Farish worm gear spacing - help needed

[Mr Sprue]

The other option is to print in bronzed steel.  At £15 from Shapewys the extra weight might be worth it on a DCC 0-6-0 but the screw fixing would need to be insulated with a plastic tophat.

The only deciding factor here is how hot will the motor get, I confess I have not much dealings with small coreless motors. But if they do get warm then the bronze steel option could act as an heat sink.

[Snowwolflair]

After 3 hours running no heat at all.

[ntpntpntp]

How's the torque? 

Had another thought, could you fit a double ended motor and include a flywheel?  A bit like the small motor I used in a Minitrix ivatt tank a few years back

[Snowwolflair]

How's the torque? 

Had another thought, could you fit a double ended motor and include a flywheel?  A bit like the small motor I used in a Minitrix ivatt tank a few years back

The motor I'm using is double ended (the bearings are better) and there is a 7mm by 6mm flywheel available.  The mount has enough clearance to fit one.

[Mr Sprue]

How's the torque? 

Had another thought, could you fit a double ended motor and include a flywheel?  A bit like the small motor I used in a Minitrix ivatt tank a few years back

That's a very tidy looking mod.

[Snowwolflair]

I have just re-motored my LMS Flatiron which has a Zimo sound chip.  The original 5 pole Farish motor was horrible.  The motor refit was easy, tidying up the aged Farish chassis too longer to fix.

[ODRAILS]

I have just re-motored my LMS Flatiron which has a Zimo sound chip.  The original 5 pole Farish motor was horrible.  The motor refit was easy, tidying up the aged Farish chassis too longer to fix.

Thanks for the video. Please show a photo of the motor and mounting.  I,m very interested in re-motoring my older Farish locos.
Ian

[Snowwolflair]

I'm going to be converting a couple more, LMS Highland Tank Locos, and I will take and post step by step photos.

I'm also waiting for proper black nylon plastic ones from Shapeways as the ones I am using are of a brittle plastic, not that they are inferior just they are grey and need paint.

[Southerngooner]

Is there any chance you might be thinking of doing the same conversion for Poole era Farish diesels? Is it even possible?

[Snowwolflair]

There are about 12 different types and most can be replaced with a simple motor shape block with a hole down the middle, and they are available.

[Southerngooner]

Where can they be bought please?

[Snowwolflair]

Various ones form https://tramfabriek.nl/ but not Farish specific, but he may be interested in producing them, and there are some on Shapeways.

[thebrighton]

Very interesting, does it bring the height of the chassis down from the Farish original. I'm thinking of smaller loco classes as I currently have to glue the motors to the chassis block.

[Dr Al]

This is an interesting idea, and particularly useful if need low profile motor in a kitbuild (I can think of one I have that'd probably make use of this).

However, those considering replacing their Farish armatures - do bear in mind you are replacing a 5 pole unit (generally) with a 3 pole, and the coreless motors rev higher, so super creep needs proven - a properly overhauled Farish 5 pole will do a very good creep.

Moreover, they clearly have much shorter lifespan (commutation/brushgear) and as such, several (myself, @Fredastaire ) have seen extensive numbers of failures of these already - something the old Farish armatures won't do (many 25-35 years old still going). Another post went up only today on this on yet another coreless failure.

Tramfabriek's motors may be different, but they have not carried out tests requested of longevity yet as far as I know, so jury is out. If they are similar then for me they are too expensive to be replacing every couple of years I'm afraid.

Anyone who does decide to convert - please don't throw working Farish armatures! If you don't want, I'll happily purchase them.

Cheers,
Alan

[Fredastaire]

As Alan has mentioned, I've now had a number of Farish Coreless motors in bits after their failures. All but one have failed because the 'brushes' have worn through and broken in half. The latter one just mentioned today has failed because the 'brushes' have sliced into the commutator segments and decapitated them. the Farish locos have varied from Duchess, 5mt's, Austerity and Fairburn. These locos are only a few years old. I just find their short life is unacceptable. The Coreless motors are designed for high speed, the commutator diameter is tiny so as to get the linear surface speed of the 'brush' low; you have to appreciate that the 'brush' is not a conventional brush as we know it. It is in fact a tiny pair of metal fingers, they look like stainless.
Whilst I have replaced some motors with Bachmann genuine spares, I have also repaired a number by fitting new motor end caps from phone vibrator motors.
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Now let's come back to Farish 5 pole motors.
These just keep on going and going, stripping a Poole design Farish takes minutes, cleaning parts is quick, polishing the com is fast, brushes last donkeys years. A quick lube and away you go.
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Armature failures are very few, I've had to touch solder the commutator connections on a couple. I do have to report 2 having thrown segments of the com these I think were early China build of the Farish design and may have had old damage.
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I just don't think that there is any contest.
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While ever armatures are available from BR Lines for those very very odd failures there is no justification for retro fitting them with short life expensive Coreless
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The new Farish with Coreless are also a nightmare to dismantle as almost all of them have the motor hidden inside a split chassis, they take care and ages to to strip and reassemble, with risk of breaking parts, just compare that to the few minutes to do the same with a Poole design.......
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Beware Coreless......