Quick Sketchup question

[tim walker]

When drawing your designs in SketchUp, do you use nominal for your plywood or actual, i.e. 0.75" vs actual 0.709"?

[Mark Bolton]

You'd be best to use your actual material thickness if you can if you are going to rely on the drawings for accurate cutlists to the shop. If you draw each part as a component you can somewhat quickly go back and adjust as needed but unless your using dynamic components its a lot of work to go back and change each individual part. If you material is on hand its would be best to start with relatively accurate material thicknesses.

We run a paid plug into for cabinet parts that allows global adjustment of material thicknesses through a project component but theres no easy way that I know of to do it if your drawing from scratch.

[andrew whicker]

Inaccuracies start to build on each other and if you aren't careful they can be very painful (even with parametric design) to change / fix towards the end.

[Lisa Starr]

I don't know if Sketchup offers parameters as Fusion360 does. I usually setup parameters named things like "Plywood750" and "Plywood500" etc. You then reference these parameters for dimensions when drawing the sketch. Later, when you know the actual thickness of the Plywood you purchased, you just change the value of the parameter and all appropriate changes are made to the sketch.

Maybe someone that works in Sketchup can advise as to whether this is available to you.

[Mark Bolton]

I don't know if Sketchup offers parameters as Fusion360 does. I usually setup parameters named things like "Plywood750" and "Plywood500" etc. You then reference these parameters for dimensions when drawing the sketch. Later, when you know the actual thickness of the Plywood you purchased, you just change the value of the parameter and all appropriate changes are made to the sketch.

Maybe someone that works in Sketchup can advise as to whether this is available to you.

It is with an asterisk. Dynamic components can be setup but when your building a lot of parts there are issues of inset points, reference faces on dado's and other joinery/hardware if your going that deep. It's not really something worth the effort for a part here or there or a single project.

[Tom Bain]

I typically use 23/32 for “3/4 ply” in sketchup.

[glenn bradley]

Plywood thickness is too variable for me. Probably due to the intermittent use and random supply sources. This makes it too unpredictable to bother with a "standard" plywood dimension for me. Since sheet goods are normally used for things like shop fixtures or jigs I will do both of the things you mention.

For speed I will just use 3/4", 1/2", 1/4", etc. The diagram becomes a guideline and I measure the actual dimensions off of the base parts as I build. For accuracy, like on jigs, I will measure the plywood I plan to use in several areas, average the dimensions and use that. In practice I will, for example, make a rectangle that is 12-1/4" x 23" and then pull it to the thickness of 23/32 or whatever if that makes sense.

The diagram is still a guideline to some extent. An outline, if you will, for where I am going with the build. I started measuring many final parts off the piece as it is being built years ago and this is my typical method still. Don't get me wrong, I am not selling the idea of being loose with your dimensions. I can build a piece and build another one a year later that matches. I just don't use the method of cutting out all my parts per the plan and expecting them to go together beautifully :)