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General Category => N Gauge Discussion => Topic started by: Snowwolflair on February 24, 2020, 03:42:43 PM

Title: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 24, 2020, 03:42:43 PM
Does anyone know the distance between the axle centres and the motor centre on a classic pool Farish locomotive.

It has to be around 6.5mm but as I am making a gearbox it would great to be sure.

Can anyone help?


(https://www.ngaugeforum.co.uk/SMFN/gallery/87/3761-240220154224.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=87885)
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 24, 2020, 06:46:09 PM
I'm having a play to see if it is possible to convert an old Farish loco with a coreless motor.


(https://www.ngaugeforum.co.uk/SMFN/gallery/87/3761-240220184521.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=87889)
Title: Re: Farish worm gear spacing - help needed
Post by: ODRAILS on February 24, 2020, 08:32:35 PM
Quote from: Snowwolflair on February 24, 2020, 06:46:09 PM
I'm having a play to see if it is possible to convert an old Farish loco with a coreless motor.


(https://www.ngaugeforum.co.uk/SMFN/gallery/87/3761-240220184521.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=87889)

A great idea. I'd be interested in buying at least one if it's 3D printed.
How would the rear of the motor be fixed to the chassis?
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 24, 2020, 09:18:45 PM
Once i'm happy with the shape and prove it works I will list it on Shapeways.  I need to do it that way as it will need to be a polythene type plastic which Shapeways do.  Looks like £7-8 a unit but i'm removing mass so that might go down.
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 24, 2020, 09:44:44 PM
Quote from: Only Me on February 24, 2020, 09:34:53 PM
@Dr Al (https://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=263)  would be the holy grail on this..

Sir Gawain surely  :)
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 24, 2020, 09:50:26 PM
Cutting away the unnecessary plastic it looks better.

Shapeways are indicating about £5.50


(https://www.ngaugeforum.co.uk/SMFN/gallery/87/3761-240220214835.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=87894)
Title: Re: Farish worm gear spacing - help needed
Post by: stevewalker on February 25, 2020, 12:11:09 AM
And removing that extra bulk will maybe leave more space for a dcc decoder, which will be much easier to fit with a motor that is isolated from the chassis.
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 25, 2020, 12:21:21 AM
Almost there with the shape. I need to pick up the tube adaptor to fit the worm gear and test it next so I can make the final adjustments.

Yes, it will be possible to hand trim it further to get a DCC chip in if its tight.

(https://www.ngaugeforum.co.uk/SMFN/gallery/87/3761-250220001913.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=87899)
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 25, 2020, 12:39:26 AM
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.
Title: Re: Farish worm gear spacing - help needed
Post by: stevewalker on February 25, 2020, 08:41:41 AM
 Looking very good! I might well consider that for converting some of my locos.
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 25, 2020, 05:39:53 PM
These videos used a print straight out of the printer without any modification.



Title: Coreless replacement motor for Farish early chassis
Post by: Snowwolflair on February 25, 2020, 09:59:14 PM
Very sweet, not had a Farish loco of this era behave this well under DCC and very little noise.

Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 25, 2020, 10:17:19 PM
I have ordered up some sample parts in various materials and finishes from Shapeways to see what will give the best results.  This will take a few weeks and in the interim I'm going to convert a number of my white metal kit built models all which labour under poof Farish motors.
Title: Re: Farish worm gear spacing - help needed
Post by: ODRAILS on February 25, 2020, 11:15:37 PM
Quote from: Snowwolflair on February 25, 2020, 12:39:26 AM
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.
Hopefully we're talking about the Farish motor which was used in the nearly all the later Poole locos and the revised Chinese locos not just 0-6-0s
Ian
Title: Coreless replacement motor for Farish early chassis
Post by: Snowwolflair on February 25, 2020, 11:31:30 PM
Quote from: ODRAILS on February 25, 2020, 11:15:37 PM
Quote from: Snowwolflair on February 25, 2020, 12:39:26 AM
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.
Hopefully we're talking about the Farish motor which was used in the nearly all the later Poole locos and the revised Chinese locos not just 0-6-0s
Ian

Yes, for all their steam locos the motor was mounted identically as far as the plastic carrier, bearings and magnet.  I have a lot in white metal kits and in handmade models so my motivation to get a better result was high and I will be checking a number of locos across the range.  If I come across any differences the design can be changed to suit them but I'm not expecting to find any.

The key to getting it to work is a 7mm diameter motor available from @Sven (https://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=6993) of Tramfabriek  https://tramfabriek.nl/ (https://tramfabriek.nl/).  It has very good torque, much better than all the others I have tried and it gives serious pulling power.  He also supplies a 1mm to 1.5mm adaptor that allows the motor to use the Farish worm.
Title: Re: Farish worm gear spacing - help needed
Post by: Mr Sprue on February 26, 2020, 08:25:11 AM
Quote from: Snowwolflair on February 25, 2020, 12:39:26 AM
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.
Title: Coreless replacement motor for Farish early chassis
Post by: Snowwolflair on February 26, 2020, 09:21:28 AM
After 3 hours running no heat at all.
Title: Re: Farish worm gear spacing - help needed
Post by: ntpntpntp on February 26, 2020, 04:11:21 PM
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

(https://www.ngaugeforum.co.uk/SMFN/gallery/75/5885-160319165411.jpeg)
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 26, 2020, 04:15:14 PM
Quote from: ntpntpntp on February 26, 2020, 04:11:21 PM
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

(https://www.ngaugeforum.co.uk/SMFN/gallery/75/5885-160319165411.jpeg)

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.
Title: Re: Farish worm gear spacing - help needed
Post by: Mr Sprue on February 26, 2020, 04:35:33 PM
Quote from: ntpntpntp on February 26, 2020, 04:11:21 PM
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

(https://www.ngaugeforum.co.uk/SMFN/gallery/75/5885-160319165411.jpeg)

That's a very tidy looking mod. :thumbsup:
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 28, 2020, 07:30:47 PM
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.

Title: Re: Farish worm gear spacing - help needed
Post by: ODRAILS on February 29, 2020, 09:43:41 AM
Quote from: Snowwolflair on February 28, 2020, 07:30:47 PM
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
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 29, 2020, 09:49:15 AM
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.
Title: Re: Farish worm gear spacing - help needed
Post by: Southerngooner on February 29, 2020, 03:40:16 PM
Is there any chance you might be thinking of doing the same conversion for Poole era Farish diesels? Is it even possible?
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 29, 2020, 03:50:45 PM
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.
Title: Re: Farish worm gear spacing - help needed
Post by: Southerngooner on February 29, 2020, 04:20:26 PM
Where can they be bought please?
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on February 29, 2020, 04:40:58 PM
Various ones form https://tramfabriek.nl/ (https://tramfabriek.nl/) but not Farish specific, but he may be interested in producing them, and there are some on Shapeways.
Title: Re: Farish worm gear spacing - help needed
Post by: thebrighton on February 29, 2020, 05:03:01 PM
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.
Title: Re: Farish worm gear spacing - help needed
Post by: Dr Al on February 29, 2020, 05:06:09 PM
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 (https://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=5202) ) 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
Title: Re: Farish worm gear spacing - help needed
Post by: Fredastaire on February 29, 2020, 06:41:15 PM
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.
.
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.
.
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.
.
I just don't think that there is any contest.
.
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
.
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.......
.
Beware Coreless......
Title: Re: Farish worm gear spacing - help needed
Post by: Southerngooner on February 29, 2020, 07:14:27 PM
As has been noted before on this forum we run our locos hard on James Street and haven't seen any failures on cordless motors on around 100 locos. I actually prefer taking the new split chassis apart as they are simplicity in itself, except where there is valve gear, which is a problem on older Farish too. It's like Hornby Dublo v modern Hornby, crude and simple or detailed and more modern. You pays your money, you takes your choice.....
Title: Re: Farish worm gear spacing - help needed
Post by: Fredastaire on March 01, 2020, 02:58:41 PM
@Southerngooner (https://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=3680) , I can only give my personal thoughts and opinions on what I have stripped and investigated. My opinion is that these coreless motors fail through total accrued lifespan running, the brushes and commutators show to have mechanically failed through being worn out. Ive seen no burnt out armatures, no burnt brushes so my opinion is that it is not a case of 'hard running' overheat damage. Those motors where I have fitted replacement end caps / new brushes are still working now so definitely have not suffered winding burn out.
.
Ive also bought a non runner Bachmann coreless from an Ebay seller, with the same bust brushes, so this is clearly from another layout elsewhere in the country, that motor ive rebrushed, it too works, ive tested it in a STD 5 then put it in my bits box for future use.
.
I would wish to clearly state that anything ive said is from my hands on dismantling and vieweing thro magnifying glasses. I would welcome others who have stripped faulty Coreless motors to add their post mortem observations.
.
Surely one of our members must have experience of a coreless motor post mortem?
Title: Re: Farish worm gear spacing - help needed
Post by: Southerngooner on March 01, 2020, 03:20:58 PM
Hi

I am not trying to disagree with your observations, it just seems to me that if Farish were selling something with a 100 hour life motor there would have been lots more problems by now, as that only equates to one hour a week for two years. A lot of locos will have done more than that. Could it be that the problems are a normal failure rate for any batch of product as per the standard distribution curve, in that 5% or so will fail early? If a whole lot of locos were failing (as per the Farish broken gear issue years ago) then it would be more common?

With a replacement motor at around £20 from Bachmann or cheaper from the likes of Tramfabriek then I would rather replace than repair, on the basis that my time is money, but if you can do it and they continue to work well than that's great. I just wouldn't know where to start and I suspect most people would be the same. It's probably very easy to do, but unless you know where to get the parts, what to do and have the skills to do it, then replacement is a safe option.

This has rather taken over a really useful thread on remotoring old Poole stuff, which is a good option for those who wish to continue to run them!
Title: Re: Farish worm gear spacing - help needed
Post by: jpendle on March 01, 2020, 03:41:07 PM
Quote from: Fredastaire on March 01, 2020, 02:58:41 PM
Surely one of our members must have experience of a coreless motor post mortem?

I have to agree with @RailGooner (https://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=5427) . I think most of our members, me included, would just replace the whole motor, a post mortem would consist of having a look and a sniff and chucking it in the bin.

But don't get me wrong. I find your threads along with those of @Dr Al (https://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=263) and others fascinating. Keep up the good work.

Thanks,

John P
Title: Re: Farish worm gear spacing - help needed
Post by: thebrighton on March 01, 2020, 05:35:24 PM
Dragging this back on topic rather than reliability of coreless motors is it possible to add a channel to the print to run the blue wire along rather than having it loose?
Title: Re: Farish worm gear spacing - help needed
Post by: ntpntpntp on March 01, 2020, 05:52:35 PM
Just to reply to the thread drift:

Quote from: Fredastaire on March 01, 2020, 02:58:41 PM
Surely one of our members must have experience of a coreless motor post mortem?

Yep. I've replaced two so far in a friend's locos ( a 4CEP and one other multiple unit type which I forget).  I know he certainly doesn't run his models for long periods or under heavy loads.  Post mortem on one of the motors revealed broken brush "fingers". I got that one going again but I wouldn't trust it in a loco now.

As a Continental N modeller I've had a Liliput multiple unit fail and need a replacement motor (they're part of the Bachmann empire too and it's a similar chassis design).

Overall I'm not convinced/happy with this move to smaller limited life motors. The old motors just work and work for decades and can be serviced when needed.
Title: Re: Farish worm gear spacing - help needed
Post by: Dr Al on March 01, 2020, 07:19:14 PM
Quote from: ntpntpntp on March 01, 2020, 05:52:35 PM
Yep. I've replaced two so far in a friend's locos ( a 4CEP and one other multiple unit type which I forget).

No. The 4-CEP is not a coreless motor - it's a 3 pole standard 1015 sized can. No Farish multiple units have coreless motors.

Cheers,
Alan
Title: Re: Farish worm gear spacing - help needed
Post by: Dr Al on March 01, 2020, 07:22:58 PM
Quote from: Southerngooner on March 01, 2020, 03:20:58 PM
This has rather taken over a really useful thread on remotoring old Poole stuff, which is a good option for those who wish to continue to run them!

It's highly relevant though, if people are starting to think of wholesale re-motoring - I can see the need at times (if you need a low profile chassis), but one has to balance that with the knowledge that there are real question marks over the longevity of the 0716 coreless motors - relevant when you'll be spending a fair amount to replace a Farish armature that should be able to perform as well.

More data is needed, and I wish Tramfrabriek would have undertaken the longevity test I asked of them a while back.

Despite that, I will be interested to get one of these mounts though - I have a kit tank loco that needs a low profile chassis for it to work. But, I won't be re-motoring everything.

Cheers,
Alan
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on March 05, 2020, 05:34:56 PM
I have been removing material to make the motor mounting as small as is structurally stable.  I am still waiting for the material samples from Shapeways, however even in a brittle resin this new design is strong enough.  My guess the black polished nylon will be ideal.

(https://www.ngaugeforum.co.uk/SMFN/gallery/88/3761-050320173127.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=88331)

(https://www.ngaugeforum.co.uk/SMFN/gallery/88/3761-050320173148.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=88332)
Title: Re: Farish worm gear spacing - help needed
Post by: Snowwolflair on March 10, 2020, 11:30:13 AM
Various materials to test.

(https://www.ngaugeforum.co.uk/SMFN/gallery/88/3761-100320112951.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=88524)