Re: A big ol' chunk of delrin

On 4/19/2025 11:41 AM, Bob La Londe wrote:

On 4/18/2025 6:45 PM, Snag wrote:

   Since no one currently has X axis leadscrew nuts available for my RF45 clone mill , I must make one . So I ordered a piece of acetal/ delrin . I've been studying videos of heat forming a nut to your leadscrew, all looks fairly easy . I'll use a piece probably about 2X2X3 for the nut . I bought a chunk that turns out to be 2 1/2X3X12 ... just in case it takes more than one attempt .

  Let us know how it goes.  I first heard of heat forming Delrin nuts right here on this group years ago.  For my application I went with a spring loaded anti backlash Delrin nut from DumpsterCNC back then instead.  I don't think DumpsterCNC is still around.
 

   This is interesting , your text did not show up in the post over on e-s but it did here on blocknews ...
   Now to the meat of the sammich . I have been out in the shop all morning making a tap* to match - pretty closely - the leadscrew on the mill . The plan as of right now is to tap the hole I have made in a chunk of that delrin . I'm hoping for a tight fit so I can heat the leadscrew to finish forming the threads without splitting the nut . If it's loose I'll slice the nut in half and heat/clamp to finish forming the threads . If it's too tight to thread on I can split one side to get it on the leadscrew and heat form from there .
   *I still have to form the flutes on that tap . I'm thinking a 1/2 or 3/8 ball end mill With the tap held in a 4 sided collet holder or maybe do 6 flutes since this tap is just under an inch . I used a chunk of 1.25" rebar for the tap since it was the closest in size to the finished product and I hate wasting material . I'm not planning on hardening it , this will likely be the only time it will ever be used .
   I also have 9 inches of 2 1/2 inch square aluminum stock coming to make a holder for the nut . Probably only use a couple of inches , but hay , I'll have stock for other projects down the road .
   shop break
  Well , the tap idea isn't going to work , I guess I'll stop and rethink my approach . But at least I was outta my wife's hair for the whole morning !
--
Snag
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