• January Turning Challenge: Thin-Stemmed Something! (click here for details)
  • Conversations are now Direct Messages (click here for details)
  • Congratulations to Scott Gordon for "Orb Ligneus" being selected as Turning of the Week for January 20, 2025 (click here for details)
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

Making a template from an existing bowl

Kalia Kliban

Kalia Kliban

Joined
Feb 16, 2012
Messages
196
Likes
905
Location
Sebastopol, California
I'm making a set of bowls for a friend, and though I made a template to start with (based on the original concept drawing) I've drifted a bit and would now like to rework the template based on the first of the bowls to come off the lathe. Any suggestions for how to easily make a silhouette template (both inside and outside) from an existing bowl?

The bowls don't have to be identical, thankfully, but I'd like the overall shape and curve to be pretty close.

Kalia
 
welcome

Kalia Kliban said:
I'm making a set of bowls for a friend, and though I made a template to start with (based on the original concept drawing) I've drifted a bit and would now like to rework the template based on the first of the bowls to come off the lathe. Any suggestions for how to easily make a silhouette template (both inside and outside) from an existing bowl?

The bowls don't have to be identical, thankfully, but I'd like the overall shape and curve to be pretty close.

Kalia
Click to expand...


My first thought was just cut the bowl in half and lay a slice of it on some cardboard or plywood to trace! 😀

Seeing as how it is your first post and the other members of this forum are incredibly nice to newcomers I'll try to maintain the tradition.

One option is that you can buy a transfer tool, usually looks like a bunch of little rods loosely clamped together. You just slide them up to the side of the bowl with it sitting on the table and then could trace along them to get a line on cardboard or plywood that would need smoothing a bit but the shape would be very close. A rubber band or two and some popsicle sticks or tongue depressors make a fine transfer tool in a pinch too.

Second choice is the route I usually take. Simply rough cut a template by eye and then hold it against the outside of the bowl. Get a compass or set of dividers, simple twisted stiff wire works just fine too, And holding the points parallel to the table top follow the bowl shape with one point while the other traces on your rough template held up against the bowl. I only spread the points apart an inch or less so if the first rough template is way off it may take a marking, trim, another marking, another trimming a time or two if the bowls are really big or the template really roughly shaped. On the inside you need a flat bottom to work with so if it isn't flat bottomed to begin with you will need to lay something in there that is flat bottomed to stand your rough template on and then use the dividers, compass, trammel points, a stiff wire, whatever, to follow the inside shape of the bowl and mark the template. You may have to transfer your mark to a larger template blank and fit the last little bit of the bottom by trial and error if you had to put a flat surface in the bowl to stand the template blank on.

Welcome to the forums!

Hu
 
Kalia, get a light. Set the bowl where the light casts a straight shadow. Have the shadow go on your template material. Move the light till the shadow is the same size as the bowl. Draw the bowl on your template material. Then cut out your template. Leave plenty of handling room on the bottom.
 
In this age of the digital camera, I'd photograph, then enlarge to actual dimension. Mounted and cut, should do fine.
 
One more idea:

get graph paper, a couple rulers, and a pencil.

For the inside, lay a straightedge across the top and take depth measurements at desired intervals from rim to center. Transfer these measurements to the graph paper.

For the outside, flip the bowl over and lay the straightedge across the middle of the foot. Take measurements as before and transfer to the graph paper.

In both cases, draw a smooth curve that passes through the plotted points.
 
I thought we were always nice to people on this forum?

Hi Kalia,
There is a piece of what I think is lead covered with a rubber compound. It bends around shapes and maintains that shape when you take it away from the shape. I have one and will look for it......but I have not seen it for many years. But I believe they are sold at woodworking stores. Not sure what they are called. I bet you could find one at an art store.

Hu's idea of using a compass method is what is used to draw on formica counter tops to make them fit against the wall. It should work for a bowl very easily. And I am sure you have the tools that one would need to do this.

I like all the ideas though.

Hugh
 
Poor Man's CAT Scan

Welcome to the forum.

Here's a method I've used for tracing irregular profiles:

In stiff material such as corrugated cardboard, cut a rough outline about 1/2" shy for each of the inside and outside. Then with each:

Tape small pieces of card stock to it, abutting the target shape. Use larger pieces where less detail is needed, smaller otherwise. Transfer the outline to your template material.

To register the two shapes, extend the base sheets to overlap, and mark mating points.

This can be as precise as you like.
 
Am finding all the ideas interesting!

Hugh said:
I thought we were always nice to people on this forum?

Hi Kalia,
There is a piece of what I think is lead covered with a rubber compound. It bends around shapes and maintains that shape when you take it away from the shape. I have one and will look for it......but I have not seen it for many years. But I believe they are sold at woodworking stores. Not sure what they are called. I bet you could find one at an art store.

Hu's idea of using a compass method is what is used to draw on formica counter tops to make them fit against the wall. It should work for a bowl very easily. And I am sure you have the tools that one would need to do this.

I like all the ideas though.

Hugh
Click to expand...


Hugh,

Definitely more than one way to skin this cat! I'm finding all of the approaches interesting. No idea what your thing is called but I used to see them at drafting supply stores too. Art supply stores almost certainly carry them. I would think solder would work pretty good too, the heavy solid core stuff if Kalia has some of that around.

Joe's idea is simple and should work well. Adding to the rough template instead of whittling it away like I suggested.

Any of these approaches could work, Kalia has a lot of choices!

Joe, the Poor Man's Cat Scan reminded me of a trip to the vet with a rabbit. Cost an extra $240 after the cat scan and lab tests!

Hu
 
hu lowery said:
Second choice is the route I usually take. Simply rough cut a template by eye and then hold it against the outside of the bowl. Get a compass or set of dividers, simple twisted stiff wire works just fine too, And holding the points parallel to the table top follow the bowl shape with one point while the other traces on your rough template held up against the bowl.
Click to expand...

An alternative to use a compass or set of dividers is to use a small bearing. Set a pencil in the center hole of the bearing and then run outside edge of the bearing along the surface of the bowl.
 
Kalia,

The suggestions for a template are good, but.....

In the end, you will have to prep your blanks to the same size, rough tthe OD of the top end to a target dimension using calipers, face the blanks to a target thickness using calipers, make a tenon to a target diameter with calipers, and then turn the outside of the bowl profile that makes the tenon and top OD come together with a pleasing curve. A template won't fit the bowl until the shape is finalized, and trying to use is part way through may be more of a hindrence than a help. Most people rough between centers, and if that method is used it will further complicate the use of a template.

If you do use a template, consider the use of a woodworm screw for mounting with tailstock support. Pulling the tailstock for template use will leave the blank mounted with a woodworm screw.

My suggestion is to prep the blanks, rough the first bowl to the dimensions and shape that you like keeping track of the dimensions of the foot/tenon, Rim OD, and total heigth of the roughed out bowl. Then when doing the rest of the bowls, use the dimensions of the first to establish the above on the rest, and when doing the shape of the remaining bowl rough outs, set the first bowl on the headstock so that you can hold it up near the bowl in progress and visually 'meassure' the profile of the one that is being turned. If you are going to do a set of six, plan on roughing out eight. Muscle memory and your hand eye will give about as good a result as using a template.

Use the same method when doing the final turning. The inside profile is pretty much determined by the outside shape by holding the wall thickness from rim to near foot.


When the entire batch is finished turned, pick the set that matches best, and put the other two in your cupboard for personal use.
 
Dale Miner said:
Kalia,

The suggestions for a template are good, but.....

In the end, you will have to prep your blanks to the same size, rough tthe OD of the top end to a target dimension using calipers, face the blanks to a target thickness using calipers, make a tenon to a target diameter with calipers, and then turn the outside of the bowl profile that makes the tenon and top OD come together with a pleasing curve. .
Click to expand...

The way I would approach a set is the same way Dale recommends right down to making a couple extra. Especially important if you are double turning them.

Same size blanks essential, set the rim, turn the tenon, set the foot. Turn the curve.

If you want to use a template you just need one for the curve on one side as the other side will,be the same.
So it can be used with the bowl between centers.

Have fun,
Al

.
 
Keith,
I really like the idea of the bearing. Too simple......but very effective. Cool!

I like the idea of just putting the finished bowl in front of you while you are turning the second bowl, third bowl, etc. Try to make them the same.....they may be close, but yet still different. These are hand made items anyway.

We could break out the duplicator.

I can not make two of the same thing exactily for the life of me. Oh Well! I have fun at it.

Good luck Kalia. I hope to see the results.......soon.....after you get over your cold.
Hugh
 
use a bright light, cast a shadow over it on to the paper you want the diagram on, then trace the shadows lines.
 
You must log in or register to reply here.
Back
Top