A1A chassis update

In my last update, there were a few outstanding tasks to complete before finishing off the A1A chassis:

• Tabs for the contact whipers

• Designing weight holders

• Resolving the gear binding issue

I’ve finished off two of the above, but the third (and most complicated issue) is still a work in progress. I’ve come to the conclusion I need to do a re-design of how the bogie gearing housing works, which means many more hours of CAD design and then the testing that comes with that.

At the same time, following a suggestion by Karl Morris at Woodville, I’ve been experimenting using micro ball-bearings to provide bearings for smoother running. Basically the original set up was just using the central split gear (the black gear in the picture on the left) to also be the bearing against the sides of the gear housing.

As a result, performance wasn’t great. So I’ve rejiged the design again to accomodate ball-bearings, which are fortunately plentiful and don’t add to the cost too much.

As well as re-designing the gearing housing, I’ve had to create a new jig for cutting down the split gear to the correct size to accomodate the two bearings. As you can see in the picture on the left, the red split gear is not cut to the correct size.

Long story short, I haven’t met the end of July deadline I set last month - mea culpa. I’m working to iron out these issues as I really don’t want to ship a product that is half-baked and doesn’t work. For everyone who has pre-ordered the chassis, I thank you for your patience.