I've managed a couple of hours in the workshop this week. I've realised that the current situation is nice in that I can move to something else once I get bored of a particular task and go back to it later; but also frustrating in that nothing is complete. Obviously getting the chassis ready to powdercoat is the big task, but I reckon that is about 6-weeks off given the current rate of progress. I'm therefore going to try to get the axle finished along with the front uprights in the mean time - mostly by farming some blasting and painting work out.
Anyway, I did say that the upper engine mounts were progressing. The blurry photo below provides some evidence. If you squint a bit.
If you look really closely you'll see several new tubes, and a couple of tabs, all of which have been shown in previous posts. In addition, there are four threaded top-hat bushes waiting to be tig-welded into place.
I've also done some work on the roll-cage mounts. The rear mounting plates are pretty conventional. In mounting these I've discovered the benefit of decent drill-bits. Having become frustrated by the amount of time that it was taking a couple of 10mm Erbauer drills to cut through what is admittedly some very thick plate, I visited my local tool shop and spent £10 on a single drill bit. I can't recall the brand (helpful eh?) but it made an enormous difference. Lesson learnt: Avoid cheap shit from Tool Station.
The mounts for the front hoop have required a fair amount more thought. The chassis wasn't really designed to take a front hoop so I've had to weigh-up various possible mounting points. As I believe I've mentioned before, the cage needs to be removable to allow the bodywork to be fitted so this has added further complications. I came-up with a final plan when lying on a sun lounger in Majorca - proof that the project is frequently on my mind! I'm actually really happy with the solution that I've come-up with.
The L-shaped section has been folded, welded and drilled to my design, albeit a flawed design as I'd read an angle straight off my inclinometer without realising that it was the difference between the displayed value and 180degrees that I really needed. Thankfully Joe, who was making the parts, spotted the error. The folded L-Shaped part sits atop a simple folded plate designed to help spread any load put through the front legs of the cage. I think of it as a 'striker plate' which bridges over the welded join. At the side of the tube beneath the L-shape, turned top-hats like those in the foreground will be welded in place to avoid tube crush and generally help to provide strength. The difficulty in fitting this lot is getting everything nicely lined-up for drilling. I'm a third of the way through the first side. Even with one makeshift bolt in place it feels pretty sturdy however. The front hoop will be cut in such a way that it can be welded to both legs of the L-shape.
One purchase to arrive this week was the gear that will sit between the prop-adaptor and propshaft as part of the reverse mechanism. This, it has to be said, is a real case of 'Me Too Engineering.' I've blatantly copied what Dan Bromilow has done, albeit I'm planning to use a pre-engaged starter motor to act upon this gear, rather like Austen Greenway has done. The only problem with this is that the pre-engaged starter is bulkier than Dan's Fireblade starter, meaning that I can't get the standard starter gear onto the prop-gear without the body of the starter clashing with the propshaft. The proposed solution, in fact the route I'm taking, is to replace the starter-motor gear with a larger diameter one. This is a little easier said than done - I've already chopped bits off the starter motor with a hacksaw and the Dremmel. I'll no doubt return to this in due course - I need to get the engine mounts finished before I can determine how big the smaller gear needs to be. Incidentally, my prop-gear is ever so slightly (one tooth) larger than Dan's as I'm trying to keep the torque-relationship as close as is possible to those of proven systems (i.e. Dan's.)
The above photo simply shows the prop flange sat atop the gear sat atop the prop adaptor. The gear now needs to be machined to sandwich neatly between these parts. Yet another job for Dave and his lathe.