Restoration and improvents to a Varney Super Mikado - Model Railroader Magazine (2024)

1471 Sir Frederick Banbury

• Member since
  June 2024
• 6 posts

Posted by 1471 Sir Frederick Banbury on Wednesday, June 26, 2024 7:01 PM

Hello all! This will be about the restoration of old Varney Super H0 Locomotives (the ones with sprung drivers), starting with a Super Mikado I recently bought on Ebay.

I've only made an account after having stripped the paint, reassembled the mechanism, repainted most of the body, and after returning from being out of town for a week and firing the thing up, just finding out that a coil in the motor was mostly dead and the ball race bearing with a shield on only one side was reversed.

After putting in an new, extremely good ball race bearing, I now know that the motor will be in need of a full rewind before it can even fee spin again, let alone power the heavy cast brass locomotive. If Varney was still around, it would be easy enough to get a new armature for the motor, but it seems that I'll have to remove the resin, rewind the motor completely.

I Just ask that anyone who has done successfully or not share their experience in fixing these motors, as I would like to get this lovely locomotive back in service, better than ever.

Thanks for leaving a comment. It means a lot.

Tags: motor rewinding , Restoration , super detailing , Varney

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rrebell

• Member since
  July 2006
• From: west coast
• 7,633 posts

It has been done but wshy not just put in a new motor, that one took too much juice anyway.

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Overmod

• Member since
  September 2003
• 21,568 posts

Bet it's less the armature and commutator/brushes and more your field magnets.

Make up a stack of good modern NIB magnets and suitable shims, per some of the posts on the topic here over the years, and see what that does.

(NIB magnets should not be cut or filed, hence the use of a suitable shim to get the right stack dimension).

OH WAIT, this is a Varney V2, isn't it? That's the one with the streamlined one-piece magnet, and the armature designed to spin at 16,000rpm with 37:1 gear reduction. Be interesting to see what Darth Santa Fe recommends for 'improving' the magnetic field for these motors...

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1471 Sir Frederick Banbury

• Member since
  June 2024
• 6 posts

Posted by 1471 Sir Frederick Banbury on Sunday, June 30, 2024 7:57 PM

rrebell

It has been done but wshy not just put in a new motor, that one took too much juice anyway.

I'd absolutely prefer to, if you could show me where to buy another Varney 7 pole v2 motor?

I would prefer not to put in a new make of motor, as I want to experience the model the way it was intended, so that I can use it to test clutches and refine its suspension and such, as well as my sheer appreciation of the design of this decades old mechanism.

my regards,

Rohan

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1471 Sir Frederick Banbury

• Member since
  June 2024
• 6 posts

Posted by 1471 Sir Frederick Banbury on Sunday, June 30, 2024 8:23 PM

Overmod

Bet it's less the armature and commutator/brushes and more your field magnets.

Make up a stack of good modern NIB magnets and suitable shims, per some of the posts on the topic here over the years, and see what that does.

(NIB magnets should not be cut or filed, hence the use of a suitable shim to get the right stack dimension).

I tested each coil outside of the motor with my power supply to see for sparks. Considering that the power supply can shoot decently long sparks, I have no doubt that the coils are as dead as a doorknob.

The motor uses a horseshoe shaped magnet, so I added some additional magnets to try and slow it down and give it more torque.

Now that I know that the lack of torque was due to a couple of coils being half-dead, and that it won't run at all now, I have three options:

I get a new coreless motor and just totally remake the drivetrain (which I'd prefer not to do),

Wait for a new Varney V2 motor to show up on eBay or something,

Guess which option seems best to me?

my regards,

Rohan

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snjroy

• Member since
  November 2013
• 2,720 posts

I can understand why you want to keep your parts "stock". But I'm not too sure what you mean by "new Varney V2 motor". Are you referring to old new stock? You would still be looking at motors that are over 50 years old. The magnets would probably be very weak and need a refresh.

I would go for a nice, new can motor. The biggest one that would fit.

Simon

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"JaBear"

• Member since
  August 2011
• From: A Comfy Cave, New Zealand
• 6,153 posts

Purchasing a new can motor, as already mentioned, would be the “easiest” option.

However, and I’m thinking back to the early 70s, I remember schoolmates who were right into slot car racing, rewinding motors to get more oomph!

Somehow, I get the feeling that you’d like the “challenge” of improving the original Varney motor, and as fflokes have their own favourite, even be it niche, part of the hobby, go for it, Have Fun, and let us know how you go.

Cheers, the Bear.

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Overmod

• Member since
  September 2003
• 21,568 posts

I encourage him to rewind -- and document the 'journey' here.

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Darth Santa Fe

• Member since
  June 2005
• 4,361 posts

Rewinding is difficult on these Lindsay-designed motors with how tightly they're put together, but it can be done. I tried that once before and was almost successful, but a shorted commutator stopped it from working completely. I believe they used 32AWG wire with 50 or 60 turns per pole, and with the 7-pole armature, the windings wrap around 3 poles at a time to get the proper magnetic field. Just be sure to make good note of which way they're wound, how many turns there are and which segments of the commutator they're connected to, then test each winding you've finished before moving onto the next. Once it's all done and working and the windings are packed in tight, a few drops of liquid super-glue here and there will hold them in place.

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1471 Sir Frederick Banbury

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  June 2024
• 6 posts

Posted by 1471 Sir Frederick Banbury on Wednesday, July 3, 2024 9:55 PM

Overmod

I encourage him to rewind -- and document the 'journey' here.

Oh I will! Its just a matter of finding a way to get the epoxy off of the armature. I've rewound motors before.

I recently had to rewind a bachmann n scale 3 pole motor. I doubled the amount of turns, but still need to remake a commutator plate because that decided to free itself and was damaged, that being the main problem of the motor in the first place.

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1471 Sir Frederick Banbury

• Member since
  June 2024
• 6 posts

Posted by 1471 Sir Frederick Banbury on Wednesday, July 3, 2024 10:17 PM

Darth Santa Fe

Rewinding is difficult on these Lindsay-designed motors with how tightly they're put together, but it can be done. I tried that once before and was almost successful, but a shorted commutator stopped it from working completely. I believe they used 32AWG wire with 50 or 60 turns per pole, and with the 7-pole armature, the windings wrap around 3 poles at a time to get the proper magnetic field. Just be sure to make good note of which way they're wound, how many turns there are and which segments of the commutator they're connected to, then test each winding you've finished before moving onto the next. Once it's all done and working and the windings are packed in tight, a few drops of liquid super-glue here and there will hold them in place.

Hi Darth! I've rewound more conventional motors, but the part thats troubling me is the epoxy covering the coils, as it seems somewhat integral to the commutator. Did your motor have this, or is this something more on the rare side?

Mechanical removal would be hard, as it could screw up the commutator assembly, but a mostly chemical removal could also destro the commutator.

Once I have that off, it should be smooth sailing to rewind the motor, I'll probably add a few more coils to add as much torque as possible, then the only obstacle will be balancing, as there is no flywheel to drill holes in, so I'll have to use tungsten putty to test, and then use tungsten powder + super glue to balance, but that shouldn't be too much trouble.

I'll add some photos in a bit. You'll note that the tender is abhorent in both cosmetics and its trucks, which swivel between the inner and middle axles. I may just write "ES&D" on it and use it as scenery, probably laid over on its side! XD.

I also handbrushed gloass black on it, because I only have gloss in black (an oddity of modelling Britain pre-war) and because it's old Humbrol, it sticks better to the brass than any primer I've ever tried. The gloss also makes it look like the Varney catalogue, which is the sort of effect I'm going for. For an enjoyable ~10 minute job with a $2 brush, I'd say it strikes a good low gloss look, ready for some coal dust and such!

Of course piping will also follow suit, due to the odd nature of the model having a Worthington BL feedwater heater right next to a Westinghouse pump, that be a kerfufle and a half, but first I need to get the highly sprung beauty running under her own power first!

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PRR8259

• Member since
  March 2016
• 1,553 posts

I don't know the difference between the old Varney motor and the Pittman, and later made by Bowser (former Pittman) motors, and whether or not the Pittman/Bowser motors could substitute--but they are out there and not 50 years old.

I just looked on ebay and there are 15 Bowser motors on there...is one of them a drop in replacement for the old Varney mikado? idk.

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Darth Santa Fe

• Member since
  June 2005
• 4,361 posts

PRR8259

I don't know the difference between the old Varney motor and the Pittman, and later made by Bowser (former Pittman) motors, and whether or not the Pittman/Bowser motors could substitute--but they are out there and not 50 years old.

I just looked on ebay and there are 15 Bowser motors on there...is one of them a drop in replacement for the old Varney mikado? idk.

The Varney V-2 motor has a very unique design with a 7-pole skewed armature, ball bearings similar to what Rivarossi used to use, and then a flat commutator at the end. The worm and axle gear are contained within the motor housing, allowing the motor to float with the axle. Replacement with a new motor is possible as long as the gearbox is also changed out, but when working properly, these were pretty incredible motors for their time.varneyv2motorinstr.jpg (840×1139) (hoseeker.net)

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Overmod

• Member since
  September 2003
• 21,568 posts

It does occur to me that, in theory, a good coreless motor could be easily adapted to mate up to the end of the V2's drive housing, with the bearings, long spring, etc. adapted to fit the replacement-motor shaft. (Note that the required bearing puller 'fixture' mentioned in the V2 documentation would be very easy to make....)

If you want a quiet motor with reasonable back EMF at 16k working RPM, a coreless certainly seems an attractive alternative to a complex rewinding without service literature.

But don't let me dissuade you from doing the rewinding! I suspect your best bet for epoxy solvent that you can find stocked at a hardware store would be Jasco '15-minute paint and epoxy remover'. There are industrial chemicals like Attack and Stripoxy that you could order if that doesn't do what's needed. I would use a proper non-soluble syringe and fine needle to apply this stuff. It will almost certainly 'strip' the varnish on the winding wire too, but that shouldn't matter because all you care about is how the armature needs to be rewound.

Get, or make, a good set of agate rails or knife edges to balance the armature. You will want horological-level balance precision for 16000 rpm...

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