Whacking the Spur Drive

[Jamie Straw]

Even though Bonnie taught us how to cut grooves in the end of spindle stock and tap the spur drive into the wood, I never do this on my lathe. I have one of those 4-spur drives with a spring-loaded point. I make small center marks with an awl on each end, hold one up to the drive center with the point seated, slide up the tailstock into the right position, and then use the hand wheel to tighten (not too tight). Usually will take a couple passes with the roughing gouge, tighten again, repeat. After 2 or 3 times, no need to tighten any more. Any reason (or certain circumstances) I should change my ways?

 

[hockenbery]

Even though Bonnie taught us how to cut grooves in the end of spindle stock and tap the spur drive into the wood, I never do this on my lathe. I have one of those 4-spur drives with a spring-loaded point. I make small center marks with an awl on each end, hold one up to the drive center with the point seated, slide up the tailstock into the right position, and then use the hand wheel to tighten (not too tight). Usually will take a couple passes with the roughing gouge, tighten again, repeat. After 2 or 3 times, no need to tighten any more. Any reason (or certain circumstances) I should change my ways?

If it is working and your are not drilling holes with the spur drive, not reason to change.

I always knock the spur drive into the blank with a wooden mallet before mounting it in the lathe.

Spindles that weigh less than twenty pounds I drive with a cup center with a point either a safe center or dead center.
I just stick the point in the marked center and tighten the tailstock. If it slips a bit during the turning I tighten the tailstock more.

Advantages over the spur are:
A blank taken off the lathe always recenters perfectly.
A blank can be flipped end to end and centers perfectly
When using the index wheel,the tailstock can be loosened slightly and the spindle rotated by hand to line up any side with zero on the index wheel.
If you get a catch the blank will stop and the drive spins in the wood- tighten the tailstock and continue turning.

Have fun,
Al

 

[Jamie Straw]

[Snip]
Spindles that weigh less than twenty pounds I drive with a cup center with a point either a safe center or dead center.
I just stick the point in the marked center and tighten the tailstock. If it slips a bit during the turning I tighten the tailstock more.

Advantages over the spur are:
A blank taken off the lathe always recenters perfectly.
A blank can be flipped end to end and centers perfectly
[Snip]
Have fun,
Al

Thanks, Al. It'll be awhile before I turn spindle stock weighing more than 20# Question, though: Since my spur drive has a pointy little tip, why wouldn't the blank be able to be recentered/flipped as above and work "perfectly"? I'm embarking on spindle-stock Christmas presents this week, I may need to know this!

 

[Bill Boehme]

Even though Bonnie taught us how to cut grooves in the end of spindle stock and tap the spur drive into the wood, I never do this on my lathe. I have one of those 4-spur drives with a spring-loaded point. I make small center marks with an awl on each end, hold one up to the drive center with the point seated, slide up the tailstock into the right position, and then use the hand wheel to tighten (not too tight). Usually will take a couple passes with the roughing gouge, tighten again, repeat. After 2 or 3 times, no need to tighten any more. Any reason (or certain circumstances) I should change my ways?

Spring loaded point has a small bit of wiggle room and also wood will crush a bit when the spurs dig in. When you reverse a spindle, the four spurs will want to pull the center point a bit and wood can crush slightly. If you swap ends on the spindle and then go back to the original orientation, the alignment won't be precisely the same ... maybe close and maybe not.

I do like Al and whack the spur onto the spindle with a wooden mallet OFF THE LATHE. Doing it on the lathe is abusing the bearings and can cause brinelling (Google it if not familiar with the term). Be kind to your lathe's bearings or else the machine abuse police will be after you for brinelling the bearings. Cranking in an excessive amount of tailstock pressure is also bad.

 

[john lucas]

Most of the time I simply put the wood on the lathe, engage the tailstock and push with it. The lock the lathe spindle and twist the spindle back and forth which digs in the spur drive. Then I tighten the tailstock some more. I'm not sure this is the best thing because it puts a lot of stress on the threads of the tailstock. I've heard of people stripping the tailstock threads but so far on my Powermatic that hasn't been a problem. I keep thinking I should drive the center in before mounting but that requires removing the center and when I'm turning a dozen spindles that's just too slow for me. One of these days I may make one of the cool V shaped jigs to go on the bandsaw that perfectly centers work so I can notch it with an X cut but it's probably on my really long away one of these days things.

 

[hockenbery]

Thanks, Al. It'll be awhile before I turn spindle stock weighing more than 20# Question, though: Since my spur drive has a pointy little tip, why wouldn't the blank be able to be recentered/flipped as above and work "perfectly"? I'm embarking on spindle-stock Christmas presents this week, I may need to know this!

You will get close and sometimes as good as you always get with the matching cup centers with points.

But often you will get one or both centers off a 1/16" of an inch or so.

When you flip a spindle with a spur and a cup most likely one spur will contact the blank first pushing it off center.
Also on the cup side one side or an area raise by the spur bite will contact first pushing the blank to one side.
If you have no finished surface this is insignificant

Even taking a spindle off the lathe and putting it back on will cause a reentering problem on the spur drive side.
Marking and using the same spur positions help.

Also I think a cup drive is essential for multi center turning.

 

[robo hippy]

Well, not some thing that I use often. I prefer the steb centers, so spring loaded center point and a bunch of tiny teeth around it to dig in. Almost every time I turn a spindle, I may start between centers, but only long enough to get a tenon turned on one end, and then reverse it and put it in a chuck. I to do turn a bit on the heavy hand, and I have never had anything spin out of a chuck... Very secure then. If I use a spur drive, I do try to square up the end first on the chopsaw, then mark the center, and seat it mostly by pressure from the tailstock. It seems like when ever I try to seat it with a carving mallet, it ends up being out of line with the blank, and then never seats securely when I mount that whole mess onto the lathe. I do like an awl to mark the center, especially if centering is really important like for table legs. On tool handles, it doesn't matter a whole bunch... Most of the time, they do need to be tightened up as I turn, wood fibers do compress.

robo hippy

 

[john lucas]

I'm on the fence on Steb centers. On larger ones they work great. The smaller one that I bought for turning my mirror handles has such a strong center spring that it actually increases the chatter problems on long thin spindles. I went back to my 3/8" mini spur drive for the mirror handles.

 

[hockenbery]

In addition it advantages I mentioned earlier,
I like a small cup center I have because when I'm doing a batch of Christmas ornaments I never have to take it out.
Chuck screws on with the center in the lathe. I can rough several ball or finial blanks, put on the chuck and finish them, Take the chuck off, and when I rough the next batch the cup center it's already in there.

I am not a big fan of spring loaded points. I like the cup center point locked in about an 1/8" proud.
I can press the point into any penciled center.
On anything critical I mark the center with a scratch awl.

I use spur drive for starting bowls and hollow forms and for spindles over about 20 pounds.

 

[Bill Boehme]

I recently bought a large size steb center just to see whether I thought it would be useful. It has much larger teeth than the 3/4" steb center that I have and appears to hold very solidly for medium size pieces.

I agree with Al about the spring loaded points. The problems that I see with most of the spring loaded points are: the spring is too stiff, the point sticks out too far, and the point is too fat, but spur drives with fixed points are usually similar in shape. I think that the spring loaded points (and maybe the fixed points as well) would be more satisfactory if the points were thinner and sharper sort of like the center point on the Oneway live center and didn't extend out quite as far.

 

[Gerald Lawrence]

I recently bought a large size steb center just to see whether I thought it would be useful. It has much larger teeth than the 3/4" steb center that I have and appears to hold very solidly for medium size pieces.

I agree with Al about the spring loaded points. The problems that I see with most of the spring loaded points are: the spring is too stiff, the point sticks out too far, and the point is too fat, but spur drives with fixed points are usually similar in shape. I think that the spring loaded points (and maybe the fixed points as well) would be more satisfactory if the points were thinner and sharper sort of like the center point on the Oneway live center and didn't extend out quite as far.

But Bill the point of a steb is not supposed to do anything except initial alignment with marked center (if one is there). So what difference would it make if the point was slender. I can see what you say on regular four spur drives, I like the adjustable point. I have noticed that some drive spurs have the center point unsupported and stick out too far so it bends.

 

[Bill Boehme]

But Bill the point of a steb is not supposed to do anything except initial alignment with marked center (if one is there). So what difference would it make if the point was slender. I can see what you say on regular four spur drives, I like the adjustable point. I have noticed that some drive spurs have the center point unsupported and stick out too far so it bends.

A point with a fat angle doesn't line up with the center hole as accurately as one with a more "needle-like" profile. Additionally, a stiff spring on one of those blunt-object points tends to make the point drift more, especially in wood that has a pronounced difference between early and late wood hardness, before the outer teeth of the step center engage the wood.

One other reason that I don't like the stiff springs is when I am using a mallet to to "set" the drive, it is more difficult to hold the drive in the same position when more than one whack is needed.

 

[Jamie Straw]

A point with a fat angle doesn't line up with the center hole as accurately as one with a more "needle-like" profile. Additionally, a stiff spring on one of those blunt-object points tends to make the point drift more, especially in wood that has a pronounced difference between early and late wood hardness, before the outer teeth of the step center engage the wood.

One other reason that I don't like the stiff springs is when I am using a mallet to to "set" the drive, it is more difficult to hold the drive in the same position when more than one whack is needed.

Now we're getting down to the real nitty-gritty! (Seriously).