Is there a trick?

[Mr Finch]

Can one of the Coronet single bed way owners please share how on earth they get the tail stock lined up straight when doing spindle work?

I have just spent an hour turning a candlestick in a piece of Iroko, removed the tail stock to hollow out for the cup and the piece moved about 7mm, throwing the end waaaay out.

I now have a cup that is off centre.

I will take pics and upload in a mo.

To say this lathe is getting in my nerves is an understatement! No capacity for bowls (I need to make a free standing tool test) and the tail stock issue makes me want to cry, no matter how careful I am about marking the centre and lining it up.

TIA for any advice!

 

[Mr Finch]

A few pics...

Just a smudge off centre...

The piece with Liberon spirit sanding sealer applied.

Great alignment huh!?

Another shot of the alignment.

If I align the two marks, it goes even further off centre.

Any help, tips, advice is appreciated. Unfortunately I simply cannot afford to upgrade my lathe yet.

 

[Phil Pascoe]

Try to put your holes in anything first, then turn around the hole - it's guaranteed to be concentric.

 

[Mike Wingate]

Make a Lathe Support Rest.
http://www.woodworkersguide.com/2010/04 ... eady-rest/

 

[paulm]

Might not be the tailstock that's the problem, it could be that the workpiece has moved in the chuck jaws (even a mil or two movement at the chuck end would throw the tailstock end out considerably), or that the timber itself has distorted a little after the initial spindle turning ?

Could also be that if the tool wasn't sharp and too much pressure was being applied to compensate it could have been flexing the end of the timber sideways a bit whilst turning ?

Turning the cup in the end first, and then using that (stuffed firmly with paper towel or a suitably shaped piece of timber or similar over the tailstock centre) to centre the timber before turning the shaft, should mean the cup stays central to the finished piece ?

Hope that helps

Cheers, Paul

 

[CHJ]

Firstly you are creating a problem for yourself by holding the 'spindle' in the chuck.

For Spindle turning with the wood driven by a pronged centre the alignment of the tail stock is irrelevant within very broad margins, just look at a pole lathe construction.

As to the alignment problems, from what I can see the headstock spindle may not be aligned with the bed bar.
Don't rely on aligning scribed lines at a single face, place a true running steel bar in your chuck and align it by eye along its top surface with the bed bar, likewise arrange to do the same with the tail stock spindle.

 

[KimG]

I had a coronet for many years so I do have some experience with the machine. I think you made an error though, (just guessing as you do not fully describe your mounting process).

It looks as though you turned the blank between centres, then mounted it in the Sorby chuck and assumed that the tailstock mark was central, possibly not tightening the sorby up until the tailstock was in place. this would have hidden any off centre bias that the sorby chuick would introduce (due to very slight differences in wood compression around the tenon perhaps, whatever, stuff is rarely bang on from a reversal anyway)

Once you removed the tailstock the wood springs back to it's true centred position.

The way to avoid this is to mount it in the Sorby chuck, use the tailstock to set it to the assumed centre, BUT, before you begin work, remove the tailstock and true up the end, removing the original centre mark and creating a new, true and accurately aligned mark, bring the tailstock up to this new mark and set it.

Now when you are ready to trun the hollow it will be aligned correctly. If it isn't, then you know it has moved in the Sorby chuck, because that is the only way it can get out of alignment.

For long projects such as your stick, I recommend you get the deep Jaws for the Sorby chuck as they will have the grip to hold something like that true.

You problem is not with the lathe, it's with your process.

 

[Spindle]

Hi

As said above - it doesn't look like a fault with the tooling, its your procedure that is wrong.

I'm guessing that the length of the spindle is about 12" which is rather long to expect the standard jaws in your chuck to secure without support from the tailstock - especially if you are trying to hollow into end grain. The tenon you cut needs to be a very good match for the jaws and you'll need to take light cuts with sharp tools. The shark jaws available for that chuck would be better suited to this type of situation.

It would be far better to drill the hole for the candle using a forstner bit in either the lathe or a drill press first and then use the tail stock to support this end, (you can use the centre point from the forstener bit to accept the tail centre). Once supported in this manner you can finish the item confident that the recess will remain concentric.

Regards Mick

 

[Mr Finch]

Folks

Thank you so much for all the responses, having calmed used a little (I was rather frustrated when I first posted) and read all your responses, I absolutely agree that it's me, not the lathe that's at fault.

After all, 50 years people have been successfully using these lathes with no major issues!

To answer a couple of bits:

The piece is about 10 inches in length, which is why I wanted the tail stock supporting in the first place. Yes, different jaws are on the shopping list, long jaws and cole jaws. I have had the chuck about 4 days and this is the first time I have used it!

A Forster bit or three is also on the shopping list, but like the jaws they will come as money allows.

Should I not use these jaws for long spindle stuff at all and stick to short pieces and bowls?

I did turn a second stick this afternoon, hollowing the bowl for the cup first, packing it out and then bring the tail stock up and that seemed to work well. Now I just have to work at repeating the design from the first one to make a pair!!

Thanks again

Collin

 

[Spindle]

Hi

If you want to continue making tall hollowed items and the above method doesn't suit - consider making the item in two or three pieces, (cup, stem and base) tenoned together. This would be no problem with the tools you have, especially if you have a drive centre, (or drive spur for the chuck), to allow you to turn the stem between centres.

The chuck will be fine for bowls and platters.

Regards Mick

 

[procell]

For making copies it is probably best to make up a stoy board from a scrap of hardboard or thin ply. you can then mark transition points along the spindle on it and note the diameters at those points.

 

[KimG]

It's not that you should not use the standard jaws for such items, it is that they offer less reliable purchase than deep grip jaws under these circumstances, for fairly obvious reasons. You can get away with the standard jaws, but the likelyhood of it going pear shaped, particularly should you present a gouge to the end grain, is greatly increased due to the greater leverage such a cut exerts (this is of course minus the tailstock, freeturning) and the reduced area the standard jaws have to resist such leverage compared to deep grip types. again, this is related very much to the length of the item, the shorter it is, the less the leverage and vice versa.

 

[pip1954]

hi the way to check the lathe is not out of alinement is to put a drive centre in the head stock and push the tail stock up to it and it should touch tip to tip
i think you can adjust the head stock if it does not line up so you can make it line up.
pip
ps is that the tail stock in picture, have you got the bowl fittings for this lathe.

 

[Mr Finch]

It's not that you should not use the standard jaws for such items, it is that they offer less reliable purchase than deep grip jaws under these circumstances, for fairly obvious reasons. You can get away with the standard jaws, but the likelyhood of it going pear shaped, particularly should you present a gouge to the end grain, is greatly increased due to the greater leverage such a cut exerts (this is of course minus the tailstock, freeturning) and the reduced area the standard jaws have to resist such leverage compared to deep grip types. again, this is related very much to the length of the item, the shorter it is, the less the leverage and vice versa.

Excellent info, thanks! More jaws are definitely on the shopping list! Turned a smallish bowl today with no issue whatsoever.

The bowl didn't end up being very good but the lathe was perfect!

 

[Mr Finch]

hi the way to check the lathe is not out of alinement is to put a drive centre in the head stock and push the tail stock up to it and it should touch tip to tip
i think you can adjust the head stock if it does not line up so you can make it line up.
pip
ps is that the tail stock in picture, have you got the bowl fittings for this lathe.

Hi Pip

I will do that, thanks.

Yes, I have the bowl attachments for the lathe - still doesn't allow a deep bowl though. I am going to have to just accept that until I can afford a new lathe!

Collin