# How to mill round protrusions out of a solid?



## Maplehead (Mar 15, 2021)

Hi All
How would you machine something like this so that it's one solid piece?


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## Reddinr (Mar 15, 2021)

If no CNC and if not too big a rotary table could work.


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## mmcmdl (Mar 15, 2021)

Mill it out . Leave bosses where the posts are . Use a boring head to round off bosses to size . Or , just press pins in as needed . Why the need for one piece ?


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## John O (Mar 15, 2021)

You could use an annular cutter with the right ID then mill the rest.


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## Shootymacshootface (Mar 15, 2021)

Is a lathe not an option?


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## Mitch Alsup (Mar 15, 2021)

Boring head with the point facing inward. (I.e., bore an outside diameter.)


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## Maplehead (Mar 16, 2021)

mmcmdl said:


> Mill it out . Leave bosses where the posts are . Use a boring head to round off bosses to size . Or , just press pins in as needed . Why the need for one piece ?


Curiosity as I believe I've seen it before where it's not a pin or a cast. I've imagined end mills that are hollow and cut from the inside rather than outside. Lastly I may want to try this on a project I'm working on now.


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## jwmelvin (Mar 16, 2021)

What is a rose cutter/bit?
					

Saw this in an old machining text. At least as I understand it it is a tool for reducing stock to diameter but it is not a single-point lathe bit. Each diameter required would need an individual bit. What does it look like? how is it used? Any use today?




					www.hobby-machinist.com


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## BGHansen (Mar 16, 2021)

It would be a lot easier to machine if you could post-press pins in after the fact.  If they're an even 1/16", there are over/under reamers at 0.374" (for example) for a 3/8" pin.  Drill a hole with a 23/64" drill, ream the hole to 0.374" and press in a 3/8" dowel pin (and a little red Loctite).  Even if it's an oddball sized pin, there's probably a reamer out there that would work.  

Another way would be to ream a known hole size and make the base of the pin 0.001" - 0.002" over-sized and press it in.  Yet another way would be to knurl the end of the pin and press it in with some Loctite.

Bruce


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## homebrewed (Mar 16, 2021)

Make a pattern and cast it?  3D print it?  Redesign the assembly so you don't need to make it?  Retire when asked to make it (I like this one)?  Farm it out to some other poor sucker?


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## macardoso (Mar 16, 2021)

I second using a boring head. Get a tool that fits between the clearances and turn the cutting point inward. Start from a larger diameter and close in on the side you want, opposite of boring. Done it a few times and works well. For larger diameters, the offset boring head can make the machine shake.


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## Maplehead (Mar 16, 2021)

homebrewed said:


> Make a pattern and cast it?  3D print it?  Redesign the assembly so you don't need to make it?  Retire when asked to make it (I like this one)?  Farm it out to some other poor sucker?


I actually think it'd be a fun project. If I had items that regularly needed posts then I'd just do the pressure fit version or something but for this one off I think I'll try the boring bar method on the mill.


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## Shootymacshootface (Mar 16, 2021)

Maplehead said:


> I actually think it'd be a fun project. If I had items that regularly needed posts then I'd just do the pressure fit version or something but for this one off I think I'll try the boring bar method on the mill.


And, you could start with a much smaller piece of material.


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## markba633csi (Mar 16, 2021)

Agree with Bruce difficult to make as one piece and have the posts be in exact locations and diameters. 
You can try to make it as a curiosity- a challenging project
-Mark


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## hman (Mar 16, 2021)

Maplehead said:


> ... I've imagined end mills that are hollow and cut from the inside rather than outside. Lastly I may want to try this on a project I'm working on now.


I've recently "discovered" annular cutters.  The annular path they cut is about 1/4" wide.  So before they brak through, they leave a circular "peg" in the workpiece.  This might qualify as an example of what you're thinking about.  Of course, the set of available peg sizes is a bit limited.  But if you're not too worried about the exact diameter of the peg, you could take a look at a suitable annular cutter.


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## Larry$ (Mar 17, 2021)

I've done the boring head thing. If I can do it anyone can. Mill away excess. Use DRO for locations. Use knee for depth. My Chinese boring head will repeat to .001+- snugged up and using the dial. If you don't have a boring bar the correct size, make one.


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