Official Luthiers Forum!

OK those of you with a number of guitars under your belt (mind those buckles don't scratch the back) can go look at the next topic, but some of the newer builders may be interested in the way I produce a side profile template for a new body shape. As I never buy plans and always make my own body shape I have to do this myself. If you have a radius dish and an outside body mould you have all you need to find the profile.

First thing to do is run a piece of low tack tape accurately onto the edge of the mould.



Place the mould into your 15' radius dish, tape towards the dish.



Drill a hole in a scrap piece of wood, round the end off, with a pencil pushed through the hole, run this around the radius dish marking the profile onto the tape.



Make sure that you mark the waist and the bottom edge and also the join at head and tail.

Remove the tape this will now have the profile of the back edge of the side on it. I then stick this tape onto heavy paper and cut to the line giving me a paper template. I also do this for the top profile so that I have a paper template of the final side shape with the top edge perpendicular to the ends and with the the back profile having the correct taper.


Use this paper template to cut a solid template from hardboard, MDF, whatever you like. This is then used to mark the side and cutting the profile before bending. Don't forget to also transfer the waist reference mark.



I use the paper template to mark the top profile after bending so that I can roughly plane to the line before rotating in the sanding dish.

Hope this helps.

Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Thank you very Much Colin, great tip!

I've a few under my Belt Colin, but you just taught me something, I go through a highly complex series of calculations and plots to achieve the same thing.

Not anymore, Thanks for posting that Colin

Agreed...thank you.

Bill

_________________
Eagles may soar, but weasels don't get sucked into jet engines.

Excellent tip Colin! And timely too. I need to make a side template in the morning and this is just the tip I needed. Thanks!

_________________
Dave Rector
Rector Guitars

Colin, I follow how you get the profile. However, I guess I'm being daft as I don't understand how you figure out your taper. Thank you for sharing.

_________________
Joe Breault
Merrimack, NH
Perpetual novice

joe, the pencil indexed to the sanding dish and the mold is going to produce the profile line on the tape. when the tape is placed on the hardboard in a straight line, the pencil line will still retain the tapered side profile to which you can trim your template.

colin, that is just about the simplest method i've seen short of buying a ready made template. thanks!!!! crazymanmichael38951.8061226852

Very cool Colin! I think you could also use a small flat washer with a pencil stuck through the center and just roll it over the 15' dish just as you did with the little square. I love it! Way to go, and thanks for the tip!
Tracy

_________________
Tracy
http://www.luthiersuppliers.com

Great tip, thanks very much Colin

Cheers

Kim

WOW!!!, Mr. Mahogany is full of good ideas. Colin, that is so simple and brilliant. I can even do that. Thanks a whole bunch.

Ron

_________________
OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

Dang, that's clever. I don't know if I ever would of thought of this and, to me, it's a major breakthrough.
Sorry for two posts, but I'm excited.

Ron

_________________
OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

I think I get it..... Being of a slow nature it may take a few minutes more.

I'm guessing that after you make the top and back profile you just spacing them at the ends to give you your depth at the neck and tail block?

_________________
Joe Beaver
Maker of Sawdust

I gotta say it once again too, Thank you very much Colin, really great tip!

Serge

Colin -- it slays me how the simplest solutions come from the brightest people.

Just a thought -- your method would make a good GuitarMaker short article or a It Worked for Me in GAL.

Thank you!

Anthony, you got a great idea, and may i suggest that Colin's method stays in the jigs-tools and techniques for every newbie to see? Serge Poirier38952.0480671296

A woops on my part - Colin -- by "simplest" I meant most elegant.

Serge - that's a great suggestion! Anthony Z38952.0519328704

Joe, to get the side taper, first draw a line the length of your side on the paper, then at right angles at the ends put lines to the height of head and tail. Then when you put your tape onto the paper, connect the lines together. (Make sure you have the waist towards the head end!) You then have a profile of the back with the right taper as well. I then add the top profile to this, again connecting the end of the lines, the waist will be higher than the head end.

Tracy, you can use a washer, the problem is finding a washer with a large enough diameter but with a small enough centre hole to accurately position the pencil, I always round off the end of the wood so that I have a single contact point with the dish. Make sure if your dish is sandpaper covered that you put some paper on it or you'll sand away the wood!

The advantage of making your own profile is that it will be accurate for your radius dish, I make my own so dish so I don't gaurantee that it is accurately 15'.

Colin

Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

What an excellent idea! Thanks! Ron M.

one of the woodworking houses, lee valley if my decrepit grey matter is functioning, sells brass "washers" in various diameters with a pencil lead sized hole specifically for scribing things like this.

Sweet Colin!

Way simpler than the method described in American Lutherie a while back.

Thanks!

-Mark

_________________
Pullman, WA

The more I know, the more I know I don't know.

trippguitars.com
OR
Find me on Facebook

Good stuff.

I need to make a binding bending form for my ridgeback (a la Vega cylinder back - with a 1" 'speed bump' running from tail to heel) mandolin things and this will nicely give me the contour I need to bend by using my outside molds over the female back mold.

Cheers
Steve

Last night I profiled an orphan walnut side using this template and bent it on my bender. As you can see the fit is pretty good before any sanding, in fact, its ready for the kerfing to be attached.





Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Colin, that's impressive! Thanks for the tutorial and the pics of how well it works!

_________________
Dave Rector
Rector Guitars

[QUOTE=crazymanmichael] one of the woodworking houses, lee valley if my decrepit grey matter is functioning, sells brass "washers" in various diameters with a pencil lead sized hole specifically for scribing things like this.[/QUOTE]

Michael you are spot on. It is Lee Valley and only $8.50 for a set of five. Not bad.

_________________
Joe Breault
Merrimack, NH
Perpetual novice

Way cool, I'll be using that tip on my current build.

_________________
Horton, MI