Mandrel saver, Holdfast or TBC

[MRDucks2]

OK, Gang. Nearly lost some nice walnut on my first Panache to warped mandrel. I like warped because "bent" makes it sound obviously my fault.

So, saved and completed Panache TBC and have turned TBC with stock bushings a few times. Normally no issues but did lose "flow" on the design of one 2 piece that ended up looking like that substitute teacher in the 7th grade, narrow on top with a wide bottom and curves that seemed abnormal.

As such, at times I prefer turned on a mandrel over TBC. Recommendations: get a mandrel saver with new mandrel, invest in the holdfast dual live center system, just focus on TBC or something else? Interested in your wisdom and experience.




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[McKenzie Penworks]

Mandrel saver is kind of a no brainer to have in the inventory of tools. Yea, I like to turn between centers but for 2 part pens I'm not going to turn each one separate every time if I don't need to. Sometimes it helps to have both pieces on the lathe so you can see how the lines flow. I'm sure someone will be along shortly to say that turning between centers is the only way to turn but a straight mandrel and the mandrel saver seems to work for me.

 

[Dehn0045]

Sorry about the warped mandrel, surely wasn't your fault... I use a mandrel and mandrel saver when I turn slimlines. I really like the mandrel saver, I think that it substantially improved accuracy on my slimlines. For all other pens I go with TBC, I get close with bushings (usually 60 degree TBC style) and then go to final diameter and apply finish without any bushings (using vernier caliper to check diameter). I have found that I get better results with no bushings even compared to using the tapered TBC bushings.

 

[Woodster Will]

Unless you make a lot of slimlines you may be better off with the larger diameter "B" type Mandrel as these are more difficult to "warp" than the skinny "A" type. As said though mandrel savers are a good option.

 

[RobS]

I like a Beall chuck with a 1/4" collet, a mandrel loaded into that and a mandrel saver.

 

[eharri446]

Have you taken a look at the new PSI turn between center mandrel system?

I have one, and it is great. The drive side has about a 1 inch mandrel sticking out of it and the live center has a 1 inch mandrel built into it. The only draw back is that you can't turn a two piece pen at the same time.

For me that is not a problem since most of the pens I turn now are either one piece or I just turn the two pieces straight with no bulges.

Just a word of caution, a mandrel saver is great and I used one when I first started. However, you can still get a warp on the mandrel shaft, especially if you get a catch while turning.

 

[MRDucks2]

We like the PSI TBC mandrels, but have had no issues so far using stock bushings and TBC.

Overkill, I am sure, but invested in the Holdfast system. WoodTurningz had the tail piece, head piece and two sizes of mandrel plus some bushing for about $90. I have little doubt it will last a long time and I can replace/add mandrels easily if/as needed.


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[TonyL]

If you asking my preference, I would say TBC. If you are asking my advice, whatever works best for you, and you may not know that until you turned dozen of pens. I use very highly quality TBC bushings made by a family member and every few dozen pens or so, I may get a slightly out of round hole (and I am not ashamed to admit that). I have seen beautifully turned pens turned by folks that use all of the aforementioned methods and tools. Given my skill level (or lack thereof), TBC with TBC bushings and non-tbc bushings is what works best for me. I have also turned directly on centers (no bushings). I don't like this method because I am too lazy to keep checking the dimensions. Much success with your pursuit for a method that works best for you.

Last thing: about half way through my turning, I rotate the bushings a quarter turn in opposite directions. This may serve no other purpose than throwing salt over my left shoulder or carrying a rabbit's foot, but someone told me to do it, so do.

 

[leehljp]

. . .
Just a word of caution, a mandrel saver is great and I used one when I first started. However, you can still get a warp on the mandrel shaft, especially if you get a catch while turning.

Two other often unthought of problems (but mentioned many many times in the past) is that to the un-initiated or newbie to turning - 1. drawing the tail stock up and insuring that it is "tight" - "tight" is ambiguous. Just an ounce of too much pressure will or can cause the normal mandrel to flex by 3/1000 (or so) of an inch, enough to throw the blank into a small elliptical orbit.
2. Two or three times a year, we get turners with a wobble in the mandrel. The tail stock for wood turning comes with a drive center that is intended for turning WOOD. Sounds normal, HOWEVER the drive center is pushed into the MANDREL, which is NOT wood. There is a HUGE difference. Mandrels have a 60° cone hole in the end and require a 60° cone to fit it correctly. IF not, the wood drive center cone will wallow around inside the mandrel, causing vibration or eleptical out of center turns.

 

[Talltim]

This may serve no other purpose than throwing salt over my left shoulder....

Actually the throwing salt over the left shoulder technique has worked well for me, especially if someone is standing there breathing down my neck while I am trying to concentrate.

As far as turning goes, if I could point to one thing that instantly moved our quality forward it would be TBC.

 

[MRDucks2]

Thanks to everyone for the feedback. I expect with the Holdfast system I bought something's my I may use less of as time goes on.

So far, I have had good success TBC with standard bushings. There are still some designs I prefer on a mandrel and, much like TonyL, there are times I switch between the two simply because I had a couple of tough turns and needed to change something. Maybe superstition, but it has always worked to date.

Turning directly on center has produced decent turnings for me, but with HF setup, I struggle maintaining consistent end pressure without having to really crank into the centers. Maybe future changes will help.

For the future I will use the Holdfast for mandrel turning and continue TBC on stick bushings for larger single tubes. Once I order a new tool rest and post from Rick, that may become a more preferred method.

My sharpening also continues to improve, which has a huge impact on what ever method I use and I try to stick with a skew for everything to help steepen the learning curve.

The biggest thing I believe is sometimes missed, though hinted at with the "do what works for you" comment, is to for us beginners to shoot first for consistency, then for improvement.

I certainly appreciate all of you and the IAP.


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[yaroslaw]

I don't turn slimlines. And I don't use neither mandrels nor bushings for turning pens (I do use pen mandrel with conical delrin bushing for finishing). Done more than a thousand pens that way already. Oh, and I don't normally use squaring jigs, pen mills or anything like that. Just a lathe and a skew.

If you are curious, I can briefly describe my routine.

 

[Dehn0045]

I'd be interested in how you square up on the lathe -- I have heard of others doing this, but haven't come across a description of the technique.

I don't turn slimlines. And I don't use neither mandrels nor bushings for turning pens (I do use pen mandrel with conical delrin bushing for finishing). Done more than a thousand pens that way already. Oh, and I don't normally use squaring jigs, pen mills or anything like that. Just a lathe and a skew.

If you are curious, I can briefly describe my routine.

 

[MRDucks2]

Please share your technique. I am quite interested.


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[Dehn0045]

I'd be interested in how you square up on the lathe -- I have heard of others doing this, but haven't come across a description of the technique.

I don't turn slimlines. And I don't use neither mandrels nor bushings for turning pens (I do use pen mandrel with conical delrin bushing for finishing). Done more than a thousand pens that way already. Oh, and I don't normally use squaring jigs, pen mills or anything like that. Just a lathe and a skew.

If you are curious, I can briefly describe my routine.

I decided to try squaring with the lathe. I'm not sure how anyone else does it, but here is what I came up with:

1.) I glue the tube in the blank with about 1/16" to 1/8" excess on both ends.
2.) Mount the square blank between centers. I am careful not to apply too much pressure because at this point the centers are contacting the excess wood and not the brass.
3.) I turn round to about 3/4"
4.) mount in collet chuck and using very light cuts with the skew I trim to the blank square. My skew grind has about a 30 degree angle, so using the sharp point (toe) I can get really light cuts and even cut the brass ever so slightly without much trouble.

I considered turning round to 3/4" prior to drilling, but I thought that drilling slightly off-center (or angle) would cause poor results. Also, I like drilling with the drill press when doing non-segmented just because its faster...

I would definitely recommend this method -- probably the best fits that I have been able to achieve, with almost no risk of chip-out. That said, I think a collet chuck is probably necessary to get really good results...