Bachmann 2 EPB

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Simon_S
Posts: 89
Joined: Wed Aug 06, 2008 7:32 am

Bachmann 2 EPB

Postby Simon_S » Sun Jul 17, 2011 4:37 pm

This lovely model is simple to convert to P4, here’s how I did it:

The motor bogie uses stub axles pressed in to a central nylon gear muff. Electrical pick up is via the bearings that have an additional groove for a brass contact strip. There is just enough room between the sideframes for P4 wheelsets. I simply drifted the Bachmann wheels off the stub axles (who's outer section is conveniently 2mm diameter) and replaced them with Maygib wheels; it was necessary to extract the stub axles slightly from the muff to get sufficient engagement of the wheels but the axles stayed true and seem solid enough. As the Maygib wheels are insulated, I shorted them to the stub axle with conductive paint. Before refitting the sideframes, I cleaned up their inner faces to remove some moulding flash; with P4 wheelsets, there is hardly any sideplay so I haven’t bothered with any other spacers.
Bachmann 2-EPB P4 Conversion 007.jpg
Motor bogie
Bachmann 2-EPB P4 Conversion 007.jpg (74.6 KiB) Viewed 3766 times

On test running, the motor bogie had an unfortunate tendency to derail in curves. A little investigation found that the bogie was slightly twisted so two diagonally opposing wheels were unloaded; this only occurred when the sideframes were attached. Witness marks on the frames showed that they were pressing on the axle bearings so I pared a little plastic away to remove this contact. This solved the derailment problem.
The unpowered bogies are a little more complicated due to Bachmann’s pick-up arrangement that uses split axles with pick-up via pressed brass outside bearing strips. As with the motor bogie, there is just enough space between the sideframes for P4 wheelsets, but not with the pick-up/bearing strips in place. Fortunately, bearings are still moulded in to the inner faces of the sideframes so normal wheelsets can be used. It is also necessary to trim the corner of the wheel aperture in the bogie frame and clean up the inner faces to remove some moulding flash.
Bachmann 2-EPB P4 Conversion 005.jpg
Unpowered bogie frames
Bachmann 2-EPB P4 Conversion 005.jpg (124.16 KiB) Viewed 3766 times

I snipped the bearing sections off the strips and soldered 40mm lengths of 0.45mm nickel silver wire to the upright section, taking care to be quick with the soldering iron so as not to affect the brake shoe moulding that is heat staked on the remaining centre section of the strip. The wire was bent to bear against the rear of the wheels, as close to the centre as possible to minimise drag.
Bachmann 2-EPB P4 Conversion 001.jpg
Unpowered bogie pick-ups
Bachmann 2-EPB P4 Conversion 001.jpg (131.88 KiB) Viewed 3766 times

Before re-assembly, I blackened the upright section with a permanent marker pen. The resulting bogie runs quite freely. I was pleasantly surprised that the brake shoes didn’t need any attention, especially as the Maygib wheels are slightly oversize.
Obviously this is a very basic conversion, but it works for me. Now, how to improve on that bar-coupling…

PS I’ve seen the forthcoming Hornby 4 VEP and that looks like it’ll be an easy conversion too – inside bearings in the unpowered bogies, horrible inter-car couplings though, I’ll be replacing them with Kadees.
Last edited by Simon_S on Sat Jul 23, 2011 11:23 am, edited 1 time in total.

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Ian Everett
Posts: 385
Joined: Tue Jul 21, 2009 9:43 pm

Re: Bachmann 2 EPB

Postby Ian Everett » Sun Jul 17, 2011 6:43 pm

I'm interested in your use of conductive paint to short wheels to axles, as I have not come across this before. Can you point me to the type to use, please.

I wonder if anyone has used it on steam loco wheels? I fear the soldering shorting etches will damage the plastic centres of Gibson wheels, although I seem to have managed disaster so far!

Ian

User avatar
Simon_S
Posts: 89
Joined: Wed Aug 06, 2008 7:32 am

Re: Bachmann 2 EPB

Postby Simon_S » Mon Jul 18, 2011 7:40 am

Hi Ian,
This is the conductive paint I used:
Ebay Conductive Silver Paint
It was easy to apply, dried very quickly and resulted in a zero ohms connection. I can't see any reason why it wouldn't work on steam loco wheels but I would paint every spoke with it to give as much conductive area as possible.
Best regards,
Simon


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