What is the BACK GEAR RATIO for Bridgeport Series II Interact 2?

[ichudov]

I need to know the exact back gear ratio for Bridgeport Series II Interact 2. I need to know it exactly, because I need it for rigid tapping.

I know that it is between 8.2 and 8.42 from just looking at my dial, but I need to know the exact value, not approximate.

The specs on my spec sheet say 8.3:1 ratio, but I am not totally sure if this is this ratio exactly or approximately (as in teeth ratio).

http://igor.chudov.com/projects/Brid...Mill/specs.jpg

Thanks

[Torsten]

Originally Posted by ichudov I need to know the exact back gear ratio for Bridgeport Series II Interact 2. I need to know it exactly, because I need it for rigid tapping. I know that it is between 8.2 and 8.42 from just looking at my dial, but I need to know the exact value, not approximate. The specs on my spec sheet say 8.3:1 ratio, but I am not totally sure if this is this ratio exactly or approximately (as in teeth ratio). http://igor.chudov.com/projects/Brid...Mill/specs.jpg Thanks

You will need an encoder on the Spindle to do rigid tapping.
The Spindle speeds given in the manual will only be aproximat anyway.
So your 8.3 : 1 should be close enough.

[ichudov]

Originally Posted by Torsten You will need an encoder on the Spindle to do rigid tapping. The Spindle speeds given in the manual will only be aproximat anyway. So your 8.3 : 1 should be close enough.

I already have an encoder, it is on the driven pulley.

So the encoder is 1:1 when I am in straight gear, and in 1:RATIO when I am in back gear.

I need to know that RATIO.

i

[Torsten]

Originally Posted by ichudov I already have an encoder, it is on the driven pulley. So the encoder is 1:1 when I am in straight gear, and in 1:RATIO when I am in back gear. I need to know that RATIO. i

You need the encoder on the spindle, so it is allways 1:1.
else it would be useless.

[ichudov]

Originally Posted by Torsten You need the encoder on the spindle, so it is allways 1:1. else it would be useless.

Why is that so, if I can use a ratio to convert pulley rotation into spindle?

I already do rigid tapping in straight gear. I just need to find out the back gear ratio and I can then also tap in back gear.