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Showing posts from December, 2020

Instrument cluster and CAN Bus

 The car has quite a simple instrument cluster, and a single CAN Bus network.  The instrument cluster is mostly simple signals but a few are required to keep it happy. The cluster has a dynamic oil pressure warning, meaning that over ~800rpm the oil pressure pin needs pulling to ground otherwise the cluster shows an error and beeps. The RPM signal is on the CAN Bus, ID 0x280 where Bytes 2 and 3: RPM*4, I'll have my custom ECU replacement send out this signal. 2 Other CAN BUS messages appear to be required:  0x 488, this contains a counter,  Byte 0: Counter 0-F << 4 + 8, Byte 1-4: 21, 21, 7E, A6, Byte 5-6: 0, Byte 7: Counter 0-F << 4 0x580, this also contains the counter and some static data,  Byte 0: 0x80 + counter 0-F,  Byte 1, 2: 0, Byte 3: sequence 0x0f, 0x28, 0x7f, 0x28, Byte 4: sequence 0x1e, 0x10, 0x00, 0x10, Byte 5: sequence 0x70, 0x56, 0xf0, 0x56, Byte 6: sequence 0x0c, 0x48, 0xa7, 0x48, Byte 7: sequence 0x46, 0x90, 0x28, 0x90

Gearbox to Motor motuning plate

 There's about 30mm space between the gearbox and motor that needs making up and they also need some way of affixing. I decided to try and use some box section to bolt the 2 together. This might have been successful, had I drilled more accurate holes. The motor has a wiggle on when the bolts are loose and when it's all tightened up, the motor is unable to spin, due to the mis-alignment.   I should have used a drill press and some proper transfer punches instead of a hand held drill and a bolt that had a point for a punch. If you are following along at home, take your time with this step and drill accurate holes, others have managed it. Anyway, photos attached for your amusement. I went in search of help from an expert, I put a post in a couple of the motorbiking groups on Facebook looking for someone to help with the situation. Garry from G S Precision engineering answered my call, and with the gearbox and motor dropped off a couple of days before Xmas, I move on to other thing

Gearbox Motor coupling

 I have the original Beetle clutch and a clutch plate from a Ford Fiesta. I just needed to join them together, simple, right? I cut away the friction material from both clutch plates and had someone from EBay make a part on a lathe that both halves could be pressed in to. Spoiler, I don't think this resulted in both clutch spline patterns being perfectly true. After welding the parts together and trying to clean up without a lathe, the result isn't pretty.