble trying to hollow goblet

[trojan62]

hi all,
hope someone can give me a few pointers about this.
i recentley got rid of my old crappy lathe and bought a new axminster AWVSL 100 lathe and also a clubman 100mm chuck with c dovetail jaws. im quite good on spindle turning , but have not really had a chance to try bowls or goblets and so forth, until i got the scroll chuck.
anyway, i turned my first bowl, which you can see in the pic below, and it didnt turn out too badly, the hollowing seemed to go ok and it came out ok. but ive had real trouble trying to hollow out a goblet as you can see in the pics. i keep getting catches and it seems to take forever to hollow out what i did manage to hollow out, which wasnt much.as you can see the walls of the goblet are totally uneven, why would this be, what did i do wrong here. in one of the pics is the tools i use, the axminster set, which seems pretty good, and 2 pics of the bowl gouge, to show you the bevel, in case this is the thing that is making this hard do do. also. im only using wood at the moment that i can get hold of, leylandi and pine. i realise these might not be the greatest woods to turn. could these be the problem.
anyway, if anyone has some ideas of what im doing wrong , can they give me a few tips.

thanks in advance....

chris....

 

[Tazmaniandevil]

Same set up as I currently have, so I know the Clubman is capable of holding the goblet. The uneven turning is because the piece is not running true.
Make sure the end mounted in the chuck is not touching the jaws end-on. The clubman c jaws use a dovetail to hold, so the spigot needs a shoulder to stop the jaws drawing the timber down to "bottom out" in the chuck. If the end of the timber touches the jaws, this will act as a pivot, turning the timber into a lever. As soon as you touch it with a gouge, it will move off-centre.

HTH

Tom

 

[trojan62]

thanks for the reply Tom,how would i go about making it run true and cutting a dovetail that the chuck could grip properly.

regards,

chris.....

 

[Tazmaniandevil]

I always try to leave a few mm between the end of the timber and the bottom of the chuck. I use a ¾" skew to cut the dovetail on the tenon/spigot, make sure the shoulder is square and covers the face of the chuck jaws.

Image ©woodmagazine.com

The image shows a smaller shoulder (flat bearing surface) than I would like to keep on a goblet, but it does show the general idea. As the jaws tighten, the dovetail pulls the shoulder tight against the face of the jaws, and the space at the bottom prevents pivoting.

 

[Dalboy]

Even though the pine and other soft wood are cheap they don't take very well to being held in the chuck with a beginner as any catch will soon knock it out of true. I would change to a hard wood and try again. Start by making a cylinder and cutting a tenon on one end to go into the chuck making sure it is tapered to match that of the chuck, now bring up the tail stock for support. Shape the outside of the goblet section down by 2/3rds. Remove the tailstock and start to hollow the inside by 1/2" segments to the thickness required, keep doing this to the depth of the goblet. If you have an old tennis ball hold this in the goblet opening and bring the tailstock back up th the goblet this will hold the open end while you finish the outside of the goblet as well as the stem and foot. Apply finish a needed.
When working with anything like this keep the tools sharp and take little cuts, it is nice to be able to hog out something quickly but wait untill you have a little more experience. I found it took me ages to do a simple bowl when I first started now I can do it a little quicker.
Hope this makes some sort of sense.

 

[Bodrighy]

I make dozens of goblets and only use a spindle gouge and, for speed a ring tool. Get the outside of the bowl section done as said to about 2'/3rds of the shape then drill down to the depth you want inside the goblet. The quickest, easiest and cleanest way to remove the wood from the inside is to shear scrape it with a spindle gouge. It takes me approx. 4 minutes to get the guts out. If you try and hollow it out as you would a bowl you are pushing the wood and exerting forces that are almost guaranteed to shift the spindle in the chuck. Finish the inside off totally apart from polishing / lacquering and either use Dalboys tennis ball or, as I do, stuff it with paper towels and bring the tail stock up and finish the rest of the goblet off.
The ring tool I use isn't a standard tool but rips the wood out at a phenomenal rate once you get used to it.

When making the goblet don't try and have the same thickness all the way down. People don't like drinking from a thick piece of wood so the rim needs to be about 2mm thick but taper it down so it is thicker as it gets towards the stem for strength.

Leylandii is a lovely wood to turn ( there is a goblet in Leylandii in the gallery) and as long as it is dry you shouldn't have any problems.

Hope this helps

Pete

 

[trojan62]

Thanks for all the replys so far.
Can I just ask a question about how you get the ends of the piece your turning nice and square and flat, like for chucking etc, obviously you get the piece nice and round when spindle turning, but how do you get the ends nice and square, if you see what I mean.
Do you do it on the lathe or cut it another way, such as with a band saw or table saw or something else.

Thanks

Chris.......

 

[Bodrighy]

I use a parting tool to make sure the chucking end is flat. Actually I make it slightly concave so I know that the outside edge is butting up against the chuck tightly. The other end you can do as you work it once in the chuck.

Pete

 

[CHJ]

As Pete says, use a parting tool to face off the end and a small 1/2" skew to form the dovetail as seen on the end of this small vase.

 

[chipmunk]

If you're using a parting tool on softwood to square up the end face, remember to rub the bevel as you peel off the outside timber - don't just push in straight for the centre. You might get away with that on harder wood but you'll get no end of tear-out on softwood.

If you can, use a skew chisel on its edge to sever the fibres of the end-grain a bit at a time. You'll get a much better cut with less tear-out - or easier use a spindle gouge on it's side.

HTH
Jon

 

[Mark Hancock]

Chris

I may be wrong but I think you issue is more about grain direction (parallel or gross grain) and cutting with the grain as well as using the appropriate tool presented the correct way. As Pete has said a spindle gouge with a fingernail grind is the more common tool used for hollowing a goblet rather than the bowl gouge. This can be used moving from inside to outside or vice versa depending on presentation to the wood or in a shear scarping mode.

Mark

 

[Paul Hannaby]

Most of the points have already been covered and there's plenty of good advice in there but here's a few more suggestions that might help.

For goblets and similar projects I find the gripper jaws generally give a better hold than dovetail jaws but if you only have dovetail jaws, try to make the dovetail almost as deep as the depth of the dovetails to get maximum grip.

Also, make sure your chosen tool is sharp and sharpen frequently. Blunt tools increase the risk of a catch.

The gouge you show in the photo has a fairly short grind. To make life easier for hollowing, a longer grind would be better.

This article on my website might be of use too http://www.hannaby.com/turn-a-goblet.html

 

[Harry 48]

As well as Paul's excellent website have a look at Mike Waldt on you tube .

 

[Bodrighy]

Only thing I would differ with Paul about is the use of beeswax. I agree it was the traditional way but I have had to 'repair' a few goblets that have been treated this way then used with red wine which eats the bees wax away very quickly and stains the wood. If it is too deep there is nothing that can be done other than to sand back as much as possible then coat with a food safe lacquer. I use Rustins Plasticote which is both food safe and alchohol proof. Also add laburnum to the toxic woods that shouldn't be used.

Pete

 

[graduate_owner]

Hey Trojan, you are not alone in this. I have had significant issues in trying to hollow out end grain. I posted a message entitled ' not afraid of dig ins any more' because I have had so many when hollowing. I am working on some of the suggestions posted by helpful members, especially regarding gouge grinds.

I don't know if this would be regarded as cheating by purists, but I was thinking of drilling out a substantial section with a saw tooth bit first, then cleaning up with a gouge and a scraper, just to see how it would work.

K

 

[trojan62]

hi all
thanks for all the replies, i will give some of these tips a try.
i have watched loads of youtube vids and mike waldt in particular who is very good, but watching other people do it, it seems quite easy, but doing it yourself is another matter.
well, ill just have to keep practising.

thanks again,

cheers,

chris....

 

[CHJ]

......
I don't know if this would be regarded as cheating by purists, but I was thinking of drilling out a substantial section with a saw tooth bit first, then cleaning up with a gouge and a scraper, just to see how it would work.

K

Nothing wrong with that if it helps you gain confidence, acts as a depth marker to aim at but be aware that the central spigot does not go too deep, can be several mm long and needs taking into consideration when setting depth.

A useful guide on bowls as well.

 

[Robbo3]

I don't know if this would be regarded as cheating by purists, but I was thinking of drilling out a substantial section with a saw tooth bit first, then cleaning up with a gouge and a scraper, just to see how it would work.

Nope - not cheating.

However one member of our club drilled out a goblet & forgot to remove the evidence before entering it in a club competition.

 

[Bodrighy]

There is no such thing as 'cheating' in wood turning just different ways of achieving the goal. The only rules are those applying to health and safety. If you do a bit of research into the old ways of doing things before all the fancy equipment was invented you might be surprised at the ways that things were made in the past.

pete

 

[woodfarmer]

My so far one and only attempt at a goblet shape was me testing fig to see how it turned. I used a forstner bit to take out quite a lot. in fact two or three sizes. Th ewood turned beautifully, but split possibly worse than cherry.