Line Boring on a Lathe with a Twist (or a rotation)

A discussion with pictures of a line boring job I did back in 2007. Inspired by Max Grant's excellent videos on the same topic. Similar to what Max did in his video but with one more degree of freedom to complete a job otherwise too large for my equipment.

[@outsidescrewball]

Enjoyed…great discussion on a ingenious setup

[@brianleblanc5052]

just found your channel when mentioned by Max Grant on his last video. Great work and as always I keep learning stuff and using the procedures in my small hobby machine shop.

[@hmw-ms3tx]

Thanks Brian. Ken

[@hilltopmachineworks2131]

Nice job Ken.

[@swanvalleymachineshop]

Nice one Ken , i like the set up . Using the reamer would have saved a ton of time . 👍

[@hmw-ms3tx]

Thanks Max. Looking at these old pictures reminded me how much more paint my lathe used to have on it.

[@swanvalleymachineshop]

@@hmw-ms3tx My one is the same !!!

[@TrPrecisionMachining]

good video hmw1972

[@hmw-ms3tx]

Thank you. Ken

[@danf6070]

Fascinating stuff. Thanks for that. Did you have to shim the part to get the bores in line with the spindle or did you just get lucky on the measurements? I've seen line boring videos in the past but nobody ever seems to discuss how to adjust the part vertically to align it with the lathe spindle.

[@hmw-ms3tx]

Hello Ned. In this case I did not have to shim. I knew the offset distance between the datum bore and the holes I had to bore out. I then built the fixture so it would hold the part at the correct elevation. This is what made this fixture so quick to use. I simply put the part on the fixture, lightly tightened it up, levelled across the bolts and then firmly tightened it up. The boring bar was installed and the work could start. For a good example of how to shim to height watch Max Grant's recent videos where he does exactly that. Ken

[@danf6070]

@@hmw-ms3tx Ah, right, that makes a lot of sense. I think you actually mentioned that in the video but I somehow just glossed over it. A followup question I had was in regard to possible concerns about putting that much weight on the cross slide. Is there any concern about putting too much stress on there?

[@hmw-ms3tx]

@@danf6070 The weight isn't really a concern. The whole set up probably weighed about 200 lbs. When the lathe is used in a normal fashion taking a heavy cut can easily apply more than 200 lbs. down through the cross slide. Machine tools are designed to minimize deflection while under load and because of this they are many times stronger than they need to be to carry the loads they see without fracturing. It's why it is so rare to see the main castings of a machine tool broken unless something catastrophic happened. Ken