June 27th, 2014

Yesterday I spent the afternoon building my regulator. I am using the ‘Regulator 7’ design of Dr Hugo’s site. I was talking to him and he suggested some modifications for use in an A7. I am using a MBR3060 Schottky diode as the main diode (which replaces the cut-out), a 47R 5 watt base resistor, a 10SQ050 instead of a 1N5822 and a 6A10 as the snubber diode. It’s all built into the RB106 housing. It’s not the prettiest thing I have ever made but I made this to be strong.

IMG_2080_1 IMG_2081_1

IMG_2082_1 IMG_2083_1

It’s not finished yet as the snubber diode hasn’t arrived. Once it does I can finish it off by soldering that in place across the field windings. I was wondering where I was going to put the fuse but then I remembered I have a proper Austin 7 fuse holder so that can be separate. If it works I’ll draw out the circuit and post it here.


The inside isn’t pretty but with the lid on it looks fine.

Today my parts from the spares department arrived. A new head gasket, flywheel puller and dynamo bits. Am a bit confused about the dynamo end bush. The one I pulled out seems to be plain bronze. The replacement is steel with a hole and oil grooves.

IMG_2077_1 IMG_2078_1 IMG_2079_1

This fits at the commutator end of the dynamo. The housing has a hole and a small cap covering an oilway so I imagine the steel one with the hole is correct. I’ve asked on the A7 friends site, someone on there will know (and 27 others will have an opinion) I am sure.

Joss came over and was working on his chassis. We’ll be ready to weld in the boxing soon. Ian provided a picture of how to do the nose piece which we’ll follow. While Joss worked on his chassis I repaired my lathe. The new gear went in easily. I also fixed a long term problem I had on it. On high speed it used to hunt, that is the motor seemed to be pulsing. I never did work out why. It did it again today after I reassembled everything so I looked online and found out the reason is to do with the controller board. This YouTube film shows the exact problem and the comments have the solution. A tweak of one of the pots on the controller fixed the problem.

So I have a working lathe again! With that going I can change the dynamo to 2 brush (once I know about the bush) and hopefully can spin it up to see if it works. Then, once I finish it, I can test the regulator.

The other small thing I did today was drill the rivets to remove the old clutch linings from the flywheel. I need to look at repairing the plate that holds the toggles next. I will repair that with grub screws probably. Once done I will have the whole lot balanced. Balancing my MG engine made a big difference to how smoothly it runs.


Leave a Reply