Thursday, October 23, 2014
I looked at a few forge ideas on the web. They all seemed to have a deep fire pot filled with coke. I thought it might be worth scribbling my idea for the forge down here. I didn't see the point in having all that coke burning when the only bit used was up top and I didn't like the idea of burning so much to heat so little.
I had an old circle of 6mm plate, so I drilled that to act as the tuyer, if one can call it that. I welded that plate onto a short length of 120mm diameter pipe cut to a slight angle pointing toward the blower end, then sat the weird kind of top hat shape in the pot over the air pipe and packed the space around the thing with ash. I cut some scraps of fire brick to leave a nice little tapered pit space for coke to burn well insulated and bring the tops level with the barbecue tray.
Fire bricks can then be arranged as needed on the tray (as in the hammer picture) to make different shaped fire areas depending on the work and hold the stack of coke waiting to burn in place where needed. I thought I was going to need a blast of air and was worried my little blower wouldn't cut it, but really the problem is keeping the air flow low enough not to be cooking coke for no reason.
Although smiths are commonly seen working on the tip of a bar, one also needs to work on sections mid bar and on odd shaped pieces too, so flexibility is good and having the fire high up with space around it allows that to happen without having a massive mountain of coke to play around in.
One idea I would incorporate if building again would be a water trough at the front edge with a dipper or wiper squirter pump to cool bar or tongs when they get too hot to be held as well as for quenching work where needed. Between the fire and that I might have a section cut out and covered with course mesh to allow ash to drop down when sweeping out the fire pit, but not course enough to let coke lumps fall through. You can see a selection of buckets under the forge in other photos set to catch ash. Most of the ash can get down the air holes and down through the cinder flap, but a bigger drop zone would be good to have. The cinder flap is just a circle of steel welded to a small bolt head, with the bolt on and the flap in position the nut is welded to the down pipe so the flap can swing out sideways when one is cleaning out.
One advantage of the scaffolding is that the clamps don't have to be tight so the whole thing can be swung out of the way, or into different positions within a given area. I imagine one day I will set up the forge, etc near to the press and make some kind of more permanent arrangement with a hood etc, but this works for now.
I don't have a hood set up yet, but the ceiling is fireproof and there is a big fan set up next to the forge to blow smoke and fumes out the door, so not entirely stupid.
I hope that the changes in the shop tooling and the purchase of the anvil will be factors that give me more leverage in working with iron. I got to the point of assembling one of the grilles today and brought it up to the house for a little relaxed viewing to check for balance issues in a place with a little less clutter.
For a long time I have been scanning the auction sites here for a suitable anvil to replace my little homemade rail track unit. This one caught my eye as it had several little features I liked. There are a couple of little cleats on the heal for bending, the step up to the face from the horn is steep and rounded off, and there is that little rounded flat coming off of the horn, which creates a nice little depression for knocking things out in. The other feature is that the anvil comes with a steel top and an aluminium base, these are bolted together with a rubber pad in between. This makes the unit quite a bit lighter than it would be if it were all steel, and the rubber pad knocks out any ringing. I believe it is a delta future 1 anvil for farriers made in America. I checked prices and I guess I paid the equivalent of the price for a new one in the US. Anyway, I enjoyed polishing it up and hope to enjoy many happy hours with it in the shop. I am considering swapping it on to the newer stump at the back, but having just fitted the swage block into that I am reluctant to chop it down to the proper height and lose that bit of work. Maybe a trip to the dam to pick up a suitable stump when the weather picks up.
I built a little forge to facilitate the ironwork. I had an old hammer head welded to a length of bar for a long time, I played with forging it with the press, but it was hard going with only the torch to heat it. Having got the forge fired up for some grille work I was tempted to use the heat on the hammer head and got it into this shape after a few heats. It started out as a pretty square lump. Hard to believe that the mass of metal is the same in both ends.
I had to redo the hammer a little after taking this picture, the long end was slightly too shapely. It doesn't look as good after adjustment, but it works better. The one by its side is something like the original shape, but slightly smaller. I just let the head cool down on the forge when I had done shaping it to let it anneal, then I heated the face up to non magnetic and dropped it in the slack tub. And the same for the tip of the long end. It seems OK, not quite as hard as the face of the anvil, but the body should still be soft enough to take shocks without thinking about cracking up.
Sunday, October 12, 2014
More scaffolding uses
So, as you will know from the movie 'The great escape' one of the biggest issues in digging is where to put the spoil. Luckily we had no need to maintain secrecy and created our molehill in plain sight. As we have dug out the space under the house we have expanded the field area in terraces out front between us and the river. With the digging in 2013 I needed more stone to hold up the terraces that would be formed with all the spoil, so I built a scaffolding rail system for a little trundle to haul large stones up from the river using the electric winch again.
Sammy did a huge amount of work shifting stones up one by one and also in a bucket suspended from a rope, but I didn't want to break him, so this seemed like a good solution. There was still a lot of work involved in dragging in rocks from further afield as they grew scarce at the railhead, but the vertical shift was achieved by the railway. I had to make some special fitments at the joints to allow the rollers to ride over them smoothly. I think I used six three meter lengths of scaffolding, so the winch wire was at its limit.
The tipping bucket is separate from the carriage, there are a couple of cleats on the front face, a square bar is slotted between them, then the whole bucket is heaved over sideways to dump out the rocks while remaining on the carriage if possible. The little blue rag taped to the rail is there as a marker to show the winch operator down by the stream where to stop.
The actual digging took a while, but I seem to have neglected to take any pictures of the progress in that.
The same system came in useful for building another concrete delivery chute down to the workshop from the road when it came to forming the retaining walls for the new digging.
Friday, October 10, 2014
I had a fairly successful morning working at the forge and using the flypress. When lunchtime came around I took a quick diversion down to the greenhouse dome to check on the sole surviving cucumber plant. For future reference I am interested to see how long it can survive. As I was leaving I noticed these two monsters on the doorframe. The mantis seemed to have the advantage in size and....
also as it turned out moments later, in strategy, she (judging by size and plumpness) was clearly waiting for some sustained movement to properly assess an attack from the side and she seized the opportunity when it came. I suspect this is just general practice, not specifically spider catching behaviour. I saw a similar sized mantis chewing on a large species of bee the other day and she also had the body grasped side on. The scene of the bee struggling despite half of its body having become subsumed by the mantis did actually make me feel a little queezy as I empathised a bit too much with the victim. In this case though I didn't stick around to witness the disappearance of the body, the first spurt of inards from the back of the abdomen of the spider was sufficient to let me know that this might be a PG entertainment I would not be able to erase from memory, so I headed off for my own lunch. The mantis did seem to relish the fluids that emerged and no doubt the nutritional burst will help her see it through to autumn and the ordeal of egg laying.
Wednesday, October 08, 2014
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.
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.
Movingly heavy objects
Some years ago I bought a battered old fly press and built a kind of shed around it. In 2013 I decided to dig the final section of my workshop out from below the house, this involved shovelling about 20 cubic meters of rock and earth and is a separate story, but before digging I wanted to move the press down into the workshop using the slope that I would be digging out. We erected this scaffolding structure to await the arrival of the press body and the large flywheel, which we shifted along the path in front of the house. Then used rollers to get the press body in under the tripod and hoisted it onto a scaffolding pipe slope down to the shop.
This is the view back up the slope showing the structure, we used two sheets of 25mm plywood interchanging them along the way as we lowered the press body down on pipe rollers using an electric winch.
Again the view from below.
Monday, October 06, 2014
I had a go at making tongs to grip the little sections of bar as they were being worked hot. The tongs on the left were made from pieces like those two on the right. They are what is left of a grate I made for the wood stove, the fire eventually ate the central portion and left tapered bars that I kept for later use. The three bars in the middle are marked out ready to be slotted and drifted two have been drawn down slightly in the press, it has sufficient power to do that with the bar cold, which is convenient.