And now the fun begins!

[Spindrift]

Today I took delivery of a new SC3 chuck.

Tomorrow... new adventures in bowl turning!

(The Pratt Burnerd chuck that arrived with my lathe has now gone to a good home).

 

[SVB]

Sounds promising - if you’re new to turning then make sure you pay close attention to how to cut chucking points and which surface should / should not bottom out on jaws. This should help

 

[Spindrift]

Sounds promising - if you’re new to turning then make sure you pay close attention to how to cut chucking points and which surface should / should not bottom out on jaws. This should help

View attachment 121297

Thanks for the info and the drawing. Very helpful!

 

[Sachakins]

Also build up your piggy bank rapidly, this "fun" can empty your piggy bank faster than SWMBO in the January sales......

 

[Robbo3]

That's a nice clear picture Simon. Where is it from .... & may I re-post it please?

 

[gregmcateer]

That's a nice clear picture Simon. Where is it from .... & may I re-post it please?

If you look really carefully, bottom left shows,
Turnawoodbowl.com.
You could always contact them and check

 

[Richard_C]

Good diagram. I think, from memory, it being too dark and cold to visit shed right now, that the SC3 standard jaw instructions say to use a plain sided tenon not a dovetail. Chucks and jaws vary. The jaws are designed to grip straight sides. For a recessed grip you do cut a dovetail.

Best read the instructions that will have come with the chuck kit.

Take care with the jaw fixing screws, they roll and bounce a very long way if you drop them. I keep my jaws etc in an old square biscuit tin and use the upturned lid on the bench as a worksurface for jaw fitting and removing. The lip prevents disasters.

I found it all took a long time when I started, but after a few goes it gets quick and intuitive. I keep a table pinned up on the wall with the min and max tenon sizes for contraction and expansion, saves having to feret around for the spec or think too hard.

 

[Linus]

@Richard_C is correct. The SC3 standard jaws are parallel on contraction mode and dovetail for expansion On contraction the jaws have a parrot's beak which bites into the spigot to grip better. See Figs 8.25-8 in your manual.

Happy turning!

 

[Wood&StuffLtd]

Good diagram. I think, from memory, it being too dark and cold to visit shed right now, that the SC3 standard jaw instructions say to use a plain sided tenon not a dovetail. Chucks and jaws vary. The jaws are designed to grip straight sides. For a recessed grip you do cut a dovetail.

Best read the instructions that will have come with the chuck kit.

Take care with the jaw fixing screws, they roll and bounce a very long way if you drop them. I keep my jaws etc in an old square biscuit tin and use the upturned lid on the bench as a worksurface for jaw fitting and removing. The lip prevents disasters.

I found it all took a long time when I started, but after a few goes it gets quick and intuitive. I keep a table pinned up on the wall with the min and max tenon sizes for contraction and expansion, saves having to feret around for the spec or think too hard.

That is good advice on those bouncing jaw screws. I use engineers magnetic bowls to keep the screws and Allen keys safe. I keep all the chuck jaws and bits in Really Useful Boxes stacked underneath the workbench. I also use a telescopic magnetic pickup which is great if they fall into wood chippings. When doing any jaw changing I have made up a temporary shelf from building board with a batten which
I lay on the lathe bed with a small towel so screws don't bounce.

 

[Stigmorgan]

I've just recieved my SC3 set, the manual says I should remove the oil coating with white spirit or similar, is something you guys do or can I leave it?

 

[Richard_C]

Maybe a slight risk of marking the wood if you don't, but high risk of dust and stuff sticking to it. If I recall mine felt tacky straight out of the box. Suppose it depends how long it's been in storage.

Feels lots nicer to handle if you clean it and only takes a few moments.

Enjoy.

 

[Stigmorgan]

Yeah I guess, it's not something that was covered in any of the unboxing and setup videos I watched on YT.

 

[Spindrift]

I haven't had a chance to use my SC3 yet - and it arrived on Nov 2 - but it was well oiled when I unpacked it so I have spent a bit of time cleaning it up. It would have attracted loads of dust and shavings if I hadn't.

I can't stand the smell of white spirit/turpentine so I used a little WD40 and a blue paper towel of the type that comes in big rolls in Wickes.

 

[stuart little]

Good diagram. I think, from memory, it being too dark and cold to visit shed right now, that the SC3 standard jaw instructions say to use a plain sided tenon not a dovetail. Chucks and jaws vary. The jaws are designed to grip straight sides. For a recessed grip you do cut a dovetail.

Best read the instructions that will have come with the chuck kit.

Take care with the jaw fixing screws, they roll and bounce a very long way if you drop them. I keep my jaws etc in an old square biscuit tin and use the upturned lid on the bench as a worksurface for jaw fitting and removing. The lip prevents disasters.

I found it all took a long time when I started, but after a few goes it gets quick and intuitive. I keep a table pinned up on the wall with the min and max tenon sizes for contraction and expansion, saves having to feret around for the spec or think too hard.

I use a magnetic tray & ball-end hex screwdriver. Wish there were 'standard' jaws available.

 

[Phill05]

" make sure you pay close attention to how to cut chucking points and which surface should / should not bottom out on jaws. This should help "

Can anyone explain the reasoning on not bottoming the woodwork on these chucks please, I have done wood turning most of my working life and this is the first time I have come across this, on metal lathes you also bottom your work to keep it true to your chuck and also save any movement that could cause your work to fly out.

 

[Richard_C]

Wish there were 'standard' jaws available.

It's a record power thing perhaps. They describe their 50 and 35mm as standard in the brochure, the 50 comes with the starter kit, all others have fancy names.

 

[gog64]

" make sure you pay close attention to how to cut chucking points and which surface should / should not bottom out on jaws. This should help "

Can anyone explain the reasoning on not bottoming the woodwork on these chucks please, I have done wood turning most of my working life and this is the first time I have come across this, on metal lathes you also bottom your work to keep it true to your chuck and also save any movement that could cause your work to fly out.

If you have faced off the (bottom of the) workpiece before forming the tenon then it will be parallel with the tenon shoulder. If you haven't and you bottom the workpiece onto the chuck then your chuck will be out of alignment with the tenon. Much more reliable and safe to make the tenon shorter than the depth of the chuck jaws and seat the tenon shoulder against the chuck shoulder support.

I hope that makes sense, I've had a couple of glasses of red, so blame that if not!

 

[Robbo3]

Can anyone explain the reasoning on not bottoming the woodwork on these chucks please, I have done wood turning most of my working life and this is the first time I have come across this, on metal lathes you also bottom your work to keep it true to your chuck and also save any movement that could cause your work to fly out.

The grip of the jaws is mainly for rotation. It's the shoulder of the work in contact with the front face of the jaws that keeps it true. Thus the tenon has to be shorter than the jaw depth.

 

[stuart little]

It's a record power thing perhaps. They describe their 50 and 35mm as standard in the brochure, the 50 comes with the starter kit, all others have fancy names.

Hi Richard, it is a Record Power thing. What I meant by 'standard' was ; as fitted to 3-jaw chucks. I've tried to find one as I do a lot with various sizes of dowels, but to no avail.

 

[Phill05]

Hi Gog & Robbo, thanks for that information, Many many years ago I was instructed to 1st turn your tenons or shape as this was where the most stress was, make them slightly longer then face back to size, facing back has the least amount of stress involved, then when you invert to use in jaws you have a planer face to hit back to the face of the jaws and a tenon to grip to stop rotation. (a dovetail tenon has the possibility to pull the work back to the flat)

And this is used in metal turning as well, example in the last few months I have made some fitting for members on here to fit on motor shafts I grip a chunk of ally bar and rough turn down the o/d of the spigot (most stress) then one finish cut to size, I then have the means to hold true in a collet while I form the rest all true to the centre (with the least amount of stress)

If a chuck manufacturer said don't use the flat on the jaws I would say they can't be bother to make a precise chuck and would not buy off them.