C30T RTR HO scale - Wombat Models surprise release

 
  dthead Site Admin

Location: Melbourne, Australia
if you put a steel ruler on the tender wheels, does the middle wheel touch, and if not any idea what the gap  rought might be ?

Regards,
David Head

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  apw5910 Deputy Commissioner

Location: Location: Location.
The sleeves provide a very generous bearing surface. Rather than enlarge their inner diameter, would it be better to shorten the sleeves?
I think someone should try this first & let me know how they get on.
The railway dog
They're only 3mm long and quite hard, so a bit tricky to hold while you're cutting them (or boring them out like I suggested doing with a clock brooch, so I gave up). You could replace them with a ring of brass 1mm long or less.

I'm now thinking about folding up some thin sheet brass to form a U around the axle to replace the sleeve bearings and held in with the plastic keeper. But unless you're looking very closely to see the lateral wheel wobbles, removing the bearing sleeves from the middle axle completely and bending the pickups away so they don't touch the wheels and just running like that is fine. The old sloppy hole principle from the early days of compensation.
  The railway dog Junior Train Controller

Running the wheels on a steel rule- the centre wheel turns erratically, better than on my track (Rolling Eyes) but it doesn't turn consistently.

5910- good luck. I want all the pickups to be working, guess I'll just have to avert my eyes from that part of the engine's anatomy.
  a6et Minister for Railways

Running the wheels on a steel rule- the centre wheel turns erratically, better than on my track (Rolling Eyes) but it doesn't turn consistently.

5910- good luck. I want all the pickups to be working, guess I'll just have to avert my eyes from that part of the engine's anatomy.
The railway dog
A silly question but, what are the axles made from? metal/brass or a plastic type?  If plastic type such as delrin, which is supposed to be a lubricating help but, can also bend and cause resistance, thing is the problem seems to be on the single axle, middle one?
  apw5910 Deputy Commissioner

Location: Location: Location.
Running the wheels on a steel rule- the centre wheel turns erratically, better than on my track (Rolling Eyes) but it doesn't turn consistently.

5910- good luck. I want all the pickups to be working, guess I'll just have to avert my eyes from that part of the engine's anatomy.
A silly question but, what are the axles made from? metal/brass or a plastic type?  If plastic type such as delrin, which is supposed to be a lubricating help but, can also bend and cause resistance, thing is the problem seems to be on the single axle, middle one?
a6et
Axles are steel.

I've only bent the pickups away from the middle wheelset, the outer wheels still pick up as bought. Haven't had a problem with pickup or stalling, and I haven't cleaned my track for a few months! For some reason, it's the middle wheeset that locks up (on mine, anyway), the outer ones revolve ok as the loco goes along.

I've just made the middle wheelset as loose as possible to keep it rolling along. Adding more weight to the tender would probably get all the wheels rolling in an as-bought 30T, but the loco is far too light as it is without giving it more dead weight to pull.
  DJPeters Assistant Commissioner

Just a thought here but has some electrically conductive lubricant been put onto the axle at all, something like Peco's Electrolube or some Wahl clipper oil etc it only needs a very small drop of either to do the job. Thinking if it works and you use the locomotive frequently then the centre axle might free up from use the more it is used. Both these could also be used on the eased pickups as well to give a bit of lubrication to stop some friction. Just saying as a little bit of lubrication even on a new locomotive sometimes does wonders.

If any factory applied grease or lubrication is there clean it off the bearings and the axles and try the above.

Might not make one iota of difference but worth a try.

The only other thing that could cause this problem that I can think of is that both sides of the bearing/s are not dead exact across from one another in plane and thus it jams up, a bit tricky to get this one right though without the right equipment to sort it out. The only other thing to do might be to file out gently the slot used as a bearing for the axle a little bit to ease the friction on the axle itself, don't forget to add some lubrication to it though after you clean it up thoroughly.
  apw5910 Deputy Commissioner

Location: Location: Location.
Might not make one iota of difference but worth a try.
DJPeters
I tried that and it didn't make one iota of difference.
  dthead Site Admin

Location: Melbourne, Australia
how about conductive paint? gradually build uol layers until the wheel turns, ie  minutely increaste the diameter of the wheel ?

David
  DJPeters Assistant Commissioner

Might not make one iota of difference but worth a try.
I tried that and it didn't make one iota of difference.
apw5910
Back to the drawing board then on that.

I would be looking for anything that might stop the axle revolving and moving slightly up and down. I had the same problem almost on some Bachmann Thomas stuff that were running on a layout used for display. Some wheels turned and others did not but they are cheap and shoddy models to start with though and blind flat ended axles are not a good idea on any model, but that was what Bachmann had on them, some pinpoint metal axles and wheels fixed the problem but the bearing area had to be deepened a bit to allow the wheels to rotate, it only needed a smidgen or a bee's whisker but it was enough to free them up though.

The only other thing you might possibly need to do is redesign how the axles are held in place on the original bearing block and rebuild that area of the model to give complete rotation of the wheel at all times. You could just rebuild the centre wheel bearing section or it might be better to do the whole tender underframe area. It might also be adventagious to rebuild the pick ups on the tender as well.
  The railway dog Junior Train Controller

When I started trying to fix this my idea was to get some springing above the middle wheelset to force it into contact with the rail. I thought there'd be room between the bearing sleeves & chassis to get a small piece of spring brass from an ordinary Kadee coupler box spring. But not so, it jammed the centre wheelset down hard on the rail so  it acted as a pivot, allowing the tender to rock up & down on it.
But I reckon that springing might be the way to go. This would mean carving material from the chassis to allow spring material to fit between it & the bearings.
My engine's in the paintshop right now, so I won't be doing anything about this for a while.
  dthead Site Admin

Location: Melbourne, Australia
When I started trying to fix this my idea was to get some springing above the middle wheelset to force it into contact with the rail. I thought there'd be room between the bearing sleeves & chassis to get a small piece of spring brass from an ordinary Kadee coupler box spring. But not so, it jammed the centre wheelset down hard on the rail so  it acted as a pivot, allowing the tender to rock up & down on it.
But I reckon that springing might be the way to go. This would mean carving material from the chassis to allow spring material to fit between it & the bearings.
My engine's in the paintshop right now, so I won't be doing anything about this for a while.
The railway dog
won't springing force the tender's other 2 wheel off the track, maybe forcing you to add weight to conteract the  spring, and then adding  tot he load the loco can pull ?

David
  The railway dog Junior Train Controller

Won't springing force the other wheels off the track?
Quite bloody likely. Some careful surgery to the chassis would be needed, plus trial & error to get the right spring pressure.
And it might not work at all.
  DJPeters Assistant Commissioner

So who's bought one?

For us more distant prospective buyers, how does it rate - is at an SR 10 or an Austrains 36?
Neither of those models, best compared to the Ixion 32 Class as that basically what it is...well this time as a C30T

The tender is an Ixion 32 Class 6 wheeler, identical inside and out.
Loco is possibly a little heavier than the 32 and has a cab roof light as an extra.
Running characteristics similar the the 32.

It will basically suits those who are more interested in price.
Captain Underpants
Well this says something if the tender is identical for both then maybe both locos will or have the same problem so it might be better for whoever owns the tender tools to have or get a redesign done to cure the problem.   Now to ask the big question if the tender is identical to the Ixion 32 class has any one who has a 6 wheeled tender on their 32 had the same problem though and if not, then why is only the C30T affected and not the Ixion 32 class. This does need asking though.
  The railway dog Junior Train Controller

I have an Ixion 32 with a 6 wheel tender. The problems are identical.
  ajbrown Junior Train Controller

I have an Ixion 32 with a 6 wheel tender. The problems are identical.
The railway dog
I don't suppose anyone could post a nice, clear photo of the underneath of the tender?  After all, a picture says 1,000 words.
I, for one, am curious.

Allan Brown
  kingfisher Chief Train Controller

I have an Ixion 32 with a 6 wheel tender. The problems are identical.
I don't suppose anyone could post a nice, clear photo of the underneath of the tender?  After all, a picture says 1,000 words.
I, for one, am curious.

Allan Brown
ajbrown
If you go back to page 4 there is a post from Oscar that has clear photos of the problem area.
  PoidaGarratt Station Staff

In regards to both the model and real 30T, can anyone enlighten me as to what the two 'screw car jack' looking things are that appear on some locos (and not others) on the running board directly over the cylinders.
I have determined that the spare parts bag in the box for the model has these parts included.
I have seen that on the real loco (I have the Train Hobby publication) these items are not connected to the boiler at all, but that is all I can ascertain.
Cheers.
  apw5910 Deputy Commissioner

Location: Location: Location.
In regards to both the model and real 30T, can anyone enlighten me as to what the two 'screw car jack' looking things are that appear on some locos (and not others) on the running board directly over the cylinders.
PoidaGarratt
They are indeed "screw car jacks" - big screw jacks to help with re-railing after a mishap etc. I know they are (or at least were) on 3001 when she was running around in preservation times.

The Wombat 30T comes with some along with the fire-irons.
  The railway dog Junior Train Controller

And it comes with a shovel too!
Just the thing to have jammed against the cab side.
  dthead Site Admin

Location: Melbourne, Australia
I'm very interested in this thread as I got  one recently. Wombat Modelsalso numbered it for me, thankyou so much. It was a present to me after my near death experiance  in WaggaWagga BaseHospital in November.  

The model is unopened for now, awaiting a DCC decoder, and since I'm  currently in the Austin Hospital for a seperate issue, still have to wait.

Regards,
David Head
  The railway dog Junior Train Controller

I'm very interested in this thread as I got  one recently. Wombat Modelsalso numbered it for me, thankyou so much. It was a present to me after my near death experiance  in WaggaWagga BaseHospital in November.  

The model is unopened for now, awaiting a DCC decoder, and since I'm  currently in the Austin Hospital for a seperate issue, still have to wait.

Regards,
David Head
dthead
Well, best wishes for a speedy recovery so you can open your new treasure.
  Oscar Train Controller

Right, I've had a bit of time to work on a tender and I've fixed it. Based on a few ideas from apw5910, DJPeters and others, what works is for the centre axle to rise and fall freely beyond it's original limits. My modded keeper plate allowed downwards motion and apw5910's bearing removal allowed upwards motion. Combine the ideas of both and the tender's weight is fully supported by the outer axles which keeps them turning with pickups.  The middle axle rides on its own weight with pickups off it's wheels, but I have left the bearings in place. With respect apw5910, I now think your improved running was due to introducing more freeplay rather than removing bearing friction.

Regardless how flat one thinks their track is or how accurate the chassis bearing blocks, wheel and axle assemblies appear, some minuscule differences means that the weight of the tender is supported by two of the axles most of the time and the third axle, (not necessarily the middle) will stall when the friction between wheel and rail becomes less than that of the bearings and/or pickups.

I know compensation has been around for years though this is the first time I've dabbled with adding some to a model and only adding to the middle axle of the tender. Here's what I did...

I used a dremel extension seen in the background and cutter bit 193. Ignore the other ones, too big.

https://flic.kr/p/2c7rNs6


The bearing block in the centre of the pic has a flat bottomed trough to accommodate the axle and has two wider recesses at the ends for the 3mm OD bearings to fit into. The trough is also wider than the 2mm axle and doesn't contact it at all. My plan was to deepen the areas below the bearings only by a smidge so the bearings can move up into the spaces, hence raising the wheels for when the tender rolls over a comparative crest and avoiding it becoming a pivot point which would lift and stall an outer wheel.

https://flic.kr/p/RnhRTq


This is the result. A little bit of engraving, less than a mm deep. I tried as best I could to remove only the areas below (when tender upside down as pictured) the bearings and tried to stay away from the walls of the trough that locate the bearings. It was difficult not to occasionally scrape the sides but the end result works and only took a couple of minutes all up.

https://flic.kr/p/PK17Jp



Now reassembled, notice the centre axle wheel drop (or rise, for when it's right way up)

https://flic.kr/p/2cpa4NY
https://flic.kr/p/2dv5BYn


And here's the centre axle's wheel fall achieved in the keeper plate mod on page 4. Way more than what's needed but you get what's going on.

https://flic.kr/p/2dvyMdi


In summary, if you haven't got the tools to grind the bearing blocks where shown, simply remove the bearings as apw5910 did. The keeper plate can be changed a number of ways or replaced with something else, I'll leave that for others. All that matters is for the centre wheel to move up and down by less than a mm either way.  

Which brings me to future 6 wheel tenders. I'm not well versed on what tender ran behind what loco in my own NSW let alone other states and I don't know who uses the same factories but I'm sure the manufacturers of this six wheeled tender can see what minor changes could be done to stop the minor wheel stall. A deeper trough in the bearing block and a slightly taller bearing block with indentation for the current keeper plate's retaining clips would solve it and without the tooling for a modded keeper plate.

It might seem a bit nit picky to some and I get that, and things like the funnel doesn't bother me but it does others. There's rarely a bit of kit I have that I don't want to mod or improve. Whether I ever do or not is another thing. But for me the wheel stall seemed very noticeable and gee it looks good when all the wheels turn. So I'll finish with a vid...

This is over a section of track yet to be finished with one modded shortened points and a bit of a twist in the flex track between two others.  You might note the loco at the end of the video appears to stall but it doesn't. I'm using a gaugemaster with brake/inertia controller and I inadvertently applied the brake when I meant to reduce power.



https://youtu.be/mDuE5z5af4Q
  PoidaGarratt Station Staff

Thanks apw5910 for the info on the re-railing jacks.
Thanks to Oscar for your well documented and detailed fix on the tender pickup issue.
Cheers.
  apw5910 Deputy Commissioner

Location: Location: Location.
If the bearings are now loose enough to move up and down, I'd say they are also revolving with the axles.
  DJPeters Assistant Commissioner

I would have thought and this is just my take on it that pinpoint bearings into the tender axle boxes with pickups on all wheels would have been the better solution actually the centre wheel needs a bit of side play in it though. But it would simplify construction of the tender a lot and the wheels would just clip in. They could provide brass bearings in the axle boxes though so that you do not wear out the plastic. In other words set it up a bit like the old Tri-Ang models were but add pickups to each wheel. It seems stupid to try and reinvent the wheel pardon the pun, when the old fashioned method or way would be probably cheaper and easier to both design and make. Then the only thing to stop a wheel turning would be because the pickups are doing it and that would be easily corrected by the modeller. A weight inside the tender body and you should have no problems.

I say this because if you look at a 6 wheeled tender underframe all you are really looking at is a six wheel bogie, three axles and wheels in a solid frame. It works for bogies so why not a tender.

I am not overly impressed with models that appear to be over engineered in the first place, when simplicity would be the better option.

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