From: clare@snyder.on.ca
On Sun, 20 Apr 2025 22:42:39 -0500, Snag wrote:
>On 4/20/2025 7:51 PM, Jim Wilkins wrote:
>> "Snag" wrote in message
>> news:68053d6b$6$5278$882e4bbb@reader.netnews.com...
>>
>> 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 !
>
>I did see Bob's post on E-S.
>
>For a single use tap you could flute it with one corner of a square
>ended endmill, perhaps one with dull corners that you beveled sharp
>again, using your endmill fixture at the back relief instead of the
>cutting edge angle. If a hard spot in the rebar dulls it you can regrind
>it the same way. It's my go-to endmill for roughing steel of uncertain
>parentage and upbringing.
>
>A tap drill size pilot plug on the tap may help keep it centered and
>straight.
>
>In aluminum at least unhardened steel dulls quickly.
>
>I will soon try making a tool from a scrap of broken rock drill pipe,
>and see how easy to saw and turn it is.
>
>-----------------------
>
> I'm thinking at this point that I might try threading the inside with
>a boring bar and a cutter that is close but narrower than the groove
>width of the thread . This will make it necessary to split the nut and
>hot form the thread . My main concern about splitting the nut is whether
>the halves will fuse together into a solid unit during the forming
>process . I'm once more stepping off into unknown territory ... but you
>know what they say "keeping learning will keep you young" .
Don't be a wuss -chuck it in the 4 jaw and single point it. If you
grind your tool right you won't even need to heat form it - - - -
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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