Giles' misc. Work bench.

Giles

Giles

Western Thunderer
You learn something new every day!

I've made up about 15, which will do for the moment!

The diff works well in this application, and was worth going to the extra trouble over - all in all, quite a successful exercise (just looking for the layout to play on now...)
 
Last edited:
Giles

Giles

Western Thunderer
Gearmotors have always been at the heart of the radio control stuff (and other bits and pieces) in the earlier days, the motors were of fairly good quality with good starting characteristics. However, we are now swamped with cheaper versions which run fine, but are off like a scalded cat! A couple of years ago we had the incredible little K20 5v gearmotors, which were superb - but the supply has now completely dried up. I thought I found a cache a couple of months ago, and bought four, but when they arrived, they were a different type, size and ratio - and no use to me. Likewise, i have five 100rpm N20 gearmotors, whose motors are too poor quality to use. So I'm going to try mating the 8mm motor from the unworthy gearmotors that were supplied to the N20 gearboxes. It will create something reasonably short, but with a large gearbox, but hopefully might perform reasonably well......
We will see!

Top is the 'donor's 8mm gearmotor - output speed about 40rpm
Middle N20 gearmotor - useless motor, output 100rpm
Bottom cut'n'shut 8mm motor mated to N20 gearbox. Looks to give around 100rpm.

The test will be when it's hooked up to a receiver and started at slow speed.
2020-10-06_05-06-23 by giles favell, on Flickr
 
Peter Insole

Peter Insole

Western Thunderer
Ahah Giles, you have just answered my question before I got round to asking!

Richard (son and new member on here) and me have been pondering how to power a scratchbuild, 4mm scale Tube train! I pointed out the tiny motors that you use and suggested to him that they might fit the bill better than the usual type of motor bogies available.

Speed of the train is not such an issue as the incredibly low clearance under the floors on all contemporary Underground stock.

I was about to seek your advice about it, but it looks as if the supply problem will require a major rethink anyway now?!

Pete.
 
simond

simond

Western Thunderer
There was an article years ago about using memory wire for MU doors.

can’t remember where or when...

Atb
Simon
 
Giles

Giles

Western Thunderer
Peter Insole said:
Ahah Giles, you have just answered my question before I got round to asking!

Richard (son and new member on here) and me have been pondering how to power a scratchbuild, 4mm scale Tube train! I pointed out the tiny motors that you use and suggested to him that they might fit the bill better than the usual type of motor bogies available.

Speed of the train is not such an issue as the incredibly low clearance under the floors on all contemporary Underground stock.

I was about to seek your advice about it, but it looks as if the supply problem will require a major rethink anyway now?!

Pete.
Click to expand...

I can see two possible/hypothetical ways of how one might scratchbuilt a very low-profile bogie.

Much depends on axle spacing etc!

One is using Nigel Lawton type motors and drive belts slung transversely between the axles, probably with idler axle to reduce the speed. These could be configured for 12v operation.

If you could hide an under-floor motor centrally, then driving the bogies via cardan shafts is no massive deal - either home made, or using components bought abroad. You can then drive the second axle using bevel gears on an in-line shaft.


2020-06-11_06-40-59 by giles favell, on Flickr

I'm planning on doing something similar with another steam crane with a gearmotor along side between the axles - but I doubt you'll have room for that.
 
Giles

Giles

Western Thunderer
Giles said:
Gearmotors have always been at the heart of the radio control stuff (and other bits and pieces) in the earlier days, the motors were of fairly good quality with good starting characteristics. However, we are now swamped with cheaper versions which run fine, but are off like a scalded cat! A couple of years ago we had the incredible little K20 5v gearmotors, which were superb - but the supply has now completely dried up. I thought I found a cache a couple of months ago, and bought four, but when they arrived, they were a different type, size and ratio - and no use to me. Likewise, i have five 100rpm N20 gearmotors, whose motors are too poor quality to use. So I'm going to try mating the 8mm motor from the unworthy gearmotors that were supplied to the N20 gearboxes. It will create something reasonably short, but with a large gearbox, but hopefully might perform reasonably well......
We will see!

Top is the 'donor's 8mm gearmotor - output speed about 40rpm
Middle N20 gearmotor - useless motor, output 100rpm
Bottom cut'n'shut 8mm motor mated to N20 gearbox. Looks to give around 100rpm.

The test will be when it's hooked up to a receiver and started at slow speed.
2020-10-06_05-06-23 by giles favell, on Flickr
Click to expand...

This cut'n'shut on first power up isn't as smooth as it should be - so ive had the motor off and have just refixed it to see if the mesh was slightly off - or whether the gearbox itself is a bit dodgy.

However, meanwhile, I've taken another of the 40rpm gearmotors, taken the planetary gearbox off, removed one stage of gears, shortened the case and refitted it. I'm now getting something like 130rpm out of it, and it is lovely and smooth all the way up!! So that's a real win. It now becomes an extremely useful gearmotor. It's a little larger than the K20s, and not 'off the shelf', and £10 instead of £3, but still.....
I also remembered to fully dismantle the gearbox and lubricate it, as this does improve its performance (I have forgotten to do this over the past couple of years....)

The centre gearmotor with the brass sleeve is the shortened 130rpm version

2020-10-07_03-14-55 by giles favell, on Flickr
 
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