Welding fiasco - resolved

Last time round, I "just" had to weld the adaptor to the nose of the 40 taper body. Then it would be done and dusted, job done. However, I stupidly handed the job over to The Stupid Fat Bloke. I mean, what could possibly go wrong etc.

Firstly, there's a large (M14) grub screw inside the centre bore that protects the internals from stray muck and swarf from getting into the bearings etc. It needs to go in before Fat Boy welds the adaptor in place. But hold on, if I do that, I won't be able to drift the output shaft out if I ever need to disassemble it later. Hmm.

At this point, I tried a dry fit of the adaptor and found that it jammed into the end of the taper body - it's a light press fit. But when I forced the issue, it turns out that there's a threaded adaptor I'd missed. It's held in with some for  of thread locking adhesive - heating it up had softened it enough to come free. That was a lucky discovery and actually helps me.

So at this point, The Stupid Fat Bloke took over. Rather than set up the TIG welder, he went for the easy / lazy option of the Lidl / Parkside stick welder. Nice piece of kit for the price (£90?) but these things are rather brutal and lacking in finesse.

The result sort of looked OK superficially but it was deadly quick, so the metal below was doubtless rather brittle afterwards, with questionable penetration. More on this later....

It seemed like a good idea to quickly see if the thing actually fits the spindle before going too far down the road. 

For one thing, these drive dogs will need to be removed before the speeder can be fitted. That's not a problem in terms of function - just like the tang on a Morse taper, they shouldn't be imparting any torque as such. Besides, the actual torque in this instance will be tiny, as we are talking 3-4mm cutters max.

No luck. The drawbar screw bottoms out before the taper is tight. I'm going to need to bore out the central hole so that the drawbar doesn't bind on the bottom of the internal thread.

This 16.5mm drill is exactly what I need. The Drill Doctor thing cleaned up the chipped edges reasonably well:

Done. It's 16.5mm all the way through to the fully threaded portion.

Time to retry it in the spindle. We must be getting close now?

Ooops. The weld snapped - as mentioned before, the stick welding event was very brief and of questionable penetration.

Bollocks - time to move the machinery round and bring Bertha the TIG welder into play. No, I didn't name it - that's how it was known in its previous habitat before I acquired and repaired it.

It needs to go where the black tool cabinet is, so that it can reach the 63A socket you can see on the corner of the wall.

Sorted. 

Now to TIG weld the thing. I won't let The Stupid Fat bloke try his hand at TIG, so will do this myself.

That's better.

Note the obvious difference here. The Thread on most of my tools doesn't start until 9-10mm into the bore. Let's get it in the lathe (again) and rectify that.

That looks better. We must be getting somewhere now, surely? Well, nearly. There's now excessive weld penetration on the inside of the bore, causing the drawbar to foul before it has tightened fully. A bit of action with a carbide burr and an M16 tap and we are (finally?) good.

Cleaning out the thread took its toll on the M16 tap. This was bought as a used tap in an assortment of sizes. It's not going to be much use for tapping new threads now, with half of the teeth missing. I won't throw it out though, as it can be used to clean / chase threads.

Finally, I have a taper body that work with the machine. That was a bit of a marathon but finally I can get back to reassembling the speeder itself in the knowledge that it's likely to actually work....

"All" I have done here is weld an adaptor on the end of a taper toolholder, taking perhaps 2 hours in the process. I'd starve to death if I was doing this for my day job.