Metric Threading on a 1954 Series 61 Imperial Monarch

[nt1953]

Once again I have needed the ability to cut metric threads on an Imperial lathe, so I made 4 gears to be able to cut most metric threads. Using the 25T gear that was already on the lathe (top left gear in the picture below) along with the 4 aluminum gears shown in the second picture I can cut most of the metric threads I might need to cut with acceptable errors. Gear selection, quick change gear box setting, metric thread, and error are shown in the table. Note that the error is not in percent, if you want percent move the decimal two places to the right.

 

[nt1953]

Just in case it was not clear, the gears are used one at a time to replace the existing 25T gear at the upper left.

Now that I have cut some metric threads using one of the aluminum gears, I have noted that the tooth loads are much higher than what I had when I made a similar gears for a 16" South Bend. The higher tooth load means that it is likely that if I use the gears very much, I will need to remake them using steel.

 

[johnoder]

Once again I have needed the ability to cut metric threads on an Imperial lathe, so I made 4 gears to be able to cut most metric threads. Using the 25T gear that was already on the lathe (top left gear in the picture below) along with the 4 aluminum gears shown in the second picture I can cut most of the metric threads I might need to cut with acceptable errors. Gear selection, quick change gear box setting, metric thread, and error are shown in the table. Note that the error is not in percent, if you want percent move the decimal two places to the right.

Lead screw reverse and leave half nuts engaged?

 

[texasgeartrain]

I bet you could sell some sets of those gears if you were inclined to make more.

I'd certainly be interested.

 

[nt1953]

When cut the last metric threads, I did leave the half nuts engaged and reversed the lead screw. However I have also used the method Ox Tool shows in this video:

 

[alcro1998]

I like this a lot. Great work!