I managed to make some progress on assembling the first of my Hobby Holidays hornblock kits tonight. As I wanted to take a photo of the parts in the kit next to an assembled one for future possible use in an article anyway, I thought I’d post the photo on my blog as an illustration. Once all six hornblocks are assembled it will be a little late to photograph the parts.
The miniature ball race is obvious just below the milled brass horn guide. This is retained by a small, fold-up etched component that can be seen at the bottom of the photo. The cheeks of this etched “box” keep the assembly in place and are the part that slide up and down in the milled guide. A 12BA nut is let into the top of the box and soldered into position and this is used to keep the countersunk bolt attached to the box. A spring around the shank of the bolt provides the suspension and thus the movement for the axle and the wheels.
Thus far I’ve found the components to be high quality products. I’ve had to do some fettling of the etched box to get it to slide smoothly in the guide and the nut needed to be filed to size so it would fit in a little “cage” that is formed on the top of the box, however this is par for the course with etched components in my experience. They almost never fit perfectly first time and always need a little adjusting and gentle persuasion. The ball races are sealed and don’t require lubrication according to the instructions, however these also suggest a small dot of oil won’t hurt.
I’ve worked very carefully to ensure that all the parts are scrupulously clean as I’ve assembled them, especially in the areas where I’ve used an acid flux. I can only imagine what will become of the steel ball races if there is any acid residue left in the vicinity of these components. I’ve scrubbed all the components multiple times with Jif cream cleanser to ensure the flux is removed prior to any following steps and to allow me to get at areas which won’t be accessible to later. Because Jif is mildly alkaline it has a cleaning action but it also helps to neutralize the acid from the flux. You’ll know you’re keeping things clean enough when all your tools and components don’t go rusty between projects. Don’t ask me how I know this 🙂