Captured hollowing systems - question

[Thom Sturgill]

I am getting ready to build my own captured hollowing system based largely on Lyle Jamieson's design and have a few questions about it and other systems. It looks like Lyle makes his rear support about 3' long with the post attached about 1 foot from the front with two foot hanging over the back. Randy's monster looks to be about two feet wide and adjustable on 2" centers - is that right? Any advantage/disadvantage to being adjustable rather than fixed other than size?

Next, do any of the systems lock the support square to the bed? It appears not. Any reason that you would need to set it at an angle? or prevent it *from* being set at an angle?

[Ken Fitzgerald]

Thom....I have the Jamieson. It doesn't lock square to the lathe bed.

What type of lathe are you using? What is it's throw?

[Thom Sturgill]

Ken, I have a JET 1642, I did not think that it did, but could not tell from the pictures and did not remember from the one time I had seen one up close. I am making the height adjustable - just in case I see mustard in the future - from slightly less that 8" height to over 12". I will be using 3/4" steel tube with a 1/4" dia rod JB welded to the lower brace. Connections for the vertical support and the D-handle will be brazed as my torch will not get hot enough to weld.

[Dennis Ford]

I have a home built based on the Jameison design, it is handy to be able to set it at an angle for some shape HFs.

[Thom Sturgill]

I have a home built based on the Jameison design, it is handy to be able to set it at an angle for some shape HFs.
Thanks for the reply. I've only used hand held hollowers, so I was not sure about that.

[Harry Robinette]

Thom
My system was modeled after Frank Sudals system,the rear captured rest sets off center also,(same reason as Dennis said) and mine is hard set for my 18" General. I also put UHMW material on the top and bottom of the captured holder for the boring bar to ride on.I have the same cutter Frank used which is a tear drop shape,you use the small end to rough and the large and back to smooth.Frank sanded the inside of his pieces to at least 220.
When you start to use it you'll wonder way you waited so long.Love mine.
Harry

[Steve Schlumpf]

Thom - my captured system is on 3" centers and I have it set up so that everything is hanging off the back of the lathe. I end up swinging the support arm quite a bit when hollowing - especially with HFs with deep shoulder areas. The deeper you are trying to cut in the shoulder area - the more the far end of the support arm needs to be angled towards the turning to support the cutting arm.