Need change gear help with a Vevor model YS-1835-A mini lathe!

[6Sally5]

Well everyone…yesterday was a smashing success with the help from all of you and my SIL. We got the 55T and 65T gears 3D printed and trimmed to fit. Despite my inability to find any actual videos of my lathe model wherein the change gears were inserted, I decided to jump into the deep end, dismantle the banjo ad whatever else was in the way. The gears didn’t mesh together at all…about 1/2” out of mesh on the average. Then I noticed the adjustment slots in the brackets…similar to an alternator bracket. I loosened up all the adjustables them kind of worked all the gears in a handful until everything meshed. Note that the large belt pulley had to be removed in order to get the 40T gear in place at position “A”. Nowhere in any manual or video was this explained. I tightened up all the bolts, greased the gears, and rotated the assembly by hand to ensure no issues. Turned on the lathe at 100 rpm, threw the 1/2 nut lever as the indicator came to “1” and…magic! It worked! I’m going to hang my first bolt on the shop wall!
Thanks again!

 

[6Sally5]

One more question because my SIL thinks somethings wrong…although it worked for me and I have seen it in two other YT videos that are the same. When the 1/2 nut is disengaged, the dial on the thread indicator spins. In my particular case, when it rotated around to “1” I engaged the 1/2 nut lever, the dial stopped turning, and the carriage moved on to cut the threads. Is it normal that the thread indicator dial stops turning when the 1/2 nut is engaged?

 

[GrifterGuru]

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[VicHobbyGuy]

Is it normal that the thread indicator dial stops turning when the 1/2 nut is engaged?

Yes. Once the half nuts are closed, the carriage and threading dial are 'tracking' along with the leadscrew. So the dial stops turning.

 

[VicHobbyGuy]

We got the 55T and 65T gears 3D printed and trimmed to fit. .......... and…magic! It worked! I’m going to hang my first bolt on the shop wall!
Thanks again!

Excellent! So you used a 40T-65 idler-50T combination to get your 20 TPI thread?
So your lathe has a 16TPI leadscrew?

 

[6Sally5]

Thanks. I will see if I can figure out what’s going on.

 

[6Sally5]

Excellent! So you used a 40T-65 idler-50T combination to get your 20 TPI thread?
So your lathe has a 16TPI leadscrew?

yessir. This was the recommended combo on the placard and manual.

 

[6Sally5]

Yes. Once the half nuts are closed, the carriage and threading dial are 'tracking' along with the leadscrew. So the dial stops turning.

View attachment 501424

Thank you! This is exactly what mine does. I tried loosening the mounting screw and adjusting the indicator body to try and engage the leadscrew while it was running, but it wouldn’t mesh. As soon as I disengaged the 1/2 nut, it would start turning.

 

[VicHobbyGuy]

Excellent! So you used a 40T-65 idler-50T combination to get your 20 TPI thread?
So your lathe has a 16TPI leadscrew?

yessir. This was the recommended combo on the placard and manual.

In your original post, you said : "The manual and the label on the case say the gear setup needs to be a 40-tooth on A, a 65-tooth at B, nothing a C (?), and a 55-tooth at D. There are no 65 or 55 tooth gears in the set or even on the lathe."

The 65 tooth is just an idler; you could have used any gear that fits in that space (with adjustment). No matter; the 55 tooth may come in handy some day. It took a while before I understood how change gears worked - it's just arithmetic (ratio between the spindle and leadscrew rotations), but it can be confusing.

 

[VicHobbyGuy]

Thank you! This is exactly what mine does. I tried loosening the mounting screw and adjusting the indicator body to try and engage the leadscrew while it was running, but it wouldn’t mesh. As soon as I disengaged the 1/2 nut, it would start turning.

For regular turning (not thread cutting) I either remove the threading dial or swivel it so the gear teeth aren't engaged with the leadscrew. No point putting a lot of wear on it when it isn't being used, IMO.