adrian
Flying Squad
Earlier in the year I stumbled across a neat little live steam engine on YouTube. I posted the relevant video earlier in the year but will repeat it again here to start this thread. As my 3F build is nearing completion I thought I'd have a go at making one of these as a little Christmas/New Year project.
I emailed Les Proper for a set of plans earlier in the year and have been slowly accumulating some of the material for the build. The dimensioning on the plans is a little unusual to what I would normally expect from an engineering drawing. You can work out the required dimensions but the formating is not what I would call conventional. Also everything is dimensioned in decimal imperial, so you have dimensions like 0.68", 0.22", 0.3" etc. I ended up using the dimensions as a guide.
So today I made a start deciding to tackle the crank axle first. For reasons that will become apparent later on the axle is made from 2mm dia. silver steel. I then got a short length of 3/8" steel bar and using a centre drill spotted the centre. Before drilling the centre hole I marked out the 1/8" radius circle for the "big end". The centre 2mm hole was drilled in the lathe. The bar was then transferred to the pillar drill for drilling the offset hole for the crank. The bar was then returned to the lathe for parting off the two disks.
This was then assembled for silver soldering, using some soft iron binding wire to hold it together.
Having seen others use silver solder paste I was keen to try it on this job. I tried it on a test piece with some pieces of nickel-silver sheet and it worked fine so I gave it a go.
Unfortunately it didn't work out that well, I'm not sure what went wrong but the solder didn't really flash across the joint as I expected it too but rather just ended up as blobs around the work piece. So everything was taken apart as none of the joints worked and cleaned up. For the second attempt I went back to my silversmithing technique of easyflow flux and small pallions of silver solder. This worked better as the solder flowed into the joints as expected but somewhere along the route the discs twisted such that the crank pin wasn't aligned along the main axle.
So attempt number 3 involved making the crankpin much longer so when I wired it together I could check everything was parallel.
Once I'd silver soldered together the extended crankpin was cut to length and the discs were tidied up in the lathe before finally cutting out the centre part of the axle.
So the next stage is making up the base plate and support pillars.
I emailed Les Proper for a set of plans earlier in the year and have been slowly accumulating some of the material for the build. The dimensioning on the plans is a little unusual to what I would normally expect from an engineering drawing. You can work out the required dimensions but the formating is not what I would call conventional. Also everything is dimensioned in decimal imperial, so you have dimensions like 0.68", 0.22", 0.3" etc. I ended up using the dimensions as a guide.
So today I made a start deciding to tackle the crank axle first. For reasons that will become apparent later on the axle is made from 2mm dia. silver steel. I then got a short length of 3/8" steel bar and using a centre drill spotted the centre. Before drilling the centre hole I marked out the 1/8" radius circle for the "big end". The centre 2mm hole was drilled in the lathe. The bar was then transferred to the pillar drill for drilling the offset hole for the crank. The bar was then returned to the lathe for parting off the two disks.
This was then assembled for silver soldering, using some soft iron binding wire to hold it together.
Having seen others use silver solder paste I was keen to try it on this job. I tried it on a test piece with some pieces of nickel-silver sheet and it worked fine so I gave it a go.
Unfortunately it didn't work out that well, I'm not sure what went wrong but the solder didn't really flash across the joint as I expected it too but rather just ended up as blobs around the work piece. So everything was taken apart as none of the joints worked and cleaned up. For the second attempt I went back to my silversmithing technique of easyflow flux and small pallions of silver solder. This worked better as the solder flowed into the joints as expected but somewhere along the route the discs twisted such that the crank pin wasn't aligned along the main axle.
So attempt number 3 involved making the crankpin much longer so when I wired it together I could check everything was parallel.
Once I'd silver soldered together the extended crankpin was cut to length and the discs were tidied up in the lathe before finally cutting out the centre part of the axle.
So the next stage is making up the base plate and support pillars.