Another Offset Tailstock Question

Bumlak

Bumlak

AzB Silver Member
Silver Member
Ok. So my wife decided she wants yet another cue. I found a nice Brunswick Double Butterfly to convert but now the quandary (and it may be a dumb question.)

If you are only tapering the forearm, do you only use the length of the forearm between centers for the taper per inch formula or do you simply set the offset to about .200 to give your typical .84 at the joint and 1.24 at the butt cap?

Erich
 
Bumlak said:
Ok. So my wife decided she wants yet another cue. I found a nice Brunswick Double Butterfly to convert but now the quandary (and it may be a dumb question.)

If you are only tapering the forearm, do you only use the length of the forearm between centers for the taper per inch formula or do you simply set the offset to about .200 to give your typical .84 at the joint and 1.24 at the butt cap?

Erich
Click to expand...

This an excellent question, but...

Are you asking about tapering a 12 inch piece - or only tapering the first
12 inches of the 29 inch butt?

From "Ask Doctor Google"

============================================
Calculating Tailstock Setover

The tailstock setover must be calculated for each job because
the work length plays an
important role in the calculation. Often plans do not specify
TPI, TPF, or T/mm, but do provide pertinent information.
If inch dimensions are given in fractions, they must be converted to decimals.

Formula: Offset =

L × (D – d)
_____________
2 × l

Where

L = Length of workpiece

D = Major Diameter (large end)

d = Minor Diameter (small end)

l = length taper section
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Formula: When taper per inch is known, Offset =


L × TPI
_________
2

============================================

HTH
Dale
 
An off-set tailstock is dependent on knowing the starting and ending diameters. 1.24-.840=.4

.4 divided by 2 gives you you .200 offset. If your cue is 29 inches then .4 divided by 29 gives you a taper of roughly .014 per inch.

If you have a 13 inch forearm the difference between end diameters is (13*.014) or .182

.182 divided by 2 would yield an offset of .091 for the tailstock, using the exact taper per inch, it really would be .090

This offset would be for tapering a 13 inch piece of wood center to center.

Taper bars are easier in my book, since you only need to set a taper bar once, but to each his own.

Hope this explanation helps.

Alan
 
Formula: Offset =

L × (D – d)
_____________
2 × l

Where

L = Length of workpiece

D = Major Diameter (large end)

d = Minor Diameter (small end)

l = length taper section
++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++

Formula: When taper per inch is known, Offset =


L × TPI
_________
2

I think that's what I said.

I think?:confused::confused:

Alan
 
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aphelps1 said:
Formula: Offset =

L × (D – d)
_____________
2 × l

Where

L = Length of workpiece

D = Major Diameter (large end)

d = Minor Diameter (small end)

l = length taper section
++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++

Formula: When taper per inch is known, Offset =


L × TPI
_________
2

I think that's what I said.

I think?:confused::confused:

Alan
Click to expand...

Except the offset is really the distance from the chuck's face to the live center in the tailstock.
If you add a 3" long center with spur in the tailstock ( for safety reasons, I hope you do ), you will need to add that 3" in the L.
And technically, it's the angle that is being calculated. :-)

Or you could use a boring head .

Joey~Hates the .400" straight butt taper. Ugh!~
 
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JoeyInCali said:
Except the offset is really the distance from the chuck's face to the live center in the tailstock.
If you add a 3" long center with spur in the tailstock ( for safety reasons, I hope you do ), you will need to add that 3" in the L.
And technically, it's the angle that is being calculated. :-)

Or you could use a boring head .

Joey~Hates the .400" straight butt taper. Ugh!~
Click to expand...

I hate to disagree, but it is the distance between the tip of the centers. The chucks face or spindle nose have no part in the equation.
 
Canadian cue said:
I hate to disagree, but it is the distance between the tip of the centers. The chucks face or spindle nose have no part in the equation.
Click to expand...

Well, duh me!
Between centers is right.
You are right.

In tapering just forearms, I like to keep the bottom fatter and take a straight pass for some 3 inches.
Makes chucking a lot easier.

In handles, I like tapering the top a little fatter for the same reason.
 
So this was on a 12 inch forearm only. I've seen videos where the forearm is tapered finstead to make sure the point height is maintained (though that process should be the same regardless of the length of the piece.) It's really a curiosity question more than anything. I want to make sure I know all of the in'some and out's of offsetting the tailstock before I start depending on the taper bars. It's more about spending the time to learn the machine and techniques at this point for me. I'm years away from putting pieces comparable to what many of you guys put out now.
 
aphelps1 said:
An off-set tailstock is dependent on knowing the starting and ending diameters. 1.24-.840=.4

.4 divided by 2 gives you you .200 offset. If your cue is 29 inches then .4 divided by 29 gives you a taper of roughly .014 per inch.

If you have a 13 inch forearm the difference between end diameters is (13*.014) or .182

.182 divided by 2 would yield an offset of .091 for the tailstock, using the exact taper per inch, it really would be .090

This offset would be for tapering a 13 inch piece of wood center to center.

Taper bars are easier in my book, since you only need to set a taper bar once, but to each his own.

Hope this explanation helps.

Alan
Click to expand...
Ahh I knew i forgot a step.

Sent from my SAMSUNG-SM-G935A using Tapatalk
 
Bumlak said:
So this was on a 12 inch forearm only. I've seen videos where the forearm is tapered finstead to make sure the point height is maintained (though that process should be the same regardless of the length of the piece.) It's really a curiosity question more than anything. I want to make sure I know all of the in'some and out's of offsetting the tailstock before I start depending on the taper bars. It's more about spending the time to learn the machine and techniques at this point for me. I'm years away from putting pieces comparable to what many of you guys put out now.
Click to expand...
with some of the old cues,
there isnt a whole lot of xtra meat there to work with.

if youre wanting to just true it up before going on with assembly,
put your indicator on toolpost , coming in from the side.

to match the existing taper of that particular piece,
when you have zero zero at both ends, you know you're dead on it.

i use this same method when i go back in to cut a wrap groove after finish is completed


 
BHQ said:
with some of the old cues,
there isnt a whole lot of xtra meat there to work with.

if youre wanting to just true it up before going on with assembly,
put your indicator on toolpost , coming in from the side.

to match the existing taper of that particular piece,
when you have zero zero at both ends, you know you're dead on it.

i use this same method when i go back in to cut a wrap groove after finish is completed


Click to expand...

So basically here is the concept the wife wants. Right now, the piece is roughly 30". It's right at about .87 at the joint and I would have to mic out the butt however if memory serves me it's about 1.46" right now. I could mount the entire piece up as it is here, cut my taper and be done. True...there isn't much meat to work with as the splice she wants to use for the joint collar was already almost at finish size. I'm fairly certain that what I am going to hear is "It's 29". Just taper the damn thing, cut your A-Joint and move on with life." My question is, what if that (for whatever reason) was not an option at the moment? What if all you had was a 12.5" forearm? Probably almost the same answer...out one on...but this is about learning for me LOL.
 

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aphelps1 said:
Formula: Offset =

L × (D – d)
_____________
2 × l

Where

L = Length of workpiece

D = Major Diameter (large end)

d = Minor Diameter (small end)

l = length taper section
++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++

Formula: When taper per inch is known, Offset =


L × TPI
_________
2

I think that's what I said.

I think?:confused::confused:

Alan
Click to expand...

If you check - you 'said it' at 4:12 EDST, I said it at 3:51 EDST

But thanks for stopping in.

Dale
 
pdcue said:
If you check - you 'said it' at 4:12 EDST, I said it at 3:51 EDST

But thanks for stopping in.

Dale
Click to expand...
I type as I think.

I started before you did, you just finished first.

Alan

(Still getting the pointy things to touch)

(My middle name is Dale) :grin-square::grin-square:
 
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