Unable to centre sketch

[steve.hooper]

In the screenshot you can see a slot extruded into a block.

The block is a sketch using a centred rectangle and is centred at 0,0,0. It is then extruded in the Z axis

The slot began life as a centered rectangle in a sketch centered on the extruded face at 0,0,19 and combined with another to give the keyway before being extruded to 0,0,12

The problem is that the slot is not centered in the block and I have spent a couple of hours trying to move various bits and bobs to get them both aligned on the centre.

Of course, I could redraw them but then I would not learn what I'm doing wrong.

The .f3d file is attached if anyone can please have a look and show me my error(s)?

Thanks.

[daniel_lyall]

Your very first sketch is not centered fix that and it comes good

[steve.hooper]

Daniel,

Not sure I understand, but I found a screen cast using Sketch Dimension to position things. Once I removed some constraints this seemed to work. I think it may be something to do with the filet messing around with the centre-point.

Steve.

[daniel_lyall]

Nup it's the first sketch, the constraints and the rest of the sketch's are ok same with the fillets 

[steve.hooper]

Thanks for identifying the fault, Daniel.

How do I centre the first sketch? How do I know if it is centred?

Steve.

[daniel_lyall]

check back in 10 mins I am just doing a vid now for you.

[steve.hooper]

Daniel,

Thanks!

That worked, though I don't know how changing the Y dimension also changed the X dimension. Is this some kind of constraint?

Steve.

[daniel_lyall]

It's a center squire what i set to be parallel the top and bottom lines were not constrained to the sides there was a constraint missing.

The center square itself was not sitting on the origin it was to the left and down a little bit by making the top and bottom lines parallel they will move together and the two side lines were constrained and dimensioned to the top and bottom line so they move as one.

By putting a diamention from the origin to one of the lines on the side or top, bottom line what is half the diamention it pulls it over so it is dimensioned to the center and being a center point squire the whole thing moves.

If it was a single point squire I would of done the samething.

When you first did the center square it would/should off of been constrained to the origin, then by mistake you would've deleted the constraint or it just broke by itself.

It was easy to find the problem as I have done the samething and seen it quite a few times you get use to seeing the mistakes people make most times it's one I have done or seen before

[steve.hooper]

Thanks for the explanation, Daniel.

Steve.

[daniel_lyall]

It's something you get use to doing over time in a year or less you will be there if you ask anytime you have a question or have a problem stuff goes easy then if you see that something is not quite in line you know what to check.

With your model I looked at each sketch checking dimensions and constraints to I found the sketch that was out.

Trying to work out how to put it down is hard so the person you are replying to can understand it that's the hard part about helping.