3rd design set for the clutch bracket. As we ran out of ColorFabb HT filament it gave me a few more days to consider the design so I’ve revised some angles:
All 3 versions, note the middle one didnt finish printing:
Extra support structures
Clearance for the fluid fill. You can see the layers don’t look very smooth – that’s by design as it makes the print stronger by having thicker layers. For a display piece we’d print with much finer layers that which would look a lot smoother. As this is a functional piece you can’t see it doesn’t matter.
Watch the print!
Ran out of ColorFabb HT with a bit to go on the print unfortunately, however this is a great strength test piece. It’s very strong already with 2/3 of the triangulation structure missing. This part will work in the car, no need to remake in metal.
I may make a few more design tweaks before starting another print. More material is due at the end of the week.
Mike on mad about kit cars brought up a point about pedal / master cylinder angle. The standard placement moves the piston in at an angle which can cause failure – I’m going to check this on the car make sure the master cylinder won’t get damaged.
V2 clutch bracket with room for pipe and holes to bolt to the top of the scuttle.
If this were printable as usable part then I’ve done an extra version with more structure and cleaned up edges – there would probably need to be more material to the front mount point as well:
Updated: going to try a 3D printed one using ColorFabb HT
Added a load of extra structure to strengthen the part were it’s bolted.
The print is sliced like this giving the most strength in the direction the force of pushing the clutch would go through the part.:
The yellow lines are the movement of the print head, the black cylinder is the print head, it’s shown with the top 1/4 left to go, the corrigated stuff is support material – without it gravity can take effect and the runs of plastic can sag. It’s set to print with 100% fill so that it’s as strong as it can be. The prototype had less fill which saves both print time and plastic but is not as strong.
10 hours into the print:
3D model of the clutch bracket prototype made with Autodesk 123D
Printing the object on an Ultimaker 2+
The 3D printed object, which is incredibly accurate:
Clutch master fits on the 3D prototype print without any adjustments needed. The design needs a bit more clearance for the fluid feed pipe and it needs to be extended forward to make use of my second scuttle mount hole. I can probably add more re-enforcement where there is room.
Fits into the car too!
Added a hole for the scuttle mount and tested the spacing for the pedal fit.
A few cm forward of it is the second mount hole so the bracket can be lengthened to make use of it.
Next step is to refine the design and create a metal version.
Since first installing the brakes a spring has been missing off one of the pads which means the passenger side calliper rattles. I decided to switch from the jurid to ATE pads – the ATE’s bite a bit better initally than the jurids – something I’ve found on my daily drivers. Also the ATE pads are OE for E46 / E9x.
A few bits of rust, here under the drivers door:
Chipped off, brushed and some rust remedy:
Sprayed with rollbar and chassis paint, you can see the hole in powder coat but I’d rather this than have the surface rust carry on creeping:
The wing mounts had also started to rust, so took these off while the wheels were off for the pad change. Also cleaned up any chips in the powder coat on the front suspension:
Refreshed with new nuts and bolts:
3D part has also finished printing, need to how this fits:
The clutch slave failed – not sure why, perhapse the master cylinder was pushing too much fluid into it. The reason is not so important, I’ve decided to use the BMW master cylinder as this will be matched to the slave. Unfortunatly the original design for the clutch attachment is very poor – the whole pedal box twists.
Therefore I’ve started protyping a new bracket design that will be a strong mount for the master cylinder with a bracket the bolts up through the top of the scuttle – already re-enforced for the pervious alternative clutch arrangment.
I’ll 3D print this bracket for test fitting and if it works OK I’ll try to recreate this in aluminum.
A couple more hours:
Fix the jump leads – no continuity = useless jump leads. The copper was crimped and cut straight through at the factory. Trimmed and now soldered – much better.
Inside the rocker cover still looking very clean. Adjusted all the valve gaps to 0.25mm, glad there are only 12 valves to do! Most needed a little tweak. Also gave the oil spray bar a good clean out with brake cleaner while the cover was off.
The rocker gasket was a bit very second hand, luckily a local parts shop had one in stock.
New oil – fully synthetic ester
Managed to avoid spilling anything on the ground for a change!
Being able to take the side off the engine bay really makes filter swaps easy!
Also done is 6 new spark plugs (they’re pretty cheap so why not!)
Found a minor vacuum leak so the idle is much better now.
The current clutch slave is about to pop, the mechanism for moving the clutch in and out appear to be overly stressing the hydraulic components.
As I’ll need to take the gearbox off anyway so it seemed like a good time for an upgrade. Apparently the ZF 6 speed from the E46 320d is a straight fit and as a bonus the same angle as the M20, it’s also a more solidly built and younger than the getrag that’s in there now. Only down side is that I might need a different final drive ratio to make full use of the new ratios.
One eBay special later:
But the shift linkage at the top was smashed in transit 🙁
So decided to try and fit it using HTS 2000 brazing rods. I tired this with propane but it wasn’t hot enough. I instead got a can MAPP gas and a new burner from B&Q:
Braced with a bolt and a custom cut piece of rod
Seems pretty solid, will see how long it lasts!
Bonnet (hood!) off in Roadkill tradition, but to change the battery, not overheating 😉
The old bosch has taken too much abuse over the years and doesn’t hold it’s charge that long even after conditioning on the CTEK charger.
Pulled the battery out, gave this area a bit of clean. Ther rubber disks are actully old bump stops with the tabs cut off. Gives a sold yet slighly squishy place for the battery to rest against.
New battery is an Optima Yellow Top R 3,7 D35 deep cycle. It’s a little bit smaller than the old battery. CCA is 660. The terminals clear the battery which makes it much easier to put charge clamps on them.
Don’t forget to change your charger setting to ‘AGM’ if you don’t there’s a risk of overcharging – which will end up venting water than you can’t put back in.
Cold start and luke warm start: