Novice bulding identical parts

[bdk5]

So one of these days in the (hopefully) not too distant future, I plan on starting to make an entertainment center consisting of two identical side towers with a center "table" between them (based on the Wood plans from several months back). Here's the question.

Since the two side towers are identical (mirror images, actually), should I:

1) Cut and build both at the same time to minimize machine setups and maintain consistency; or

2) Build one completely before even starting the second, to iron out any problems/mistakes that may be made without wasting too much wood.

I think I'm leaning toward #2, since I've never attempted a project of this magnitude, but I wanted to get other's views.

[LCHIEN]

definately 1) build at the same time using the same measurements - preferably using stops to set the location repeatably rather than measuring but even when measuring will be more likely to use the same dimension.

When making many copies of small parts, cut a few extra - there will always be some better than others and will improve as you go, too.

[just4funsies]

Method #1 is for efficiency, time savings, and accuracy of duplication. Method #2 is for peace of mind. Which is more important to you?

[Tom Miller]

While there are obvious merits to #1, it's not as big a deal as if you were cutting four identical parts that need to fit together. In that case, you'd want to cut them at the same time (with the same setup) to ensure a good fit. In your situation, that's not a concern. So, one at a time is fine, given the reasons you stated.

Regards,
Tom

[LarryG]

+1 on #1

Yes, absolutely option #1. Even if option #2 suggests where you might make mistakes, you could still make entirely different mistakes on the second unit.

But you're actually thinking along the right lines. ALWAYS make test cuts on scrap, to check your setup before committing the good wood to carbide. And if you're trying an entirely new and unfamiliar procedure, you might want to first mock up a small trial project using the same basic techniques. Together, these precautionary measures effectively become the same as your option #2.

EDIT: Okay, where's the smilie that means, "Backpedaling Furiously"?

I just noticed the "mirror images, actually" bit. For building dead identical assemblies, I still say build both at once. But mirror-imaging sometimes requires you to change your setup anyway, so that element of efficiency is moot. And even if you don't have to change the setup, it's all too easy to get your mind turned around and happily toil away making two mirror-image pieces that you subsequently realize won't fit either larger assembly ... because while they may indeed be mirrored, they're also both backwards from what you meant to make (right, you got it: DAMHIKT).

So it will depend on how much "mirroring" your project actually involves. If the right/left differences are small, build both at once but triple-check everything at least twice. If the differences are large, then maybe building them separately is better.

[scorrpio]

#1 - build both at once, using same setups to cut parts for both towers. In my experience, an asymmetrical piece looks a lot more ugly than the one with symmetrical errors.

[bdk5]

Scorrpio, I like your justification best. With asymmetrical pieces, you can't hide your errors. With "symmetrical errors" (I think you should coin that phrase), I can at least tell people, "That's how I meant to do it--see, I even did it twice!"

[Stan]

One of my first projects was a corner shelf unit for one of my sisters. My method of attack was to make trial run pieces out of MDF rather than the eventual Black Walnut.

Once everything was cut for a proper fit, the MDF parts were used as templates and the Black Walnut pieces were then rough-cut to size and then routed with a flush trim bit using the MDF template. Should be able to just flip an MDF template over for a 'mirror copy' of an opposite side.

On the other hand, if this is the 4-piece entertainment center I'm thinking of (2 towers, upper bridge and lower table), I don't see why building one of the towers first wouldn't work. The are spatially separated enough that very minor differences would be hard to spot without measuring. Matching cuts for the second unit, using the 'same' tape measure, should get you close enough to appear virtually identical.

[John Hunter]

I often cut projects that are identical such as a set of end tables and like to make the cuts for both at the same time. I think it all depends on how confident you are in making the initial cuts or how much spare wood you have if you screw them up.

[AlanJ]

I often cut projects that are identical such as a set of end tables and like to make the cuts for both at the same time. I think it all depends on how confident you are in making the initial cuts or how much spare wood you have if you screw them up.

No such thing as a screw-up. They're just 'unique design features'

[Wood_workur]

#1: so all (if any) mistakes should also match, and look like they were designed into the piece.

[monte]

Number 1 for sure.

[JimD]

I generally make big things like this one at a time because of shop space. I think of setup issues when things have to be all the same size which is not the case here. If your parts are even 1/8 different from side to side nobody would ever know - and you should be able to hold much tighter tolerances than 1/8.

Jim