Adjusting Dimensions

[Woodworking_Hobby]

I have a quick question about relative dimensions in a project. I am still relatively new in my woodworking adventures and trying to use some more traditional joints.  I have also followed the school of thought when constructing my projects to use relative dimensions.
 

The question I have though, is there a good way to adjust your M&T joints when following plans but using relative dimensions?  For example if I am building a project that calls for 3/4 inch parts and I get them all the same thickness but maybe a hair over or under 3/4 when done milling, do you adjust your joint location so it is dead in the center or do you just adjust so it is flush on the visible side.  I am not sure that makes sense but what I am struggling with is if my wood is not exactly 3/4 I cannot follow the plans exactly for the M&T location or they will not be centered in the wood based on my parts relative dimensions. 

[legenddc]

If you’re attaching two pieces together of the same thickness it doesn’t matter where the mortise is, as long as it’s in the same spot in both parts. 

Also, mill up some extra pieces and test it. 

Edited December 23, 2021 by legenddc
Edited after Chestnut's correct post.

[Chestnut]

If the material the mortise will be made into is the same thickness as the material you'll cut the tenon into. I'd just center both the mortise and tenon. If you are using a router for the mortise set your edge guide and reference both sides essentially cutting the mortise twice. One main hogging pass and the opposite side would just remove a tiny bit. Cut the tenon out by flipping the board over removing the same material from both faces equally. Tenons can be cut reference a band saw fence or with a tenoning jig on the table saw or a dado stack on the table saw. I prefer the dado stack as if you use a miter gauge you can both get a good clean square shoulder and a well fitting tenon with relatively little work.

If your mortise is 0.2657438743" it doesn't matter it'll be centered. The tenon would than be made to fit, also centered.

[wtnhighlander]

Consider that traditional hand tool M&T is cut with reference to one face or edge, therefore rarely 'centered'. By the same token, the mortise is generally sized to fit the chisel at hand, not the stock (within reason). I never go by joint dimension on a plan, even plans I drew myself. So long as the mating parts match, the actual dimension is all but irrelevant.

The only critical dimensions on a plan are those in which modification would cause the overall piece to not fit its intended location, purpose, or structural integrity (objective), or those in which modifications would ruin the design aesthetic (subjective).

[Ronn W]

You do not mention what tools you are planning to use to make the mortise and tenons.   Laout would be different if done by hnad thatn if using, say, a router for the mortises.  In general,  If you wnat the tenon piece (like a table apron) to be flush with the mortised piece ( like a table leg) you would wnat to alyour out the joint from the face that is to be flush.  Do the  mortise first so that you can make adjustments to to the tenons as required.  There is no reason that the mortise or t the tenon must be centered on either piece.  I try to get my tenons centered if I can because with power tools its easier that way.  If your pieces don't match the plan thickness - no problem - make a full scale drawing and work it out with your new dimension.  Iven when I desigm my own projects the dimensions on my drawings seldom survive unchanged for very long.  You can do it.

[man of wood]

I never use dimension wood, even if I buy it. My goal is to make the piece I size I want.  When jointing two pieces together, you just do......  Don't weary about the size your wood is, just build you project. of course it have to be structurally strong, you just can't willy Nelly thought parts together........... Actually you can.  

 

Thomas