using extrude to cut away material, but its backwards

[CmptrGk]

i am having a problem with using the extrude function to cut away some material. i know to choose the extrude option, then to change it to cut mode, and then i select the part of the sketch that i want cut away, but it removes everything that is not selected. its been a while since i used inventor but i dont remember that ever happening. btw im using inventor 10.

i have included some screen shots of what is going on.

[Fireworks 234]

I see what the problem is, you chose the bottom cut feature; that one leaves everything around what you chose. You need to choose the one above it but below extrude, that one should work.

[CmptrGk]

oops, i geuss i didnt see that.

[Ebolagirl]

Is there any particular reason you aren't using the cut feature under sheet metal features? Afterall, that's what it's there for, so I think it works better than the extrude backwards thing. Just a thought.

[Daniel Brim]

Cut is there to see cuts on sheet metal flat patterns. Either that's one thick piece of sheet metal or extrude is the correct feature to use.

[Ebolagirl]

Originally Posted by DanielBCR

Cut is there to see cuts on sheet metal flat patterns.

You can use cut the same way that you use extrusion, except it cuts. You simply create your sketch, select it, and specify how deep you want it to cut, and press 'ok'. Perhaps you should investigate the features a little more. It's good to know different ways of accomplishing the same task. Using cut as opposed to extrusion just allows you to keep your features a little more organized (cut coincides with cutting and extrusion coincides with extending).

[EricH]

Originally Posted by Ebolagirl

You can use cut the same way that you use extrusion, except it cuts. You simply create your sketch, select it, and specify how deep you want it to cut, and press 'ok'. Perhaps you should investigate the features a little more. It's good to know different ways of accomplishing the same task. Using cut as opposed to extrusion just allows you to keep your features a little more organized (cut coincides with cutting and extrusion coincides with extending).

No. There is no Cut feature in the part feature list for a standard part. Extrude only (well, there is also Shell, which can be a little tricky to use).

[Ebolagirl]

Originally Posted by EricH

No. There is no Cut feature in the part feature list for a standard part. Extrude only (well, there is also Shell, which can be a little tricky to use).

Originally Posted by Ebolagirl

under sheet metal features

I never said it was under the 'part features' section. I said it was under the 'sheet metal features' section.

Although, I think I now realize where the confusion is coming from. The original poster, CmptrGk, did not specifiy whether he was working in a new Sheet Metal.ipt or a new Standard.ipt. And since I always work in a sheet metal (because that's what I was taught), and from what it sounds like, you work in a standard, we are talking about two different things. In a sheet metal, under the 'sheet metal features' section, there is a cut tool. It is a little yellow square with the center cut out (if I had Inventor in front of me I would post an image). That tool allows you to cut out sketches similar to a backwards extrusion.

[Stu Bloom]

While it is true that there are many ways to generate most features, best practices for a NON sheet metal part would be to use the extrude/subtract option as was originally shown (attempted) by "CmptrGk"

[Ebolagirl]

ok, I'll agree with that one.

[Andy A.]

EbolaGirl is close. I would have used an extruded cut, but there is another way thats not bad.

There is a similar command to Cut for a standard part. It is call 'Split'.

It can be used in the same way as Extrude/Cut, but it is rarely from what I've seen. I suppose it is a legitimate use, but I don't see any reason to over it unless someone asks you to. Split is supposed to be used to break a solid body into two separate pieces. Although, given how well Inventor handles separate solid bodies in a single part file, I don't know why you would want to do that. Solidworks is way ahead here.

It's one of those commands no one seems to use. I'm sure someone asked for it and it gets plenty of use by them, but I can't think of any good reason why.

I can post pictures and a quick howto if someone wants it. Otherwise, check the help file.

[negfrequency]

I myself would have shot for the shell command in a standard.ipt. Just a remove face and a thickness means that you dont have to measure out the rectangle on the surface, and if left with a whole to deep in the bottom, it could have just been a move face upwards.

A sheetmetal as previously mentioned would have to have been extremely obease to look like that. However, my knowledge with sheetmetal.ipt files is limited, and i am actually going to go flirt with it right now because it sounds more useful than i previously inferred.