By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

tapered tap

All Topics | Latest Posts

Search for:  in Thread Title in  
bricky06/03/2022 13:33:55
575 forum posts
68 photos

I have in my posetion a wooden pantograph by Conti of Paris,both of the split tapered collets for holding the lead and a stylus have their tapered threaded closers missing.I have this implement for 40years and was given it by an old friend whose farther used it at the turn of the last century.I would like to make the collet closers and I am unawhere of any suppliers of tapered taps unless someone knows of one.Failing not being able to get one I will have to make one.The dimentions of the collet are 8.85mm long 6mm tapering to 4.13 the thread is 0.7 mm.My trigonemetry is not good so if someone can work out an included angle for me it would be much appreciated.Working with pencil and paper I got it to 8 degrees but I am sure I will be out.


David Senior06/03/2022 13:39:53
18 forum posts
5 photos

Are you sure the female thread needs to be tapered? If you were to try an M4 nut would it start, and would it tighten up the collet as it moved up the thread?


not done it yet06/03/2022 14:12:56
6812 forum posts
20 photos

As Dave says, the threads will be parallel and clamped to the male thread by the outside taper.

Two halves glued/soldered together (or held by other means), drill and tap the hole, separate the two halves and skim/file/grind the closing edges to allow them to tightly clamp on the male thread.

You can set the taper angle either by trig calculation or by setting the female outer onto the lathe centre line and adjusting the compound so that a dti on the taper shows no change, as the compound is wound along the taper. I would prefer the latter method, if possible.

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Support Our Partners
Rapid RC
Eccentric Engineering
Eccentric July 5 2018
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest