Vice that went >PING<

I have NEARLY finished my quick-release tangential toolholder. It works, but I needed to finish the angled seat for the head of the securing screw. Tightening up my angle vice there was that dull thud (rather than a ping) we all dread.

I had apparently overtightened it and the slide part pulled right off the fixed jaw.

A close inspection revealed the mother of all blowholes right in the corner where the stress is greatest - it even come through into the hole for the pivot. You can see its reduced the metal to a tube.

It's one of those cheap tilting vices with two side plates that everyone sells for £15-£20, and I can't remember who I bought it from.

Funilly enough, when I took the pivot out the moving part was a really good fit in the base, and all the functional flat surfaces seem to be ground accurately to a decent (if not miorror) finish. Shame it was made out of honeycomb iron.

They are only £16 in Machine Mart so I might pick one up on the way home from work tomorrow so I can finish the job. The old one can become a simple sine table, perhaps?

Neil

<edit> I quite like the idea of having an Angel's seat - they can rest there when they finish pinhead-dancing, but I think I meant an angled one!

Edited By Stub Mandrel on 24/02/2013 19:08:32

Another quality product bites the dust. LOL Why not try a slightly better quality vice, one you can rely on? I will leave it up to others to provide recommendations.

Tony

from where have you got the drawing to the tolholder?

from where have you got the drawing to the tolholder?

Not only cheap products of cast iron will break the casting error. A close friend of mine worked for Sabb Motor A / S (marine engine factory in Bergen) told me ... he had problems with balancing the flywheel when he drilled the balancing holes in the flywheel to get the correct balance. The flywheel was hollow inside cause of casting defects.

Edited By Jens Eirik Skogstad on 24/02/2013 20:20:32

Hi Skarven,

I sketched out a possible arrangement on p.55 of MEW 198. The actual thing has turned out a bit different. It needs a tidy up but here's a couple of pictures that may help you. I've increased the front and side rake to 10 degrees, so the top surface needs to be ground more acutely. I also made it jut out less and filed a nice curve to give better visibility. It still needs the screw shortening and a height adjuster adding.

I used flash - which exaggerated the finish on the test piece (free cutting stainless). It is actually quite fine although I didn't do anything to 'blunt' the square corner of the HSS for this test, but it looks awful in the picture! The tip of the tool needs slightly rounding for a really good finish.

Tony - I don't have a need for a top-notch tilting vice, it's just a convenience for things like steam passages and the odd angled surface. If I was making a 'Hydra' it might be different, but if I bought an expensive vice I would be better off with a new rotating vice, as a tilting one just wastes headroom..

Neil

Edited By Stub Mandrel on 24/02/2013 21:14:29

Tony,

I ended up taking your advice. Although the MM vice looked superficially identical, the finish of the machined surfaces was really poor

Neil