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 .
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.
"Snag"Â 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 !
On 4/20/2025 7:51 PM, Jim Wilkins wrote:Don't be a wuss -chuck it in the 4 jaw and single point it. If you
"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" .
On Sun, 20 Apr 2025 22:42:39 -0500, Snag <Snag_one@msn.com> wrote:
On 4/20/2025 7:51 PM, Jim Wilkins wrote:Don't be a wuss -chuck it in the 4 jaw and single point it. If you
"Snag"Â 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" .
grind your tool right you won't even need to heat form it - - - -
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 !
On 4/21/2025 10:19 AM, Clare Snyder wrote:
On Sun, 20 Apr 2025 22:42:39 -0500, Snag <Snag_one@msn.com> wrote:
On 4/20/2025 7:51 PM, Jim Wilkins wrote:Don't be a wuss -chuck it in the 4 jaw and single point it. If you
"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" .
grind your tool right you won't even need to heat form it - - - -
The problem with that is that I'm not certain what the thread profile
is - probably acme but ... I was just thinking that I can make an
impression of the leadscrew , wax might work or clean the leadscrew well
and apply a release compound and mold one out of JB weld ... and use
that impression to grind a cutter . That piece of plastic is dialed in
on my 4 jaw , and ain't coming out just yet .
"Joe Gwinn" wrote in message >news:d67d0k1b0fms28q1afa8madabr02umtm7t@4ax.com...
From the discussion, I'd guess that it may be a ISO Trapezoidal
thread, specifically TR24x3.
.<https://www.engineersedge.com/hardware/iso-metric-trapezoidal-threads1.htm> >------------------------------
The Acme thread flank angle is 29 degrees, trapezoidal is 30.
On Mon, 21 Apr 2025 13:44:28 -0500, Snag <Snag_one@msn.com> wrote:
On 4/21/2025 10:19 AM, Clare Snyder wrote:
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 - - - -
The problem with that is that I'm not certain what the thread profile
is - probably acme but ... I was just thinking that I can make an
impression of the leadscrew , wax might work or clean the leadscrew well
and apply a release compound and mold one out of JB weld ... and use
that impression to grind a cutter . That piece of plastic is dialed in
on my 4 jaw , and ain't coming out just yet .
From the discussion, I'd guess that it may be a ISO Trapezoidal
thread, specifically TR24x3.
.<https://www.engineersedge.com/hardware/iso-metric-trapezoidal-threads1.htm>
Otherwise, it's likely an Imperial Acme thread, 8 TPI.
Measure the thread pitch to tell. 3mm pitch is 8.47 TPI, a ratio of
1.058 compared to 9=8 TPI, which is easily distinguished over the
length of the leadscrew.
Joe
"Snag"Â wrote in message news:vu63mc$2qjrd$1@dont-email.me...
 The problem with that is that I'm not certain what the thread profile
is - probably acme but ... I was just thinking that I can make an
impression of the leadscrew , wax might work or clean the leadscrew well
and apply a release compound and mold one out of JB weld ... and use
that impression to grind a cutter . That piece of plastic is dialed in
on my 4 jaw , and ain't coming out just yet .
On 4/21/2025 2:37 PM, Joe Gwinn wrote:
On Mon, 21 Apr 2025 13:44:28 -0500, Snag <Snag_one@msn.com> wrote:
On 4/21/2025 10:19 AM, Clare Snyder wrote:
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 - - - -
The problem with that is that I'm not certain what the thread profile >>> is - probably acme but ... I was just thinking that I can make an
impression of the leadscrew , wax might work or clean the leadscrew well >>> and apply a release compound and mold one out of JB weld ... and use
that impression to grind a cutter . That piece of plastic is dialed in
on my 4 jaw , and ain't coming out just yet .
From the discussion, I'd guess that it may be a ISO Trapezoidal
thread, specifically TR24x3.
.<https://www.engineersedge.com/hardware/iso-metric-trapezoidal-threads1.htm>
Otherwise, it's likely an Imperial Acme thread, 8 TPI.
Measure the thread pitch to tell. 3mm pitch is 8.47 TPI, a ratio of
1.058 compared to 9=8 TPI, which is easily distinguished over the
length of the leadscrew.
Joe
It's definitely an 8 TPI leadscrew , moves the table .125"/revolution
plus/minus a few tenths . OD is within a few thousandths of 15/16" .
Tell me more about this imperial acme thread ... this machine is a copy
of the RF45 , made in China in 2001 . I got it new IIRC in '02 or '03 .
I've made a lot of stuff with this machine .
On Mon, 21 Apr 2025 16:49:06 -0500, Snag <Snag_one@msn.com> wrote:
On 4/21/2025 2:37 PM, Joe Gwinn wrote:
On Mon, 21 Apr 2025 13:44:28 -0500, Snag <Snag_one@msn.com> wrote:
On 4/21/2025 10:19 AM, Clare Snyder wrote:
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 - - - -
The problem with that is that I'm not certain what the thread profile >>>> is - probably acme but ... I was just thinking that I can make an
impression of the leadscrew , wax might work or clean the leadscrew well >>>> and apply a release compound and mold one out of JB weld ... and use
that impression to grind a cutter . That piece of plastic is dialed in >>>> on my 4 jaw , and ain't coming out just yet .
From the discussion, I'd guess that it may be a ISO Trapezoidal
thread, specifically TR24x3.
.<https://www.engineersedge.com/hardware/iso-metric-trapezoidal-threads1.htm>
Otherwise, it's likely an Imperial Acme thread, 8 TPI.
Measure the thread pitch to tell. 3mm pitch is 8.47 TPI, a ratio of
1.058 compared to 9=8 TPI, which is easily distinguished over the
length of the leadscrew.
Joe
It's definitely an 8 TPI leadscrew , moves the table .125"/revolution
plus/minus a few tenths . OD is within a few thousandths of 15/16" .
Tell me more about this imperial acme thread ... this machine is a copy
of the RF45 , made in China in 2001 . I got it new IIRC in '02 or '03 .
I've made a lot of stuff with this machine .
In the US, Imperial (meaning inch) Acme is better known as ANSI Acme,
as documented in Machinery's Handbook. The biggest standard ANSI Acme
is 5/8-8 Acme, which is only 5/8" in diameter, not 15/16", so we may
have a franken-thread here.
Cutting one thread or the other into the same size leadscrew blanks
would make production sense.
The cleanest way to tell is to measure the pitch diameter with three identical number-drill blanks and a micrometer on some unworn area (so
the flanks are good).
.<https://www.engineersedge.com/hardware/external_acme_thread_13360.htm>
Joe
PS: It may have been Ox Tools who did a video on melting delrin to
make a new nut to fit an existing leadscrew. JG
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 - - - -
"Jim Wilkins" wrote in message news:vu44rs$vrlu$1@dont-email.me...
I will soon try making a tool from a scrap of broken rock drill pipe, and
see how easy to saw and turn it is.
--------------------------------
It wears an HSS bit dull in a few minutes unless the lathe is in back gear. Annealing or tempering in the wood stove to at least 600F when I removed it from the tin can after the fire died down seems to have helped tool bit
life.
"Jim Wilkins" <muratlanne@gmail.com> writes:
"Jim Wilkins" wrote in message news:vu44rs$vrlu$1@dont-email.me...
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.
--------------------------------
It wears an HSS bit dull in a few minutes unless the lathe is in back gear. >> Annealing or tempering in the wood stove to at least 600F when I removed it >> from the tin can after the fire died down seems to have helped tool bit
life.
I once made a (finger) ring from pattern-welded mild steel and a piece
of VW Beetle front suspension torsion spring. File glided off of it
as if it were glass. Put it in the coal of the wood range and left it overnight as the fire died. Next day, it filed nicely.
Those yard-long VW spring leaves can be clamped in the vise and bent
180 and will violently spring back. Heated to red in the forge and
cooled in air on the bench, can easily be snapped of by hand with a
very few degrees of bend. Glassy-hard. Air-hardening alloy.
So, good lo-tech annealing trick. Dunno about rock drill pipe, though.
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