TX 18 Build

[Steven]

If the shape is correct, why not just leave a 1/8" gap on both seams. Shouldn't be a problem.

[Aripeka Angler]

If the shape is correct, why not just leave a 1/8" gap on both seams. Shouldn't be a problem.

The problem is Derrick doesn't know which part is correct. They don't match, maybe both are wrong?

[jacquesmm]

There was a problem with the plywood all through that kit.
Doing the kit nesting, I located some of the parts edges along the edge of the plywood. This will work if all plywood sheets are exactly 48" wide but in one plywood batch, we had sheets that were 1/8 to 1/4" wider.
If one sheet is 1/4" wider than the other, that will result in one side being 1/4" wider.
We never had that problem and did not expect it especially from the best plywood manufacturer in the world.
That is why one side may be wider than the other.
It is not difficult to correct, use the smallest side as a template to trim the wider one.

It took me a while to understand where all those 1/8 to 1/4" differences came from in a few kits.
Since that time, we changed the files and as much as possible, we do not line up parts with the edge of the plywood anymore, we cut all around.

Sorry about those problems but now that understand the reason, you can progress.

[dborecky]

Jacques,

I just have one question. If I trim the larger panel to the smaller one and it is smaller then spec, will I have a problem when it comes time to stitch it together?

[jacquesmm]

No.
The smaller one is correct.
Some of the plywood sheets were larger but none were smaller.
And in all cases, smaller with a large gap is always better.
The panels are cut exactly to the developed shape without any gap but during the assembly, it is always easier to have a gap.
In some cases, I deliberately cut a larger gap to avoid contact between panels.

[SmokyMountain]

Derrick,

If your matching the smaller, then I would suggest using a straight router bit with a bearing on the bottom and use the smaller panel as a template. Should be a perfect match. Good luck!!

[Joe H]

Hey Jacques,
I too had oversized panels for my P19, when I set-up the files for CNC cutting I used the same process we use for sheet metal in the auto industry, two locating pins along the C/L of the plywood, as you can see in the picture below.



I only cut the bottom panels this way but they came out perfect.

Hello Derrick, no hi-jack intended, your build is looking good, I'm glad it was an easy fix.

Joe H

[Cracker Larry]

Dang Joe, that sure beats a jig saw

[jacquesmm]

Hey Jacques,
I too had oversized panels for my P19, when I set-up the files for CNC cutting I used the same process we use for sheet metal in the auto industry, two locating pins along the C/L of the plywood, as you can see in the picture below.

Good idea but in many cases, the pins would be smack in the middle of a part.
Since we discovered that plywood sheet size is unreliable, I changed my files and always cut along all edges.

[Joe H]

That was one hell of a machine, and fun! But to complete the whole process was a pain, loading unloading,,,,,,,it didn't beat the jig saw, or circular saw in this case! ha.

Joe H

Good idea but in many cases, the pins would be smack in the middle of a part.

Yeah, that was the case for the transom, no more CNC cutting for me.