HEY, THESE THINGS READ LIKE STEREO INSTRUCTIONS! Just kidding, I actually understand stereo instructions. Thanks for the help. I think I might need some ungrading. Just not sure how far to ungrade to.
Faraway,
I have my 2-8-0 spectrum now and have had it for about 2 weeks. I purchsed the one with the tsunami sound decoder in it and love everything about this locomotive. It is excellent running and great sound. It starts very smooth with low voltage. It surely beats my BLI 2-10-2 with QSI decoder. I will see how that one is this week when the sound chip upgrade for the QSI arrives. I was told that will take care of a lot of the running issues with the BLI 2-10-2.
Jeff
Though it seems to be overlooked in this thread, Bachman locomotives, even Spectrums, have severe quality control issues from the factory.
That said, ALL my Spectrums run. perfectly.
That’s because I KNOW they sell bad ones, to the point my LHS calls them “Botch-mans”.
When I need one, it comes out of the box at the LHS, and goes onto their test track. When I SEE it running perfectly, forward, reverse, low spped, high speed, stopping, starting, and when I INSPECT it closely for fit, finish and detail, and everything meets my approval, it comes home with me.
Otherwise it goes BACK IN THE BOX and I do without, or , more often, the LHS orders some more and they usually order quite a few so that at least one will look and run right.
If you insist on quality, you will get it. Whatever Bachman’s problem is, they do get it right, in my experience, about half the time. That’s based on experience with exactly ten Spectrum steam locomotives. Not a huge statistical pool, and not a generalization based only on one good or bad experience either, somewhere in the middle, but my assumptions are bourne out by what others have to say about the breed too.
Pick and choose, and you’ll get a beautiful locomotive that runs like a swiss watch.
Buy without testing, and you’ll get a lemon, frequently.
Your money, your choice.
I have to agree that your power pack could use an upgrade. I have quite a few Bachmann 2-8-0s, and all start and run smoothly on straight DC. I left the flywheels in mine, but I don’t think that they do much good. I did remove the flywheel and the circuit board from my Proto 0-8-0, and was able to add enough weight in their place to more than double its pulling abilities. Even though it is an early version with no tender pick-up, I have had no problems with it stalling on turnouts.
Wayne
My Grizzly Northern has eleven Spectrum steam loco’s ie four 2-8-0’s, four 2-10-0’s, one 2-10-2, a 2-6-6-2 and a three-truck Shay. All are now very smooth runners, some straight out of the box, others after a bit of tinkering, and in one case an exchange with Bachmann. I believe the Spectrums are very good value for money considering the level of details provided, comparing favourably with many brass models.
Regarding the cog belt drive, I’ve been told that the belt design is borrowed from satellite servo-mechanisms and is very robust. The cog design, like a timing belt or chain drive, allows no slip in response to sudden stops or starts, unlike conventional flat or vee type belt drives, which means that if the motor stops or starts suddenly so does the drive system, despite the flywheel. This can result in jerky behavior if electrical power is lost momentarily e.g. faulty track or switches, DCC glitches etc. In the case of DCC this can be compensated for, if a problem, by building in a bit of momemtum to CV3 and CV4.
[:)]
(bold added by me)
you’re right , the whole point of adding a flywheel is to stop the motor from stopping or starting suddenly , if , for example , the engine passes over a turnout and momentarily drops electrical contact . the problem we’re seeing here is that the flywheel isn’t heavy enough to keep the motor spinning long enough to have a noticeable momentum effect . your DCC fix for the problem works well , unfortunately the original poster is running DC . i think the only fix for DC would be to add a heavier flywheel and i don’t know if that’s possible in the bachmann
Sorry to disappoint. Setting all the momentum in the world won’t help a DC or DCC-powered motor keep turning when power is lost, even momentarily. Good decoders have “keep-alive” circuits that keep the decoder from resetting during a momentary power loss. But unless you have a special add-in circuit like the Lenz designed to keep the motor going for a second or two (involves adding fairly large capacitor(s)), the flywheel is the only defense to carry you through the track power loss. As has been pointed out, flywheels tend to be less effective on steamers due to extra friction from from side rods, valve gear, longer rigid wheel bases, and tender drag. And flywheels on steamers are usually smaller than on diesels to begin with. For a flywheel, adding diameter is the quickest way to build rotational inertia. Adding length and total mass don’t increase inertia as much as moving the mass away from the axis of rotation does.
my thoughts and experiences
Fred W
I think Fred W is right. The Bachmann 2-8-0 I kitbashed to better represent a B&M K8c ran beautifully on DC. When I initially put a (budget) DCC decoder in it, it started mis-behaving - stopping and starting with a jerk, hesitating at the slightest bit of dirt on the rails, etc. The flywheel just isn’t big enough in diameter, no matter how much momentum you program in …
… I switched the budget decoder for a Lenz Gold with the UP1 module and now its my best running steam loco.
Yes, it has a flywheel, not 2 of them like even the smallest diesel does. Diesels benefit from this, as well as not being encumbered by the additional friction of running gear. The more flywheels and the larger their diameter, the greater the momentum. That’s why the old Athearn BB FP45’s and the Proto 2K PA’s will coast into next week.