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:

Double Lead tapping on HAAS Super Mini Mill


Recommended Posts

OK, so I have a difficult time figuring this out (mental block of some sort).  I have a job that requires a metric  3.5 x .5 DOUBLE LEAD TAP to be used, for some holes in 1/2" aluminum plates  with the threads being only 1/4" deep (heli-coiling), but i can't for the life of me figure out how to get MC to spit out  code that works without stripping out threads or pulling out the part from the vise!  Has anyone power tapped double lead threads and how did you set up the process on MC, as a (per my tool example) .5 pitch or 1.0 pitch?  Any ideas or even how to hand write the code would be great help!

Thanks and have a  great day.

Geo A

 

Link to comment
Share on other sites

Can you even tap a double lead thread? I have never tapped a double lead. I have turned many double leads ID and OD on a lather and Thread milled them, but tapping them I have never done. Be interested in seeing how you get it sorted out.

My 1st thought is to set a Z value the pitch or half a pith higher to see if that allows you to do what you are trying to do.

Link to comment
Share on other sites
10 minutes ago, htm01 said:

so you would tap at 1. with 2 leads would give you .5 pitch

No you would take a 1 Pitch normal thread that is a double lead and tap it a 2 time your feed rate to your RPM.

Your 1. would go to 2.0 not half like you suggested. It is still a 1. pitch just there is 2 threads next to each other have starts that are 180 from each other. We use to do 3 lead threads by marking the Jaw on a 3 Jaw chuck to the half nut number. Then when we did 4 lead threads we would use a 4 jaw chuck and again match the chuck jaw number to the half nut. 4 Lead threads are fun to watch on a conventional lathe. Been 25 years since I had to cut them, but not something you forget. Still remember setting the compound at 29.5 degrees for standard threads, 44.5 for buttress and 14 for acme.

Link to comment
Share on other sites

Hi Geo,

I found this chart on Harvey's website, and thought it could be useful for anyone that might need to do this in the future. It describes the relationship between Lead and Pitch...

https://www.harveyperformance.com/in-the-loupe/multi-start-thread-guide/

http://www.harveytool.com/secure/Content/Documents/Chart_MultiStartThreads.pdf

 

 

 

  • Like 1
Link to comment
Share on other sites
  • 2 weeks later...

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...