Rod Placement on Drivers

Here is one more question.
I am trying to restore to operation a Minitrix 4-6-2 K4 Pacific. I have the motor running like a top, but the drivers are binding. I believe
that at least one set of rods was removed and then reattached 25 years ago. What is the proper placement of the rods on the drivers on the left and right sides of the engine. I have a side image from
http://www.visi.com/~spookshow/trix462.html
which makes the layout on one side very clear, but it does not tell me if the rods are placed directly opposite each other, i.e., so that both are say fully forward and/or the same height from the railbed. I can accept that for balance reasons that they might be 180 degrees out of phase, i.e., one forward and one rearward or one up and one down.
Thanks for the input.
Baumgrenze
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baumgrenze wrote:

- 90 degrees apart from side to side - right side leading. Minitrix drivers are always fun o put back into the chassis! Pull it apart now and do the following: Look where the screws come from and which way around parts go! - clean everything. - with the chassis empty, check the current collection wipers are all sprung out from the chassis evenly. - The first axle/wheelset to go back in is the one driven by the geartrain.
- the next driver is going to be affected in position by the chassis gearing, so you must slot it in about 45 degrees out of line with the already installed driver so that it rolls around the idler gear until it is precisely aligned with the first driver. I make it so the side I am viewing the crank is at the bottom.(or top) - When all three drivers are in and aligned turn the loco around. All three cranks sould face forward - or all rearward. - replace the keeper plate. - test run. - reinstall the valve gear. - if you've moved the wheels relative to each other on the axle then you have another problem!
Regards, Greg.P.
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Most likely one or more of the drivers is out of quarter ie they're not all the same number of degrees apart. That's what usually causes binding.
What you do is disconnect one driver at a time from the side rods until you find the one that is binding. Then requarter it or more likely in n scale try to find a replacement.
On model locomotives the placement of the rods doesn't really matter. Just aesthetics.
Eric
Baumgrenze wrote:
"I am trying to restore to operation a Minitrix 4-6-2 K4 Pacific. I have the motor running like a top, but the drivers are binding. I believe that at least one set of rods was removed and then reattached 25 years ago. What is the proper placement of the rods on the drivers on the left and right sides of the engine. I have a side image from
http://www.visi.com/~spookshow/trix462.html
which makes the layout on one side very clear, but it does not tell me if the rods are placed directly opposite each other, i.e., so that both are say fully forward and/or the same height from the railbed. I can accept that for balance reasons that they might be 180 degrees out of phase, i.e., one forward and one rearward or one up and one down."
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I'm not so sure about that... I think it does matter. Especially if only one of the drivers has the gearing and the rods move the other drivers which is the case for 90% of the models out there...
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Big Rich Soprano wrote:

More or less correct. In reality, it can be quite confusing, especially to a "newbie". Not all models are constructed anything like a real steamer.
IF the axles are all geared together, as is the case with a fair number of N-scale steam locos, and some HO ones too, then the 'phase' angle of the driver cranks (from one side to the other) does not matter ... AS LONG AS THEY'RE ALL THE SAME!
If only ONE driver axle is geared, as is usually the case, then the phase angle *IS* important for exactly the SAME reason as on the prototype. The 'other' drivers are powered via the rods, just like the prototype, and the phase angle must be somewhere near 90 degrees ("Quartered") in order to drive at all. Precisely 90 degrees is NOT required, but, ALL AXLES MUST BE EXACTLY THE SAME!
On a model, the issue is somewhat complicated by whether the rods are rigid, or jointed. Most model rods are jointed (as are the prototype's). With three or more axles and rigid rods, then the phase angle can be almost anything and they will usually still work, sort of. AND, EVEN THEN, ALL AXLES MUST BE EXACTLY THE SAME! They will still work BEST if somewhere near 90 degrees, however.
On a few models with rigid rods, the rods are not even connected to the intermediate drivers at all, just the first and last (or some other combination). In this case only those drivers connected to the rods need even be at the same phase angle.
And, to complicate things even further,the hole spacings in the rods must match EXACTLY the axle spacings in the loco frame (which is NOT always the case with poorly made models). AND, the crank 'throws' must all be equal in length (which is NOT always the case with poorly made models).
It's a SWAMP, until you understand how it's supposed to work.
Dan Mitchell ==========
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baumgrenze wrote:

[...]
Actually, these locos never did run well. Atlas actually sold some of them as "display only" models! Presumably these were returned for repairs, and Atlas gave up on them. I have one, and got it to run failry well for about 5 minutes. The side rods are the main problem, but the tolerances in the gears etc are way too large, which makes for a sloppy mech, and sloppy mechs always bind eventually.
I suggest you adopt Atlas's solution, weather the thing, and park it on a spur near the roundhouse waiting for "future repairs."
HTH
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Wolf Kirchmeir wrote:

Atlas sold _Rivarossi_ products and those weren't well engineered. Rivarossi took over several N scale loco models from the firm Roewa in the mid 1970s which were well engineered (a Berkshire and a Mallet from memory)
Minitrix always were excellent quality and even the models designed in the 1960s ran well and were reliable. Most of them are still in the Minitrix catalogue today. Because they have been around for so long, there are plenty on the second-hand market that are worn out, which may give rise to the feeling that they can be unreliable.
Regards, Greg.P.
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Greg Procter wrote:

[...][...]
Yup, you're right, I checked the li'l beast and it says "Made in Italy." [...]
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Wolf Kirchmeir wrote:

The Rivarossis were quite good looking - the motor was rubbish!
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Looks to me like the siderods are 1 pi3ce rods rather than the 2 piece rods of larger scale locos. As such, there may be a "side" requirement due to offset axles. If so, try swapping the sides and see if things work better. The position of a driver in the frame shouldn't matter as all of the drivers should be quartered the same. I'll also note that it may be one of the drivers has slipped on the axle and, if so, you'll have to find it and requarter it to the same as the rest of the drivers. IN many cases, it may be easier to just find a new set of drivers that are all quartered correctly. I'd start troubleshooting by removing one of the drivers and see if that one is the problem or the other driver is the problem. Good luck as this can be an interesting problem. -- Why do penguins walk so far to get to their nesting grounds?
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