Hi all,
I've got a Roundhouse Ready-to-Run Old-Time 2-8-0 (one of these: http://www.pacificcoastairlinerr.com/1905/roundhouse_2-8-0/image/fireman_side.jpg), which I have rebuilt into an On30 locomotive. Now, when I was programming it on my SPROG DCC test track, the mechanism was working smoothly in both directions. There was no binding (I made sure to run wires to clear the motor and flywheel), and all of the wheels are correctly aligned and in gauge.
However, when I put it on my layout to test run it, the locomotive barely moved. Running along a straight section of the track, it struggled going forward, and didn't move at all going in reverse unless I gave it a bit of a push. Yet on the test track it runs fine.
The only change I've made to the wheels has been to replace the original traction tyres with bullfrog snot.
Given that the mechanism is not binding and the wheels are alright, I'm a bit lost fow what to do. I'd like to get this loco running, given the time I've put into building it.
The Location: Forests of the Pacific Northwest, OregonThe Year: 1948The Scale: On30The Blog: http://bvlcorr.tumblr.com
Haven't used BFS, but have heard what others have done. One of the issues is that it needs to be thin. Too thick and it may be lifting the other drivers without it -- which need contact to feed power up -- clear of the rails. See if you can slip the edge of a piece of paper under the tire. If there's clearance there, instead of good contact with the rail, that may be the problem.
Mike Lehman
Urbana, IL
mlehman Haven't used BFS, but have heard what others have done. One of the issues is that it needs to be thin. Too thick and it may be lifting the other drivers without it -- which need contact to feed power up -- clear of the rails. See if you can slip the edge of a piece of paper under the tire. If there's clearance there, instead of good contact with the rail, that may be the problem.
I've just done the paper test, and I can get paper under the two middle sets of drivers. Looks like the loco is sitting just on the front and rear ones.
The bullfrog snot was replacing traction tyres, so it's filling the slots for them on the rear drivers. Obviously it's a little too thick. How could I correct this - holding a file against the BFS while the wheels are turning slowly?
I'm curious why you would want to replace traction tires with BFS, unless the traction tires were missing in the first place.
And was the addition of BFS before or after you ran the loco with the Sprog?
maxman I'm curious why you would want to replace traction tires with BFS, unless the traction tires were missing in the first place. And was the addition of BFS before or after you ran the loco with the Sprog?
In my experience, traction tyres usually fail. I figured that doing them while the loco was being built would save trouble later on. Of course, it goes and causes trouble . What makes it worse is that the geared axle is one of the ones being lifted off the tracks.
The BFS was added before the sprog testing was done - all runs on the test track and layout have had BFS with them.
Update:
I've run the loco with a fine-toothed, single sided file against the rear wheels until the BFS was down to the point where the metal bits on the sides of the wheel (the sides of the slot containing the BFS) were visible and polished. However, I'm still able to slide a sheet of paper under the middle two drivers. Having said that, there is a bit more resistance this time, and the locomotive did perform slightly better on the layout, although still with the same problems as before.
Should I keep turning down the rear wheel until all four axles pass the 'paper test'? Or would this risk damaging the wheels?
I can´t follow your statement that traction tires usually fail. Of course, they were off and need to be replaced now and then, but they seem to be a much better solution than to fill the slot in the wheels with BF. Ge that stuff off your wheels, replace the traction tire, clean the wheels and the track and your loco will run properly!
tbdannyUnfortunately, I don't have the traction tyres any longer.
tbdannyShould I keep turning down the rear wheel until all four axles pass the 'paper test'? Or would this risk damaging the wheels?
I'm pretty sure the RTR version of these had plated wheels. The original kit version had brass tires, which were a pain to keep clean. They switched to a plated driver in late kit production. I assume that the RTR built-up version would have used the plated wheels. If they are shiny versus brassy looking, then they are the plated ones.
Since plating is very thin, grinding it will soon take it off. I would advise against that.
I'm trying to remember whether these are sprung or not. Not sure where my old kit-built version is right now. But I think there's no springing on the drivers. If the middle pair of drivers isn't touching, then I'd consider disassembly to see if there's an issue making them sit high -- or the end drivers sit low. You can either shim down the middle ones or deepen the slot in the frame for the ones that sit low on the ends. But if the driver tires don't all sit at the same level, you'll likely continue to have traction problems. You need all 4 pairs sitting on the rail when level.
But wait, there's more...
Assuming the traction tires were on the middle drivers, they may be set up to sit high for that reason and it may be normal. In that case, you want a coating of BFS just thick enough to bring all the drivers level and you don't want to mess with the drivers going up or down until you've had a chance to verify with another, carefully thinner coat of BFS.
Mike,
Funny you should mention that. Having taken the BFS down to the point where the plating is now showing through, I did some checking with a ruler. It seems that the 'blind' drivers in the middle do sit high. It looks to be a gap of about 0.5mm or so. I'm not sure why - maybe a manufacturing defect?
The connecting rod along the side is a single piece, and appears to be in line at the moment. Raising the end wheels would likely cause more problems. It would appear that adding a layer of BFS to the middle drivers would be the way to go.
Unfortunately, this would remove most of the power pickup from the locomotive, but all the tender wheels pick up power anyway.
You said that the loco ran okay on the test track, but not on the railroad. And there was no change to the loco in between. I don't understand how this can be.
You also said that you made some changes to go from HO to On. Did any of these changes affect the frame, drivers, or other parts of the mechanism?
I have never used the BFS so I really shouldn't have an opinion on it. Suffice it to say that I just never liked the thought of the stuff.
As far as the traction tires go, if this is a model that Athearn now sells after taking over the MDC line, I would think you should be able to get the tires from them.
The only thing I did with the frame was paint the silver part graphite, to match the smokebox. Nothing to do with the mechanism was changed.
It seems that the middle drivers are riding high - they've got a slightly smaller diameter than the flanged drivers at the end. This is in comparison to the untouched front driver, as well as the traction tyred one (which is now back to its original diameter).
tbdannyIt seems that the 'blind' drivers in the middle do sit high. It looks to be a gap of about 0.5mm or so. I'm not sure why - maybe a manufacturing defect?
If that's where the now gone traction tire were, that difference is likely intentional, per me previous comments. Usually, there's a groove in the driver to hold the traction tire. If they both have that, there you go.
The trick here is that you need to get the BFS on just thick enough to be where the traction tires were and no higher.
You mention that the tender is equipped to pickup power. Does it do that on both sides or just one? Both sides is much better, but if not you can add wipers there to help with that. If only one side, the loco is probably the same, just one side. If you can add wipers there, even better. For good sound in HOn3, that's what we do and you have a weight advantage in On30 that should make it even better.
Yeah, if things that I've said about the traction tires apply, then I would not mess with trying to adjust axle ride heights. If you not comfortable with doing it, all the more reason, as you want to be confident you'll still have a square loco after you're done above all.
As for the differences between layout and test track, if applying a light touch at either end makes contact and get things going, I suspect that this is not relevant and just happened for other reasons.
Mike,The middle drivers aren't where the traction tyres were. The traction tyres were on the end axle (one of the flanged ones), and this is now back to its original diameter with the BFS filling the groove. It seems I may have to add extra diameter to the middle wheels to get them to contact the rails properly.The tender has power pickup for both sides, on all eight wheels. I've made sure they're clean, and I've added extra weight in the form of two fishing sinkers glued to the inside of the shell. I can add more if needed.Power pickup isn't an issue. I've got a sound decoder in it, and I can hear the sound going throughout. It's just that the engine doesn't move when it should, and I suspect this is because the side rod is taking the full force of the movement. The axle with the gears on it is one of the ones that doesn't touch the rails.
That's rather stranger. Almost would make me want to see another sample to see if they didn't slap the wrong drivers on it?
I suppose if you could find someone to plate them, building that up over several sessions or however they make plating thick (maybe just one longer session in the vat?) might do enough to add the difference.
Better yet would be four driver sets all the same diameter.
But if the driven gear driver isn't sending power to the others via the rod, that makes me suspect the quartering may be off, which could account for the issues you note, but not any difference between the test track and layout.
I've just had a realisation that may throw some new light on this. On the test track, I was using a powerpack and socket (identical to the one in the tender) to feed DC power directly to the motor. On the layout, it's running on DCC.
I wasn't able to do proper DCC testing on the test track, as it's rather short - it's my programming track. I'll try a decoder reset and see how that goes. Then I'll have to see about why it runs better forwards than it does in reverse.
EDIT:
I just tried this, and it doesn't work . I don't know what it is. The model runs smoothly forwards, slightly slower in reverse when I have its wheels up in the air, but when I put it on the track, it barely moves at all in either direction. I've checked the mechanism but it's not binding.
Honestly, these mechanical problems do my head in.
One other thing I've noticed is that I'm now getting an electrical burning smell from the motor, and that it slows down at all but full speed if I apply any load to the wheels (e.g. a toothpick of BFS).
Looks like I may have built a shelf baby. Perhaps I should reconsider doing this sort of thing. I've had more success with detailing On30 ready-to-run models (changing cabs, etc.) than I have with converting HO to On30 models. Of the 5 HO to On30 models I've done, 4 (including this one) are offline. In contrast, only 1 of the On30 rtr models is not working.
Hmmm... sounds like you need to disassemble the thing and check everything. In these situations, I put the thing aside a few days and do something else. I looked at the blog and it would be sad to see it die given the great results so far.
I have a feeling it may be the motor. I'm getting a slight burning smell whenever I turn it on. The mechanism runs smoothly, but as soon as I apply a load (e.g. its own weight), the loco has trouble moving.
OK I just found manufacturer's picture of that model and the two center drivers do not sit on the rails. It's made that way and they are flangeless. From what I have read I'm thinking this was a used loco. Sounds to me either of several things are wrong here. maybe the loco needs a good cleaning and lube job, missing thrust washers in the drive mechanism, bad brushes in the motor or the motor mount is bad, letting things slip out of alignment. But the center axles are as they should be from the factory. Ken
Ken,
Thanks for the advice. Unfortunately, I've got a history with taking apart steam locomotive mechanisms. I mean completely apart. Namely, they don't go back together afterwards. One of my weak spots.
I'm thinking that I may model this locomotive as 'under repair' on one of the turntable tracks, with a blue flag in place, workmen inspecting it, etc.
Righto, I've done some further testing.
On DC (i.e. with power supplied directly to the motor pins on the locomotive's plug), the model will run smoothly - slightly slower in reverse, but I can adjust the forward/reverse trim for this.
However, when I plug the locomotive into the tender (with the TSU-750) and try to run it, I get the behaviour described above. I did measure the stall current of the locomotive prior to installation. Despite having an open-frame motor, it only draws about 0.3A - around 300ma, which the TSU-750 can easily handle.
I was just thinking, could the open frame motor somehow be interefering with the back-EMF functionality in the decoder?
tbdannyI was just thinking, could the open frame motor somehow be interefering with the back-EMF functionality in the decoder?
Possibly.
It may also be an issue of starting current. While the running draw might be 0.3A, starting could be considerably higher, possibly at or above the 0.75A rating of the Micro-Tsu.
I don't recall if you've tried a full reset on the Micro-Tsu yet? One issue you may want to check first is the speed curve. If using a custom curve and you have even one setting that is at odds with the others in the middle of an otherwise smooth curve, it can cause similar problems, now that I think about it.
BTW, what is the output voltage of your DCC? Probably not your issue, but I've dialed back my NCE system to put out 12.5 v to help keep my Blackstone C-19 fleet cool.
The 0.3A is the stall current (the most the motor will draw), not the running current. I have tried a full reset on the micro-tsunami, with the same results as before.
My DCC is running on 12v, so that wouldn't be an issue.
Just now, I've double checked the wheels, and found that the ones on the rear axle were crooked. I've straightened those out, and removed the power pickup wipers for that axle in order to allow a bit more sideways travel.
I don't know what's going on. Nothing I've tried seems to work so far. It'll run slowly along straight track, then stop as soon as it hits a curve.
Oh, so the problem only occurs on curves? I have three of these locos and this would be unusual. It sounds like a wheel contact problem. Since you fiddled with your tender, is the drawbar causing problems on the curve? Is the loco staying in balance over the curve?
Simon
As long as You are still tnkering with it....try this...disconnect the motor drive line, including the worm gear and set the entire engine on the tracks and see if You can push it around the layout with no binding on any parts....You should be able to do that, with just a little resistance.......My guess is You can't and there-in lies Your problem.....a electric motor working hard to overcome resistance, will get pretty warm, to the point of burning up.
Good Luck!
Frank
Hi,
I've tried pushing the loco by hand without any motor, etc. and didn't get any resistance.
I have taken the motor out, cleaned the brushings, etc. and put them back in. Still the same result.
I tried running the engine on DCC both with and without the body shell on, and without the body shell it seemed to run alright. No slowing down, etc. Now, the only thing I can think of is the cab that I added. It's metal (from the Bachmann On30 4-4-0), and is right at the back of the loco. Could this be throwing the loco out of balance somehow?
Well, I tried it without the cab, having to remove some of the boiler piping detail in the process, and still the same results. Nothing.
I have literally now tried everything I can think of to get this model running, to no avail. Looks like it'll be going into the same shoebox where I keep my other failures. It's now only causing me stress.
Looks like eBay has some good prices going on the Bachmann Porters...
The new cab could be shorting some thing out. Is it posible that the cab is touching the motor somehow?
Will the train run with the boiler on but not the cab? If it does run, will it start without a push....under it's own power?
Ok, so it looks like its related to the changes you made to the body. Something is probably rubbing against the drive train, and only in the curves. Could it be something rubbing against the wheels, the rods or the valve gear?
snjroy Ok, so it looks like its related to the changes you made to the body. Something is probably rubbing against the drive train, and only in the curves. Could it be something rubbing against the wheels, the rods or the valve gear?
Nope. All the changes I made were above the footplate of the original. I've checked for rubbing, and nothing.
At this point, I'm not pursuing this any further. I've already spent more than enough time on this model, and all I'm getting from it now is stress.
I've ordered an 0-4-0 Porter to be the BVLC's new No. 7. I'll be putting one of the Backwoods Miniatures slope-back tender kits behind it.