Metric vs Imperial lead screws on a G1550 lathe

[unscrambled]

I posted this in another thread then decided it's probably better on it's own.

I bought a G1550 back in March of 1994 and never attempted to cut a thread on it till today because the lead screw was off it this whole time (long story). So anyway, after putting it all back together, shimmed and adjusted etc. to have it completely functional the 3/4 x 16TPI thread I attempted to cut was a total mess. I just couldn't figure out what was happening. Then I measured the lead screw and found it wasn't a 16TPI as stated but rather a 1.5mm pitch. The labeling on the lathe and the manual lists the lead screw as a 16TPI but it isn't.

My Harbor Freight 7 x 12 has an actual 16TPI lead screw and this is how I know for sure the one on my G1550 is metric.

So I'm thinking that I could possibly get a lead screw along with the other required parts from a G4000 to use on this G1550 lathe. Does anyone know for sure if the 16TPI lead screw from a G4000 is actually a 16TPI.

Thank you.

 

[markba633csi]

Is the G1550 a Grizzly product? Looks like it's long discontinued, not surprising after 30 years
If the G4000 is similar I would think you could swap parts

 

[homebrewed]

Given the age of your machine it's unlikely that an LS for the G4000 would work. Grizzly's customer service dept. MIGHT know if it would but I wouldn't hold my breath on that one.

Your best bet might be to add an ELS to your machine. The LS pitch is just a number as far it is concerned.

There is a Grizzly sub-forum on hobby-machinist so who knows, someone here may be able to directly answer your question.

Good luck!

 

[dabear3428]

I posted this in another thread then decided it's probably better on it's own.

I bought a G1550 back in March of 1994 and never attempted to cut a thread on it till today because the lead screw was off it this whole time (long story). So anyway, after putting it all back together, shimmed and adjusted etc. to have it completely functional the 3/4 x 16TPI thread I attempted to cut was a total mess. I just couldn't figure out what was happening. Then I measured the lead screw and found it wasn't a 16TPI as stated but rather a 1.5mm pitch. The labeling on the lathe and the manual lists the lead screw as a 16TPI but it isn't.

My Harbor Freight 7 x 12 has an actual 16TPI lead screw and this is how I know for sure the one on my G1550 is metric.

So I'm thinking that I could possibly get a lead screw along with the other required parts from a G4000 to use on this G1550 lathe. Does anyone know for sure if the 16TPI lead screw from a G4000 is actually a 16TPI.

Thank you.

excellent excuse to add an ELS.

 

[WobblyHand]

I was going to mention an ELS. They are not for everyone, but they sure are handy. There a few DIY solutions available, or you can roll your own. Mine took me about 6-8 months to get going, but it was my own design. Had more trouble with some of the mechanical parts than the software, but it all was great fun to do. Every time I use my lathe I smile, because I get to use my own creation.

An ELS can accommodate any lead screw and practically any thread pitch (TPI). It's just a ratio of numbers to the algorithm. Want a 9.4248 TPI thread, no problem, or 31.4 TPI, no big deal. 0.95mm pitch, 1.015mm, or 3.1416mm, still relatively easy.