Screw head bevel and arc

Sorry for the NOOB question. I have a design i am working on. i have 2 through holes and need a countersink with 82 degree bevel for the screw. I have the through hole .120 and i need the countersink to go .030 from the bottom on a .260 thick part hole size (to accomadate the head diameter) of .270 ans i need to cut a curve/arc for a battery in the bottom side .07 deep and .350 wide and .490 long. can someone please help me i can make a copy of the base part if anyone needs it

Welcome @masterchucksemail
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One approach is to create two circles, one representing the base of the countersink and one representing the top of the countersink. Loft between circles. If you need a solid use PlanarSrf.

than you i will try that. i am not very good with cad. i am trying to learn i have heard rhino is very good so i have been trying it. I thank you for the help i hope i can get it. oh just so everyone knows i was not trying to get someone to do it for me i was just trying to be concise with what i was looking for. i will do my best and hope i dont have to bother anyone for more information

i made a truncated cone and put it in the hole making the countersink. i cant get it to attach to the plane and remove the material for the screw any hints?

It is much easier to provide assistance if a .3dm file with the geometry is available. You can upload a .3dm file by dragging the file to where you type a post, or by clicking on the vertical arrow icon above where you type a post?

How much experience do you have with CAD?
How much experience do you have with Rhino?
Have you gone through the Rhino User’s Guide?


very little with cad its been 20 years and only did minor stuff.
Rhino hard at it about a week
read through a lot of it but i am more hands on.
parts for upload.3dm (120.3 KB)
i have a wire frame where the solid goes made the truncated cones cant get them in and attached from the top down. have not gotten the battery relief made or put in.
i want to learn and i don’t mind doing the work. the only person i know that does cad (autocad for fire systems) does not want to help because of covid and does not how to do 3d
please let me know if you need anything else. i really want to learn how to do this

Hi - I would suggest making the 2D profile of a hole with countersink by help of some construction lines and then use Revolve to create a solid that you can place where you need and subtract that from the main part. I couldn’t find a 82° angle on your cones so I’m probably not understanding the requirements…

For the battery well, it sounds like you could just use a cylinder that represents the battery and subtract that from the main part.
If that’s what the blue part in your file is - I’m not sure why you’d use a pipe with wall thickness and not just a cylinder. Also, that object is tilted - is that by design?


the blue part is a tube that need to go into the top face halfway for a rod to slide in and out of for alligment. the tube is what i am adding to the face just to remove some play the rod moves slow and has lots of play on both sides of the tube just trying to make it more consistanat. i will try the 2d and use resolve. and will try the cyldner as well. idk if we are working today so idk when i can try it. thank you

i made the cylinder for the battery i have tries all the different trims and wire cut. on trim it takes either the cylinder above the part or the part itself am i missing or miss using the commands

think i got the battery cut done

hey can someone please check my work battery relief on the bottom and the countersink on the top. i left the cylinder and cones i used to make my modified parts
can someome check my work. i lest the cones and cylinder i used.3dm (143.7 KB)

Hi -
You are going to need to check the Accurate Modeling part of the help file - nothing in your file lines up:

Here’s a file with a few objects on different layers. These represent the main features of your model. When all these features are created from basic primitives or curves, they are in the end subtracted from the main part with the BooleanDifference command.
I have no idea which dimensions are correct (I placed several on your model but things are not symmetrical, not aligned, not the same size…) so this is just a sketch …
can someome check my work -wd-RH6.3dm (1.9 MB)

i think it will work as is. i have been working on attaching the pipe to the cover since i uploaded the file. any hints?

Hi - once you have that first part with no naked edges, simply putting that pipe in the correct place and using BooleanUnion should work - as in the attached…
can someome check my work -wd-RH6.3dm (2.2 MB)

what do you mean by no naked edges. i know that must be a NOOB question

Hi - a naked edge is an edge of a surface that is not joined to an edge of another surface. When all surface edges in a polysurface are completely joined to other surfaces in that polysurface, the polysurface is “closed” and is considered a “solid”.

In your file, you had an object intersecting the pipe but the object didn’t have top and bottom surfaces and was therefore an open polysurface. You can perform boolean operations on open (poly-) surfaces but then you need to know which direction the normals of your objects are pointing.

To check for naked edges run the ShowEdges command and look at the results in the command line. To see the location of naked edges check Naked Edges under Show in the ShowEdges panel.

thanks your help is much apreacheted. i do need to rotate the battery relief but now waiting on ups to deliver the 3d printer so i can print it and see what changes if any i need to make

i want to thank everyone for the help i know i will need more. i learn by doing with some guidance. i cant read it and do it sorry i am a dumb like that