Segmented Question

[Philip Morris]

I currently use a tablesaw sled to cut segments. I find the results are satisfactory when using dark woods. However, when using light woods, the joints are not seemless. I know that disc sanding is the solution, but was wondering if I could build a disk sanding set up for the lathe that would yield acceptable results.

[robert hainstock]

only if you have a miter tabel on the sander.
Bob

[Alex Elias]

It would yield the same result. The action of sanding is the same, as long as you control the angle the result shoud be the same and more so there is more control since you could change the speed at which you sand.
Also. why sand after cutting the piece? It should be nice and clean of the blade. I would
A) Fine tune your saw
B) Check you have the right saw blade for the job and it is sharp and free of sap.
C) make sure you secure the wood tight on the cuts so it does not meve during the cut (this is most likely the cause of missaligment) when cutting specially at an angle the piece frequently gets pulled in a hair or so, enough to bother you when doing this king of joints.
Good luck either way you choose.
Make sure you let us know how you solve the issue.

[Malcolm Tibbetts]

Phillip, regardless of what type of saw you use, an accurately adjusted disc sanding jig, with a decent disc sander, will always give you better-looking joints. It's not always apparent, especially with darker woods, but when joining two pieces of white holly, it can make a big enough difference to be worth the trouble.

Regarding the option of making your own disc sander using your lathe, it's definitely possible. The down side is the hassle to constantly install, etc. The hassle will often convince you not to go through the trouble, whereas, a dedicated disc sander will always be there for you.

[Philip Morris]

Malcolm,
Thanks for your response. I have your book and it is what has me looking at a sanding disk setup (although not one the size of that honking monster on your video...Wow!).

Anyway, I agree that dedicated machines are the way to go. However, right now my budget and shop space are very limited. I thought I might use my mini-lathe for the sanding set up on a temporary/permanent basis since I have another larger lathe that I usually turn on.

I felt I could use the setup method Curt Theobold describes in his video to get the table square to the disk. I Just was not sure if attaching MDF or similar material to a faceplate would yield a disk that was sufficiently flat enough and vibration free.

Thanks again,
Philip

[Malcolm Tibbetts]

Phillip, using your mini-lathe will work for small pieces. Your challenge will be creating as perfectly a flat surface on the disc as possible. Any wobble (run out) will mess with your sanding. If you have to use your lathe cutting tools to eliminate run out, then you will lose the smoothness of the MDF. Then you'll have problems with adhesion with the sanding disc. The best set-up might be to flatten the disc (if it needs it) and then apply a layer of some type of laminate. A kitchen counter top sink cut-out material is cheap. Good luck.

[Pat Salter]

Malcolm (thanks for the Seggy's Dream video, awesome), what about using one of those sanding discs made for a table saw? since he already has a sled made up for the tablesaw??????

[Brian Weick]

an ornamental candle holder for Earl on the Ornamental exchange this year and I cut the desired angles ~ 22.5 degrees and I had no problem - joints were all tight - no gaps at all- am I missing something in this thread? this was my first segmental piece and It came out exceptional in my opinion but this sanding the joints thing in here - is this what all you segmental turners do on here?
Brian

[Philip Morris]

Brian,
You did not indicate whether you used light or dark wood for your segments. The main issue here is when using light woods like maple or holly. If you want the joints to be invisible, sanding seems necessary.

[Brian Weick]

The same and both light and dark - I have a 12" diameter segmented column x 4' that I did not sand the joints - I had no problem- I would think sanding these would have caused some serious gaps in areas- never heard of that-? but then again it's not bowl turning.
Brian

[Richard Madison]

Philip,
Also use an 80-tooth carbide blade on TS. Most joints are perfect but not all. Built another sled to trim half rings square and can set it to cut off 0.004". If only one cut on each half ring is needed, the 0.008" loss is barely discernable. But more than that requires tweaking the segment sled. All the joints really should be virtually perfect.

All that said, am a believer in Mr. T.'s disc sander method (and the rest of the book), and intend to do it that way eventually. Have also seen some actual test data somewhere showing that sanded surfaces make a stronger joint than saw-cut surfaces, no matter how good the saw cut.

[Dwight VanSickle]

If you are talking about gluing together pieces to make the ring, sanding is a plus. I did see a demo in one of out meetings with a 24" disc sander, a sled with permanent miter angle. He said It was worth the time (5 hours) setting it up for just segment angels. As for gluing up the pieces together he used sink cut outs cut into circles on the top and the bottom in a press and that eliminated most of the unevenness. There was little truing up to glue the rings together. I don't have a disc sander but there is one in my future just for segments'
Dwight