laser template technique

[Kevin Jenness]

I am making a "tripot", three conjoined hollow forms symmetrically arranged around a center. I hadn't worked out how to make the three vessels equal in size and shape beyond making a template, but after shaping the first and considering the problem I remembered that Lyle Jamieson mentioned devising a laser template method. This is what I came up with.

I cobbed together a template support bar from a 3/4" x 4" plywood drop screwed to a short mast held in my outboard tool rest, just above the swing of the eccentric workpiece. I screwed a 1/4" 4" x 12"plywood template blank to the top edge of the horizontal bar and used a construction laser on the lathe ways to shoot vertical lines tangent to the first pot's profile and plot a set of points on the template's underside. I bandsawed out the template curve, remounted it and used the laser on my Bosch hollowing rig to shine points down on the next blank for milling to shape with toolpost mounted grinders. Trent's fine adjuster on the laser housing is very useful for getting a vertical beam of light.

After making this I thought of the hinged finger jigs I have seen in magazines for sizing spindle cuts. I don't think that would work here as the fingers would hang up on the eccentric lobes, but maybe someone else has figured out how to make it work. The laser is not super precise but it gets me pretty close. One could use offsets and outside calipers on some pieces but these lobes are close enough together that I can't mill a full semi-circle, making caliper measurement a bust.

 

[Dennis Weiner]

Pretty cool! Are you carving or turning?

I made a 12 laser storyboard tracing-turning aid where you set the lasers to an exact drawing then replace the drawing with stock and turn similarly to your idea. I too own a Jamieson hollowing system where I got the idea. I got sucked into this project because I found a package of lasers for less than a dollar each on Amazon. It ended up taking me months to finish! Everything was made using my woodturning tools.

 

[Kevin Jenness]

Pretty cool! Are you carving or turning?

I made a 12 laser storyboard tracing-turning aid where you set the lasers to an exact drawing then replace the drawing with stock and turn similarly to your idea. I too own a Jamieson hollowing system where I got the idea. I got sucked into this project because I found a package of lasers for less than a dollar each on Amazon. It ended up taking me months to finish! Everything was made using my woodturning tools.

Mostly milling with toolpost mounted grinders and carving. Traditional turning is limited to hollowing and what portions of the forms can be accessed from the end without being fouled by the adjacent eccentric sections, but the work could not be done without a lathe. My methods are rather crude and require a lot of handwork.

This work would lend itself to cnc 4th axis carving but would require a cnc router with a high gantry and a large swing on the lathe attachment (and a facility with 3D modeling). No doubt Doug Rasmussen has other methods. This guy, Earle Vogels, could do it with his handrailing experience. cnc handrailing

I don't know how much utility the laser templates have for traditional turning, but maybe someone will find it useful or get an inspiration to make it so.

 

[Dennis Weiner]

For those that have an interest in CNC and other Aluminum Extrusion projects, browse through this sight or just view it for the wow factor. https://openbuilds.com/ You could get lost for hours.