Wednesday, October 08, 2014

More moving

So, after several years of scrabbling about to get in and out from under the press in order to use it I finally decided to make a stand for it. I had some 100mm H beams and 90mm pipe that had been taken off of roadworks on damaged traffic mirrors which allow drivers to see what is coming around a bend. I am sure the bright orange color will be familiar to locals of Japan, especially whoever hit this one and bent it. The press is sitting quietly in the background waiting for its vertical promotion. The stand is on its back doing its impression of the Tommy Cooper 'dead one of those' while I weld in underneath.
Having had a sturdy set of stretchers fitted the stand was de-benched and shunted over to the press area. The press again found itself broken down into its major components. I don't think the beam I am using to sling the chain block from would take the weight of the whole thing without permanent compromise. I did accidentally put the weight of the whole thing on it when trying to lift the fly wheel off, it is a little stubborn and when swivelling it around to loosen it up it caught and the screw action of the press acted to lift the whole thing up until it lost friction with the ground. Interesting.
I knew I was only trying the press out for height on the stand, but I didn't realize at this point that I had slightly snookered myself several months ago when I performed a small surgery on the press screw. I got tired of having several degrees of play in the flywheel motion before the screw engaged, so I poured some molten white metal into the top and hoped for the best. This worked nicely and there is no play at all now, but it also meant that the screw would no longer travel through its full range of motion, I presume this is because the screw had worn slightly at the most used area and the ends are still their original size, I only mention this in case there is someone out there considering a similar procedure. I would suggest measuring things first to check if the screw is true all the way and maybe heating it prior to pouring in your metal so that when it shrinks down on cooling you will have a tiny bit more play. Anyway, this is not a problem for the press, because the range of motion is still fine for work, but it meant that I was left with the screw poking up and there was very little clearance above the press to raise the flywheel onto it. 
I had a rethink, cut a little off of the stand legs and made another attempt to lift the press with the chain block slung high up beside the beam. The sling on the beam slipped its moorings and dropped the whole thing back down after rising a few inches, it was slung properly, but the grips on the wire didn't like the stresses they were under. So I took this harmless accident as a warning and called it a day for that session and let the semi subconscious work on it over night. In the morning I made a U shaped steel strap with holes in the top that would hold a 16mm bolt that rode on top of the beam and clamped the U sides to the beam. This then had a loop of steel welded onto it raising the chain block body to the highest point possible in the space with its main body at the side of the beam. I raised the press a little with this and made some adjustments.

 I observed the degree of twist it was putting into the beam and realised I had over done the length of the hook loop, you can see silver where I have cut off some from the sides so that the chain block body rested snug as near to the beam as it could get. That slight difference greatly reduced the twist. I put a little slab of steel plate in under the bolt to stop that biting into the top of the beam, the cosmetic damage to the wood is from that sling slip I mentioned earlier.
There he is at a much better working height. The whole thing is a bit rough and ready as usual, perhaps one day when I have an immense swathe of free time I might put a dab of paint on it, but for the most part the rest will just be fiddling, making fitments to clamp the press to the stand and making whatever adjustments necessary to make it easier to use. The chair is just in there to indicate scale. The speaker magnets on the right side of the press are really handy for holding the spanners and whatnot for swapping out tooling, they are held up out of the way and it stops them from straying off, which is something that all my tools are prone to.

During my rethinking phase with the press back on the ground I used it to bend some shaped dogs to bolt on the stand at each corner, they stop the press from twisting itself off of its perch. This reactive torque as the press bears down is what you have to consider most when fixing these instruments, the force of the blows is contained within the body of the press, so there is no significant stress beyond the weight of the machine applied to the floor. Obviously, having secured the press to its stand it will now try and twist that as one body, so I will anchor it to the floor using the foot plates attached to bottom of the legs.
On the web I saw a couple of people had retractable wheels on their stand units, and I was going to do the same, but on thinking it over I realised I would be leaving a set of wheels idle for almost their whole lives as the press will hardly ever be moved. I think I will invest in one of those low hand lift trolleys instead, that will serve to move this and whatever other heavy object finds itself in need of spacial readjustment. That and the need to prevent torsion within the framework is the reason for the overkill on the stretchers, I put the H beams on their sides to act as little trays for the most used press tooling and I might put a shelf between them one day. It should be possible to slide the forks of the lift in under the stretchers, lift the thing a smidgen and wheel it away.