Centering?

[arcos]

"Can you make one of these for me?"

"Yeah for sure" 

So, I grab a piece of olive and look to see if it is viable for this project... Yep, it is certainly possible

BUT

It's a piece of branch about 7" long maybe inch and a half across and NOT straight!

So, I have square off the bottom but now need to try and center it to be able to hollow, end grain, the top!

Because it is not a straight piece is there any way of easily centering the top or am I just going to have to try and do it by eye?

[Bryan Milham]

Arcos,

short of some fairly heavy calculus involving rotation around a centriod, I'd recommed the eyeball method.

[arcos]

Thats what I thought too!

As it is only to hold a T light it didnt have to be too deep BUT tolerances were pretty tight on the diameter with no more than 2 mm edge to keep. Having got the piece fairly central I started turning and found it was WAY off (where did I leave my glasses?)....

Anyway I found that by turning in the center and then adjusting the piece in the chuck and turning again it got pretty close, or t least closer! It was just a case of turn, adjust, turn, adjust

It isn't perfect but it looks ok and works.

A little bit of hand finishing was required to try and even the side out and smooth everything of but as a 'natural' holder does it need to be perfect?

Certainly gives some ideas and good practice at minot end grain turning 

[BrianH]

Hi again Arc
Probably too late for this project but if you always start between centres you can take a light cut then move either, or both, ends of the blank, in order to remove the biggest area of remaining bark, before cutting again. This process can be repeated until all the bark has disappeared leaving  as large a round blank as possible. Then remount it in the chuck and away you go.
Hope that makes sense and helps a little
Bye bye from Bri

[ru55ell1]

What a good idea Brian :-)

[arcos]

Yes, this was an idea of how I thought I may center the piece...

The issue was that I had no intention of removing ANY bark, nor did I want a perfect cylinder shape....

The issue was that I wanted to try and maintain the natural bark AND shape whilst turning out the end grain AND keeping the sides as thin as possible WITH the bark.

I will try and get a photo tomorrow of the piece to try better to explain....

I'm not overly impressed with the outcome to be honest, it was a test project that someone has asked me to look at. They havent seen it yet to comment but I will know more on Saturday. These damn fancy designer books are full of 'bright' ideas eh!

[woodndesign]

I've tried to look up a supplier to send you too and see what is a center finder but with no luck, what had been available at one time and may still be, is a large 14" (35.6 cm) diameter clean thick plastic disc with concentric circles  marked ever 1" (2.5cm) or 1/2" (1.3cm) the smallest circle about 3" (7.6cm) there is a small center hole for a pin or pencil and the same size hole to every circle line, the idea is aline the nearest circle over whatever you want to find the center of an mark the center or to find the best size blank out of a piece and draw a circle for cutting the blank round, I have one and should check as to how correct I've been in the details.

Another idea and hope it's of help.

David

[malcy]

What you are referring to is at www.woodcraft.com as The Bullzeye Woodturner's Center Finder  Item #846243 . I can't find anything in UK.

[john taylor]

Stiles and bates do one http://www.stilesandbates.co.uk/product.php/section/0/sn/SBLCM

Or there is this type https://www.turners-retreat.co.uk/component/magebridge/centre-finder

I use both for different jobs.

john

[woodndesign]

Well done John,  I'd checked Stiles and bates under center finder ... they call it something else ...    ...  but that's the job.

The other I found too, I mark off blanked once in the round, as well as for squares if it's alot that I've to prepare or if it's a newel.

Cheers          David