Turned a suitable bushing on the lathe for the clutch to pivot around on to the pedal:
Assemebled and in place, the 3d printed part feels very solid. First time I bolted up the pipe to the front the banjo joint didn’t seal up enough – lots of fluid everywhere… added an extra washer and it’s all good now:
The clutch is now quite similar to how it was originally, but without lots of movement of the master cylinder. It’s now much nicer to drive again.
Engine service has made a big difference, it’s a lot smoother and quieter again now. Setting the valve clearances as reduced the M20 rattle by quite a lot.
I can also recommend the ATE pads, they bite much better than the jurid ones that were on there.
It was also a good opportunity to re-glue a lot of carpet in the footwell where the spray mount glue had failed over the years.
A few minor things need doing before the MOT – one ball joints rubber cover is rotting away and the upper control arms need some extra large washers adding on the inside – there’s a bit of movement on the drivers side.
I had help today – nothing like being upside down with your feet in the air in the foot well with a cat wandering over you:
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.
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.
The new clutch system is now installed. The master cylinder has more than enough capacity to dis-engage the clutch without pushing it all the way down. The pedal position can be adjusted with the thread on the master cylinder so we’ve moved the clutch inline with the brake pedal. Due to the different leverage on the clutch it is now very easy to use. Only time will tell if all the problems are solve once we can go further than the end of the drive!
Constructing the scuttle panel re-enforcement plate
Heating along the cut to bend the 3mm steel.
Re-enforcing the pedal box
The metal is welded on in various places to strengthen the pedal box.
Welding complete on the pedal box
Scuttle re-enforcement plate painted and bolted in place, it bolts on to the bar than runs from one side of the car to the other. There is no flex at all when the clutch is operated now.
Pedal box and new clutch assembly reinstalled in the car.
Connected up the clutch this evening, the bite point is right at the bottom of the pedal travel, but is really controllable. It means the clutch will sit higher up that the brake at the moment so we’ll have to see how it goes. The whole scuttle bends all over the place so reinforcement is required now.
And finally warm weather – well not freezing anyway :o)