Dead center

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markgum

markgum

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I know, I'll get a zillion answers by asking this but don't want people to get bored.. :D
so after someone used my Lathe for a day; I noticed that my spurs on my dead center are now bent over. :( I have a Jet Mini lathe; and now I want/need to replace it. So the question is:
is it better to have a spur center; a point center; don't really matter; just get a mini chuck?? My turnings are of course pen's bowls and mini stuff.
I'm sure there are other options also. As a newby to turning, I ask this great group to help educate me.
thanks for your time.
 
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Some chucks have interchangable drive centers that can go into them so you don't have to remove the chuck when a center is preferable.

Look into them. I know CSUSA has at least one in their catalog.
 
Well, I think your problem is with having spurs on your dead center! Do you mean a drive center? A dead center should not have spurs, just a smooth 60 degree taper.

I like the newer "fine tooth" drive centers myself compared to the old four bladed ones. If you had a chuck they make special drive spurs that are held by the chuck jaws.

If you do small stuff, go with a fine tooth drive as it will give you a better grip.

This one is just $20 from Penn State
LCENTSS22.jpg
 
Originally posted by markgum



so after someone used my Lathe for a day; I noticed that my spurs on my dead center are now bent over. :( I have a Jet Mini lathe; and now I want/need to replace it. So the question is:
is it better to have a spur center; a point center; don't really matter; just get a mini chuck?? My turnings are of course pen's bowls and mini stuff.
Click to expand...


Mark; Sometimes the terms related to centers are slippery and not always interchangeable. A chuck should be used for bowl turning.

Dead Center: The two ends cannot rotate relative to each other.

Live Center: The two ends can rotate independently. Usually has a bearing inside the center.

Headstock Drive center: A dead center with some method of gripping the stock for the purpose of turning the stock. Can't be a live center.

Tailstock center: A live center is preferred, but can be a dead center with no spurs. Allows the stock to rotate freely on a pin or cone while keeping the stock on the lathe.

Spur center would go in the headstock.

I like the Stebb Centers pictured by Lee (Firefyter-emt) These are available in both dead (headstock) and live (tailstock) versions. The advantage is that you are less likely to catch a tool on the many teeth.

How did the spurs get bent??? Most unusual. The most common reason for this is hitting the spurs with a turning tool. That can be *VERY* exciting / scary!

Most pens are made on a mandrel that fits into the taper in the headstock and a live tail stock center with just a pin or cone.

There are many ways to set up the headstock and tailstock. Some are preferred, some will work, and some will work poorly or not at all!

:)
Hope this helps.....
 
Go with what Firefyter said. I have one of those from PSI and it is high quality. The spur drives that come as included accessories with most lathes are made of soft, very soft, metal. Do not blame the user of your lathe. The spurs will often collapse with the use of hard-hardwoods. File them sharp again and just save for back-up use. Buy the PSI drive, it will be money well spent.
 
Thanks all. I'm putting an order in for the fine tooth drive center posted above. I asked the person who used my lathe what they did and they said they had to pound the center into the block to get it to grab ahold. Not sure what wood they were using; guess it was tough. I will also file the old one and keep as a spare. Randy; thanks for the definitions. all this new 'lingo' is sometimes confusing.
 
Another lesson learned ... Do not lend your lathe to a friend unless they know what they are doing in the first place.

BTW, Sorbey has MT centers that are definitely the cat's meow ... pricy yep, but worth it if you turn bowls and such. Available at your local Woodcraft and are other items you want! You know you want them, so go get them ... Now!:D
 
Mark,
Your friend was correct in mounting the drive center off lathe. Normally, a saw cut is made in an "x" to allow easier mounting and to define center...

Pounding the wood into place on the lathe ends up wearing out the bearings. They are designed for radial force.
 
Frank,
A lifetime ago (Junior High Wood shop) I learned to cut the "x" to find the center and then to mount the live center with a rubber mallet, off the lathe.
This was re-enforced though out school and the military.

Back then a bowl gouge or spindle gouge were unknown. Turned bowls with round nose scrapers. Had skews and parting tools.

Brent (Robust Lathe) and Kevin (Oneway Lathe) both said the main reason from bearing failure was pounding the wood into the drive center while on the lathe. It takes time, yet bearing failure, due to excessive end force. As noted, Lathe bearings are made to take radial force.

Doing it this way should also help in not having so many requests for "stuck" drive centers.

I remember an "old Timer", (heck now I'm one) telling us that the lathe is not a vise...
Just tighten the tail stock enough that the wood spins and can be cut...
 
This is also the same idea as that metal block made to hammer the "X" into the wood spindle that is sold is most wood turning stores.

I will agree that tapping the spur into the stock and them lathe mounting is the proper way to do it. Never hammer a taper into the lathe or hammer wood into the spur while on the lathe.
 
Basic Procedures

Procedures for installing a center off lathe come in many lathe owner manuals. Also procedure is outlined in many learn to turn books.

Many woodturning demonstrators and authors, forget to mention or show basic procedures.

I stopped cutting an "x" when got a couple 2 prong centers. Part numbers 55-6202 & 014-3411 Craft Supplies Catalog. Wish now had gotten a 5/8" 2 prong center too! Still, mark the centers both ends, and use a awl before seating 2 prong centers with a mallet off lathe.

Following procedure already posted here and in owners manual also helps some what in not over tightening tail stock center.

Beauty of 2 prong vice 4 prong, or multi prong center is ends of the wood don't have to be cut perfectly square to get a good hold. You can true up both ends of a spindle pretty quick. Also if your rough turning a bowl can really hog off wood turning between centers safer than using a chuck or glue block. All of my bowl blanks come from logs so mounting between centers before installing in a chuck is safer & and faster for me.
 
According to WH460, "The cheaper brands teeth are sharpened on side while Sorby is sharpened on both sides.:

I have a very nice set of scars to prove how sharp on both sides they actually are and all I did was reach over my tail stock to get something and the MT2 steb center got me!

The Sorby steb centers are however, a VERY nice addition to ones arsenal of tools for the lathe and definitely worth the funds if you turn very many bowls or off center tool handles. :)
 
randyrls said:
How did the spurs get bent??? Most unusual. The most common reason for this is hitting the spurs with a turning tool. That can be *VERY* exciting / scary!
Click to expand...

This is a good question that I've been asking myself... I have two spur centers.. the first came with my Jet 1014, the second with the Jet 1442. I used the second with a peppermill blank to round it out before I started drilling. After the first use, the spurs are all bent over, and I did not hit it with the turning tool (I have done that and it does get "exciting"... I was turning a round tenon on the peppermill blank to fit in the chuck for drilling.
The first, which I've used for about 5 years is fine and now get the brunt of all my between centers work. Can't figure out what I did that bent the spurs. I turned much bigger pieces between centers using the 1014 spur.... and they appear to be identical in construction..
 
jwoodwright said:
Mark,
Your friend was correct in mounting the drive center off lathe. Normally, a saw cut is made in an "x" to allow easier mounting and to define center...

Pounding the wood into place on the lathe ends up wearing out the bearings. They are designed for radial force.
Click to expand...

Yep; The normal method is to mark the center point, use an awl to make a hole, the put the drive center on the piece (off the lathe) and whack end of the drive center with a soft headed mallet.
 
RE: drive centers, while I prefer the type that Lee pictured, the new (relatively) safety centers are also a good start. PSI sells them, as do many others. Although it looks contrary, they provide good grip. Their best feature is that catches are less likely to cause UFOs (undesireable flying objects).
 

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