I'm remotoring my C30Ts. If you're Wombats are chipped I'm guessing you'll have no desire or need to change out the motor and will question what's the point. Indeed the OEM motor has no trouble emulating realistic starts with DCC. For example, check out Marcus Ammann's video showing a smooth start and acceleration on DCC.https://www.youtube.com/watch?v=B9wNzDp0q_Q
But if you're DC, I refer back to a number of posts ago where it's noted the Wombat 30T and Ixon C32 leap to life unrealistically but can coast to a nice stop. In this video and using a Gaugemaster controller the engine will move at about 2 volts and stall at around 0.9 volts.https://www.youtube.com/watch?v=dSQI5nfTr9U
I thought it might be due to some bits in the lighting circuitry or on the PCBs sucking up power, but after digging through the tender and engine a couple of weeks back and isolating the motor it became clear the motor is the culprit. When I removed the motor and turned it by the flywheel I noticed some cogging and six identifiable movements. With two magnets I presumed it was three pole.
When disassembled, sure enough it was straight wound and three pole.
I'm not experienced or knowledgeable about remotoring but have read a few things to remember which have reappeared when searching for candidates.
- five pole motors seem to be better than three pole motors
- skew wound as opposed to straight wound, better still.
- five pole and skew wound together, bees knees
- fit the biggest motor possible
- a longer motor can negate the need for flywheels
- Mashima and NorthWest Short Line (NWSL), top quality and pretty much the only choice for replacements
The OEM motor body measures 10mm on the flat, 12mm on the oval and 15mm in length. The shaft is 1.0mm and the worm has a pitch of 1.25 with 5.2mm OD, 3.45mm ID. (I'm not overly familiar with quoting thread sizes but hope that makes sense)
The candidates for replacement motors include:Mashima 1015, 1020 and 1024.
These motors are ideal being 5 pole and skew wound but they have a 1.5mm shaft which means the worm and flywheel have to be drilled, or another worm and flywheel sourced. The 1015 has the same measurements as the OEM motor (10 x 12 x 15mm), but isn't exactly a drop in replacement which I'll explain soon. These motors are still available from various sources. Casula Hobbies (where I got mine from), ebay and Hollywood Foundry to name a few. I haven't been in contact with Geoff from HF but his closing down sale has the cheapest Mashima's I've seen http://www.hollywoodfoundry.com/default.htmNWSL 1215D-9, 1220D-9, 1225D-9.
The sizes of these three are all 10mm on the flat, 12mm on the oval and in lengths of 15, 20 and 25mm. The first one (1215D-9) is the same size as the OEM and Mashima 1015, ie 10 x 12 x 15mm. The 1215 and 1220 also have 1.0mm shafts which means the worm and flywheel can be used unmodified. The 1225 has a 1.2mm shaft but may be a bit long regardless. The NWSL motors are all 3 pole in this size and straight wound. I had doubts they'd be any better than the OEM motor however an email received by them said there's zero cogging and a smooth power curve. I've had trouble getting them locally so next pay day will put an order in direct.
The longest motors Mashima 1024 and NWSL 1225 will be too long to use the flywheel. The 1024 will hopefully fit with the second shaft cut off. I've found the flywheel is not needed.
The 1020 and 1220 I'm still trying to get hold of but I'm making a prediction that these two will be the sweet spot so far as the flywheel may not fit but the extra torque and length of the motor will assist in maintaining smooth slow speed.
The shortest motors, 1015 and 1215 are the physical match to the OEM. The 1015 I've tested with great success. I'm hoping the 1215, when I get hold of one, will prove to be just as good and a true drop in replacement without any modifications.
Testing the Mashima 1015 and 1024.
All the motors mentioned should physically fit in the same spot the OEM motor vacated, but note the locating/retaining tab in the boiler between the leading driving wheels. The 1015 should fit but it doesn't so the tab had to be removed, the one modification I was trying to avoid.
I used a Dremel and die grinder bit, same as used in the tender mod, to remove the locating tab. The area has to be shaved back so there's no raised bits to mess with motor alignment.
This is the 1015 fitted. The cage fits perfectly. The 1024, same deal, although it is a tiny bit too long. It will have to have it's second shaft removed and the boiler will hopefully clear the length of the motor.
Here's the vid. I prefer the 1024. There is a tiny bit of cogging in the 1015 whereas there's none I can feel in the 1024. This Wombat chassis has a little bit of binding in the mechanism which is due to siderods, or gears. The 1015 will hesitate a little at the same spot but the 1024 readily overcomes it, particularly noticeable during the constant crawl test.
Anyway, check the vid below which has a really good demo of the 1015 v's OEM on the same track, 1024 performance and some scale speed comparisons.https://www.youtube.com/watch?v=pEjoJWapt7Q&feature=youtu.be