How would I fully constrain this sketch and create the part?

[Ameldur]

Hi there,

I'm new to inventor and i've been struggling a little bit getting a sketch to match. I've never made this sort of shape before, i dont know how long the arcs are supposed to be and i dont know where to place the R6 circles (between the R108 and R96 arcs) so i can draw an arc that will fully constrain the sketch.

I'd be extremely grateful if you could show me how to do it 🙂

Thank you in advance.

[NathanGMartin]

Did you attach the correct pdf? I'm having trouble figuring out which circles/arcs you're talking about, looking at the drawing.

[jddickson]

Here is the finished model with constraints and dimensions. The only dimension that I could not find was the height of “Extrusion 7”. You can turn on the constraints so you can see them. I hope this helps.  

[mcgyvr]

Sure looks like the OP posted the wrong file..

[JDMather]

You might want to zoom in here real close (Sketch 6).

For example on how not to do a sketch.

[JDMather]

Also,

this hole is the wrong size in the attached example.  Should be a tapped M4 hole (which is not 4mm).

[Ameldur]

Wow, i added the wrong file. So many people have replied, so sorry! 

Thanks for the replies! Again, really sorry about that 😕

Attached the correct file now 🙂

[NathanGMartin]

There we go! 🙂

[JDMather]

Now attach your *.ipt file to show what you have attempted so far.

[Ameldur]

I deleted my .ipt file as i couldn't manage to draw it.

I started from the top and drew the two arcs (R108 and R96), offset copy'd them both inwards and constrained the innermost ones by 6 and the two outer ones by 3 like on the drawing. I tried several constraints to make them line up but I didnt manage it 😕 

I don't understand how long the arcs are supposed to be either, or where to place the R6 arc that connects the R108 and R96 😞

[JDMather]

Try again.

[JDMather]

Sketch vertical center line from origin.

Sketch the two arced "slots".

Sketch the two angled lines.

Add Symmetry constriant selecting the two angled lines and then the center line.

Add your dimensions.

[JDMather · Accepted solution]

...and wait for it.... the next question.  (see attached)

[jddickson]

Parts not done right. The Fillets need to be added...

[NathanGMartin]

I would use a skeleton of construction geometry, sketching solid lines and arcs on top, leaving any fillets/blends for a second operation after the intial extrusion.

Note, however, that all fillet radii from your drawing (and your part thickness) all appear to be off by a factor of +2.  The part pictured above is as-specified by the drawing but with the thickness halved to 2MM.

[Ameldur]

Like this JDMather? 🙂 I noticed you only have one dimension with 40 degrees, how did you do that? I keep getting two,

[JDMather]

You must have missed the instruction to attach your *.ipt file here.

[Ameldur]

Sorry, hehe 🙂

Attached!

[NathanGMartin]

Part File (for inspiration) attached; note that this file exhibits 1.5MM raddi on major fillets and .25MM minor fillets, as well as a 2MM thickness.

[Ameldur]

Thanks Nathan!

Why do you have incorrect fillets and 2mm thickness? Just because you can or is there something wrong with the drawing? 😮