Non-standard use of a track saw

[Crazyraceguy]

So, I have this reception desk job in the shop, with a partially angled section of the exterior wall. The tricky part is that is has radiused corners. Angle and radius works out to be a segment of a cone.
How do you wrap a cone with plywood? Kerf cutting, not the "easy way" (which is not really as easy as it sounds either) but it needs to be tapered.
Back in the day, I did learn some long formula to figure out that shape. Today we have the interwebs and some nice person figures this out for you and makes an app for that. Put all of that into the CNC machine and out comes the C shapes, but it still won't bend. How to Kerf it? Track saw. I made a jig to hold the parts with a pivot point to swing the track from.
I had to be adjustable enough to cover the two different radii on this job. I made the stops that hold the parts removeable, because of the 2 different sizes. Simple plywood strips with a couple of Dominos worked well.
I suppose that you could do the kerf cuts on the CNC, but that would take forever. Sawing is far better for this many narrow cuts that nearly go all of the way through 3/4" plywood.
With this jig, I cut 48 separate kerfs in less than 10 minutes, in some of the parts, and 43 cuts in the others. Altogether that came out to 556 cuts, 48 yesterday, when this was a proof-of-concept test and 508 today.  Yes, 8 of the one size and 4 of the other.
Apparently, I didn't take a pic of it with the saw actually on the track? but here is the jig and the cut parts. More to follow as the job develops.

 

[cubevandude]

Got any pictures of these bent?

 

[Crazyraceguy]

Sort of, but not great. They are the corners of a large nurse's station.  One pic shows the frame they wrap around, upside-down. The other is a few of the sections skinned in the upper/angled part, another section is on the bench behind.
I got the rest of it skinned in ply today and got started with the finish layer on the upper section.
I just didn't take any more today. I'll get some more tomorrow.

 

[Cheese]

Nice job on the skinning . How deep are those kerfs, there can’t be more than .030” of skin left? Are there any lines telegraphing through?

 

[Vondawg]

Really nice ! and great thinking outside the box…looks like this one will have to go out the door as is….or have you come up with a way to break it down for delivery

 

[tjbnwi]

The rails work well as a router tramel also.

It is necessary to cover the grip strips with masking tape.

Tom

 

[Crazyraceguy]

Nice job on the skinning . How deep are those kerfs, there can’t be more than .030” of skin left? Are there any lines telegraphing through?

There is actually more than twice that. This is not the greatest ply ever, in the first place, supply is still not like it used to be. I adjusted it so that the tips of the ATB are just off of the last layer.  I did the first 8, which are the 90 degree corners, and they worked out great. Then I got switched to another job for a few hours, still using the saw tough. When I went back to kerfing on the other parts for the 45 degree corners, I thought I had mis-adjusted the saw. It took me a second to realize what was going on, they were so much "softer" easier to bend. Then it hit me, it was about how they came off of the CNC. They were nested on the sheet perpendicular to the others. This meant that the kerfs and grain of the outer veneer were going the same direction. It makes a huge difference. The others were not hard to bend in any way, but these are significantly easier.
Yesterday I got them all laminated and the lower sections skinned with ply too.
It could never ship whole. This thing is huge and very oddly shaped, not even close to the biggest thing I have built, but still pretty big. The center straight section is just under 12' at 139". It comes apart into 4 pieces. I have started skinning the inside, where the access panels allow for wiring and for connection to the walls and floor at install. Pics as it develops.
The lower part gets the same laminate, but the inside will be a totally different color. That is fairly common, especially when they go wall to wall.

 

[Crazyraceguy]

The rails work well as a router tramel also.

It is necessary to cover the grip strips with masking tape.

Tom

Yeah, that would work too. The grip tape would be quite the challenge. The blue tape seems like it would take care of that though. I remember having to do exactly that kind of thing back in the day, but a 5' x 12' CNC machine speeds the process quite a bit.
I build things like this virtually every day and the "shaped" parts are cut that way (CNC) and brought to me. It is usually top and bottom plates of the "wall" section and the vertical studs. The studs have wiring holes, which we used to do by hand with a hole-saw or router jig (by hand). The particular wall has 3 entire sheets worth of the studs. On the radii sections the studs are 6" on center of the outside radius, 16" everywhere else.

 

[Michael Kellough]

You do amazing work!

“kerfs and grain of the outer veneer were going the same direction”

Bending ply, Wiggle Wood etc.

 

[Crazyraceguy]

You do amazing work!

“kerfs and grain of the outer veneer were going the same direction”

Bending ply, Wiggle Wood etc.

We used to use wiggle wood, with it's own challenges, until a couple of years ago. The company I work for bought a big beam saw. It can cut the grooves (kerfs) in a full sheet of ply (either direction) in a matter of 15-20 minutes, fully by itself. Set it up and walk away while it works.
It is far easier than "blending" the joint between the curved and straight sections when using wiggle wood (bending ply). This doesn't work with the radial pattern required here, thus the original point of the post.
On this particular wall, the outer sheets were done by only cutting 36 kerfs, 1" apart, and leaving the rest un-cut. So, I end up with a long straight rigid board, that bends on one end. No joint, no concern with squareness as it wraps around the corner.
I'm just not a big fan of wiggle wood. Used it for years, because it was the only real alternative, but it definitely has issues. Not the least of which is the thickness. The only choice we have here locally is 8mm. Two layers puts you close to 5/8", so you have to either shim it out in some way to match up to 3/4" ply, use the crappy 5/8" ply, or skin the straight sections with the wiggle wood too. (Not ideal)
None of those choices are great. Then you also have the issue that you are doing everything twice and having to use and spread so much glue. Couple that with the fact that it doesn't always want to bent straight and isn't the highest quality wood in the first place and it makes kerfing much more attractive.
The only downside to kerfing is actually doing the cutting itself. Once that gets automated, game over.

Thank you for the compliment and your interest in this kind of work.

 

[Vondawg]

When you post these I always enjoy how you worked things out and too wonder, are your co workers building simular orders in that big facility or do you get the big interesting ones ?

 

[Crazyraceguy]

When you post these I always enjoy how you worked things out and too wonder, are your co workers building simular orders in that big facility or do you get the big interesting ones ?

The shop is laid out in "departments" even though it is one huge open room. There is an area that does laminate countertops and another that does Solid Surface tops. These two are separated by quite a distance to keep the chips and dust from routing and sanding away from the contact cement. Back in the far corner is the sheet goods storage, which is close to the CNC machines and the "assembly" department. They build cabinets in a production format which go to an "upfitting" department for the doors/drawers/hardware. Then comes the "Special Projects" department. There are two of us there. I do most of the big and especially odd stuff and the other guy does the things that just don't fit anywhere else. We are somewhat known for doing these odd shapes. Angles, radii, etc, combining them is not so common, it does happen though.
Bessey gets a good chunk of my money too.

 

[mino]

The Crazy guy. Always crazy and always uncompromisingly creative.

Thumps UP and thanks for sharing!

 

[Crazyraceguy]

The Crazy guy. Always crazy and always uncompromisingly creative.

Thumps UP and thanks for sharing!

Thank you. I actually get inspiration/education from many sources and just store them in my head, waiting for the chance to use them. I've been doing this for a long time now and have come across a lot of challenges. Sometimes realizing that there is a better way, while I'm already in too deep to change, then saving that for next time. That is at least part of my obsession with tools. I try to be equipped to do anything, because I never know what is coming up. Sometimes even buying a tool, that would have been better, for a job after it is done, because I know the need will come up again later.

This angled/curved unit is a perfect example. I am going to have to do 7 more of these, so I have already designed a major change for the following units. From the finished appearance, you will never know the difference, but it will speed up the process considerably.
I will post some pics and updates when that happens, but I'm not sure when that will be? There are already 2 other jobs in the que first.

I have pics of all kinds of old jobs, if you guys want to see them? I usually only post the new stuff.

 

[Michael Kellough]

I would like to see pics of weird jobs. The ones that required some of your creativity to produce.

 

[Vtshopdog]

CRG - I always read your posts because they likely will show how to solve a difficult challenge and I file away ideas in case your solutions apply to one of my little hobby projects.
Thanks for sharing.

 

[ChuckM]

Thank you. I actually get inspiration/education from many sources and just store them in my head, waiting for the chance to use them.
Snip.

Same here, except that I rely on a copy or scan of any clever ideas or techniques instead of my declining memory to retrieve them.

 

[Crazyraceguy]

I have a couple of shots of the inside. I got it skinned and laminated below the counter top level. All of the access panels are made, but not in place here. The sub-tops are test fitted. The rectangular holes will be pockets for monitors, so they sit lower than the regular top height.
The spaces where there is no laminate are where matching file cabinets will be installed.

 

[Gregor]

The rectangular holes will be pockets for monitors, so they sit lower than the regular top height.

They use tiny monitors  [blink]

Apart from that: nice execution.

 

[Packard]

I'm curious about the math. 

The depth of cut is easy enough to figure out. 

The width of the cut is fixed, so no math.

The distance between cuts needs to be calculated so that the bend is smooth and not a series of flats with a "hinge" of veneer.

Can you tell us how you did the calculations?

If I did it, I would have to make a dozen samples before I would get it right.