making replacement pawl and pivot bolt
ken king, King Design | 11/07/2018 11:24:42 |
![]() 144 forum posts 239 photos | We've all, at some time, attempted to push through a turnstile which wasn't ready to allow passage, resulting in stress to both parties. At my son's local swimming pool the pawl had had enough, and shed its tip. The pivot bolt was badly bent and worn, so replacements were requested. The tip had been roughly reattached to give the shape required, whilst it had been necessary to tack a hex onto the chewed-up slotted bolt head to enable its removal. The hex seemed a good idea, and so was incorporated into the pawl design. The outline was traced onto !" thick plate, marked all round with centre punch dots, then a series if holes were drilled to facilitate cutting out the rough blank (this being my only means of doing so) Thicness was reduced by 0.2" on the mill, then the pivot hole and 1" c'sink were added After completing the profiling process (quicker to say than do !) a new bolt was made, from three pieces to reduce machining. Contrasting new pawl and bolt shown below. Clickety-click ! |
Michael Gilligan | 11/07/2018 11:39:38 |
![]() 23121 forum posts 1360 photos | Elegant result, Ken Just out of curiosity; was the original pawl a forging or a casting? MichaelG. |
ken king, King Design | 11/07/2018 14:18:07 |
![]() 144 forum posts 239 photos | Hello Michael, yes, definitely one of those ! Sorry to be facetious, but I am unsure, though tending toward casting. It will be intersting to see how M.S. stands up to the job, otherwise guage plate or similar might be needed, with heat treatment. At that point I might decline, reluctantly of course, Regards, Ken. |
Michael Gilligan | 11/07/2018 14:49:54 |
![]() 23121 forum posts 1360 photos | Posted by ken king, King Design on 11/07/2018 14:18:07:
Hello Michael, yes, definitely one of those ! .
|
Samsaranda | 11/07/2018 15:22:22 |
![]() 1688 forum posts 16 photos | Is this just half a topic or have I missed something, it doesn’t make any sense. Dave W |
SillyOldDuffer | 11/07/2018 16:27:04 |
10668 forum posts 2415 photos | Made sense to me. Good job Ken. We could open a book on how long the new pawl will last - I imagine it will have a tough time in a turnstile. My guess, 5 years. Dave |
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
Sign up to our newsletter and get a free digital issue.
You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy
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.