Jaws and chuck

[jase158]

Hi All,

I have bought a lathe for xmas, absolutley love it but I am having issues getting pieces on the lathe to level up.

I have this lathe:
http://www.axminster.co.uk/axminster-ho ... the-501245

This chuck: (bought this second hand)
http://www.axminster.co.uk/axminster-cl ... k-ax919059

These Jaws:
http://www.axminster.co.uk/100mm-o-donn ... ws-ax22836

I make bowls and lidded Pots,
I have only tried one bowl and 1 pot but it was wiggling all over the place. I tried several different things to level it up.

Is there a way to check the jaws/chuck are set correctly?
Is there better jaws for making pots?
Is It possible that the chuck is incorrectly adjusted or broken?
I am happy to but whatever needed but really struggling to find something that makes my life a whole lot easier.
Is there a way to level work pieces up properly?

 

[CHJ]

Do your jaw carriers and accessory jaws run true without anything attached ? just checking you have carriers in correct locations.

To be honest the small diameter of the O'Donnell jaws will not give you maximum stability and you need the sockets or spigots carefully matched to jaws when they are at true circle.


Using standard "C" jaws would give you more stability.

 

[SVB]

Can you post a photo of the chuck with the jaws closed completely and also a second photo showing the jaw / wood interface when you've got work gripped in the chuck.

I think with the above we can help else it's conjecture that may confuse as much as it helps.

Thanks

Simon

 

[jase158]

Do your jaw carriers and accessory jaws run true without anything attached ? just checking you have carriers in correct locations.

To be honest the small diameter of the O'Donnell jaws will not give you maximum stability and you need the sockets or spigots carefully matched to jaws when they are at true circle.


Using standard "C" jaws would give you more stability.

1. It looks like it but how do I test this? Is it just by eye or is there a better test?
2. Ahh I see so the spigot has to be the same shape as the jaws! I do worry with the smaller jaws as I have had a few pieces fly off when working on them with smaller spigots. But from your picture I can see it will work a lot better if they are smaller and properly cut. Thank you

 

[SVB]

Chas makes the right points and his drawings are spot on.

Pay particular note to where he has indicated there should be a small gap and especially to the areas indicated as providing max support. These should be at worst parallel to the face of the chuck and perhaps ever so slightly undercut so the blank is supported at the widest part, not just on the timber adjacent to the jaws.

The final 'tip' is to design in some wood adjacent to the jaws that will be waste. This avoids trying to turn right up to the jaws and weakening the grip and allows for an adequate grip to be maintained.

Happy turning,

Simon

 

[CHJ]

1. It looks like it but how do I test this? Is it just by eye or is there a better test?

When you initially attach the auxiliary jaws just lightly pinch up the fixing screws.
Then close up the Jaw carries completely, this settles the auxiliary jaws into 'best fit' positions.
Now fully tighten the Auxiliary Jaw fixing screws completely.

 

[woodpig]

O'Donnell Jaws aren't designed for bowl turning, you'd be far better off with standard "C" jaws.

From the Axminster site: "Designed to give access around the jaws for close-in tool work"

The further you move the work away from the headstock the more unstable the work is likely to be.
Do you really need the access that O'Donnell jaws provide? I've turned boxes and even a small bowl about 2" diameter using C jaws quite happily. I do have a set of O'Donnell jaws myself but rarely use them.

 

[Keithie]

As a newbie to turning I've had the same problems ...indeed with the same jaws (the O'Donnell) and now only use them for pretty small pieces.

Obviously what Chas & Simon & Woodpig have said is exactly right and I'd like to emphasise the point Chas & Woodpig made about 'C' jaws.

What I found with the C jaws is that they are a good size for medium pieces and also Axminster sell some really good 'extras' to go with them. I got the :

1. 100mm faceplate ring ...turns the jaws into a 100mm faceplate which is big enough to turn bowls up to and beyond the max size of my lathe (12" diam)
2. Four prong drive centre ... nice to have so that you dont need to take the axi chuck off each time you want to turn between centres (fits the inside of the c jaws)
3. Axi screw chuck ... standard screw chuck which fits in the jaws, has two different screw widths and also can act as a small faceplate (3 countersunk screw points) for when the 100mm faceplate ring is too big (I think it can also act as a three point drive but I prefer the 4 point one for what I do).

The reason for mentioning this is that, when combined with a small sharp skew chisel to make good dovetails, the C jaws and accessories transformed my turning exoerience from 'I wish the piece would stop falling off' to trouble free turning (from a falling off point of view) allowing me to focus on turning better without fear of 'death by a significant bump on the head' ..lol!

have fun!

 

[Phil Pascoe]

I have found that for the couple of seconds it takes it's wise no matter whether it's a chuck or some sort of spindle drive to mark exactly where your piece has come off. Often the wood will compress slightly more on one side than the other - not by much, but if you're close to finishing your work or it's particularly fine it can make a difference. If you do it a dozen times on the trot for nothing, so what? You'll still be glad on the other occasion. If spindle turning (especially lamps) I mark drive and tail centres on both ends so that I can easily reverse the piece and keep it on centre if needed - more often than not it isn't but for the minute it takes it can save some hassle when it is.

 

[Random Orbital Bob]

+1 to Keithie's expose of the Axy C jaws. They're incredibly useful especially when you add in the extras. I don't use a 4 prong drive centre, preferring instead a steb centre but whichever you use, it doesn't matter because there is an accessory 2MT holder that fits into the C jaws which more or less means you never need to take the chuck off the lathe because that attachment turns it into a spindle drive.

The screw chuck with small screw is fabulous for turning fruit. I'm a big fan of the Axy chucks, they've really thought through the varying needs of turners and designed a range of jaws that do the job well.

I also have the gripper jaws for spindle pieces that are heavy and a long way from the headstock. These have a massive clamping capacity for a long and large tenon. Nothing has ever flown off when they're in use.

Final tip, I always buy a spare set of carriers when I buy new jaws so when changing them I just wind the unwanted jaws right off the chuck with the key and inversely, the wanted jaws back on. Saves the faff of messing with screws and their inevitable loss in the shavings under the lathe!

 

[selectortone]

I'll weigh in to agree with pretty much everything that has been said above.

I like the O'Donnell jaws for small pieces where you need to get in close around a narrow base, but the small depth of the dovetail does mean that they are not suitable for larger jobs.

I had problems with bowls running true after reversing for hollowing when I first started. When I discovered the importance of a gap between the base of the spigot and the bottom face of the jaw dovetail, and a flat area adjacent to the spigot for the jaws to sit flush with, it was a step-change in my turning. A real light bulb moment. If you don't spend time getting the spigot right you are making things much more difficult for yourself.

For Axminster chucks I have found their type A dovetail jaws are really good - they have a nice deep 60mm dovetail recess for medium sized work which means you can create a dovetail with a good depth and still have clearance, and a 25mm inner dovetail recess too. They also expand into a 100mm dovetail recess which is great for large bowls and platters.

I don't like their type C jaws, they don't have a proper dovetail on the inner jaw, they have what Axminster call a 'stepped shoulder' which doesn't work for me.

 

[CHJ]

.....don't like their type C jaws, they don't have a proper dovetail on the inner face, they have what Axminster call a 'stepped shoulder' which doesn't work for me.

I personally don't have a problem with the "C" type jaws, I treat them just the same as Dovetail format and find the grip fine, rarely is there any need, or advantage for that matter in grooving the spigot to take the step in wood as the end grain component flange left is very weak in most woods and the narrow 'step' compresses well into the base of the spigot and holds well, admittedly it does not have quite the natural 'pulling/settling' power of a true dovetail form.
The step does have a serious roll to play in Axy's version of Screw Chuck adaptors and the like.

 

[Happy amateur]

With the c jaws it a simple operation to put a small groove with a thin parting tool on the inside of the spindle
I have never had a problem. Are you sure that the jaws close up tight.

Fred
orchard-Woodturners.org.uk

 

[woodpig]

What I found with the C jaws is that they are a good size for medium pieces and also Axminster sell some really good 'extras' to go with them. I got the :

1. 100mm faceplate ring ...turns the jaws into a 100mm faceplate which is big enough to turn bowls up to and beyond the max size of my lathe (12" diam)
2. Four prong drive centre ... nice to have so that you dont need to take the axi chuck off each time you want to turn between centres (fits the inside of the c jaws)
3. Axi screw chuck ... standard screw chuck which fits in the jaws, has two different screw widths and also can act as a small faceplate (3 countersunk screw points) for when the 100mm faceplate ring is too big (I think it can also act as a three point drive but I prefer the 4 point one for what I do).

Absolutely. I have a steb centre that fits the C jaws and also a pig tail for polishing mops. The only time I normally swap is to use button jaws and then I actually swap over chucks! :lol:

 

[jase158]

Thanks everyone for the help. Have bought c jaws, have tested a piece in old jaws and marking centres on both sides and then centering the piece using the tailstock (think that's what it's called) definetly helps a lot.
I have added pics!

 

[jase158]

These should be at worst parallel to the face of the chuck and perhaps ever so slightly undercut so the blank is supported at the widest part, not just on the timber adjacent to the jaws.


Simon

Not too sure what you mean

 

[Robbo3]

These should be at worst parallel to the face of the chuck and perhaps ever so slightly undercut so the blank is supported at the widest part, not just on the timber adjacent to the jaws.


Simon

Not too sure what you mean

Wobble is prevented by the shoulder of the tenon pressing against the face of the jaws not by the grip of the jaws on the tenon. That is why the tenon length must be less than the depth of the jaws. The tenon shoulder needs to be at 90 degrees, parallel to the face of the jaws or slightly undercut. If the shoulder slopes away from the jaws there is much less stability.

 

[jase158]

I just want to say a massive thank you to robbo, he invited me round on Sunday and showed me all the basics. He has the patience of a saint and definetly gave me so many great little tips. I was most surprised about the amount of work that goes into getting tools ready for turning before even turning a piece of wood. Thanks robbo.

 

[CHJ]

Practical show and tell with the chance to ask for a repeat of something you're not sure of is always worth hours of reading about it.

Well done Robbo for providing the insight.

 

[Robbo3]

You're welcome Jason. Passing on information to anyone that's willing to learn is always a pleasure.