I took the bolster wagon along to Embsay last weekend and made a start on Friday morning before it got busy. In no time at all I managed to get a pair of axle guards soldered to each body and then added bearings and axles in preparation for adding the other two axle guards on each wagon and getting them up on their wheels.
This is where it all went pear shaped. I had previously tried the bearings in the holes in the castings to ensure that they seat far enough in. What I had failed to notice is that the bearing holes in the castings are not at right angles to the rear face of the axle guards they have been cast at an angle.
It was at this point that I also realised that I didn't have 2.0mm drill bit with me to attempt to straighten out the holes. So I ended up putting these aside and working on something else for the rest of the weekend.
Last Monday I had the thought that if I could find one a 2.5mm burr, might be better to straighten out the hole than a normal drill bit. I did a search and found a set with what I needed on Amazon
Now they were only £8 for the set so probably not that hard wearing but I figured that if I only ever use them on whitemetal or brass they should be fine.
My next problem, was that the the drill chuck hit the wagon body, long before the burr reached the workpiece, so I had a choice. I could either remove the axle guards that I had fitted and then drill them out, or I could make an extension arbor to allow the burr to reach the hole without the chuck hitting the wagon body.
I chose the latter as being easiest for me.
Using a piece of 6mm steel rod recovered from a toner cartridge (my mini pillar drill chuck only opens to 6.5mm) I drilled out the end 3.25mm to take the burr and then cross drilled and tapped M3 to take a couple of grubs screws to retain the burr in the arbor.
Because the axle guard castings have a retaining strap across the bottom, they don't sit flat in the open vice jaws when laid face down. So I cut a couple of coffee stirrer type strips and double sided taped them to the jaws at one end of my vice.
Then using a couple of offcuts of steel as supports I was able to get the axle guards to sit level and use the extended burr to re-drill out the holes to allow the bearings to sit straight. I also used the Proxxon's depth stop to drill the bearing holes a little deeper without breaking out of the fronts of the axleboxes.
I didn't do any sophisticated clamping, I just held the axle guard down with one hand, while operating the drill with the other.
All the axle guards are now drilled out correctly and ready for the other side to be fitted. I can't decide whether to do it now or wait until Thirsk show at the end of this month.
I made a second slightly more modern version.
