Recently, I converted the last of my track
powered locomotives to battery power (see How I converted my Fowler diesel to battery r/c). Fowler(ish) Loco No. 7, Tollemache, was the first loco which I scratchbuilt and so has particular poignancy for me (see How I constructed an early Fowler diesel locomotive).
During the build, I had a major problem with the layshaft. The only flycranks I could find (from Garden Railway Specialists - GRS), had 8mm offsets but the cranks on Tollemache's drivers had 10mm offsets. I solved the problem at the time by slotting the connecting rod to compensate for the 2mm differences at each end of the rotation.
This, of course, meant the motion was very sloppy which was especially notable when the loco was running at low speed. I don't have any video of this - I wonder why.....?
I searched websites of various suppliers (eg GRS, Essel, Roundhouse, Brandbright) to see if anyone was marketing flycranks with 10mm centres, but to no avail. I considered making my own from brass, but precision metalworking is not one of my strengths. Then, inspirationally, I remembered that I had recently acquired skills in soldering whitemetal (see How I constructed an IP Engineering Plate Frame Simplex). The GRS flycranks were whitemetal.
The head of the crank was excised with a razor saw.
The ends of the two pieces were coated in flux, tinned with low-melt solder and then joined together with a 2.5mm fillet of solder (0.5mm to allow for the width of the saw blade).
The solder was then filed to shape - et voila, one fly crank with 10mm centres!
The slotted connecting rods were discarded and two more connecting rods cut from brass strip. These were then bolted on to the wheels and to the new flycranks which had been quartered and fixed on to the layshaft with cyano gel.
The motion is now a lot smoother and so I am more than happy to video the loco moving slowly while, for example, shunting in the Copper Mine sidings.
During the build, I had a major problem with the layshaft. The only flycranks I could find (from Garden Railway Specialists - GRS), had 8mm offsets but the cranks on Tollemache's drivers had 10mm offsets. I solved the problem at the time by slotting the connecting rod to compensate for the 2mm differences at each end of the rotation.
This, of course, meant the motion was very sloppy which was especially notable when the loco was running at low speed. I don't have any video of this - I wonder why.....?
I searched websites of various suppliers (eg GRS, Essel, Roundhouse, Brandbright) to see if anyone was marketing flycranks with 10mm centres, but to no avail. I considered making my own from brass, but precision metalworking is not one of my strengths. Then, inspirationally, I remembered that I had recently acquired skills in soldering whitemetal (see How I constructed an IP Engineering Plate Frame Simplex). The GRS flycranks were whitemetal.
The head of the crank was excised with a razor saw.
The ends of the two pieces were coated in flux, tinned with low-melt solder and then joined together with a 2.5mm fillet of solder (0.5mm to allow for the width of the saw blade).
The solder was then filed to shape - et voila, one fly crank with 10mm centres!
The slotted connecting rods were discarded and two more connecting rods cut from brass strip. These were then bolted on to the wheels and to the new flycranks which had been quartered and fixed on to the layshaft with cyano gel.
The motion is now a lot smoother and so I am more than happy to video the loco moving slowly while, for example, shunting in the Copper Mine sidings.
4 comments:
Superb. That little loco runs rather well now. You sir , are an excellent model maker.
That's very kind of you. I certainly don't regard myself as excellent, passable would be my adjective of choice, but thanks for the compliment.
Rik
I'm just bingeing these updates, having only recently discovered this site. What strikes me the most is the extraordinary progress that you've made as a modeller, both in terms of confidence and skills. I can't imagine you attempting something like this in one of your early updates, but here you are, describing a process like this as "simple". A testament to dedication and practice!
Many thanks for that feedback and well done for ploughing through my various ramblings and mutterances accumulated over the years. That's kind of you to notice but you have certainly hit the nail on the head. I can well remember my trepidation when constructing my first loco and how I was really struggling with spray painting in those early days. My skills and confidence have certainly improved, but I know I will never become an accomplished modeller. I'm happy with being an adequate or, with some things, competent modeller.
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