# Bent/Broken BS Mandrels



## VampMN (Sep 25, 2010)

Okay, in the last 3 days I have broken one and bent two bottle stopper mandrels. Now, I've read lots of people talking about having the problem of their threads stripping out and the blanks spinning on the mandrel. I wish I had that problem! After 3 moderate catches, I have two mandrels that are bent and one that snapped completely off.

Two of them went on one bottle stopper while doing finish shaping on the end. First time the mandrel bent, and the second time (with a fairly mild catch), the threaded section on the mandrel broke off all together. 

The other bent while doing the main shaping, with the blank supported by the tail stock. I haven't turned many stoppers, but I've never had this happen before. I'm guessing I am just doing something wrong, but has anyone else had this type of problem? I'm going to go broke replacing mandrels. :frown:


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## nava1uni (Sep 25, 2010)

What kind of mandrels are you using?  I sounds as if you might have been pushing too hard on the piece of wood.  What were you turning?  The BS mandrels are very thick


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## VampMN (Sep 25, 2010)

nava1uni said:


> What kind of mandrels are you using?  I sounds as if you might have been pushing too hard on the piece of wood.  What were you turning?  The BS mandrels are very thick



I am using mandrels I got from Woodcraft. I don't think I was pushing  too hard, as I try to be very aware of my pressure after blowing up a few pen  blanks from pushing too hard. 
I'm not actually sure what kind of wood it was. I got it out of the wood  by the pound bin at Woodcraft. However, if I had to guess, I would say  the one that broke and bent the mandrels may have been osage orange, and  the other may have been lignum vitae. These are just best guesses  though, based on seeing labeled pieces of that kind of wood for sale in  the store.
I'm also can't tell you lathe speed for certain either. I have a total  shop, and the speed adjuster thingy (scientific name) broke a while  back. Again, if I had to guess, I would say probably 1500-2000 rpm.

I appreciate the response.


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## MrPukaShell (Sep 25, 2010)

What speed are you turning at?


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## jttheclockman (Sep 25, 2010)

When turning why not turn with the tailstock for support???  Now if you are breaking when sanding then you have a serious problem with heavyhandedness.  Need to lighten up some.


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## nava1uni (Sep 25, 2010)

If it is the mandrel for the stoppers that are long that come from Woodcraft then I would make sure that the back piece is all the way into the chuck or whatever is holding it due to is only being approximately 1/4" stock.   I use a mandrel that I got from Ruth Niles.  It is the best mandrel that I have ever used on BS because it is on a morse taper and is very solid as it is in the headstock when turning and very thick.  I now only turn stoppers that are stainless steel as I have had the other corrode from contact with acid materials in wine, vinegar, etc.  You could only have gotten hold of a couple of mandrels that have fatigued metal.


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## JimMc7 (Sep 25, 2010)

nava1uni said:


> <snip>
> I use a mandrel that I got from Ruth Niles. It is the best mandrel that I have ever used on BS because it is on a morse taper and is very solid as it is in the headstock when turning and very thick. I now only turn stoppers that are stainless steel as I have had the other corrode from contact with acid materials in wine, vinegar, etc. <snip>


 
+1 re the Ruth Niles mandrel and stopper parts -- I bought her introductory kit (10 #301 SS stoppers, mandrel and drill bit) and couldn't be happier. I use a draw bolt in the headstock to keep the mandrel from slipping out and a tailstock support until the very last shaping of the stopper top.


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## monophoto (Sep 25, 2010)

So the broken mandrel fractured at the end of the 3/8" threaded stud?

How old was the mandrel?  Could this have been a stress fracture that built up over time?  How does (did, now) the stud join the mandrel body - was it a solid piece of steel or was the stud braised on?

I use a PSI mandrel - a very robust steel fitting that threads onto the spindle.  I also support the end of the blank with the tail stock during roughing so that I minimize stress on the mandrel and blank, and then remove the tailstock only to finish the end.  But considering the repetitive shocks that a blank/mandrel incurs as it is being initially rounded off, I could imagine that eventually something might give.  

Everything eventually will wear out - some things just last longer than others.


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## workinforwood (Sep 25, 2010)

Seems to me near impossible to break one of those mandrels.  How are you chucking the mandrel?  Are you using the tail stock for support?  No tail stock is definitely the wrong way to do it, which would cause levered stress on the mandrel, multiplied by the force of your chisel, then I suppose with no tailstock in play you could bend a mandrel, but otherwise it seems near impossible.


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## VampMN (Sep 25, 2010)

MrPukaShell said:


> What speed are you turning at?


 
As per my response to Cindy:
"I'm also can't tell you lathe speed for certain either. I have a total   shop, and the speed adjuster thingy (scientific name) broke a while   back. Again, if I had to guess, I would say probably 1500-2000 rpm."



jttheclockman said:


> When turning why not turn with the  tailstock for support???  Now if you are breaking when sanding then you  have a serious problem with heavyhandedness.  Need to lighten up  some.



I am using the tailstock for support. I only remove it to do the final shaping on the end after everything else is done. Definitely not happening during sanding. I only use enough pressure to let the sand paper do it's job.



nava1uni said:


> If it is the mandrel for the stoppers that are  long that come from Woodcraft then I would make sure that the back piece  is all the way into the chuck or whatever is holding it due to is only  being approximately 1/4" stock.   I use a mandrel that I got from Ruth  Niles.  It is the best mandrel that I have ever used on BS because it is  on a morse taper and is very solid as it is in the headstock when  turning and very thick.  I now only turn stoppers that are stainless  steel as I have had the other corrode from contact with acid materials  in wine, vinegar, etc.  You could only have gotten hold of a couple of  mandrels that have fatigued metal.



They are the thinner, 1/4 in ones from Woodcraft. I mkae sure I slide it all the way in to the jacobs chuck. Unfortunately, I can't use mosre taper stuff in my headstock, as I have a Total Shop, and it uses 5/8 in slide on pieces. :frown: 



monophoto said:


> So the broken mandrel fractured at the end of the 3/8" threaded stud?
> 
> How old was the mandrel?  Could this have been a stress fracture that  built up over time?  How does (did, now) the stud join the mandrel body -  was it a solid piece of steel or was the stud braised on?
> 
> ...



No, they were actually the 1/4 in mandrels from Woodcraft. I guess I should have mentioned that, but I didn't think about it. It looks to be one piece of steel. I had turned 3 stoppers on the first one that bent, and the other two were brand new.



workinforwood said:


> Seems to me near impossible to break one of  those mandrels.  How are you chucking the mandrel?  Are you using the  tail stock for support?  No tail stock is definitely the wrong way to do  it, which would cause levered stress on the mandrel, multiplied by the  force of your chisel, then I suppose with no tailstock in play you could  bend a mandrel, but otherwise it seems near impossible.



I'm chucking the mandrel, fully seated, into a jacobs chuck. I am using the tail stock for support for all but the very final shaping on the end. When I am doing that shaping, I try to be very light handed, as I know there is a lot of stress on the mandrel at the point.

Okay, I think I answered everything. Let me know if I missed something. Thanks for the replies!


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## workinforwood (Sep 25, 2010)

Did you get the Booyakamahana curse from an  Apache witch doctor? :biggrin:


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## VampMN (Sep 25, 2010)

workinforwood said:


> Did you get the Booyakamahana curse from an  Apache witch doctor? :biggrin:



I think I may have! I went to Woodcraft today, and they refunded my money for them. They said they have never had anyone come in with this problem before. Hopefully I just got a couple of bad ones and won't have any more trouble.


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## randyrls (Sep 25, 2010)

VampMN said:


> I think I may have! I went to Woodcraft today, and they refunded my money for them. They said they have never had anyone come in with this problem before. Hopefully I just got a couple of bad ones and won't have any more trouble.



Margaret;  I believe the Woodcraft BS are 10-24 thread.   This is far smaller than the 1/4"x20TPI or 3/8"x16TPI

Woodcraft is handling the Ruth Niles BS now!! (Way to go RUTH!) These are 3/8"x 16TPI.  The  Ruth bottle stopper base is slightly different in size than the BS that Arizona Silhouette sells.


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## VampMN (Sep 26, 2010)

randyrls said:


> Margaret;  I believe the Woodcraft BS are 10-24 thread.   This is far smaller than the 1/4"x20TPI or 3/8"x16TPI
> 
> Woodcraft is handling the Ruth Niles BS now!! (Way to go RUTH!) These are 3/8"x 16TPI.  The  Ruth bottle stopper base is slightly different in size than the BS that Arizona Silhouette sells.



The ones I have are 1/4x20. I checked them. I will definitely look for the Ruth Niles bottle stoppers next time I go in there. Thanks for the heads up.


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## MesquiteMan (Sep 26, 2010)

Moved to tools


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## nava1uni (Sep 30, 2010)

Go online to look at Ruth's bottle stoppers.  www.torne-lignum.com  She has a great introductory package and gives a lot of information about bottle stoppers.


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## VampMN (Sep 30, 2010)

nava1uni said:


> Go online to look at Ruth's bottle stoppers.  www.torne-lignum.com  She has a great introductory package and gives a lot of information about bottle stoppers.



Thanks for the link. After this experience, I have decided to not make anymore of the ones that have the 1/4" shafts. I plan on buying some of Ruth's the next time I get some. Heard nothing but good things, and I'm hoping I won't be able to bend/break the 3/8" mandrels. I wouldn't put it past me though. I may just be good(bad) enough to do it!


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## sdemars (Nov 10, 2010)

Can Arizona Silhouette's new stainless steel MT2 mandrel be used with Ruth Niles stoppers?

I have her kit, but the wife wanted a mandrel so I thought I would try Arizona Silhouette's.

Any suggestions appreciated . . . 

I'll contact Arizona Silhouette tommorow . . .

Steve


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## randyrls (Nov 10, 2010)

sdemars said:


> Can Arizona Silhouette's new stainless steel MT2 mandrel be used with Ruth Niles stoppers?
> 
> I'll contact Arizona Silhouette tommorow . . .



Steve;  Yes, but the stoppers are slightly different sizes.  I looked, but don't see that I wrote down how much different they are.  The size difference isn't very much as I remember, but enough to show.


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## KenV (Nov 10, 2010)

All of the bottle stopper I have seen in recent years are 1/4 by 20 and 3/8 by 16.  

Margaret has the Total Shop/Shopsmith which has a 5/8 inch plain steel stubb that the tooling mounts to -- ain't no morse taper going to work here.  

I turn some of the 1/4 by 20 cork stoppers with stainless steel threading from Lee Valley for oil and vinegar sets or for dry storage (think peppercorns in a bottle.    KI use a screw chuck with the hanger bolt replaced with a piece of stainless steel threaded rod.

The Woodcraft 6mm mandrel has a collar and that collar needs to be snug against the drill chuck to avoid a cantilever effect.  Snugged up does not give much room, but supports the mandrel.   I suspect the mandrel was out of the chuck -- perhaps 1/2 inch to 1 inch and it could bend.  

The 3/8 by 16 mount the same way, but are just about twice the end area of metal and are much more resistant to force.  

Margaret -- keep the mandrel collar close to the drill chuck or move over to use of a router bit holder (end mill holder) to mount the shaft.  The good news with the router bit holder is you cut the head off a bolt for a mandrel and file a flat spot for the set screw,  

(I have a shopsmith so ask away).


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## sdemars (Nov 10, 2010)

*Since . . .*



randyrls said:


> sdemars said:
> 
> 
> > Can Arizona Silhouette's new stainless steel MT2 mandrel be used with Ruth Niles stoppers?
> ...



Since a lot of the designs for stopper tops appear to be both flush & overlapping I'm thinking it would be OK. Any other comments, suggestions, etc . . . appreciated . .

Steve


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## themartaman (Nov 15, 2010)

*Mandrell*

I make my stoppers differently. Drill a hole for dowel and use a collet chuck to hold dowel. I use silicone bottle stoppers. Learned this from nick cook woodturner. There is a photo of ready to turn blanks on his site.


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