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If the replacements are indeed nylon then you don't want to use them. If they are delrin, then they might be OK. Nylon hardens and cracks with age.
Pete
Norton posted:If the replacements are indeed nylon then you don't want to use them. If they are delrin, then they might be OK. Nylon hardens and cracks with age.
Pete
Can you physically tell the two apart? So is nylon good for at least 10 years, or is it a matter of storage conditions, etc.?
They are very similar. Delrin is usually either white or black. Nylon can be found in different colors. A lot of Lionel accessories use Nylon gears and rarely last ten years. I take it the gears don't come with a description?
Pete
Actually I found three sources, one says delrin, one says nylon, the other doesn't say.
I can assure you, from experience, the nylon gears will strip. I was involved as a distributor for Darstaed for some years and they had bomb proof gears, but they were a bit noisy. Some opposition manufacturers addressed this by building locos with brass and nylon gears. They run much quieter, but after a while, they will strip. If you like to pull long consists, it will happen even quicker.
Most people go from Nylon to metal as the nylon will strip .
I have 40+ years on several of the OEM 8010-117 plastic gears without a single failure. My 8353 SF has hundreds of hours on it pulling its dummy and strings of mixed postwar & modern consists.
The nice thing about the 8010-117 gear on that 602 is that it will arrest the wear on the pinion studs, and you will get very reasonable long life from the swap. Either way, plastic or metal, assemble the truck with a film of Red 'N' Tacky on all friction & sliding surfaces(including the studs) and gear teeth for a long service interval and smooth operation.
Thank ya'll !!! I think I like the sound of a metal worm gear with delrin/nylon drive and pinion gears. If the delrin/nylon gears fail somewhere down the road, I won't mind replacing the drive and pinion gears as much as I would splitting the complete engine apart to replace the worm gear again. And I'm guessing the metal on metal of the worm and worm gear don't create much noise at all!
I did some looking around for non-metal drive/pinion gears, and I found a lot of different descriptions. Some sites say plastic, some say nylon, another says delrin, another lists gears as MLD CELC. Any idea what the latter moniker is?
I have now tried some "white lube", actually camshaft lube for new installs, and some red n tacky #2. I like the red n tacky much better because it seems to be basically car wheel baring grease which really sticks well to parts - and hopefully it is safe to all plastics. They both seem to do the job, but the white lube doesn't stay put for long.
This project is suddenly on hold for a while, real life taking precedence the way it does some times, but I will be thinking about it in spare moments.
Thanks for the many opinions to choose from - great crowd!!!!!
ADCX Rob posted:I have 40+ years on several of the OEM 8010-117 plastic gears without a single failure. My 8353 SF has hundreds of hours on it pulling its dummy and strings of mixed postwar & modern consists.
The nice thing about the 8010-117 gear on that 602 is that it will arrest the wear on the pinion studs, and you will get very reasonable long life from the swap. Either way, plastic or metal, assemble the truck with a film of Red 'N' Tacky on all friction & sliding surfaces(including the studs) and gear teeth for a long service interval and smooth operation.
Rob has it right, as usual. Just like many train people believe the myth that Super O track slices all roller pick-ups in half, an equal number immediately write-off the plastic gears found on many locomotives from 1970 forward. There's nothing inherently wrong with a well-engineered plastic gear in the right environment. Can they fail? Sure, but it's not anywhere near as often as is typically portrayed.
GeoPeg posted:I did some looking around for non-metal drive/pinion gears, and I found a lot of different descriptions. Some sites say plastic, some say nylon, another says delrin, another lists gears as MLD CELC. Any idea what the latter moniker is?
Lionel changed to DuPont Delrin for their O gauge production in the early 1970's, although the company's use of Delrin goes all the way back to 1959 or so with their HO line. Sometime in the 1980's, they switched primarily to Celanese Celcon. Both are Acetal plastics, with slightly different molding properties. I don't believe Nylon was ever used for Lionel locomotive gearing, at least since the 1970's.
MLD CELC stands for "Molded Celcon" in the Lionel engineering vernacular.
I hope this helps.
TRW
PaperTRW posted:ADCX Rob posted:I have 40+ years on several of the OEM 8010-117 plastic gears without a single failure. My 8353 SF has hundreds of hours on it pulling its dummy and strings of mixed postwar & modern consists.
The nice thing about the 8010-117 gear on that 602 is that it will arrest the wear on the pinion studs, and you will get very reasonable long life from the swap. Either way, plastic or metal, assemble the truck with a film of Red 'N' Tacky on all friction & sliding surfaces(including the studs) and gear teeth for a long service interval and smooth operation.
Rob has it right, as usual. Just like many train people believe the myth that Super O track slices all roller pick-ups in half, an equal number immediately write-off the plastic gears found on many locomotives from 1970 forward. There's nothing inherently wrong with a well-engineered plastic gear in the right environment. Can they fail? Sure, but it's not anywhere near as often as is typically portrayed.
GeoPeg posted:I did some looking around for non-metal drive/pinion gears, and I found a lot of different descriptions. Some sites say plastic, some say nylon, another says delrin, another lists gears as MLD CELC. Any idea what the latter moniker is?Lionel changed to DuPont Delrin for their O gauge production in the early 1970's, although the company's use of Delrin goes all the way back to 1959 or so with their HO line. Sometime in the 1980's, they switched primarily to Celanese Celcon. Both are Acetal plastics, with slightly different molding properties. I don't believe Nylon was ever used for Lionel locomotive gearing, at least since the 1970's.
MLD CELC stands for "Molded Celcon" in the Lionel engineering vernacular.
I hope this helps.
TRW
Thanks TRW, that's exactly what I was looking for! I knew there had to be a former DuPont engineer lurking out there somewhere! 
In general (it may not apply to the 602 with a Lionel replacement), plastic gears of the same diametrical pitch* will have a higher pressure angle** than the otherwise same metal gear. Gears of different pressure angles will not run well together if at all, and in my experience can overheat and jam in some Lionel diesel trucks if run long enough constantly. So this should be looked at.
*Note: A gear of 1-inch pitch-line diameter and 40 dpi (diametrical pitch, inches) will have 40 teeth. Lionel still uses 40 dpi in the post-war style diesel trucks, as did MPC, for the spur gears. Thus the 17-tooth idler gear will have a pitch diameter of 17/40ths inch.
**Note: The pressure angle defines the shape of the tooth. It is the angle the faces of two teeth in contact make with the line of centers. The Corporation used, for metal spur gears, two pressure angles: 14-1/2 degrees before about 1954, and 20 degrees, after per the adopted Unified Standard (Britain and the US once had inches of different lengths). Later came plastic gears, which in general (non-train) stock are found with 25- and even 30-degree pressure angles. The larger angles widen the base of the tooth, to reduce breakage.
I haven't gotten around to studying the plastic Lionel gears as yet, in regard to this. Also, with China production, there may be some metric gear sets, Some data I've seen suggests the next smaller metric tooth is in use often (can't recall which manufacturer). I believe my trouble came from getting the Corporation metal gears from both sides of the ~1954 divide into the same gear train. So the several pressure angles are far enough apart that mixing them is to be avoided. Don't forget the driver wheel is in the gear train.
These teeth are so small that it is not easy to see the differences. But I found that by making a sufficiently larger drawing of a tooth, I could recognize the several shapes at a glance, even in the small tooth. Of course, if you have an optical comparator ($$$, I assume) you don't have to make drawings. But I'm sure the process is on-line; basically unwind a string from a base circle, marking also the pitch and tip circles. This can be done in short chords using a ruler, on regular paper. I think I used 10X larger. Search for involute gear curve. It is quite easy.
***Final note: The shafts of Pullmor motors are made with a worm cut to match the helical bronze worm wheels. When the worm wheels came to be made of plastic, there was a mismatch. After a bit, this was cured by tipping the motor away from the worm wheel. Quite a bit later, this was corrected and the motor straightened again. I don't know exactly when and for what engines, or if I have an example to see the internal construction.
--Frank
F Maguire posted:In general (it may not apply to the 602 with a Lionel replacement), plastic gears of the same diametrical pitch* will have a higher pressure angle** than the otherwise same metal gear. Gears of different pressure angles will not run well together if at all, and in my experience can overheat and jam in some Lionel diesel trucks if run long enough constantly. So this should be looked at.
*Note: A gear of 1-inch pitch-line diameter and 40 dpi (diametrical pitch, inches) will have 40 teeth. Lionel still uses 40 dpi in the post-war style diesel trucks, as did MPC, for the spur gears. Thus the 17-tooth idler gear will have a pitch diameter of 17/40ths inch.
**Note: The pressure angle defines the shape of the tooth. It is the angle the faces of two teeth in contact make with the line of centers. The Corporation used, for metal spur gears, two pressure angles: 14-1/2 degrees before about 1954, and 20 degrees, after per the adopted Unified Standard (Britain and the US once had inches of different lengths). Later came plastic gears, which in general (non-train) stock are found with 25- and even 30-degree pressure angles. The larger angles widen the base of the tooth, to reduce breakage.
I haven't gotten around to studying the plastic Lionel gears as yet, in regard to this. Also, with China production, there may be some metric gear sets, Some data I've seen suggests the next smaller metric tooth is in use often (can't recall which manufacturer). I believe my trouble came from getting the Corporation metal gears from both sides of the ~1954 divide into the same gear train. So the several pressure angles are far enough apart that mixing them is to be avoided. Don't forget the driver wheel is in the gear train.
These teeth are so small that it is not easy to see the differences. But I found that by making a sufficiently larger drawing of a tooth, I could recognize the several shapes at a glance, even in the small tooth. Of course, if you have an optical comparator ($$$, I assume) you don't have to make drawings. But I'm sure the process is on-line; basically unwind a string from a base circle, marking also the pitch and tip circles. This can be done in short chords using a ruler, on regular paper. I think I used 10X larger. Search for involute gear curve. It is quite easy.
***Final note: The shafts of Pullmor motors are made with a worm cut to match the helical bronze worm wheels. When the worm wheels came to be made of plastic, there was a mismatch. After a bit, this was cured by tipping the motor away from the worm wheel. Quite a bit later, this was corrected and the motor straightened again. I don't know exactly when and for what engines, or if I have an example to see the internal construction.
--Frank
Thanks Frank! Well, I don't have a drawing of the driver gears, but I do have a couple of pictures of them, plus the two best pinion gears of the four "new" ones I received. Do they appear to emply a 14.5 degree pressure angle? The first image (IMG_8138) is the drivers and the original gears - they got kind of pointy and wallowed out. The second image is the drivers and the 2 "new" pinion gears. What's your opinion, do the new pinion gears seem to match the driver gears? Or too much wear to tell? In my opinion, the new pinion gears don't even seem to match each other....
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When it comes to gears, their materials/lubrication, noise, etc., I consult my 'gear oracle'.....NorthWest Short Line..."NorthWest Short Line is the world's premier maker of wheelsets, gearboxes, replacement motors, tools, and other products for the advanced railroad modeler. NWSL offers the widest selection of high quality model railroad upgrade and repair products since 1959."
Regarding noise, material combinations, lubrication, etc., they have this paragraph in their gear tutorial...
"Better gear life and less noise usually result if gears of dissimilar materials are mated with the driving gear harder (ie. steel worm to brass or plastic wormgear; brass worm to plastic wormgear, etc.). Noise is also a function of proper gear quality, spacing, bearing precision, and lubrication. Worn or sloppy bearings permit the shaft to vibrate causing both noise and excess gear wear. NWSL gears are of high quality and fine surface, but if you decide to lap the gears, toothpaste works well and is easy to wash out. Take extra effort to assure complete removal of ALL lapping compounds to avoid excessive mechanism wear, then lubricate the gears and bearing surfaces."
Great folks to work with! Very responsive and helpful.
For what it's worth,.......always.
KD
Nylon is an excellent gear material; not all nylon is created equal.
Note he said that his metal gears were "shot". Metals vary, and not all "metals" (which metal?) are created equal.
