Sharpening four prong drive centre?

[Mark Sanger]

With each rotation of a square blank there are four intermittent cuts, each one causing stress on the wood fibers that meet the drive center, as a .The result is loosening of the drive. In relation to the Steb Center, on seasoned stock I have found it to be good but on unseasoned wood (very fresh/just felled) I found that the fibers are too wet and flexible for the Steb center to hold due to the relatively small depth of grip resulting in slip.  For this reason I have never personally purchased one as I found for the price a good four prong is all that is needed for both seasoned and freshly felled wood.

I would sharpen your four prong with a small diamond cone bit in a dremel type tool and spend the £50 + on an enjoyable day out with the family. For me it is just another gimmick, give a good our prong a good whack with a mallet and it is more than good enough for all needs.

[Bryan Milham]

I also support the use of Steb centres...

... but there are times when my 4 prong or 2 prong drives still win out. I'd not do without them in my equipment range.

[GBF]

I like mine but as Mark says they are an unnecessary luxury.

Regards George

[The Bowler Hatted Turner]

MC although I own a selection of steb centres I still use a 4 prong drive. I sharpen mine by touching them on the grind stone lightly and have done for years. Maybe you should just make a wooden mallet and hit it harder thereby driving it a bit deeper and helping it grip better. Just be aware that woodturning accessory manufacturers are very good at convincing woodturners that they need more equipment when normally all the turner needs is an increase in experience.

[MCB]

MC although I own a selection of steb centres I still use a 4 prong drive. I sharpen mine by touching them on the grind stone lightly and have done for years. Maybe you should just make a wooden mallet and hit it harder thereby driving it a bit deeper and helping it grip better. Just be aware that woodturning accessory manufacturers are very good at convincing woodturners that they need more equipment when normally all the turner needs is an increase in experience.

Thank you

I  don't need to make a mallet since I  have a 2.5 lb engineer's hammer (that belonged to my late father) which should  sink the four prong drive into the end of the spindle sufficiently far to do the trick if my copper hammer doesn't.

MC

[Lazurus]

I use a 4 prong drive center and use the following method.

Insert the wood between centers then using the tails stock like a vice I then lock the head stock and rock the spindle back and forth until I can tighten the tail stock some more, repeat this a couple of times until you can no longer move the piece on the drive. this ensures any play or give in the timber is taken out and negates the fibers softening or working loose.

Obviously ensure your lathe has the strength to use the tail stock in this way.

I have rarely had to retighten during turning with this method. Don't forget to remove the spindle lock when completed.

Or if you have an unruly or odd shaped piece drill a hole with a forstner bit to sit the drive center into, then repeat the above.

[bodrighywood]

Some of the wood that I use Lazarus is either very soft or has splits and cracks so i need to be careful having it too tight or I would just break the piece up. In decent wood what you do sounds a sensible idea though. With the softer wood, I usually just use the centre to hold the piece long enough tpo make a tenone and then, if it is really soft, soak the tenon in thin CA glue to harden it up. If you think there is usually a way to turn most woods as long as it is safe .

Pete

[Philip Greenwood]

Also using the Tailstock as a vice could damage the bearings. I use a heavy mallet  so not to mushroom the end of the 4 prong drive,  it will damage the Morse taper in the headstock if it become mushroomed on the end due to using a heavy hammer.

[MCB]

.... just make a wooden mallet and hit it harder thereby driving it a bit deeper and helping it grip better. ......

Accepting that using a hammer may cause other problems........

What wood would  you suggest using to make a wooden mallet?

And what weight head?

MC

[bodrighywood]

Mine has an ash handle and a head in beech. if you can get hold of an old bowling bal cheaply (unlikely now) lignum vitae is good. Basically a hard wood for the head. Not oak though, tried that and it chips a lot if you hit metal as in the drive centre. Sure others will have ideas for wood as well.

pete

[seventhdevil]

for mallet heads you should use any of the following, hornbeam, apple, beech, eucalyptus, hawthorn, hard maple, plumb or pear.

exorics that can be used are jarrah, ekki, ipe, massaranduba, balau, keruing or as pete said the lignum bowling balls which will be the best solution.

here is one on ebay, http://www.ebay.co.uk/itm/Old-Lignum-Vitae-bowl-for-woodturning-/400964246914?pt=LH_DefaultDomain_3&hash=item5d5b54dd82


for the handle i would use ash.

[Mark Sanger]

I just use a carvers mallet that I keep for the job. You don't need to smash the drive deeply into the wood to drive it 3-6mm depth should be sufficient in seasoned wood. As Philip has pointed out you should not tighten to much as it will cause undue wear on the bearings, this can simply be notice by over tightening the tail stock at which time you will hear a change in sound coming from the bearings.

When I teach I lock the head stock off and locate the indents made by the prongs in the wood onto the drive, with the tail stock brought up I get the student to gently rock the wood back and forth until the slack is taken out, then a little more twist of the tail stock is all that is needed. If the prong indents are deep enough and the cuts are taken efficiently then the prong should not break out, far too often initial cuts are too aggressive causing this to happen. The intermittent cuts will cause the fibers in the end grain to move slightly so until it is round I recommend a regular check of the tail center with a little tightening to take up any slack on the drive.  

a mallet like this is all that is needed, or turn a basic one out of a lump of Ash

  

[Bryan Milham]

The problem I've found with really nicly made things like Lignum Vite headded mallets is no-one wants to damage them...

You've got a lathe, any sound piece of branchwood will make a mallet (maul), it's going to get ruined hitting the tang of the Drive.

So don't worry about it, use what you've got, when it's knackered just make another.

[Paul Hannaby]

Personally, I don't think the steb centres are worth the extra expense and the drive you get from them isn't as good as a similar size of four prong drive. Just my opinion, if you want to splash out another £40 - £50 that's up to you!

Have you considered a larger diameter four pronged drive centre instead? These are under £20.

Alternatively, how about something like this? http://www.axminster.co.uk/axminster-screw-chuck-faceplate-drive-for-c-jaws
With the centre screw removed and the drive screws added, it makes a useful drive that can be mounted in a chuck.

[The Bowler Hatted Turner]

One of the plus points of a steb centre is if you  (or a student perhaps?)gets a catch they are less scary with a steb centre and less dangerous too.