This part of the machining has been one of the most awkward due to the size of the parts. The main spine section is just over 1.5 meters and quite heavy. I needed to drill/bore a 40mm dia. hole thru the Duragal pipe (60.3mm dia) but to clamp the pipe horizontal on top of the cross-slide would be far to heavy for the lathe slides. The cantilevered pipe would break the cross-slide off and the lathe would be no more.
The original short axle tubes were no problem to position horizontally as they were only 260mm long. The photo below shows the size of the problem with the short pieces for comparison. The hole has now been bored out, so how did I do it?
The photo below explains how I set the pipe up on the lathe. I used the same split plates with the angle plate to hold the pipe, same as I did for the short ones. I forgot to take the photo as I was machining the pipe so it was just held down now with only one bolt and one clamp. You can see the problem clearer now its mounted on the lathe. The yellow panels in the background are the wings off my 1/4 scale Piper Cub. The columns for the garage can also be seen and these are what I will use to true up the ends of the axle tubes to fit the stub axles correctly. I have lots of windows in the garage as I like lots of light.
Uhmmm, the lathe has lots of crud all over it. This indicates that I have been doing lots of work.
If it were all cleaned and polished, it would indicate that it's never used or that I dont know how to.
The last photo show a close up of the mounting and how it was held. There were two bolts to hold the angle plate to the cross-slide and two "G" clamps to hold the pipe in its cradle. This was very successful and the pipe never moved. It was raised up 10mm to position the hole at the required distance from the end. The tool post and top slide (aka- Compound Rest) was removed and the angle plate was slid forward to position it fully on the cross-slide. The two bolts that held the angle plate are only 1/4" dia. It is very important that these two bolts are positioned correctly or they can rip the "T" slots out,
None of this work was hard to do, awkward at times -yes, but not hard. The most difficult part of any machining opperation is to figure out how to set the job up and hold it. Having made the angle plate and the cradle/split plates at the begining made the job very easy. The two shorter pieces will now be welded to the main spine. I have already machined the inside of the two longer axle tubes and the inserts can now be welded in place. To machine the longer axle tubes I had to remove everything at the end of the lathe and unbolt the "rack" and move it out as well. As soon as the inserts are welded in place I can machine them to fit the center section and bolt them together. More photos to come. This is indeed a very enjoyable project to do and the journey to the end is very rewarding.
Kody
