Table of Contents
Tull LT-16J (Small pillar drill)
- Adjusting the belt tension and changing the speed is done with the big nut and bolt on the right side, which allows the motor to pivot. Video on changing the speed
Maintenance log
- 22 Sept 2020 - Belts fitted, drill works
- 14 Sept 2020 - Motor replaced. It was slightly taller and box around the belt didn't allow it to pivot enough to tension the belts - the hole in the box for the motor was enlarged and slightly shorter belts were ordered
- 4 Sept 2020 - Tull drill press motor started smoking after a piece of metal fell inside (speculation) when cleaning the top box
- before 2020 - No voltage release (NVR) switch fell apart, replaced with commonly available NVR from ebay
Union PD2 by Boxford (Large Blue pillar drill)
- If you oil the stand of the blue pillar drill with PTFE lubricant, the table becomes much easier to move up and down
- Blue drill has an integrated thermal overload relay which is supposed to cut out above 2 Amps when overloaded
Maintenance log
- 1 Apr 2025 - Contactor fixed
- One of the contacts on the contactor had a bad connection and discoloration from high temperature.
- Sanded away the soot from the arcing using fine sandpaper to reveal the clean metal underneath.
- The other issue was the solenoid of the contactor having enough force to stay closed, but not close by itself. This is probably due to the capacitors that are in series with the solenoid coil and being used as a capacitive voltage divider. With age, their ESR increases (I think?) and the voltage across the coil decreases. Measured voltage was 56V. I did not have the right capacitors on hand, so I decreased the distance the switch has to travel by putting in some shims, which decreases the necessary voltage to close the switch.
- The next time it breaks, either replace the capacitors for the solenoid (and full bridge rectifier to be sure), or get a complete new NVR contactor assembly, as you may not be able to sand the contacts on the contactor more, since it would reveal the bare copper instead of the contact material (zinc coating?).
- Mar 2025 - Drill only turns on sometimes when Start button is pressed
- 28 Sept 2020 - Union drill fixed. The a coil on one of the poles of the thermal overload relay integrated into the NVR contactor melted. Fix was to replace it with the coil from the unused pole of 3 phase contactor.
- 13 Sept 2020 - Union drill reported broken
- (couple years ago, 2017?) Union pillar drill hacked to work with 230V single phase instead of 400V three phase.
- “Costa and I fitted it with a DC supply for the contactor's latching electromagnet via a mains capacitor drop so it would work off a 240V supply after the motor was replaced (it wouldn't latch when fed with 240V AC). The motor supply is switched by one of the contactor's three sets of fingers. IIRC the required DC voltage to the electromagnet to get it to latch was about 60V – much more and it would overheat.” - Rob Sneddon