Seadog
Save the planet. It's the only one with rum!
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- 11,448
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- NE London - UK
I received a sickly DTI from @indy4x yesterday so, being at a loose end yesterday, I thought I'd repair it.
It was seized and, on removing the back, it was apparent that the guide pin was also missing.
The brass block on the right is slotted and the guide pin, which is screwed into the spindle, runs in the slot. this keeps the rack parallel to the pinion.
After stripping further it was possible to twist the spindle out after clamping it in the bench drill chuck. It was just a bit of light corrosion of the top bush locking it up.
The pin was not only missing, it had been snapped off, leaving a short section to somehow remove The thread, by the way, is 10BA so the thread root is about 1.4mm.
The piece was only about a third of the way in so there was plenty of hole at the back to guide a drill. This I tried with a nice sharp number 54 drill , but no go, it just about marked the end, obviously hardened I thought.
After lots of head scratching and after sleeping on it, I decided that the only way, short of buying a carbide drill (too expensive by far), was to try to clamp the threaded piece so that it could be unscrewed. This I was going to do using the bench drill as a press, and pinning the piece between a sharp centre punch and a hardened piece of tool steel with some serrations ground into the end.
I made said piece and hardened it and then set about centring the pillar drill over a centre punch.
Now, I own a lovely old Progress 2 which has a dog clutch for the hi/lo range change. You need to remember to rotate the chuck anti-clockwise before switching on the prevent the inevitable clonk when you start it, at least you do if you want the thing to last.
Switched it on to centre the wiggler and there was a clonk, strange I thought. Anyway, lined up the centre punch and was just about to have a go at clamping the spindle when the thought occurred to me that the damned thing must be running in reverse I reversed it a few weeks ago for some reason I can no longer recall and had forgotten to change it back. It's a lash up at the moment with a VFD with no pendant so had to do this through the control panel.
OK, let's try and drill it again. Of course it went in nicely, grabbed the broken stub and wound it out
Time to make a new pin. A piece of 4mm silver steel was chucked up and I proceeded to turn it down to 0.669," which was fun and managed to thread it without any problems.
Finished article with cotton bud for scale (a mug was just too large).
End of Part One.
It was seized and, on removing the back, it was apparent that the guide pin was also missing.
The brass block on the right is slotted and the guide pin, which is screwed into the spindle, runs in the slot. this keeps the rack parallel to the pinion.
After stripping further it was possible to twist the spindle out after clamping it in the bench drill chuck. It was just a bit of light corrosion of the top bush locking it up.
The pin was not only missing, it had been snapped off, leaving a short section to somehow remove The thread, by the way, is 10BA so the thread root is about 1.4mm.
The piece was only about a third of the way in so there was plenty of hole at the back to guide a drill. This I tried with a nice sharp number 54 drill , but no go, it just about marked the end, obviously hardened I thought.
After lots of head scratching and after sleeping on it, I decided that the only way, short of buying a carbide drill (too expensive by far), was to try to clamp the threaded piece so that it could be unscrewed. This I was going to do using the bench drill as a press, and pinning the piece between a sharp centre punch and a hardened piece of tool steel with some serrations ground into the end.
I made said piece and hardened it and then set about centring the pillar drill over a centre punch.
Now, I own a lovely old Progress 2 which has a dog clutch for the hi/lo range change. You need to remember to rotate the chuck anti-clockwise before switching on the prevent the inevitable clonk when you start it, at least you do if you want the thing to last.
Switched it on to centre the wiggler and there was a clonk, strange I thought. Anyway, lined up the centre punch and was just about to have a go at clamping the spindle when the thought occurred to me that the damned thing must be running in reverse I reversed it a few weeks ago for some reason I can no longer recall and had forgotten to change it back. It's a lash up at the moment with a VFD with no pendant so had to do this through the control panel.
OK, let's try and drill it again. Of course it went in nicely, grabbed the broken stub and wound it out
Time to make a new pin. A piece of 4mm silver steel was chucked up and I proceeded to turn it down to 0.669," which was fun and managed to thread it without any problems.
Finished article with cotton bud for scale (a mug was just too large).
End of Part One.