Need some advice and input from forum members. I have a Atlas C-628 that has been noisy from the begining. Ron Bearden's technique does not work on 6-axle locos. Here is what I have done to minimize the noise so far: -Motor shifts around so I used pieces of plastic to hold the motor in the frame. -Isolate bearing blocks by wedging small pieces of plastic to minimize vibration. -Removed some slack (not too much) on the driveline. -Checked for cracks at the dogbone and found none. -Bought new trucks and didn't change noise. -Lubed with Atlas gear grease. -If I run the loco not on the track and turn the trucks, it is not noisy and sounds like any other loco. This has helped with straightline performance. But as the radius of the curve becomes tighter (9.75 max), the more it groans and slows down. This doesn't happen to my shorter 6-axle locos such as a SD-24 or my longer one, a SD-60. Any advice? Tks!
Is this the "Six Axle Hop?" That is another Ron Beardon solution. Check here for six axle hop photo clinic. Maybe it will help or you can eliminate that solution. I must say it doesn't sound like six axle hop. Otherwise you have covered most of the things I can think of. That C626/630 is a very smooth engine.
The answer is right there in front of you, quit running on tight radius curves. If you don't have space restraints, I would suggest you graduate to wider radius curves. You won't believe the improved performance of your train equipment. As a friend of mine says emphatically, "You don't run six axle locomotives on tight radius curves...period". I hope that helps.
Hey Rick.... Did you read >>> "This has helped with straightline performance. But as the radius of the curve becomes tighter (9.75 max), the more it groans and slows down. This doesn't happen to my shorter 6-axle locos such as a SD-24 or my longer one, a SD-60." Seems six axles locos WILL run on tighter radius curves :tb-tongue: .
LOL We are going to rumble. I stand under what I said. And since when did you start running on 9.75 radius curves? The last I heard your tightest radius was an 11" radius curve. You want to improve the performance of your train equipment you will grow-up, mature, graduate and move on to wider radius curves.
Your #1 problem/fix, "-Motor shifts around so I used pieces of plastic to hold the motor in the frame." is odd to say the least. Why is the motor shifting around in the frame? Also #2 problem/fix, "Isolate bearing blocks by wedging small pieces of plastic to minimize vibration" is a new one to me. I have never seen an Atlas motoror bearing blocks do this. I wonder if you got an engine with the wrong motor or possible wrong frame. Did you buy this new or on Ebay? I would check both frame and motor against the Atlas parts list either on line or with the sheet that came with the locomotive.
Bought it on eBay as "new". No wear on wheels, front handrails not installed. Took the shell off and everything looks pristine and I am the first to put my fingerprints on the virgin frame. I actually have posted this many months back over at the Atlas forum and Ron Bearden himself replied about adding shims on the bearing blocks to isolate vibrations. There was another member suggested to reduce slack on the driveshafts as he also had a similar problem. The motor saddle doesn't seem to be doing it's job and that is why I have shims to hold the motor tigher against the frame. I don't think buying another saddle will resolve that, but perhaps it will minimize the number of shims I have. Removing the 9.75" curves is not an option; but my layout is a roundy-roundy and with my expansion, I am able to bypass that section. Or, I can use it as a static model. Like I said, I have shorter and longer 6-axle locos that do not have this issue. I am stumped.
sd24 and sd60 have symmetrical axle spaceing while the first two axles on a c628 are closer together than the third one. the trucks of a c628 can not turn enough to the left/right for 9.75" curves. trucks of sd24 and sd60 can turn a few degrees more. you can change motor, driveshafts, trucks as much as you want. a c628 or c630 will always run noisy on such tight curves. anyways, 9.75" curves are a torture for every 6-axle engine.
Is there a fix? That seems like a logical answer since my other 6-axle locos don't have that issue. But even in the straights, it is still a little noisier than my other locos. Drives me nuts since the quietest and smoothest loco in my fleet of mainly Atlas locos is a cheap spring-driven Life-Like GP-38.
a gp38 is a 4-axle engine. this causes less binding than a 6-axle. no matter if it is a lifelike, atlas, kato or model power. no easy fix except do not run on 9.75" curves. you could turn down the flanges on the center axle. but i don't think this is a good idea.
I'm usually the guy that is pushing the envelope on sharp curves anyway... but.... I've got a C630. The issue isn't necessarily six-axle trucks. There are two things going on here. 1) Truck pivot point on almost all new split-frame diesels is between the worm gear and the worm. If that angle gets tight enough (and it is usually worse one way than the other) the gear relationship binds, period. Your issue may, on a slight chance, be due to the tolerances between those gears being too tight; i.e. the truck is too close to the worm due to the position of the bearing block, variability in the frame letting the truck ride low, etc. 2) The wheelbase distance between truck centers on a C630 is relatively long, one of the longest out there, and the longer the pivot points are apart the sharper the angle of attack is on those gears to get around a sharp curve. For practical purposes, a 'full length' six-axle unit (unlike a SD38, RSC2, etc) is pushing it pretty hard below 11" radius. You're just lucky if it works, even if the manufacturer says it can negotiate 9 3/4. The only way to really solve it from an engineering standpoint is to keep the worm gear relationship constant and pivot the trucks at a universal - think the old Roco E-units, some Life-Like designs, etc. That pretty much predates current split-frame designs. The only 'throwbacks' I see are units like the Kato NW2 that has it both ways. That design is usually limited on curves only by how far the trucks can physically turn. If you take the trucks off and roll them through the curve with your fingers, you may feel them binding, and if that is going on then that's another issue entirely. You may have tight gauge on the rails, lack of lateral movement on the center axle (usually a design problem) or the gears actually binding inside the truck in certain circumstances. I'm not the one to whack you for tight curves, I've got way worse than that. I run 11", but only on hidden track. I do have one 9 3/4 radius curve on an industrial siding though, so I can test things on it. My logging railroad module goes down to 7 1/2". But heck, even an Atlas GP7 binds up a little on that 9 3/4 siding, you can tell it's right on the design edge of the truck swing and gear tolerances.
OHhhhhhhhhh...Ya ready to rummmmbllllllllleeee? I am going even wider yet....just sayin some guys CANT get wider curves. AND some six axles WILL run on tighter curves :tb-tongue: * In this corner...weighing in at 285 and 6'6".....George...The 'Mountain Train Man' !! :thumbs_up: ** the crowd goes wild !! :tb-cool: .
One more thing I'm wondering is 'how' you're getting a 9 3/4 curve. If you're using flex-track - particularly C80 Atlas, it's possible the gauge has become a lot tighter than you'd ever imagine. That stuff doesn't like tight curves. The looseness of the one rail, under the right circumstances, can really bind stuff. And the C55, well, I don't have it, but on general principles it's pretty easy to run tighter than you think. For my really tight curves - I've either used 'out of the box' Atlas C80 and soldered it up (it holds gauge wonderfully) or taken sectional track and cut additional slots in the plastic ties to even get it a hair tighter. The tight ties of sectional track hold gauge far better than flex, particularly when you have NO MARGIN in this situation.
Bring it on! The rumble is on as George The Bull and Rick the Bear prepare to do battle. The bell rings and the announcer moves away from the center of the ring. Snickering can be heard in the crowd. The announcer declares, "And in this corner weighing in at 200 and 6'", the fighting machine of blah, blah, blah. With broad shoulders and a fat stomach. As the crowd comes to their feet...booing and hissing. Leaving for a commercial break...darn commercials. To the subject at hand: The six axles will climb around the curve but they don't like it and quite often derail. Never mind the noise they make. Run them on wider curves and...well....you tell me. Sorry, the fight was over so quick. Well, sometimes that's the way it goes. Isn't that Rick and George pool side with all those girls hanging on them? Wider curves? George you ok, no concussion I hope!
I'm with Rick and others here.....long wheelbase 6 axle loco's just don't work well on 9 3/4. Most newly tooled loco's are being designed with 11" as the minimum radius. As Randy said, its not the trucks, it's the fact that the wheel base is so long and the design of a fixxed worm with a pivoting worm gear puts things in a bind at extreme twist of the truck. About the only thing you can do is set the loco up on a 9 3/4 loop, crank it up and let it run. Eventually the worm/wormgear combo will wear enough that it doesn't bind. I have experience with this, running a GP15-1 on a layout with 6 1/2' radius corners. It takes about 100 hours of running before it really frees up.
Gorgeous George vs RICk Flair These are always good bouts. <Ding> Round Two. Everyone...It's your railroad...run whatcha like. If it works...kudos. If it don't...sell the loco and buy one that will. * GEORGE looks over at RICK who is staggering against the ropes. He hears the crowd chanting..."finish him! finish him !! Nah...we got girls waiting at the pool...LOL :tb-cool: .
LOL I was staggering before the "Rumble". Oh, I can't wait to get out there with those girls. OOP's. I thought we were told they were Red Hot Ladies. The add really reads Red Hat Ladies. @#$@#@#&*%$@~! George, You wrote: Everyone...It's your railroad...run whatcha like. If it works...kudos. If it don't...sell the loco and buy one that will. Did you really think I was in "Tell" mode? I couldn't agree with you more. I was sharing my experience with those bad boys. Nothing but trouble on 9.75 radius curves. The fight finished: Funny, I thought I heard someone counting to ten. What's with the stars and my ears are ringing? COL Tony, Excuse me while I pick my teeth up off the floor. My jaw is down there with them...some where. George, was that a right hook or a left hook? That might give me some idea where it is. Thanks! Well said.wink: Has the original poster responded or have we scared him off? Hey, I was busy. Yep, he's hung in here with us. He'll figure it out. George, LFMAO To much fun!
