hollowing tools for measurable and consistent wall thickness

[mrGeeze]

the project is stave drum turning.
cutting is performed on the outside and inside of a glued up stave "cylinder" turned on the lathe to round on inside & out.
consistent diameter of the cylinder is an issue we'd like to address
At present we can make it round with gouges & sanding pretty easily, but wall thickness across the length is variable in our initial projects.
There's not a lot of wood removal on the lathe inside or out.

Now we are considering a hollowing setup that will allow us measurable and repeatable results
So many systems out there.
Which ones to consider (Carter, Jamison, etc) which ones to avoid (??).
Measurability and repeatability of wall thickness are the big objectives.

Its pretty much a straight cylinder.
We want to keep the finished wall thickness as close to identical throughout.
I'm guessing the max lenth of the cylinder will be 12-14"

Thanks,

 

[john lucas]

I once needed to make an inner wall on a project perfectly straight and parallel. I used my Jamieson hollowing system. I clamped a stop to my tool rest and another clamp on the Jamieson secondary rest. I could move the cutter and bar to the right any where I wanted but it would stop when going to the left. By carefully aligning the clamps I could move the cutter forward and back for the final cuts to give me a perfectly true cylinder. My lathe is occupied right now but after christmas I could set it up and photograph it to make this more clear.

 

[Roger Wiegand]

This might be an application where you'd be better served by using a metal lathe with a cross slide to give you precise, uniform dimensions.

 

[hockenbery]

Good suggestions above. Since your goal is a straight interior wall.

I think the jaimison or the sinner will work best and you can rig a two pin stop on the handle or on tool rest like John suggested.
Pins are parallel to the ways.
When sliding against the two pins you will be cutting the same final line on all the pieces untill you move the pins.
You can hollow to depth on the back pin gradually rotating until you cut riding on both pins.

 

[john lucas]

After I did my turning set up it occured to me that I could have built clams that had a screw adjustment to control the depth of the final cut. That would have allowed for an easier initial set up as well as a micro adjustment for the last pass to get a cleaner cut.

 

[robo hippy]

Hmm, this is making me think, again, about a cutter on an X/Y jig for cutting the shoulders on lidded boxes. It could also be used for salt and pepper mills........

robo hippy

 

[Doug Freeman]

Agree with others that a captive system, ie Jamieson, and not an articulating system with joints, would work well. Add a method to stop the bar/handle assembly parallel to the lathe bed as mentioned. Need the stops for the OD and the ID. Screw position adjustment would greatly reduce set up time.

Wall t tolerance and straightness will determine how accurately the stops need to be measured against the lathe bed for parallelism. If only t is really important, then creating the OD wall will serve as the master, and wall t can be adjusted for with the ID cut, and bed parallelism is not as important, but if straightness is important (same dia top and bottom of the cylinder), then parallelism is primary.