spiral tollpath on the edge of a chain sprocket

[jan26BTZ]

Hi

i cant figure out how to make the roundness/fillet on the edge of my sprocket.

i dont wanna do that in the lathe.

if i can do it in the mill i also can do a little chamfer all around the teeth and dont have to deburr it by hand.

I tried to make a morphed spiral on another test piece without teeth and it went perfectly as you can see on pic 2.

How can i get that tool path on my sprocket.

Thanks

Janne

[Steinwerks]

You could use the Morph Spiral with the extrude suppressed, then protect the toolpath, then unsuppress the feature it should work fine.

Or Morph from the outside to inside, then pattern the toolpath by the number of teeth. Parallel could work as well.

[jan26BTZ]

Hi

thanks for trying to help me

i´m sorry to say this, but i can not follow your advise beqause i´m not skilled enough 😞

I think i understand what you mean but not how to do it.

the sprocket is a blank from "solid components" in step format and i cant see the separate file tree on the left.

i dont know how to protect the tool path.

i attached my file as step and ipt, maybe you can modify it for me and then i can take a look and see what you did and learn from that.

Thanks

Janne

[Steinwerks]

I will see about making a screencast or video in Fusion 360 (I don't have Inventor installed currently) which should be very, very similar.

Morph and the Pattern option will give you this result:

[jan26BTZ]

Yes

i get that path too.


I did something else to get forward.
surely not the easiest way to go  but i got the work done.

now i have the other side left.

the sprocket is a 28 tooth blank and i need to convert it to 24 tooth.

the backside diameter is too big that the chain hit the diameter , i have to mill off about 4mm down to 84 to get the chain to go free.

if i could start from the outside cutting the fillet and then end with a circle at 84mm i should be very happy.

I guess the easiest way is to draw a new sprocket without teeth and put a toolpath on it.

[lenny_1962]

When we make sprockets like this we bo not show the teeth until all the surface cutting is done, cuts cleaner, then we turn the teeth cutout back on, use 2D and cut them out.

there are many times you have to go back in time or model over existing features, cut, then reshot the end\finished model to cut details

[Steinwerks · Accepted solution]

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@jan26BTZ wrote:

I guess the easiest way is to draw a new sprocket without teeth and put a toolpath on it.

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Honestly this will yield the smoothest result, so I would recommend taking this approach.

Sorry I did not get to making a video.

@lenny_1962 He doesn't have a model made in Inventor so there are no features to suppress or roll back to. However, he could make a revolved surface from a sketch that would do a good job and could be easily hidden, therefor require no protecting of toolpaths.

[lenny_1962]

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@Steinwerks wrote:

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@lenny_1962 He doesn't have a model made in Inventor so there are no features to suppress or roll back to. However, he could make a revolved surface from a sketch that would do a good job and could be easily hidden, therefor require no protecting of toolpaths.

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I did state that here:

"there are many times you have to go back in time or model over existing features, cut, then reshot revert back to the end\finished model to cut details"

I do not know inventor, thought they might have a direct modeling side like SW like delete face that makes a new feature that you can suppress\unsuppress, SW guy for 20 years, wont stop till they pry the mouse from my could dead had 😜