Another Feeler FTL 618

[Graham Stabler]

But I did get it off and when I next take it off perhaps I will document it.

This is what the inside of the gearbox looked like:



It looks like the recommended lubricant may have been exchanged for hoisin sauce with a liberal splashing of chips but at least it's not rusty.

After removing the various shafts I found the two gears that were not running well. I did my best to straighten teeth and dress them again. I put the two problem shafts back in the housing to test and well it seemed worse.



So this is the shaft with the worse of the gears after dressing. Everyone I spoke to said "doesn't look too bad", "should get away with that". After two days of prowling and wondering what to do I thought I would go back to dressing to try and improve things. In the mean time at least I had cleaned up the gearbox housing.



I used some marking blue and the other gear to try and work out what material to shift and what to remove etc. I put the two shafts back in and they ran so smoothly and ... then they didn't and then they did. Totally random, what the ...

Well the free-wheeling gears freewheel but of course there is some friction, this causes the output shaft to turn, in some positions of the shaft it would bind, in others it didn't. Ah ha! The shaft is bent.

On to my makeshift metrology area, table saw top, and some parallels plus some magnets to stop it all rolling away. Oh 0.45mm runout at the binding gear. The shaft has a thick section and a thinner length shrink fitted in to it, I think. In either case the bend happened at the shoulder where the gear mounted.

Off with the gears and the dog and into the arbor press.



I ended up using a plunger type gauge to get the travel and protected the shaft from my rough-arsed press with some ali. A few presses and I was running closer to 0.04mm and I left it at that.

Back in the box and the two shafts run sweet as a nut.