Bowser motor modification for Bachmann PCC trolley with an extra feature

[LDBennett]

I would like to document my experience here with the Bowser motor conversion for the Bachmann PCC trolley. We've been talking about it on another thread but it might go missed so I decided to start a specific thread.

I bought the HO Bachmann PCC trolley. The disappointment was how high the body sat on the chassis.... it did not look right at all. It ran alright but looked wrong. Through dumb luck I found the Bowser motor conversion for it. The Bowser web page said that the conversion lowered the body a scale foot. That's a lot and I decided that is exactly what it needed.

Before buying it I inspected the Bachmann trolley internally and could see that because of the tall powered truck there was no way to lower the body with the stock motor/power truck. The motor was a tiny can motor hung horizontally from the truck itself.

The Bowser motor conversion (specifically for the Bachmann PCC trolley) included a chassis and both the powered truck and the un-powered truck, all assembled. The chassis is full length, cast metal with the motor hard mounted horizontally to the chassis, kind of centrally. The powered truck gets its power from a drive shaft with two u-joints. The motor is much bigger and is in a cast metal can. The task was to adapt the Bachmann body to the Bowser chassis. The instruction were not very clear so here is how I did it.

First off, you have to remove the Bachmann body from its chassis and remove the plastic central tower in the body that is used to mount the Bachmann chassis, using a Dremel cut-off wheel. You also have to remove the lighting clear plastic molded part. You have to run sans lights.  I just glued the red & white "bulbs" into the body and cleared the off the rest of the lighting plastics. To mount the Bowser chassis you have to glue in two cast metal threaded end plates. If you just glue them in they will never align with the holes in the chassis (the instruction don't cover this obvious potential problem). So I assembled the two brass tubes that go from the chassis to the metal plates that will be glued into the body. The conversion comes with the two really long screws, the brass tubes they go through, and a nut. I assembled these parts per the instruction along with the loose metal plates, out of the body. One of the plates is shorter that the other and that is to allow clearance for the powered truck so the short plate goes on the end of the chassis where the powered truck is. Once I got the mounts tightened down with the provided nut and the end plates, I put small pieces of masking tape over the threaded screw holes in the mounting plates to keep the glue out of those holes. Failure to do this might only allow one assembly of the trolley with no way to take it apart later.

Now it was time to glue the chassis plates to the body while they were assembled to the chassis. A trial fit might be prudent. I smeared two part epoxy on the top of the mounting plates carefully and pressed the chassis into the body. I laid out the trolly upside down to keep the chassis tight against the top of the body while the glue dried. After the glue totally dried I verified the screws did not get  glued in by slightly loosening them and then re-tightening them. Time for the road...errr.... rail testing.

I found that the trolley would now run smoother and slower (if desired). And the body was definitely at the correct height above the rails. The latter is the "extra feature".

This modification is very good indeed. Too bad the instruction are so meager but I got it right, none the less. The cost is OK when you consider what I got in the end... a Los Angeles lines PCC trolley in the 1950's Yellow paint scheme that no one else makes, and a trolley that runs better than the original. Also included was the correct body height above the rails.

Hope this helps.

LDBennettt

[LDBennett]

I may have screwed up the Bowser chassis for the Bachmann PCC (not permanently). I installed the A-Line flywheel weight which went on OK but the first test shows that the starting voltage to the motor has to be higher which limits it minimum speed on my trolley layout since  the layout has four stops, two of which are reverses. I don't see any significant improvement in the momentum stopping and starting at first run. I'll test it some more. If the resistance to startup continues I'll take out the flywheel (if I can, as it is glued to the motor shaft with LocTite 609...heat may soften it??).

Sometimes you can get carried away with modifications to anything in the pursuit of perfection, which is un-obtainable! I may have been better off without the flywheel weight (??). To be fair I have to test it more.

LDBennett

[LDBennett]

Well, I was wrong!!!

Extended testing showed that the flywheel weight made the Bachmann/Bowser PCC trolley run much smoother at a snail's pace.

I still did not notice much of a momentum effect other than allowing the trolley to run smoother. There seems to be little effect in the stops and starts.

But the contrast in the detail of the Bachmann PCC shell to the the Con-Cor PCC trolley is stark. The illumination of the Con-Cor PCC is fantastic. The Con-Cor PCC Trolley, even at very low throttle settings, is fully uniformly illuminated (from end to end). The Con-Cor interior detail, as seen through the crystal clear windows, is amazing whereas the Bachmann PCC has little painted on people in semi opaque windows (toy like). The Con-Cor will move nearly as slowly as the Bachmann/Bowser PCC trolley, just not as smoothly since it has no or minimal flywheel. There must be a voltage regulator inside the Con-Cor for the illumination and the motor as it takes a throttle setting nearly twice what all the other of my trolleys take.

So.... The flywheel weight works for the Bachmann/Bowser. The Con-Cor out of the box is more impressive for looks and nearly the match of the Bachmann/Bowser for slow running. I'm happy with both trolleys but especially with the Con-Cor!

LDBennett

[ebtnut]

Without digging deeply into the ConCor circuit design, in all likelyhood the lighting is via LED's, which basically come on steady with any voltage.  The Bachmann most likely simply has standard 12v bulbs, which only start giving you light about about 4-6 volts.  My one little gripe about the ConCor lighting is that it seems to use the "blue-white" LED's.  I think many if not most of the pre-war PCC's probably had incadescent lights which are "warmer" in color.  The blue-white color is probably OK for a car fitted with flourescent lighting. 

[LDBennett]

ebtnut:

Part of the Bowser modification chassis was the elimination of the plastic light spreader. There is just not room for the big motor/trucks and lighting and the light spreader. They used incandescent bulbs which at slow normal trolley speeds are so dim as to be useless. I stuck the bare bulbs back into the chassis but they barely illuminate if at all.

You are probably right about the LEDs in the Con-Cor PCC trolley. There is, after all, a circuit board in there for DCC (I believe it is DCC "Ready"). Including LEDs for illumination would be simple for Con-Cor. I am not a purest for this hobby and blue white or yellow white illumination makes no difference to me but I am impressed in the effect of the Con-Cor interior. I'd certainly buy another Con-Cor trolley. I have a Bowser trolley on the way and it will be interesting to see how it works and looks.

This is getting addictive (buying trolleys). Im up to five with the Bowser and all I have is eight feet of straight track. The layout is nearing completion at great expense way beyond my initial concept but it has been fun so far. I am contemplating complete Microprocessor controlled operation rather than expanding the layout. My grandson can do the programming for me (he's into programming and I want him to cultivate his natural ability to program).


LDBennett