Kind ask for help with modelling one milling operation

[michal.brychczyski1]

Hello,

I experienced a problem with modelling one milling operation.

I showed initial and final position of milling cutter, but have no idea how to merge them with smooth surface in Inventor. Can you please advice any steps to do this?

[IgorMir]

Hi Michal

Here it is in a simple form. I am sure - it can be done even more efficiently.

Cheers,

Igor.

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@michal.brychczyski1 wrote:

Hello,

I experienced a problem with modelling one milling operation.

I showed initial and final position of milling cutter, but have no idea how to merge them with smooth surface in Inventor. Can you please advice any steps to do this?

---

[michal.brychczyski1]

Hello Igor,

Thank you for your reply. Unfortunately - that is not the effect I want to achieve.

What I need is a surface after milling with milling cutter placed perpendicularly to the shaft axis. As the milling cutter goes low, the shaft is rotating slightly.

Please, refer to the attached video:

[IgorMir]

I see... Well, a bit more thoughts are needed... If I only was paid for for these thoughts... 

[WHolzwarth · Accepted solution]

Have a look here. It's done in 2019.

In 2020, Solid sweep functionality is added for similar tasks. I'll give it a try after that.

Perhaps it does it - perhaps not ..

2019 IPT attached

[IgorMir]

I would have imagined - a tool pass functionality is needed for that. Wasn't it added in 2020?

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@WHolzwarth wrote:

Have a look here. It's done in 2019.

In 2020, Solid sweep functionality is added for similar tasks. I'll give it a try after that.

Perhaps it does it - perhaps not ..

2019 IPT attached

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[WHolzwarth]

Here's the 2020 result. No problem in this case.

But I don't have unlimited trust in Solid Sweep. It fails in more difficult cases.

[IgorMir]

Thanks, Walter;

Can't view either of you files yet. But maybe OP can...

Cheers,

Igor.

[michal.brychczyski1]

Thank you Walter for your solution - it looks solid.

Still too complicated for me to understand, but at least it works. Maybe I'll try new tool in 2020 ver when I will be able to switch to it.

Kind regards,

Michał

[WHolzwarth]

The 2019 solution was not really straightforward, because of failures in Boolean combining. I had to use a different approach with partially Boolean cutting of a thickened surface. In the end, some material was added back for a realistic shape.

[johnsonshiue]

Hi! Indeed, to create the proper geometry, you do need Solid Sweep command in 2020. Like Walter mention, Solid Sweep can fail due to complicated tool geometry or the path. It has better success with simpler tool and path. The tool does not have to be round though. In theory, it can be any shape and the operation can be Cut, Join, Intersect, and New Body.

Many thanks!

[IgorMir]

Hi Johnson;

Interestingly enough - from actual machining point of view that part is not that difficult to make on a conventional milling machine. The dividing head is connected to the table's drive shaft through the set of transitional gears. That way the part has rotational and longitudinal motion at the same time. Reamers with the twisted flutes are made that way, BTW.

I am trying to replicate that part in IV2018. So far - it proves to be challenging enough.

Cheers,

Igor.

[IgorMir]

Hi Michal;

OK, here is a simple model which seems to conform to the video you have posted. IV2018 file.

Cheers,

Igor.

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@michal.brychczyski1 wrote:

Hello Igor,

Thank you for your reply. Unfortunately - that is not the effect I want to achieve.

What I need is a surface after milling with milling cutter placed perpendicularly to the shaft axis. As the milling cutter goes low, the shaft is rotating slightly.

Please, refer to the attached video:

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[IgorMir]

Since I don't like to leave the loose ends - I am replying to myself in here. Putting a bit more thoughts into the design - made me to create the model attached.  I think - the cut on the part OP posted has been produced with the ballnose endmill cutter. But since the topic has been solved - I might put it to rest too. 🙂

Cheers,

Igor.

[SBix26 · Accepted solution]

I've been working on this for the past several days, and I've finally got a solution that I'm happy with.  Unfortunately, it's Inventor 2019 format, so @IgorMir won't be able to open it.  Hopefully the images below will be sufficient to show what I did.  If I get time later, I'll try to recreate it in 2018.

I created the highlighted surface as a sweep with twist, then thickened to a new solid by half the cutter diameter, then added the rounded cutter profile to each end, then combined cut.  I believe it matches pretty closely the solid sweep results in Inventor 2020.

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Sam B
Inventor Pro 2020.0 | Windows 7 SP1
LinkedIn

[SBix26]

Here's my 2018 version for Igor--

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Sam B
Inventor Pro 2020.0 | Windows 7 SP1
LinkedIn

[IgorMir]

Thanks, Sam;

The question is - how to produce such a surface on a milling machine? One of the condition was that the milling cutter axis is normal to the part's axis. In condition like that at any given section of the groove there will be a straight line. Here are two images to show what I am talking about. But than again - from modeling point of view it was interesting enough to go for it.

Cheers,

Igor.

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@SBix26 wrote:

Here's my 2018 version for Igor--

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Sam B
Inventor Pro 2020.0 | Windows 7 SP1
LinkedIn

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[SBix26]

@IgorMir  I'm not sure that you would get a straight line at any given section through the cut.  It's true that if you bring the cutter straight into the piece, as with the OP's original part, you simply get a straight cut.  But the angular movement means that part of that groove is cut away by the leading and trailing edges of the cutter.  I think that this surface I've produced is pretty accurate, but I'm not certain of that.  I'm willing to be persuaded otherwise.

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Sam B
Inventor Pro 2020.0 | Windows 7 SP1
LinkedIn

[IgorMir]

Hi Sam,

With the cutting conditions the OP has specified there always will be a straight line once the cut passes over the radius of the cutter. Until than there will be a kink in the cut line. I have provided a screen shot earlier to demonstrate just that.

One way to see it is to actually make the dummy part and cut it in two halves. Yet I am pretty sure that to achieve the surface as in your model - the cutting tool should rotate in two axises. That's if we are talking about the standard end mill.

Still, I like your model. I do overlook the Twist option in the Sweep DB more often than I should! 🙂

Cheers,

Igor.

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@SBix26 wrote:

@IgorMir  I'm not sure that you would get a straight line at any given section through the cut.  It's true that if you bring the cutter straight into the piece, as with the OP's original part, you simply get a straight cut.  But the angular movement means that part of that groove is cut away by the leading and trailing edges of the cutter.  I think that this surface I've produced is pretty accurate, but I'm not certain of that.  I'm willing to be persuaded otherwise.

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Sam B
Inventor Pro 2020.0 | Windows 7 SP1
LinkedIn

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[michal.brychczyski1]

Hello Sam,

Thank you for your efforts and attached files. I really appreciate your pursuit to make it, despite my absence in the topic (I had short vacations, sorry).

The only thing that is still concerning me a little bit is the edge I showed on attached image. Anyway, I see that all the curves are tangential, so probably there is no need to worry.