Cincinnati Hydrashift LR metric conversion gears and index plate

Does anyone know what the dimensions of the two gears to convert my LR to cut metric threads? Per the repair manual it mentions one gear is attached to the idler shaft which has a 120 tooth gear from the factory so I assume the conversion gear is a 127 tooth. However I need the dimensions for the gear that replaces the one on the lead screw. Also I would hope someone has a photo of the thread index plate for the Quick Change gear box.

I really appreciate any help and thank you.

Might be helpful - especially starting at Page M16

http://vintagemachinery.org/pubs/177/17744.pdf

have fun

cdhthethird said:

Does anyone know what the dimensions of the two gears to convert my LR to cut metric threads? Per the repair manual it mentions one gear is attached to the idler shaft which has a 120 tooth gear from the factory so I assume the conversion gear is a 127 tooth. However I need the dimensions for the gear that replaces the one on the lead screw. Also I would hope someone has a photo of the thread index plate for the Quick Change gear box.

I really appreciate any help and thank you.

Click to expand...

Yes, I have the actual paper copy of that from when the lathe was bought new. Besides the process to switch gears the only help it offers is “Metric gears are available special order”

You have to figure it out

You are stuck with A and C (quadrant and lower gears) and spindle gear as far as what happens in the English set up combined with whatever the lead screw pitch is. The spindle gear drives the 120 tooth idler and it drives gear C - the ratio coming from spindle gear and gear C

The Metric set up will replace this English at some exact relationship (gear ratio) - and you already know a factor in this ratio due to127/120. The other factor of this overall ratio will be the ratio between spindle gear and currently unknown gear H

A start on figuring: (with English pieces in place)

Find pitch of lead screw
Find turns of chuck that produce one turn of lead screw

A for instance on 4 pitch lead screw would be the QC gear box set up for 4 TPI