Well, it was frozen when I started, that's my claim.
Repairing an accidentally drilled hole in a heating pipe (not by me) is normally a simple operation, not so with a school heating system.
With no valves installed that could be shut down to stop the flow, and a system big enough to fill a small swimming pool if it was drained, the only answer I could think of was to freeze the pipe, but I knew that even that was hazardous in the prevailing conditions in the area, but it was the only way at the time.
Using copious freezing fluid I overcame the latent heat in the area and it froze, normally, this allows about 15 minutes to operate in, but I planned to top up the freezing fluid well before that.
I had prepared the connections before starting, so proceeded to cut the pipes for the work, Having loosely fitted the first joint, I was going to top up the fluid when it defrosted and squirted me with warm water, stuffing my thumb over the pipe I stopped it from running and, one handed, completed the first joint, my loosely assembled other connections was then used to stem the flow of now scalding water, a colleague was with me luckily, but could do little to help as there was no working space.
One end located in place I now had to fit the other end - the live and now scalding end - with a pair of pliers to hold the fittings with to give me some isolation from the heat, I let go my thumb from the pipe and immediately the full force of the scalding water flooded free, at the third attempt I rammed the joint in place, this stemmed the main flow but all joints still squirted a spray of near boiling water at me with the result that my hands are well blanched.
After a series of attempts, eventually all joints were sealed, and are now in service thank goodness. My cuts and bruises will heal and my hands will look a bit more normal eventually, I just hope the stinging stops by bed time.
And so ends another day in the annuls of Captain Capable. (got to go now to wash my Lycra shorts and cape LOL).
Wednesday 9 March 2011
Friday 4 March 2011
Lifting Progress
As some of the members of HWSME already know, I have been occupied in out of club hours work, preparing the parts needed to re-construct the layout lift pulleys, and now, to my relief I can report that the machining of the pulleys, spacers and spindles are now complete.
The method of realigning the axle holes is also determined, as I have proven with the first three examples.
Due to the manufacturing methods adopted by the makers of the original pulleys, the sheaves (or frames of the pulleys) are adequately strong in construction but the axle holes do not align accurately enough to allow our revised design of pulley to locate between the sheave cheeks correctly. to overcome this fault I have adopted a method of drilling and milling to correct this.
It involves three stages of operation, with the sheave firmly gripped in the machine vice of the bench drill, a first stage 6mm drill is used to drill the upper cheek of the sheave, this drill is then replaced with a 6mm end mill and the lower cheek is carefully milled in alignment with the upper cheek, finally, the milling cutter is again replaced, but this time with an 8mm sharp drill and this drills both cheeks to complete the process.
The sheave is then de-burred and the ball bearing pulley and its spacers are assembled in the sheave and the prepared axle passed through the assembly, the 1/2mm projecting axle is then peened over to finally anchor it in place.
This renewed will then painted in the ever popular shade of Magnolia prior to being refitted to the lift mechanism to match the existing metal building frame, I intend this colouring match to spread to the exposed underparts of the layout to make the layout to blend in with the existing colour scheme and hopefully make the hanging layout less intimidating to both members and visitors alike.
During the revision work of the layout, the existing pulleys will have to have their pulley wheels removed, the sheave drilling operation performed and re-assembly with the new parts completed, then finally painted before re-use, so my preparative work should save time during the major operation of adding new lift positions (there will be eight, at present there are six) to equalise the support during lifting, this has become necessary due to the increased weight encountered by extensions to the extended surface area of the present layout.
This weight increase has nothing to do with eating habits, but is more to do with carrying unexpected luggage, all the rolling stock is now left on the layout and the extra support timbers to fix the extensions,, together with the scenic features permanently attached, has increased the overall weight threefold from the original, at the last weigh in it was 600 lbs.
I shall be weighing it again during the refurbishment work and I hope it is still within the designed lifting capability of the hard pressed hoist mechanism in its present configuration, if it is close, further provisions to carry the extra weight will have to be introduced, (another loop of lifting cable to reduce the pull to a quarter of the total weight, at present it is one third)
My fears are for the hoist motor, gears and brake, the pulleys and cabling are well within their capability but stepping over the designated capacity of the hoist is asking for trouble, and none of us want that, least of all, me !
The method of realigning the axle holes is also determined, as I have proven with the first three examples.
Due to the manufacturing methods adopted by the makers of the original pulleys, the sheaves (or frames of the pulleys) are adequately strong in construction but the axle holes do not align accurately enough to allow our revised design of pulley to locate between the sheave cheeks correctly. to overcome this fault I have adopted a method of drilling and milling to correct this.
It involves three stages of operation, with the sheave firmly gripped in the machine vice of the bench drill, a first stage 6mm drill is used to drill the upper cheek of the sheave, this drill is then replaced with a 6mm end mill and the lower cheek is carefully milled in alignment with the upper cheek, finally, the milling cutter is again replaced, but this time with an 8mm sharp drill and this drills both cheeks to complete the process.
The sheave is then de-burred and the ball bearing pulley and its spacers are assembled in the sheave and the prepared axle passed through the assembly, the 1/2mm projecting axle is then peened over to finally anchor it in place.
This renewed will then painted in the ever popular shade of Magnolia prior to being refitted to the lift mechanism to match the existing metal building frame, I intend this colouring match to spread to the exposed underparts of the layout to make the layout to blend in with the existing colour scheme and hopefully make the hanging layout less intimidating to both members and visitors alike.
During the revision work of the layout, the existing pulleys will have to have their pulley wheels removed, the sheave drilling operation performed and re-assembly with the new parts completed, then finally painted before re-use, so my preparative work should save time during the major operation of adding new lift positions (there will be eight, at present there are six) to equalise the support during lifting, this has become necessary due to the increased weight encountered by extensions to the extended surface area of the present layout.
This weight increase has nothing to do with eating habits, but is more to do with carrying unexpected luggage, all the rolling stock is now left on the layout and the extra support timbers to fix the extensions,, together with the scenic features permanently attached, has increased the overall weight threefold from the original, at the last weigh in it was 600 lbs.
I shall be weighing it again during the refurbishment work and I hope it is still within the designed lifting capability of the hard pressed hoist mechanism in its present configuration, if it is close, further provisions to carry the extra weight will have to be introduced, (another loop of lifting cable to reduce the pull to a quarter of the total weight, at present it is one third)
My fears are for the hoist motor, gears and brake, the pulleys and cabling are well within their capability but stepping over the designated capacity of the hoist is asking for trouble, and none of us want that, least of all, me !
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