So i’ve been teaching myself to work on trains. The local repair guy retired so there is knowone to fix them in the area. I must say though that i do enjoy it. Anyway ive had to rebuild a few e-units. Should the plunger or pivot points of the plastic drum be lubricated? Also should i use a special lubricant to not eat away at the plastic drum? Thanks in advance for any help.
Do not lube an e-unit, it should function dry. If it gets dirty over time a spray cleaner from Radio Shack should do the job. Tuner cleaner or any other that will not harm plastic will work.
Agree with the above. Do not lubricate the e-unit. I use denatured alcohol to clean the drum and fingers, and that’s it.
No lubrication is required. There are some other tips which you should keep handy. Here they are:
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E-units like to buzz, some very loudly. The reason is that there is TOO MUCH voltage being applied to the coil. The effect creating the buzz is the magnetic vibration between plunger and coil. To fix this, you want to reduce the voltage to the coil but not to the motor, lights etc. To do this you carefully clip the very thin coil wire going to the post where the track power is attached and connects to motor etc. Now place a 10 ohm - 10watt resistor between that post and the very thin wire. Buy resistor at electronics store or radio shack. Once all back together you have preserved your operating voltage to the engine but reduced the voltage to the e-unit coil reducing or eliminating the abboying buzz.
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E-units like to “clack” or “stick” in up position when power is interrupted. This is caused by the top of the pawl hitting the underside of the coil case when activated and reaching the top of its travel and suctioning at top because there is dirt or oil up there. To fix this, take a small piece of cardboard or other suitable material. (Matchbook cover thickness.) Cut it to fit the flat back of the pawl top which ends the upward travel of the pawl on the case. Using some supper glue, glue it to the pawl overlapping the end by 1/16". Now when the pawl travels upward, the cardboard patch hits the metal rather than a metal to metal clack. You will like your engine better with these easy modifications.
Hugh Laubis
TCA 70-3150[:)]
Reducing the voltage to the coil increases the track voltage, and therefore the motor voltage, at which the e-unit steps. This can cause the locomotive to lurch when going to the neutral position or make it impossible to start smoothly. Indeed, some motor-e-unit combinations do these things as built, in which case adding the resistor will make the undesirable behavior worse. But, if you can reduce the voltage without getting these symptoms, there is no reason not to do so.
Another way to quiet an e-unit is to operate it on DC by installing a bridge rectifier between the coil and the voltage source that feeds it. This generally also increases the coil current, since the coil inductance no longer assists the coil resistance in limiting the current; so the e-unit will step at a lower voltage and run hotter. Adding an electrolytic capacitor across the coil further increases the voltage, but will quiet even the most stubborn e-unit. In these cases the series resistor can be used to lower the coil current back to a reasonable value if the coil gets too hot.
I believe that e-units generally stick because the pawl wears a small notch into the crotch of the drum teeth. The notch catches the pawl on its return travel. I have found that smoothing out that notch restores normal operation. Restricting the upward travel may also help since it may keep the tip of the pawl from ever reaching completely into the apex of the crotch.
I also agree that the e-unit should not have any lubrication. Just keep it clean.
As for the sound of the e-unit…I enjoy hearing the sound! Much of the growl coming from a postwar diesel comes from the e-unit and that’s what gives a postwar diesel that powerful aura. You might notice that with postwar steam engines with cast metal shells you don’t hear the e-unit buzz nearly as much. I think that the plastic shell of the diesel engine amplifies the sound to a great extent. Just try running a diesel without the shell and you’ll hear the difference.
IVESBOY,
I leave it up to you. My e-unit suggestions were only meant to add some SIMPLE fixes to your notebook. I have been doing these for years without any consequence except pleasant success.
Looks as though there are some folks who just plain like “hearing E-Units Buzz” and other Electronic Engineers who are attempting to show off their high school education and “like to hear themselves talk”. Theory is one thing and SIMPLE, practical success is another.
All the Best,
My last word on the subject.
Hugh
I always apply a drop of light, plastic compatible oil to the pivot pins on the drum to reduce wear.
As I understand it, when Hugh has something to say, it is a helpful SIMPLE fix that promises practical success, while one who comments on Hugh’s advice is showing off by posting theoretical nonsense just to hear himself talk. Do I have it right?
Hugh,
The noise is also caused by loose staking points. The cardboard would be a temporary fix at best. Also, the 10W resistor is bulky, and it will produce clearance issues in some locos.
lionelsoni,
Bob,
You got the message all right, but I doubt that many members of this forum fail to appreciate your four thousand plus posts. It has to be frustrating to be criticized for working at a higher-than-average plane, but it doesn’t make sense to “dumb-down” your advice. Keep it up and those who can will catch up, and those of us who can’t will have to rely on lesser lights. You are always worth hearing – even when you are at your most incomprehensible. [:D]
Now for a real challenge. Try answering EIS2’s question about the operation of the postwar barrel-loader. I consider it to be important because the 397 coal loader, the various horse and cattle cars-and-corrals, as well as all of the “Vibrotor” driven accessories employ interesting variations of the same basic principle. It illustrates how Newton’s Laws of Motion, which work perfectly only in a frictionless vacuum, can be “finagled” by engineers to produce something that works in the real world. Based on many (not all) of the responses on the other forum, it turns out that it isn’t easy to describe the operation in terms that adults who are not engineers can understand.*
The task here, as I see it, is not only to do that, but to do it in such a way that the adults can explain it to an eight-year old without resorting to “it’s magic.”
- I found remarkably little on the internet about “vibrating conveyors” and their ilk. One source ran to 763 pages, some of which are in German. Mercifully, I will neither cite nor quote from it if I should decide to give it a try; but in any event – you go first.
Aside from realizing that there must be some non-linear behavior between the ramp and the things moving on it, I haven’t a clue. I have never owned any of the vibrating accessories and never investigated how they work.
Thanks for the vote of confidence.
I agree with bfskinner keep up the good work Bob. Your knowledge and info has been vary helpful to me and many others. Thanks for all the help you have given me in the past.
Jason
well said guys. Bob has always been helpful when Ive needed advice and I always apreciate his responses. It’s not the 4000 posts that are important…it’s the fact that the guys on here have respected and benefited from them greatly.
David, I also love the sound of the e-unit. After running my postwar stuff for a while I find the new stuff way too quiet. Lionel should introduce some kind of Rail Sounds E unit buzz [(-D]
I don’t love the sound of post war e-units, but I’ve come to learn that a loud one is nothing to be concerned about. Some of mine are quiet. Some are loud. I accept them the way they are as long as they work properly.
Wow, didnt expect the wealth of information i got but thanks. I ended up doing the following…
After taking the unit apart (prewar) i noticed a black greasy film on everything, drum, fingers, and plunger. I cleaned all the parts with dio-sol, a scale hobby craft solvent i assume to be plastic safe as it is made for HO polystyrene (sp?) kits. I then reassembled the unit. The unit functioned properly but the paw would go askew to the left when it traveled up, it would then stick in the up position. As i had not yet read the post i used a small amount of good old 3-1 household oil to clean up the pivot points of the paw, and on the plunger. I was careful to apply it sparingly. After a few dozen cycles the unit functioned as new with no malfunctions. Hopefully it continues to do so. Think it will be fine unless the oil attacks the plastic of the drum. To my knowledge the 3-1 brand oil is plastic safe. Correct me if im wrong and ill wipe it off.[oops]