Need spur drive help

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JasonM

JasonM

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Jul 6, 2008
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Waxahachie, Tx. USA
I got a spur drive to start working on bowls. It's been some time since I turned one, and even then I've only tried a couple of bowls.

Everything I could find for spur drives now has a spring loaded center, which is different than what I had in a bowl class I took, but I got one anyway. The selling point is supposedly that the center retracts so as not to dig too far into and split the piece being turned. What I'm finding instead is that the spring loaded point just wants to push the piece off of the spurs.

Trying to position the spur drive with a mallet prior to putting it on the lathe is no go - the spring just makes the drive pop off. I can position it on the lathe first and then tighten the piece down further, but it always feels like the spurs' bite is pretty superficial and over the course of turning will ultimately have more of a shallow boring effect rather than biting and driving.

I figure these things cannot be this flawed in their basic concept, so I must be misusing it. Any advice or help is appreciated.

Thanks!
 
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I read this post a few hours ago and have been trying to get my head round using a spur drive to turn bowls, I cannot see a way of doing it. As far as I can see you need some sort of chuck (Screw chuck, 4 jaw scroll chuck, etc) for bowl turning, spur drives are for spindle turning. If I am mistaken can some one please explain how you do it!

David:smile:
 
While I can see using one to turn the outside of the bowl, I wouldn't. You have to have the tailstock fully engaged at all times to use a spur.

You really need a good Scroll chuck to turn bowls.

Or use the old fashioned way and use the faceplate to turn the outside and true the bottom, then a glue the bottom to a scrap block and do the hollowing. Once you finish the hollowing, break the joint (usually you put a piece of paper between the two that allows it to break cleanly) and use a jamb chuck to finish.
 
JasonM said:
I got a spur drive to start working on bowls. It's been some time since I turned one, and even then I've only tried a couple of bowls.

Everything I could find for spur drives now has a spring loaded center, which is different than what I had in a bowl class I took, but I got one anyway. The selling point is supposedly that the center retracts so as not to dig too far into and split the piece being turned. What I'm finding instead is that the spring loaded point just wants to push the piece off of the spurs.

Trying to position the spur drive with a mallet prior to putting it on the lathe is no go - the spring just makes the drive pop off. I can position it on the lathe first and then tighten the piece down further, but it always feels like the spurs' bite is pretty superficial and over the course of turning will ultimately have more of a shallow boring effect rather than biting and driving.

I figure these things cannot be this flawed in their basic concept, so I must be misusing it. Any advice or help is appreciated.

Thanks!
Click to expand...

As always, a picture is worth a thousand words.
 
Spur drives with a spring center are intended to be used on spindle work. A bowl is best turned on a face plate, or 4 jaw chuck. In either of these two applications try to keep a live center in the tail stock pushed against the bowl blank until the whole thing is smooth and partially hollowed. Be safe! Phil
 
all of the info above is good but you most definately can turn a bowl starting between centers. a chuck is a "luxury" but not neccessary for turning a bowl. but hey don't take my word for it check out bob hamilton's method on youtube. it is not neccessary to seat the safety type drive centers like we did the regular solid spur drives.

http://www.youtube.com/watch?v=RPUwl1tpAao&playnext=1&list=PLEAE200FF4AC117E3
 
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I normally start a bowl between centers - and for a big bowl use a honking two inch big spur center that threads on ( http://stubbylatheusa.com/Online_Store.06.htm#2 in. Convertible Screw-on Drive Center ).

I then turn a tenon that fastens into a face plate/waste block or into a chuck.

Spring loaded center on the spur drives are expecting to be in compression with the tailstock. You can mark the teeth with a mallet but you cannot hold the spur center there.

The spur center allows one to adjust the bowl blank a few times to get best mount and best display of the wood. Think of clearing a hidden flaw by moving the center an inch.

once roughing is enough along the way to see the general layout, a tenon can be cut for the bottom, and a "wood worm hole" can be prepared as needed (these are commonly used to re-turn the outside and a new tenon for coring).

SO -- spur in the headstock -- appropriate live center in the tailstock (probably not the 60 degree live center for a pen mandrel) and mount the log, bowl blank etc.
 
Thanks everyone for the input. Ken's method is right along the lines of what I was taught/shown. Using the spur and live center long enough to create the tenon.

I probably should have been more clear in my description. :)

Aside from that bit of confusion, thanks for the suggestions and help!
 
A bowl can be shaped on the outside between centers then transferred to a chuck or glue block. A face plate and glue block may be the old fashioned way but I think it is the best way. I started using glue blocks two years ago and have not used a chuck for a bowl since. I just think the glue block provides a much more stable setup with less vibration than a chuck and better transfer of power from the headstock to the blank. I'm not trying to start an argument, but just telling how I turn bowls and why I do them this way.
Do a good turn daily!
Don

Russianwolf said:
While I can see using one to turn the outside of the bowl, I wouldn't. You have to have the tailstock fully engaged at all times to use a spur.

You really need a good Scroll chuck to turn bowls.

Or use the old fashioned way and use the faceplate to turn the outside and true the bottom, then a glue the bottom to a scrap block and do the hollowing. Once you finish the hollowing, break the joint (usually you put a piece of paper between the two that allows it to break cleanly) and use a jamb chuck to finish.
Click to expand...
 
I use a spur drive center to start with. I use the kind with the adjustable center so I can balance my piece. I set the center out past the spurs about a 1/8" and just bump both centers up against my piece (just enough to hold it). That will tell you if your piece is balanced on the lathe or not. Once balanced I set the spurs tighten up my tail stock and turn the outside shape and then a tenon for my chuck.
I always use a spur drive to start with, I can't stand face plats
John
 
These are the centers been using for years, PSI may have less expensive alternative.

http://www.woodturnerscatalog.com/s...2_Prong_Drive_Center___2_drive_center_1?Args=

http://www.packardwoodworks.com/Mer...e_Code=packard&Category_Code=lathes-acc-dc-2p

I have also seen a four prong/spur center that can fit in a chuck for less money. I would not use my MT-2 prong/spur centers for bowl turning. You end up with same results as step centers.

Beauty of a two prong center for both bowl & spindle turning don't need perfectly square end for prongs to get a bite. Craft Supply center better for bowl turning, but Packard's will work too!

I use both chuck and face plates turning bowls. Depends upon piece of wood and form am shooting for. Same goes for using tenon or recess.
 
I too use a big 2" spur drive to turn the outside of bowls and form the tenon. Since I almost exclusively do this with green wood, I always hold the tenon a chuck once the outside is done rather than use a faceplate.

Since 90%+ of my work is going to be twice turned, I don't really worry about the outside running perfectly true in the chuck. For the rare piece that will not be twice turned, I can re-true the outside with some very light cuts and a bit of shear scraping.

Months later, I use the dimple in the tenon formed by the point in the live center to re-center the tenon to true it up before re-chucking it and getting final shape / wall thickness.

Having a spring point should not prevent the spur drive from working. Back before I got my big spur drive, I used to put the piece on the floor and drive the spurs into the wood with a mallet. Back on the lathe the blank would easily lock onto the spur "dents". My big spur drive has such sharp spurs that it cuts into the wood easily with little force from the tailstock.

The only downside to spring points that I see is that when attempting to balance a piece, I often suspend it between points of my live center and drive center and fine tune with hand spins until it's fairly balanced before driving the spurs into the blank. You can achieve the same effect by suspending it between a standard dead center and live center and tweaking the balance by hand spins before applying enough force to clearly mark the two balance points. At this point you can drive the spurs into the blank using a mallet and the point in the balance dent formed by the dead center.

As long as you are just gently hand spinning and you aren't using a huge heavy blank, you can suspend it with just minor prick points to hunt for balance (or search for the most flattering orientation).
 
Jason, the steb centers will give you more surface contact than the four prong centers. If you center punch a hole first, you can use the hole to line up the point, before it retracts.
 
Step and four prong/spur centers designed more for spindle turning and mostly square surfaces. Yes, can use them on some bowl turning projects depends upon the piece of wood. Relatively flat surface for these centers to grab is necessary. Still do not get aggressive hogging out wood and you will be okay.

If you split a log and have bark and uneven surfaces, a two-prong/spur center is preferred. Simple, safe and fast procedure.

If do not have a two-prong/spur center try using the woodworm screw that came with your chuck. I use one that came with my Talon chuck with no problem. Just drill appropriate size hole and screw blank on. To make up for uneven surfaces or gaps use a homemade wood washer between chuck and blank if needed. I have done it both ways without and with a washer. Wood washer can limit the amount of drilling you need to do which is a plus for small bowls and platters. I use this approach for freshly cut wet bowl blanks a lot. I am not shy about removing the tailstock if needed on a securely mount blank.
 
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