From: Snag_one@msn.com   
      
   On 11/20/2024 10:44 AM, Bob La Londe wrote:   
   > On 11/19/2024 4:27 PM, Snag wrote:   
   >>    I'm in need of help finding a part for my bench top mill , RF45   
   >> clone . It's the same as the Grizzly G0484 and they show the part as   
   >> discontinued . I'm looking for a replacement X axis lead screw nut .   
   >> The Grizzly part number is P0484032 , maybe someone is making a   
   >> replacement since there must be 10's of thousands of these machines   
   >> around . The thread is Acme 15/16 (24 mm) diameter with an eight TPI   
   >> thread . I've seen articles about people making replacements using   
   >> plastic - maybe ABS? - and heat/pressure forming the threads but I'd   
   >> lots rather find a direct drop-in replacement .   
   >   
   >   
   > Would have responded sooner, but I do not have a proper Usenet client   
   > installed on the house computer.   
   >   
   > My first response would also be to sleeve the existing nut.  This   
   > addresses your request.  I would suggest very tight sliding fit and use   
   > sleeve and bearing locker.   
   >   
   > The search for a new one is what it is.  A search.  I have no special   
   > insights other than as you clearly already know that these machines may   
   > be sold under different labels.  I suggest may be ask Matt at Precision   
   > Mathews.  Admittedly he may be more responsive on parts to a customer   
   > than somebody who just wants parts, but he is very good at supporting   
   > customers.   
   >   
   > Now for the tangents.   
   >   
   > Backlash should not be a huge issue if your gibbs are adjusted, you use   
   > your gibb locks, and you mostly conventional mill.  Accuracy probably is   
   > not a huge issue, but if it is take all measured moves using the hand   
   > wheel dials in only one direction.  If you really need to be able find a   
   > postion accurately in two directions there are two solutions.  The nice   
   > one is a DRO with glass scales.  The alternative is some dial indicators   
   > mounted to the table.  I have a dial indicator mounted semi permanently   
   > on one of my lathes.   
      
      I just a few months ago ditched the Shumatech DRO and capacitive   
   scales for a nice glass scale DRO that reads to tenths ... and I have a   
   dial indicator on a mount that clamps to the front v way on the lathe in   
   addition to one on a magnetic mount . Also have a couple of Starrett   
   back plunger indicators with hardware and one NIB indicator for a backup   
   in case I break one .   
      
      
   >   
   > As was already mentioned ABS is a terrible idea for all the reasons   
   > stated.  Acetal (Delrin is a trade name) is used for bearings, axis   
   > nuts, and a variety of other things.  Its pretty tough and there are   
   > commercial products made form the stuff.  HOWEVER.  Acetal does not   
   > accept any common adhesive well at all.  It would not be a good option   
   > for boring and sleeving the old nut.  Bronze or even brass would be   
   > better.  I do not know if adhesives would stick to oilite bronze.  Maybe   
   > another rabbit hole to research there.   
      
      
      If I sleeve the original it'll be with bearing bronze or some Ampco   
   45 aluminum bronze . I have both on hand ...   
      
      
   >   
   > I looked.  I do not have an acme tap that big.  You will have to cut it   
   > on your lathe (or buy a very expensive tap) after grinding a suitable   
   > inside cutting tool.  It will probably chatter pretty bad, so it might   
   > be time to consider making a solid tool post that bolts directly to the   
   > cross slide.   
   >   
      
      I already made a post type boring bar holder that bolts directly to   
   the compound . I can use the lathe leadscrew as a pattern to grind the   
   tool since it too is 8 TPI . Actually I have another leadscrew that's in   
   very good condition that I would use .   
      
      
   --   
   Snag   
   Voting for Kamabla after Biden   
   is like changing your shirt because   
   you shit your pants .   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)