Author Topic: Determining & Shaping Tapers for Horn Sizers  (Read 4739 times)

Offline G. Elsenbeck

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Determining & Shaping Tapers for Horn Sizers
« on: March 13, 2009, 04:17:53 AM »




For all the lathe owners out there that aren’t sure how to proceed making your own horn sizers, or shapers if you will,  let me begin by showing and tell how I happen to make them.  Let’s start by assuming that the ‘average’ taper of most horns is 10 degrees.  By taking a sheet of paper (use the ¼ inch grid paper as it makes life a little easier) and use of a protractor and a straight ruler you can visually draw out what the shaping cone(s) will look like.  Start by drawing a large T on your paper.  Now at the horizontal line measure, say two inches to both sides where the vertical line meets the horizontal line and place a small mark.  Why two inches?  It’s just a place to begin. 

Now carefully place your protractor’s center hole or mark over that 2 inch mark previously left.  Once you’re sure it’s properly placed place a mark at the 80 degree position (I’m working on the right side of vertical at this point).  Now, do the same procedures at the 2 inch mark on the left side of the vertical line only this time place a mark at the 100 degree position. 

What you now have are two points on each side of vertical that give you the proper position to use your ruler for drawing your taper lines.  See first picture. 


No, I’m not quite done yet, as there may be some of you that will get a lathe and will want to know this for future reference. You’ll just have to bear with me. 
So now we have this triangular shaped picture on paper and you’re wondering, ‘Now what the $#*! do I do?’  It’s simple really. Let’s say we want to start with a sizer 3 inches in diameter but, how long should the sizer be?  Well I generally use 1 3/4 inches as a guideline for my ‘standard’ tapered body and you’ll find in a moment why setting a standard is useful. 

The next step you want to do is mark your 3 inch mark.  Measure down with your ruler until you find 3 inches between the two sloping lines and draw your horizontal line, usually with a different color.  Mark as ‘3 inches’.  Now from that line measure down 1 3/4 inches and draw another horizontal line and mark as such.  You all still with me.  Here comes the fun part.  Now measure the ‘width’ of the bottom line, in this case it should be 2 ¼ inches.  Hmmm, now lets say the overall dimension of a second sizer you want should be 2 ½ inches.  Performing the same procedures as above you will find that the bottom of this sizer should come out to be 1 3/4 inches.  Light bulb goes on.  What did we just learn by doing this?  For every average sizer that has a ‘standard’ two inch length you can deduct ¾ ( I call this my ‘variance’) of an inch from the desired starting width and end up with a ten degree taper.   

Anyway, the above holds true regardless of the desired degree of taper you want.  I have drawn up plans for 5, 7 and 8 degrees.  The only thing that changes (assuming your 1 3/4 inch standard is used) is the amount of ‘variance’ for each pattern.  Of course, if you want a shorter or longer ‘standard’, the variance will change accordingly.  I keep my simple drawings tacked on my board for ready reference and all I need to know is the ‘variance’ for each different degree of sizer I make.  KISS principle. 

Now, are we ready for chips to fly?  The only turning tools I use (again KISS principle) is a large 1 inch roughing gouge and a ¼ inch parting tool.  I’ll assume at this point you have some stock already turned round and mounted on the lathe. 

In this picture I have my stock approximately within 1/32 of the final dimension I want to start with and have started to size the end by using my parting tool approximately 3/8 inch from the edge.  Again I will leave this dimension approximately 1/32 oversize to my intended size needed to achieve the 10 degree taper.



I next progress to forming a stub or tenon on the sizer.  This gives you something to rap on either to drive the sizer home or to loosen when you want to get it out of the horn later.  It’s not necessary, just something I do if I’m not making dual ended sizers.


Once I’ve accomplished getting the bottom of the sizer to the rough size I need I continue using the parting tool in the same manner slowly working my way from right to left until I get near the top of the sizer.  After doing so you can see the rough shape of the taper taking place. 



At this point I begin using the large roughing gouge by taking light cuts beginning the cuts from left of center working my way towards the end of the sizer but not getting near the edge.  You want to start knocking off the high spots left by the parting tool so stay away from the edges in the beginning.  By keeping my eye on the ‘horizon’ of the wood you can better judge how well you’re doing.  As soon as you think the taper is looking straight and still maintaing light cuts only then do you want to go from edge to edge in one pass.  At this point stop everything and take a straight edge to see if the taper is relatively ‘straight’.  Keep in mind that while in the beginning you have an overall idea of your dimensions, e.g. large end 2 ¾ and small end 2 inches, if either becomes off a little don’t concern yourself too much with that.  After all this isn’t mil spec work and averages are just that; averages.  It is the smooth taper you want to end up with.  If the sizer ends up being 9 or 11 degrees it isn’t going to matter.  The more you make these the better you will become.  At this stage if everything is fine go ahead do some sanding and either part or cut a place on the tenon and youll have yourself a sizer.


However, if due to some aggressiveness with the gouge creates some ridges or swirls I like to call them, not to worry.  For some minor defects I’ll use a good old standby tool, one of my double cut files to clean things up before any sanding. 



If all went well you have just created a horn sizer.  Congratulations.   


Hopefully I’ve just helped someone learn something new on their path to becoming a better horn maker and turner.  I repeat I am by no means a master turner, or hornmaker for that matter.  This is just one way I figured out how to do things and can by no means to be the end all to skinning that cat the best way.  Let the chips fly and happy horning.

Gary Elsenbeck



« Last Edit: August 31, 2017, 12:21:03 AM by G. Elsenbeck »
Journeyman in the Honourable Company of Horners (HCH) and a member in the Contemporary Longrifle Association (CLA)

There is a very fine line between "hobby" and "mental illness."

Offline Tim Crosby

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Re: Determining & Shaping Tapers for Horn Sizers
« Reply #1 on: March 14, 2009, 01:33:28 AM »
 Nice job Gary.

Tim C.

Offline G. Elsenbeck

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Re: Determining & Shaping Tapers for Horn Sizers
« Reply #2 on: March 14, 2009, 01:46:17 AM »
Thanks Tim.  I don't know what came over me.   :o

Gary
Journeyman in the Honourable Company of Horners (HCH) and a member in the Contemporary Longrifle Association (CLA)

There is a very fine line between "hobby" and "mental illness."