Grub screws on NEQ6 worm / motor gear

[nigelbeaumont]

Anybody had problems loosening the grub screws holding the brass motor/worm gear onto the worm? I'm fitting a Rowan Astronomy belt conversion, but it looks like Synta used threadlock to hold these into the gear, and im worrying about stripping the internal Allen key shape in the screw heads. I'm not worried about trashing the brass gear or the bearings (replacing these at the same time), but I don't want to damage the worm itself or the cast aluminium housing. I was thinking about a micro gas torch (cooks torch?) to heat up the brass gear, so that it expands away from the grub screws and breaks the threadlock. I can drill the grub screws out, but that's a last resort. Thoughts / ideas / previous experience?

[Skipper Billy]

The grub screw will most likely be made from high tensile steel - albeit Chinese high tensile steel (read Parmesan cheese hardness!) but it will be significantly harder than what its screwed into.

The trick is heat and a top quality well fitting hex (Allen) key.

A hot air gun - not a hair dryer - will get it hot enough and with a nice even heat to soften the threadlock - then a sharp twist with the key should break the joint.

I wouldn't use the cooks blowtorch - too much heat and too localised. If you haven't got a hot air gun hold the tip of a soldering iron onto the grub screw - it heats it up and softens the threadlock.

Take your time with the heat it takes a while to get the penetration required and you might only get one go at getting it out so be patient!!!!

If it all goes horrible wrong plan B is a selection of cobalt steel drill bits slightly smaller than the grub screw and a slow speed drill !!

[nigelbeaumont]

Sorted after I bought a new Allen key. One grub screw came out with a bit of force, two of them needed the tip of a 50W soldering iron (thanks for the tip, hadn't come across that before), but the last one wouldn't shift at all - had to in the end resorted to driling it out with a 3.5 mm carbide drill from Cromwell Tools