Open Segment Project - Acoma-2

Bob Beaupre

Administrator
Staff member
That is good to know. It is the same pattern I used on the original Acoma, I just changed the profile
 

mfisher

Super Moderator
Staff member
Using Tom Lohman's new process of doing closed segment rings on a open segment glue up jig.

Using the jig to glue ever third segment
View attachment 3579
View attachment 3580

Let segment dry
Then insert segment pairs in between
View attachment 3581
View attachment 3582
Now completely glued (not perfect but good enough with extra on the ID and OD)
View attachment 3583
Works good on those thin rings
No clamps no rubber bands
Can stop half way in a ring glue up
Bob:
In using the jig for closed segment rings did you cut all the segments to the specified segment edge length or did you have to cut some longer/shorter to fit between the every third glued segment?

I am looking at possibly building a jig like the one on the carbatec web site. I think it may help in my building 36 - 60 segment rings.
Title: Open Segment Jig

Another possibility is just to bite the bullet and order from Tom L.
 

Bob Beaupre

Administrator
Staff member
I cut the segments just like I would for using a normal clamping method.

Mike I had a jig like that and was only satisfied with it up to 24 segments.

Have you checked Tom's site lately he has made some changes to his index rings for the better
 

mfisher

Super Moderator
Staff member
I need to check out Tom's site. It has been awhile since I visited.

Thanks for the tip on the jig being good up to 24. Right now I have been working with 36 segments. Seems it doesn't matter if I use my incra sled or a seg easy sled about half my rings do not come out perfect. I do build half rings. Some need touch up , some don't. I have not found a good way to glue up 36 segments all at once. The glue tends to set before I get everything glued.

Your bowl looks great so far. Very nice bottom design.
 

Bob Beaupre

Administrator
Staff member
The other thing that I have made since I did this pattern for Acoma is to change the open segment gaps. Acoma had a one deg gap when Acoma-2 the gap is reduced to 12%.

For comparison:
The row I just put on is 5" OD
A row with 1 deg gap the gap = 0.0437
A row with a 12% gap the gap = 0.315

At it's biggest diameter of 12" OD
A row with 1 deg gap the gap = 0.1050
A row with a 12% gap the gap = 0.0756

Just a tighter open gap
 

Bob Beaupre

Administrator
Staff member
I don't know! This is my first one. The ID of the opening at the bottom is not tuned to its final dimension yet. I want to get at least two segments rows on so I can turn it and put the tapper that will go down to the medallion. It most likely will not be up in until the very end. No way of putting it in now, until I break it loss from the waste block. I guess I'll worry about it then. It is turned and will fit into the counter bore at the bottom with a little extra room for expansion. I'll also finish it before putting it in. The retaining ring for the medallion ring now it a solid dish attached to a face plate, that I can use for centering if needed. When it come to the end I will have to cut the ID of the ring and cut it to a finial thickness.
 

Bob Beaupre

Administrator
Staff member
Looking good. When is the first turning planned?
Pretty soon, I'm waiting for the ID to open up a little more so the pieces that go on next have more support on the ID. The ID down at the bottom will have to be cut to about 3" ID and then the base tapper cut to blend down to the medallion that will be inserted from underneath.
 

Bob Beaupre

Administrator
Staff member
Row #7 is on
7.jpg
Some more turning on the inside.
The bottom two rows are at final diameter to match the medallion that will be put in from the bottom
 

Bob Beaupre

Administrator
Staff member
I have a new favorite tool for turning the ID on my open segment work. At the symposium Mike Hunter from Hunter Tools had a booth set up and had a show special on some of his tools.
I bought four of them!! :eek:

I got :
#1 Hunter Osprey
#2 Hunter Osprey
#3 Shallow Swan Neck
#3 Full Swan Neck

For the turning I did above I used the small #1 Hunter Osprey and it shaved those lettle segments perfectly.

Nice tool I would recommend it.
 
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