Glad to see I was on the same track as you with my thinking today. Should have thought about it sooner, but I guess I have been a bit too busy thinking about how to get this mostly done before my upcoming surgery.You're driving a tapered thread into a cylindrical hole, so of course it gets harder as you go along. One thing that might help is to use a pipe reamer to remove some of the excess material at the large end. There are also interrupted thread pipe taps that basically have every other tooth removed to cut down on the friction. They're pretty pricey; it might work to grind off every other tooth to make your own.
A few steps forward and a few steps sideways is the summery of today.
I went down to our local hardware store, (Hardware Sales) and bought a better quality pipe tap, and a Large Tap wrench that will fit the pipe taps. My nice Starrett ones dont go that bid and a Starrett one is like $250+ Dont want to do that for a one of job. I put some pipe on the ends of the top handles and managed to get 5 threads fully cut, but still not enough. I clearly need to ream the hole with the correct tapper. My experience with pipe reamers is to debure the ends of pipe to prevent cavitation, and my large Rigid Pipe reamer wont work for this.
I need a pipe reamer for cutting the internal tapper. Unfortunately, McMaster is out of stock, but I did find some on Ebay that look to be of decent quality for $25. Hopefully it gets here in time before I have my hand surgery next week.
It was way to smokey do to all of the forest fires here to work outside on sanding the drive end castings, let alone to paint. Not to mention my son woke up at 5 am puking with a stomach bug, so I got to spend most of the day on vomit patrol. I did however pick up two 16 drawer lists cabinets at an auction that I will have to pick up next Monday. I desperately needed the storage, but my wife is going to kill me when she sees what I paid for them.
Needing to get some space cleared in the shop, so that I can reconfigure it for the new Lista's I need to start to get as much back on the lathe as I can. So back to working on the access panels.
The knobs for the access panels are held together with #1 tapper pins. To align the holes, I used a flashlight to backlight them to make it easier to see when they are properly configured. Since all of different I spent a bit of time sorting them all out, and then once they where matched up I reamed them with a #1 tapper pin reamer to clean up the bores. Its worth noting the cams are all the same, but the hole is drilled at a different height on it depending on the panel. The front panel has the holes the lowest on the shaft, and the rear its the highest. This accounts for the difference in thickness in the base castings for each of those locations.
Tail stock end access panel is on, with the custom made accent pieces I made for it. I think this lathe is going to look pretty damn sharp when its done. Its nice to get a bit of a tease.
The rear panel has two bent holes but Monarch has a second dummy trim and screen piece on there for "looks" I'm surprised they did that during the war, especially in the back of the machine.
The internal vent bracket gets screwed on with two countersink screws. I purposely left it the same original color the lathe was along with the DC control panel... bit of a homeage to the lathes original color.
The two stainless screens get held in place by their covers on the rear. I replaced the screws with new Oval head Stainless ones. Looks pretty good.