Ways to mill an inner radius on manual mill?

Discussion on all milling machines vertical & horizontal, including but not limited to Bridgeports, Hardinge, South Bend, Clausing, Van Norman, including imports.

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caseydt
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Ways to mill an inner radius on manual mill?

Post by caseydt »

I have a newbie question on if it is possible to mill the inner slopes/radius shown in these pictures on a manual mill? I've been planning to get a mill for quite a few years but haven't had the time to really learn them. Now that I do I'm researching all of the types of parts I would like to make for myself so that I can look at mills capable of handling them. One project I am working on is a dry sump pan, and these are some that have been cnc machined for other engines that I like the style of. This is something I wouldn't take on for awhile but if possible I would like to have the capability.

Thanks
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SteveHGraham
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Re: Ways to mill an inner radius on manual mill?

Post by SteveHGraham »

It occurs to me that a truly ambitious or crazy person could mount a part horizontally on a vertical rotary table with a tailstock and turn it while cutting with an end mill. The radii would be arcs, not parabolic or whatever.
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John Evans
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Re: Ways to mill an inner radius on manual mill?

Post by John Evans »

Rough out to near net size with normal endmill, finish with a ball endmill with lots of stepovers. CNC is great for production on this kind of stuff as it makes the many steps super easy. Going CNC you not only need the machine but also CAD &CAM plus knowing how to use those programs!!
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caseydt
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Re: Ways to mill an inner radius on manual mill?

Post by caseydt »

Thanks guys, the rotary table idea I had actually thought about but I'm not that ambitious, I could see the part flying through my head and the wall too easily with an amateur running it.

The stepovers seems like the most likely for me, ton of work manually but it will be a one off so it makes sense. 90% of what I will be doing is brackets and adapters that are not super complex. The pan is my "holy grail" project for now.

I would love a CNC and plan to upgrade to one someday, but for now I'm mostly looking at used Bridgeports or possibly something like the 704 that I could convert later on. The software part is the one part where I'm all set, I've been doing CAD for 17 years and operate a consulting firm so I keep up to date on SolidWorks and AutoCAD, adding CAM to it will be an expense but that's a while away.
WJH
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Re: Ways to mill an inner radius on manual mill?

Post by WJH »

My 160$ 3 axis DRO has a "Smooth Arc" function that can do this sort of stuff
pete
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Re: Ways to mill an inner radius on manual mill?

Post by pete »

Either a horizontal mill or a horizontal attachment for a Bridgeport or clone would make it far easier and much faster. You'd still probably have some step over passes to do to blend things in, but a horizontal mill side cutting blade type cutting tool would get most of the material removed. Horizontal mills are pretty cheap, but a vertical is far more versatile. I wouldn't want a horizontal as my only mill though.

Pete
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Harold_V
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Re: Ways to mill an inner radius on manual mill?

Post by Harold_V »

Without CNC, there are cuts that would border on the impossible---such as sloping corners. Even they can be machined, assuming one is willing to spend the time making miniscule adjustments of the table, saddle and quill, taking very light cuts. All in all, a difficult job on a manual machine.

There are tracer mills in existence----and they'd handle the job reasonably well, although not as well as a CNC.

Harold
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