September 29, 201411 yr Author Thanks alan That actually helps a great deal.... ive been thinking of making the clearance about 0.3mm so the info you gave me confirms what i thought it should be. now for the machining..... just about finished hollowing out the billet , just have ti cut the flat , OD and tool holder.... will post pics when done... oh , and some video..
September 29, 201411 yr My measurements may be a bit off and 0.3mm sounds a lot better than 2.5mm! Alan
September 29, 201411 yr I know you are well along the way now, but did you consider getting the tup metal sprayed and then machining back? I don't know anything about the process but it may have possibilities. Would have saved you a lot off boring work! :) Alan
September 29, 201411 yr Author Yeah , sort of considered it untill i had a llok at it after i clraned it up and saw that the cap at the top had been weld repaired and has a million cracks in it.....
September 29, 201411 yr Fair enough! Three or four years after I had built the new workshop around the 3cwt, we were forging away and started hearing an extra knock, found the wedge loose so tightened it up, after a couple of blows the knock was back and the wedge was loose again, huh? I had a look and discovered the front dovetail lump on the tup was cracking off…aaagh! Couldn't face dismantling the workshop to put in a different hammer…but when I looked a bit closer I could see that it was a weld that was opening up…Huge relief, if it could work for at least three years with a weld then I could also just repair it now and then. We cleaned it up vee-d it out and TIG welded it with 312 rods and it has been working fine for the last 16 years or so. The only other problem I had was the cylinder head cracking, and we machined one up out of a bit of 3" plate… The only other problem I had (this is the third now in 20 years of use of a 60-90 year old machine!) was that my assistant assiduously greased the motor bearings too often and the grease got into the windings and I had to have it rewound :( Rubbish reliability really! Alan
December 3, 201411 yr Author ran it for the first time last night..... had a blast... will start some pics and video SOON....
December 3, 201411 yr Im a bit late to the party, but a good rule of thumb for most things power hammery is 0.001" per inch clearance. (bearings, pistons, rams etc !) I cant believe it had worn itself 0.100" clearance on the steel ram and only a few thou in the (much softer) cast iron cylinder. It must have been monkey'd around with by a previous owner, ram from a different machine or something ! Look forward to the vids :)
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