Jump to content

Welcome to eMastercam

Register now to participate in the forums, access the download area, buy Mastercam training materials, post processors and more. This message will be removed once you have signed in.

Use your display name or email address to sign in:

Designing a chuck jaw boring ring - arc dimensions?


Recommended Posts

Hi all,

Working on designing a classic boring ring for a CNC lathe.  Rather than spend hundreds, I think it would be a feasible project to do at the shop.

My only question is how do I solve for the arc diameter (see in photo in blue). Perhaps it is somewhat arbitrary? Or maybe its a spline? 

Some dimensions I used from Penn Tool Co to get a rough design, but the arc is not given:

https://www.penntoolco.com/precise-chuck-jaw-boring-rings/

 

Thanks for any help. 

 

 

Capture.PNG

Capture2.PNG

Link to comment
Share on other sites

Accuracy is really the key here. Can be spline or an arc just has to be consistent and accurate to each other is all. Don't forget the pins that have to be made and if I wasn't clear I would make sure everything is accurate like +/-.0002. Not sure what your shop rate is and what machines you have, but thinking that is a cheap price for the quality you're getting.

  • Thanks 1
  • Like 2
Link to comment
Share on other sites
20 minutes ago, ThickChips said:

@crazy^millman

 

Thanks for your 2 cents on this. I think we will still attempt to machine one as accurate as possible, then test runout and see if what we produced is suitable enough for our work.  Yep, I didn't forget the pins. 

 

Thanks a lot

Not a problem and experience is one of the best ways to understand things.

  • Thanks 1
Link to comment
Share on other sites

Can someone explain to me why a three point Adjustable jaw boring ring needs to be accurate?  IMHO there is no way the counter bores in soft jaws are held to that tight of a concentricity/runout tolerance, which would defeat the purpose of an accurate boring ring.  Nice fits to the jaw counterbores would be a nice to have, but once again, I don't think it's needed.  What's most important is that when you spin the ring to open it into the correct location, that it's close enough and won't bind sideways between two jaw, but instead pushes to the center.  If it's pushing to the center the forces will be properly balanced between the jaw, they have to as it needs to form an equilibrium.

Ready to be edumacated here. 

Link to comment
Share on other sites
16 hours ago, huskermcdoogle said:

an someone explain to me why a three point Adjustable jaw boring ring needs to be accurate? 

Because if you can't get it to adjust to create a full circle, when using it to cut jaws, you can get a out of round condition...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.

Join us!

eMastercam - your online source for all things Mastercam.

Together, we are the strongest Mastercam community on the web with over 56,000 members, and our online store offers a wide selection of training materials for all applications and skill levels.

Follow us

×
×
  • Create New...