Well, since I do recall exactly this same experience, I'll vote in with Jim here. And I only used hand pressure on the nut. I don't know the theory behind it. Perhaps since the brass pen-tubes and reference-bushings are a loose fit rather than a press-fit on the threaded mandrel, then they will tilt minutely rather than stay square under high tightening forces ???fjimp wrote:Ivan,
The the jam nut is often a difficult item to adjust properly. Left too loose and the blanks spin which makes turning them nearly impossible. The tendency is to tighten them good and tight which tends to bend the mandrel. Once bent the pens segments become bowed and do not turn evenly. I have a bent mandrel that I have attempted to straighten. I really thought I had it right and attempted to turn a couple of Mini Bullet Twist Pens. The blanks appeared correct on the mandrel yet once assembled are out of round.
Jim
Question for you Pen Turners...
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Chris
Very interesting post, Ed! Probably I shouldn't comment as I have never turned a pen, but can't resist! Your story brings to mind many personal thoughts related to woodworking in general.
As innovative 'improvements' (jigs and tools) are made available, some soon become standard, relegating the old ways and skills to the background. What happens is; over time we lose many of the basics of our craft through reliance on the 'improvements'. What we lost were once the basis of our knowledge, skills and abilities.
Then we find ourselves confused, and searching for the cause of our problems. The answer(s) may lie in use of the new jig/tool or it may be our lack of understanding woodworking basics.
As innovative 'improvements' (jigs and tools) are made available, some soon become standard, relegating the old ways and skills to the background. What happens is; over time we lose many of the basics of our craft through reliance on the 'improvements'. What we lost were once the basis of our knowledge, skills and abilities.
Then we find ourselves confused, and searching for the cause of our problems. The answer(s) may lie in use of the new jig/tool or it may be our lack of understanding woodworking basics.
Octogenarian's have an earned right to be a curmudgeon.
Chuck in Lancaster, CA
Chuck in Lancaster, CA
I do a fair number of pens-mostly premium kits and celluloids and acrylics. I have never had the brass jam nut bend a mandrel. I have never used a tool to tighten one-that is the key. A close fit between the blank bore and the brass tube makes more difference. If the drill wobbles and gives an oversized hole, then when the bushings are installed and the side load of the lathe tool is applied, the brass expands and the blank wants to spin. I drill my blanks with a centering vise mounted on right angle boards which are then clamped to my SS table and the blanks are bored horizontally. the precision of the SS avoids the flared hole and I get a close slip fit for the brass tubes.Usually I glue with epoxy though I now have an extra thick CA that has held up.
I then move to my Jet Mini-I have turned on my SS with great success, but when I'm into production mode, I leave the centered up vise on the SS.{though I don't post here often, I proselytize the dis-believers at every opportunity-short of a metal lathe-nowadays I have 2 Unimats-the beloved Shopsmith is a precise horizontal boring machine-we know it.} It is a matter of not being ham handed in drawing up the tailstock. My mandrel rods are in MT's-somewhere I bought a MT with slits and a compression nut that allows for overall mandrel length adjustment-when it gets lost in the messy shop I just throw on other bushings to take up extra length on a plain morse/rod mandrel. I turn almost exclusively with a 3/8" gouge[occasionally the Skewchigouge, an nice multi-use item]-power stropped while I work-often-very often. Thus, I rarely have a catch--NO catch= no distorting event= smooth and concentric assembly of pens. I use a commercial pen press and find it to be a great investment-I have plenty of the necessary DeStaco clamps around, but a sale price somewhere made me lazy and the ease of straight line pressing force makes a world of difference-can't recall the last time I "crinkled" a pen.( I might note that I do not always think of Penn State as top quality. However, I have spent big dollars on Sorby toothed and spring loaded centers-the Penn State clones have been a fine surprise-flawless performance-most kit purchases are at Arizona Silhouette-he is not chatty, but he delivers the good goods)
I think this is a good product-used as designed I cannot see the downside-with a pipewrench hand, anything goes to he-double hockeysticks
I then move to my Jet Mini-I have turned on my SS with great success, but when I'm into production mode, I leave the centered up vise on the SS.{though I don't post here often, I proselytize the dis-believers at every opportunity-short of a metal lathe-nowadays I have 2 Unimats-the beloved Shopsmith is a precise horizontal boring machine-we know it.} It is a matter of not being ham handed in drawing up the tailstock. My mandrel rods are in MT's-somewhere I bought a MT with slits and a compression nut that allows for overall mandrel length adjustment-when it gets lost in the messy shop I just throw on other bushings to take up extra length on a plain morse/rod mandrel. I turn almost exclusively with a 3/8" gouge[occasionally the Skewchigouge, an nice multi-use item]-power stropped while I work-often-very often. Thus, I rarely have a catch--NO catch= no distorting event= smooth and concentric assembly of pens. I use a commercial pen press and find it to be a great investment-I have plenty of the necessary DeStaco clamps around, but a sale price somewhere made me lazy and the ease of straight line pressing force makes a world of difference-can't recall the last time I "crinkled" a pen.( I might note that I do not always think of Penn State as top quality. However, I have spent big dollars on Sorby toothed and spring loaded centers-the Penn State clones have been a fine surprise-flawless performance-most kit purchases are at Arizona Silhouette-he is not chatty, but he delivers the good goods)
I think this is a good product-used as designed I cannot see the downside-with a pipewrench hand, anything goes to he-double hockeysticks
1983 Mark V- beltsander, jigsaw, Stripsander,jointer, bandsaw-double carriage and tables with molders and drums, Over Arm Pin Routers(Freestanding x 2)Second Mark V.