I am presently servicing an HO Scale Athearn Genesis 4-8-4 Loco.
Most of this product is made of plastic and die cast.
The pins are metal that hold the gears and part of the die cast frame.
The gears that go into the pins are plastic.
So, do I use light oil or light grease on the gears?
Also, synthetic products are recommended, like Labelle, which has a variety of choices.
I am enclosing a picture with the plastic gears and metal frame.
From what I have read, some people say light oil and some say light grease.
I am confused oil or grease or both?
Thanks.
Use white 'lithium' grease. Available widely. I'm pretty sure you can pay a lot more through hobby suppliers.....
Labelle 102 is a thin grease, almost a heavy oil, for enclosed gearboxes.
Labelle 106 is a heavier grease, loaded with PTFE ('Teflon') for exposed gears.
Note that both of these are advertised as 'plastic compatible'.
Either of these will work, but I think the 102 is closer to the operating conditions in the rebuilt 'tower'.
Meanwhile 108 is the light oil for bearings and journals: axle bearings, rod bearings, motor bearings. Read the documentation for which bearing types need oiling and which 'don't'.
Some bearing types are 'sintered' or pressed from fairly coarse metal powder (the 'Oilite' bearings were an early example) and these allowed a good reservoir space of light non-gumming oil and an easily-wetted bulk bearing area for long light-duty life. Some of these bearings are now made 'self-lubricating' or 'lifetime lubricated', sometimes with solid lubricants incorporated in the sintering. The manufacturer would be the best reference for type of lubrication to apply to these.
There are 'kits' available with all three of these lubes in a plastic case, if you don't want to buy them separately.
I will take your advice and use the Labelle product #102
Thanks to everyone for clarifying this issue.
Cheers!
One more thing I wanted to know.
I noticed that when I place the plastic gears in the pins, even with the Labelle #102 grease, gear #128 turns freely, whereas gear #122, which would turn the worm gear is stiff!
Could that have originaly been the problem, as I understand gears are supposed to turn freely and no friction.
So, in order to make sure the gear turns freely, is it better to try and expand the hole in the #122 gear or shave done the metal pin?
Always adjust the fit by reaming the gear, slightly.
You could theoretically make a tool that would cut the OD of the pin, and align it in the drill press. But that's both the work to make the tool and the investment in marking and measuring equipment to check the adjacent gear centers to cut the shaft so it's precisely where it ought to be.
It is nearly impossible to file a shaft in a gearbox like this so it is both smoothly cylindrical and not tapered in some way. The one exception is if there is visible scoring or scratching due to something being forced on or off; you might be able to smooth those down with a little lapping film applied to something relatively hard and straight but thin like a fine flat jeweler's file.
Having said that, you might want to look carefully at the sticking shaft, with a magnifier or loupe if you have one, to see if there is some problem with the casting. When a part is made this way, there is usually some 'draw' (taper) to make it easier to extract the part from the mold. That would cause the 'base' of the shaft to be thicker, and this may cause fun with the gear. Try turning the gear over to see if it runs better; if not, see if you can identify where it is binding.
Incidentally, in most of these drives the gear couldn't possibly backdrive a worm. The interesting question is whether the stiffness of gear 122 contributed to the force popping the worm cover off...
... you will certainly want to address that stiff action.
Overmod Always adjust the fit by reaming the gear, slightly. You could theoretically make a tool that would cut the OD of the pin, and align it in the drill press. But that's both the work to make the tool and the investment in marking and measuring equipment to check the adjacent gear centers to cut the shaft so it's precisely where it ought to be. It is nearly impossible to file a shaft in a gearbox like this so it is both smoothly cylindrical and not tapered in some way. Having said that, you might want to look carefully at the sticking shaft, with a magnifier or loupe if you have one, to see if there is some problem with the casting. When a part is made this way, there is usually some 'draw' (taper) to make it easier to extract the part from the mold. That would cause the 'base' of the shaft to be thicker, and this may cause fun with the gear. Try turning the gear over to see if it runs better; if not, see if you can identify where it is binding.
It is nearly impossible to file a shaft in a gearbox like this so it is both smoothly cylindrical and not tapered in some way.
It looks like it is tighter as I insert the gear in more.
Obviously, the pin was not perfectly round and must of come out of the mold like that.
So, I will start by reaming the gear and get to eventually fit and turn freely.
Thanks again.
I think you should start by lightly chamfering (beveling at 45 degrees) first one and then the other side of the bore in the gear. This will give clearance if something at the base fillet of the shaft is messed up, without getting into the fun of opening up the hole in the gear concentrically. Again, try the gear 'both ways' at each step of the fitting.
Overmod I think you should start by lightly chamfering (beveling at 45 degrees) first one and then the other side of the bore in the gear. This will give clearance if something at the base fillet of the shaft is messed up, without getting into the fun of opening up the hole in the gear concentrically. Again, try the gear 'both ways' at each step of the fitting.
Ok.
Doing it now.
Done.
I managed to open the hole enough so that it turns freely now.
Tomorrow, I insert the brass rod in postion #125, grease the gears with labelle #102, re-assemble the loco, put her on the track and hope for the best!
One question that I have, does any manufacturer of ho scale trains make gears out of brass or metal instead of plastic?
I would think it would be more durable.
Thanks to All.
Hawks RuleOne question that I have, does any manufacturer of HO scale trains make gears out of brass or metal instead of plastic?
To understand the plastic gears you might start with the chemistry of certain plastics, particularly acetal (Delrin). These are slippery because they have what's called low surface activity, which means they have low surface friction -- gears made of Delrin in light duty will have low running resistance and good wear characteristics in the absence of external lubrication. That makes them attractive for some types of model-railroad drive, as whether or not the gears get 'proper lubrication' they will still at least work -- even if the old lube starts to harden and push out of the contact areas between the teeth.
Some pairs of metals are better than others when run together, but if reducing noise from a cost-effective (you may choose to read that as "as cheap to manufacture as we can get away with" and often not be far wrong) very often it remains better to use a fiber, phenolic, or plastic gear in at least one position in the train, which reduces the overall noise and 'cogging' of an all-metal train of spur gears with cost-effective clearances and lash.
If I remember correctly, one of the best worm-drive systems, the multiple-thread-worm Helix Humper, used a fiber driven gear which could conform a bit to the machined worm-thread (think of it as a very long sliding-contact tooth) in operation, and which would preferentially save wear on the expensive worm.
Part of the difficulty with the drive in your FEF-3 is what that geartrain does -- it is analogous to the winding wheels in certain ultrathin watch movements, which use a train of little spur gears around the outside where there aren't any components involved in timekeeping. Instead of the old use of a worm on a big driven gear on the axle... which would be obvious from the side... Athearn has a group of little idlers translating the worm motion down to one axle (which then moves the other wheels either by rods or more gears in the chassis. Older Athearn diesels used this approach with plastic gears for many years... with effectiveness if not particular silence. Doing this with metal spur gears would require extraordinary tolerances to avoid gear noise, and of course lubrication integrity eould become far more important than with plastic.
If it helps any, grease (heavier) is used in places like gears. Oil (lighter) is generally used for bearings. A loose laymans rule because there are exceptions.
(oil drips, grease does not)
Gears spin and are generally open. An oil would just fly off. A grease however can be slung off, but some will always stay on the gear. Thus keeping it lubed.
Bearings are usually enclosed. Sometimes not, never the less, if oil can be slung around and remain on the part supposed to be lubricated, then you can use oil. Besides that, you may not be able to apply grease because of the seal, where only oil can be applied.
In your case, you need a grease - LaBelle #106 (micro gear lube with PTFE) for those gears. And the axles if your gonna lube those.
Use LaBelle #108 for your rods, slides, motor bearings, and shaft bearings.
PMR
Hello Overmod,
That is one thorugh and informative explanation!
After reading that it makes a lot of sense especially the cost factor and noise.
Thanks again for the info, very much appreciated!
PM Railfan If it helps any, grease (heavier) is used in places like gears. Oil (lighter) is generally used for bearings. A loose laymans rule because there are exceptions. (oil drips, grease does not) Gears spin and are generally open. An oil would just fly off. A grease however can be slung off, but some will always stay on the gear. Thus keeping it lubed. Bearings are usually enclosed. Sometimes not, never the less, if oil can be slung around and remain on the part supposed to be lubricated, then you can use oil. Besides that, you may not be able to apply grease because of the seal, where only oil can be applied. In your case, you need a grease - LaBelle #106 (micro gear lube with PTFE) for those gears. And the axles if your gonna lube those. Use LaBelle #108 for your rods, slides, motor bearings, and shaft bearings. PMR
Hello PMR,
So you are saying to use Labelle #106 instead of #102 on the gears?
Yes.
Clean your gears as clean as you can get them. Clean the housing in which they reside, too. Apply #106 around a gear , just enough to fill the valleys. As the gears mesh when running, the grease (106) will get moved around to all the touching gears. Lubing all the gears will be too much.
If you use #102 in this instance, most of it will have dripped off your gears before you even re-assemble them. Theyd still be 'wet' from the oil, but not protected like the grease will do.
While #102 is listed as a 'gear' lube, just like #106 is, #102 is for gears in a sealed area. The lube puddles in the bottom and the gears are spinning thru this lube. Much like oil. #106 is a grease and can be used in open areas where retention is not an issue.
In simpler terms, #106 is a goo, #102 flows like water. You want what will stay on the gears.... not leak out on your hands and track. You want #106 on the gears.
Hawks RuleSo you are saying to use Labelle #106 instead of #102 on the gears?
I don't think there is any advantage to using 106 over 102 in the bores of the gears, especially if the fit is tight.
The place where 106 is best would be on the worm teeth, and of course if you used it there it would 'print' to all the spur-gear teeth in a few seconds or minutes of running.
Thanks to everyone for your input!
This is what Labelle writes about its lubricants:
Labelle #108 fine oil for “Z” / “N” / and small “HO” locos, for light duty uses, e.g. for Small HO, N, and Z size scale model railroads- (OK to apply directly to motor brushes and bearings). Axle bearings on both cars and locos, smaller HO locomotives, including Steam Engine Valve gear.
Labelle 106 grease: (For) Model Trains: Exposed or Enclosed Gear Boxes (all scales)
LaBelle #102 is a versatile gear lubricant and has an unlimited number of heavy duty uses for home, office, or laboratory, such as model Trains: Exposed Gear Boxes (all scales).
https://labelle-lubricants.com/model-train-lubes/
Simon