Crazy Threads...

I believe someone already gave you an alternative method using measurement. That's above my pay grade....I use the thread guage.
 
Chuck K said:
I believe someone already gave you an alternative method using measurement. That's above my pay grade....I use the thread guage.
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i did try that. i wasnt sure of the result... one full revolution of the thread dial gave me about 1 3/4".
so he wrote if its metric, ill get a neat round number... so being 1 3/4" i should assume its imperial?

so whats that mean for me then? that should still be threads per inch, no? not millimeters?
 
Like I said....that's above my pay grade. Does it still lose it's place when you leave the nuts engaged and reverse back to the starting point?
 
Chuck K said:
Like I said....that's above my pay grade. Does it still lose it's place when you leave the nuts engaged and reverse back to the starting point?
Click to expand...
no, so i have that at least, as a bandaid method. will make threading to a tight shoulder tricky (which was my initial project. i was trying to remake a piece for a traditional tool post for the other lathe im selling. it had a neat method to raise and lower the tool by using a two piece threaded cylinder. you raise and lower the tool by threading in or out the piece. the threads on the old piece were destroyed. it was just a time waster project. it may just get abandoned. )

but id still like to get to the bottom of this, its very odd... its almost as if a gear is off by one tooth, or the chuck and the gears are just slightly out of timing... no idea how...
 
for those of you who were wondering... here is what happens when i leave the half nut engaged and reverse the lathe out.

IMAG0674.jpg

id call that a significant improvement... looks like i will likely use this method from now on.. time consuming, but successful.. but man, would love to find out whats actually wrong...
 
Good. As for Imperial or Metric lead screw, take a Imperial ruler and count the number of turns in 1 inch. Likely 8 per inch but could be 4,6,8 etc. If it is metric, it will not be a number that works out to a complete number of turns in 1 inch, it will be something like 10 turns in 40 mm for example which means 4 mm from crest to crest.

Pierre
 
pdentrem said:
Good. As for Imperial or Metric lead screw, take a Imperial ruler and count the number of turns in 1 inch. Likely 8 per inch but could be 4,6,8 etc. If it is metric, it will not be a number that works out to a complete number of turns in 1 inch, it will be something like 10 turns in 40 mm for example which means 4 mm from crest to crest.

Pierre
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It is 8 tpi. So it's imperial.... but what now? By all this info, it should be threading fine.
 
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