2025-12-30

Last modified: 2025-12-30 15:18:02

• Tractor
• Old Bear Biplane

Tractor

ChatGPT's advice for stopping the chain tension slipping was that clamping with just a flange-head bolt in a slot actually gives you very little clamping area, you just get one segment on either side of the slot.

So the suggestion was that you should use clamping plates to spread the load over a larger area.

So I've made up some clamping plates this morning and seems to be an improvement so far.

Also I have found out what the crunching noise is. The chain run slightly interferes with the big piece of box section that the pillow block bearings are mounted on, and sometimes catches on it. So I think the solution is to take that part off and machine/grind off the edge that is rubbing on the chain, and that should make it run much more smoothly.

I also think the issue with the tractor being slow now is simply that I haven't charged the battery for ages, so it is on charge now and will see if improved.

I strapped a brick to the top of the battery to see if that would improve the weight distribution but it still isn't satisfactory. Unsure what I can do, maybe just have to live with it. Deflating the front tyres slightly may help?

We went out for another razz after changing the battery up. It is still too slow, which is very curious. I wonder if the new throttle conditioning is limiting the power or if something else is wrong?

Is it possible that the motor simply runs at a certain speed when you're going uphill and so lowering the gearing doesn't actually help at all? Like if it is always at 25% of full speed when going up the hill, then reducing the gearing just lowers the speed everywhere but it's still only 25%? Seems unlikely?

At the end the chain jumped off. I don't know whether the clamping plates still slipped. I think next step is to take the drivetrain plate off, relieve the area where the chain rubs, and make sure when I put it back together everything is straight and square.

Old Bear Biplane

I have made a 3d-printed jig for cutting the taper on the tail.

It has been hacked about with the oscillating multitool because there initially wasn't room for me to load the parts in to it.

Using pieces of copper-clad board as shims simply because they were a convenient size and thickness.

It worked quite well:

Although the tablesaw is leaving a rather poor finish, maybe I need a new blade.