reached the limit of 8mm bending ply

[Crazyraceguy]

I finished this little project this morning. The guys in the countertop department built these little tops yesterday, but had no idea how to do the aprons. So they sent them to me. The tops have a 2" radius and the apron sits 1/2" back from that. Then the apron itself is 2 layers of 8mm bending ply, leaving that inside radius really small. I made up a couple of forms to bend them around and put them in the vacuum press for a couple of hours. This is the absolute minimum that stuff will bend around though, it was really stretched on the outside and needed some superglue filling.

 

[Lincoln]

Nice work. I make a lot of banquette seating and curved backs are pretty common. We supply the upholsterer with boards, for the foam/leather/fabric. Usually use 5mm bending ply - do you have access to that?

 

[CeeJay]

If you saw-kerf the 8mm ply it should bend a bit more tightly- this is 6mm hardwood:

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[Crazyraceguy]

If you saw-kerf the 8mm ply it should bend a bit more tightly- this is 6mm hardwood:

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Normally we use kerfed ply for larger radii, even having several different cut-spacings saved in the beam saw's computer. This almost eliminated the need for the commercially available bending ply that we used to use most of the time. The problem with kerf ply is that it really only works well when it is fully supported, meaning attached to an inner structure, or re-skinned on the surface with the cuts.
That is how I do access panels on curved reception desk walls. That will make it stiff again.
This tiny radius would have been a nightmare to do that. It also causes problems with trimming the laminate. This way it's smooth and nice to the touch.
Some thinner bending ply would have been nice, but the 8mm stuff is what we stock, so that's what it had to be. Three layers of 6mm would have been great.

 

[CeeJay]

Preaching to the converted I guess! Oh to be programming a beam saw….saw kerfs on a table saw can get pretty tedious!

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[Crazyraceguy]

Preaching to the converted I guess! Oh to be programming a beam saw….saw kerfs on a table saw can get pretty tedious!

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It sure can. In small doses, it's ok, but doing multiple full sheets? No way. We tried it years ago with the CNC, and it does work, but it's painfully slow and that cuts into production of cabinet parts. That's why we stayed with bending ply, even though it's quality leaves a lot to be desired.
I have done some small sections for radius corners in the past, because it's easier to blend into straight sections.
This aquarium stand and cover were done in '17 according to the pics

 

[Bob D.]

"We tried it years ago with the CNC,"

If only someone made a saw you could mount in place of a spindle and be able to rotate it on the Z axis to any azimuth.

 

[Crazyraceguy]

"We tried it years ago with the CNC,"

If only someone made a saw you could mount in place of a spindle and be able to rotate it on the Z axis to any azimuth.

I'm sure someone does. I would bet that there are multi-axis machines that could saw flutes into a half-round column, but that is way beyond anything I have access to. The 5' x 12' CNC machines that we have are set-up to produce cabinet parts efficiently and somewhat "semi-automatic". It's all flat work. The "main" machine runs pretty much continuously, making cabinet parts all day.
The auxiliary machine is there not only as a back-up, but it runs anything that would "get in the way" of production. That would be counter tops that are shaped other than rectangular, plywood parts for the reception desks, etc.