Crazy Threads...

[Tozguy]

Thanks,
so in the inch mode the 62T gear is idle.

In the metric mode, the ratio is changed by the 34-74 set and by the the smaller gear driven by the 62T gear behind the 51T gear. The gear behind the 51T has how many teeth? Sorry to ask so many questions but I am trying to compare your lathe with mine to see if I can discover any clues.

 

[Tozguy]

Interesting to note that on my lathe there is a setting (MII) that gives thread pitches of 1/2 less than several inch pitches. Rather useless choice for inch threads.
However, the MII setting provides essential metric pitches.

 

[GK1918]

Now I'm confused; 8 tpi on the lead screw my dial has 32 teeth with a 8 tpi lead screw????

 

[Tozguy]

Any gear a multiple of 8 makes sense to me if there is room for it.
How many lines are on the dial?

 

[Hukshawn]

Thanks,
so in the inch mode the 62T gear is idle.

In the metric mode, the ratio is changed by the 34-74 set and by the the smaller gear driven by the 62T gear behind the 51T gear. The gear behind the 51T has how many teeth? Sorry to ask so many questions but I am trying to compare your lathe with mine to see if I can discover any clues.

The 51 goes right into the gear box. the picture of the gear train diagram shows all the gears. the 51 (74/51 inch) and 62 (34/62 metric) both enter the quick change gear box. I'd have to pull it off to count any gears in there

 

[pdentrem]

Now I'm confused; 8 tpi on the lead screw my dial has 32 teeth with a 8 tpi lead screw????

Mine does too. The distance be carriage moves is 4" for 1 rev of the dial.
Pierre

 

[Tozguy]

The 51 goes right into the gear box. the picture of the gear train diagram shows all the gears. the 51 (74/51 inch) and 62 (34/62 metric) both enter the quick change gear box. I'd have to pull it off to count any gears in there

If the 51T and 62T both enter the quick change gear box each on their own shaft, in the metric mode the 51T is idle?

 

[Tozguy]

Mine does too. The distance be carriage moves is 4" for 1 rev of the dial.
Pierre

Pierre, how many marks are on the dial? Might I know what is the finest and coarsest thread you can cut with your lathe?

 

[Hukshawn]

If the 51T and 62T both enter the quick change gear box each on their own shaft, in the metric mode the 51T is idle?

No, it spins on it's own when in metric. so it must be geared onto the same shaft inside the gear box as the inch.

 

[pdentrem]

Pierre, how many marks are on the dial? Might I know what is the finest and coarsest thread you can cut with your lathe?

There is the standard 8 marks and the lathe is a full box - 4 - 112 thread. The lathe is a early version of the Jet BDB-1340A.
Pierre