With fully charged batteries it crawls a few yards and then stops and doesn't want to know anymore. I'm thinking the mechanical resistance is such that the motor is not far off stalling all the time,and drains the batteries to quickly.
I think the answer may have several prongs, and one of them is the wheels, both the material and more importantly the problem of keeping the drivers parallel to each other. Because the motor output shaft is rather too short, I had to print extended sleeves on the back of the wheels and they really aren't accurate enough. So they are constantly both under and over gauge and bind on the rails all the time.
Thanks for that info. I wouldn't mind seeing gearbox your sketch, please. No point in reinventing the wheel so to speak.GTB wrote: ↑Sun Aug 21, 2022 2:18 pm https://gardenrails.org/viewtopic.php?f=37&t=12453
The gang motor weighs 260g and with the driven axle leading (worst case) managed 34g drawbar pull. The train weighed 663g and had a rolling resistance of 22g. Well within it's capability on my more or less flat track, but it would have slipped to a halt on a 1:50 grade. If both axles were powered, it would have just managed the train on a 1:30 grade.
The gang motor is fitted with a Como 951D601/6V micro gearmotor (I now use Pololu #998 6V 50:1 gearmotors). Gear ratio is 60:1 giving 300rpm at 6V at the output. The final drive is 1:1, using a pair of 0.5mod 20 tooth mitre gears (I now use a pair of 0.5mod 16T mitre gears). The final drive gearbox is milled out of a block of brass, but would probably be possible to print. I can post the back of the envelope sketch I use if needed. I work in 45 mm gauge, but the gearbox is only 21 mm wide so should fit a 32mm gauge wheelset. Probably not enough space left though, to couple the axles by chain for all wheel drive.
The gang motor has 20 mm steel wheels, from IPE I think, leftover from some early Ezee kits before I started turning my own wheels. The battery is 4 x Eneloop cells (4.8V), which gives a scale speed of 11 mph, so a 30:1 gearmotor would give you 20+mph.
Well, many, many years ago, I did create a 4mm farm labourer who bent over and stuck his pitchfork into a pile of hay ( chopped sisal string) and then heaved it up on to the top of a threshing engine. Sadly it was before the days of commonly available video so I only have one slightly fuzzy still photo, but it kept the exhibition punters fascinated for hours, especially the kids! He was operated by a fairly complex cam mechanism which bent him over, pulled his arms back and jabbed down, then flicked back up!GTB wrote: ↑Sun Aug 21, 2022 2:18 pm The first major model railway exhibition in Melbourne for 3 years was this weekend and one of the things I saw was a HO scale bike rider furiously pedalling along a road. Nothing is impossible it would seem........
I think it would be possible to use a couple of the miniature linear rc servos used by aeromodellers (look on ebay) and some sort of linkage to raise the roof. They don't take up a lot of space, but seem to be powerful, a friend uses them to operate signals in HO.
Working out how to animate the driver to walk up, open the door and lift the roof might be a bit more of a challenge.......
Anyway, I do have an idea in mind for the roof raising, but thats a way down the line yet. No point in raising the roof if it won't move! Servo's would obviously work but with nowhere to hide them it would rather spoil the effect.