Testing the New Treadle Lathe Drive Shaft
After playing around with different lengths of steel to fix the eccentricity in my treadle lathe headstock, I decided to do things right and I bought a length of actual drive shaft from McMaster Carr. This is hardened steel that is precision ground for straightness. The irony is if was only a few bucks a foot more than the cold rolled, generic stuff I was using prior and if I had bought the right stuff originally I probably would have actually saved money. Installation went well as I now could break down and reassemble this lathe blind folded after all the work I have put into it. And as I have mentioned in several previous posts, all is running smoothly now.
So with about 30 minutes of free time last night I decided to put the new drive shaft to the test and turn something that requires an absolutely true running spindle: a pen. Pens are wonderful because they are so simple to make yet pack a big punch and make any woodworker look skilled. But you are still turning your wooden blank down to match a precisely machined bearing so any eccentricity in the motion will be very evident in the finished product.
I bought a screw on pen mandrel a few weeks back that would fit onto my 1×8 tpi headstock center and once I had drilled out the blank and inserted the brass tube (all on the lathe by the way) I loaded up the mandrel and started treadling away. I have turned thousands and thousands of pens and this was the first one I had turned on my treadle lathe. Usually I can complete a pen from start to finish in about 15 minutes. I’m happy to say that I did this pen in about 20 minutes and it is indistinguishable from any that I have made on my electric Jet lathe. Everything matched up perfectly with the bearings so I’m calling this new drive shaft a success. I’m really glad I chose to go with a threaded headstock so that I can use modern attachments like this mandrel and my faceplates and chucks. The added benefit to all of this testing and retesting is that I’m burning calories along the way and the turning just keeps getting easier. It could be the fine tuning I have done to the lathe, but I’m going to choose to believe it is the fine tuning I am doing to my legs.
Oh yeah and using highly figured, kiln dried, hardwood worked perfectly. I even made a tool handle out of kiln dried curly Maple on my pole lathe recently so while I think green wood will turn easier, don’t make the mistake of thinking you have to have it if you choose to use a foot powered lathe.