The tiny shop has languished for a long time while I worked on many other projects and chores over the last couple years. But longing once again to build engines, I've cleaned shop and moved the new lathe to where I can work on it again and got ready to finish the tailstock ram. It needs a slot, clamping cam pieces, thrust bearing, and handwheel. Slot was next on the agenda.
Things were eventually reasonable again after much mischief from mice, condensation and time. Unnecessary stored items were moved out, the floor swept. I oiled cleaned and lubricated the lathe ways, removed some surface rust from the 3 jaw chuck. Then I hooked up the lathe's DC motor controller, removing the XL timing belt from the headstock, and gave it a spin. Unfortunately the controller, a Cycletrol 150 (manual attached) had suffered, and though it spun the DC treadmill motor and responded to the potentiometer to increase speed, it didn't act right. I couldn't slow the motor very much -- minimum speed was too high, and it ran inconsistently, sending odd momentary pulsed jerks to the motor while running
I thought maybe the problem might be that the potentiometer had become noisy. I rewired with new wire, and soldered connections (I had used alligator clip jumpers for testing in the past) and tested the pot with an ohmeter. But it seemed okay, and nothing I did made a difference. BTW it always seemed odd that the only pot that worked was a 1 megohm resistance, when the manual called for 50K ohms, but that's the only way it worked in the past.
There are also three trim pots on the controller's circuit board one for min speed one for max speed, and one for max current. Adjustments to these three still did not solve the problems.
Since I was pretty much at the limit of my circuit solving capabilities here, the tailstock ram slotting has been put on hold.