This is my Heljan 37, Split gear on the right, replaced with JS brass gears ( in situ ) took only 15 minutes to replace, she now runs really well. Brass gears also fitted to my 26,33,37+55. New Nylon gears have been fitted to 20x2, 31+35 . I also have nylon spares for these. All the above are from Heljan first edition models. Tony.
Jim Snowden once did a batch of brass gearings and posted a thread over on the old Guild website offering replacements. Nylon gearings are just not to be relied upon because they not only split but the material degrades over time on contact with oil. I had a semi industrial sewing machine once to stitch new seat moquette fabrics for cushions and seat backs on my bus and the nylon gears driving the needle movement split too, so it isn't just an issue confined to model locos. RTR not being my thing tho so I wouldn't want to make comment on the Heljan manufacturing ethic but the models do seem incredibly expense as they are for something which in essence is just plastic... however hey ho that's just me.
My most troublesome new rtr OO locos are without doubt Heljan, build quality very poor, although most were so because of very rushed, sloppy assembly. In the end I preferred to resort to upgraded Lima and Dublo locos where possible even though several of Heljans range appealed, crude but generally well built, except, very few of my vintage locos were wired by anyone capable of soldering wires properly. Jim
I like the final result, I only own 1 Heljan loco and that's an OO Class 26. So far it's been a good runner, but then I don't thins it seen the light of day for nearly 10 years With Heljan, they like heavy models in both OO and O, so putting the gears under a lot more strain, not helped by driving into dead sections when the loco comes to a dead stop. You have a powerful motor which will stop dead, and all that kinetic energy gets transferred via the wheels (which can slip on the rails) to the gears, but will stop at the worm and the poor gears teeth take the hit eventually breaking from the base of the tooth to the gear center, splitting the gear, initially not an issue until the same happens further round and the gear falls apart. Flywheels will help as the motor will slow down rather than stopping instantly. Teflon may be a suitable alternative as well, we used to use them on cable making machines, as they were quieter than cast iron gears, also worked as a sacrificial part, cheaper and easier to replace than shredded cast iron gears and the surrounding casing. Just my two penneth Paul
My O gauge gears split because of poor materials , I bought some replacements and found one had already split. After removing the axle I ream out the hole in the gear and glue it back in position. I also do this on my N gauge gears , they don`t come fixed on a axle. Tony.
