How Necessary is the PC board in an HHP-8?

[richg]

I would not lubricate the wheels. Metal wheels that are free rolling only. Possibly a dry lubricant. Any kind of wet lubricant will pickup dust over time.
Using a Truck tuner might help when checking the trucks for free wheeling.
Usually cutting the capacitors is all that is needed. The inductors are very low resistance and without the capacitors, they are not even noticed by the PWM power to the motor. You can solder a short piece of wire accrues the inductors if that makes you feel better. I have never found a need to do this.

All the PC boards I have seen use just inductors and capacitors for the motor circuit..

A higher DCC voltage will help but I have never tried this.

Rich

[mlrr]

I shy away from trying to use higher track voltages than necessary although this was the first thing I thought about doing.  Tampering with the track voltage leaves room for all types of problems down the road including the possibility of frying the custom bulbs you spent time installing in another locomotive, etc.

Lubrication is not the main problem but as you indicated as well as others, it's the PC board.  I do remember the suggestion of cutting the capacitors but given the little experience I have in circuitry I did not want to risk cutting the wrong thing.

[richg]

Below is a link to see what a couple PC boards look like. One was in a Spectrum 4-6-0 and the other in a Spectrum 44 ton. Scroll down to the last message.

http://www.bachmanntrains.com/home-usa/board/index.php/topic,14147.0.html

On the PC boards, a resistor is R1, R2, R3, etc.
Capacitors, C1, C2, etc
Diodes, D1, D2, D3, etc.
Inductors, L1, L2.

The PC boards I have seen so far have the component numbers.

Rich

[ac_catenary]

I have had similar problems with the first run of the Acela and HHP-8 locomotives and was considering turning up the voltage because a Friend of mine had similar problems with an acela equipped with Sound. He turned up the booster and speed problem was solved.   I will remove the capacitors and see what happens

[mlrr]

I have had similar problems with the first run of the Acela and HHP-8 locomotives and was considering turning up the voltage because a Friend of mine had similar problems with an acela equipped with Sound. He turned up the booster and speed problem was solved.   I will remove the capacitors and see what happens

Please keep us informed.  My hardwiring method was pretty straight forward for me. 

Are the capacitors between the pick-ups and the motor or the decoder and the motor?  I assume its the latter since the motor bypass seemed to yield noticeable results.

[richg]

Are the capacitors between the pick-ups and the motor or the decoder and the motor?  I assume its the latter since the motor bypass seemed to yield noticeable results.

The inductors and capacitors are between the motor and decoder.
My Spectrum 70 ton had the capacitors right on the motor leads and the inductors on the PC board.
What people mistake for resistors are the two components that look like resistors with the colored bands.



My Spectrum 44 ton, capacitors and inductors where on the PC board.

There may be variations for different locos.

Take pictures and post them here. It will benefit the model railroad community.

Rich

[mlrr]

I found the two different boards on Bachmann's website:

Note the subtle differences between the two:

Earlier version w/o LED = $30



Newer Version (w/LEDs) = $40



I plan on doing the last modification tonight (hopefully).  I'll try and post those pictures as well.

[richg]

Good photos. I have saved them for future reference, Never can tell who might have a question about these boards.

I downloaded both photos and expanded them about three times. On both boards, C1 and C3 are capacitors for the LED's.
On both boards, C2 and C4 are connected to the inductors.
Clip C2 and C4.

The second board, Surface Mount capacitors are used.

Rich

[mlrr]

I'm curious.  Would cutting the capacitors also improve the motor's response to the throttle.  On my NCE powerhouse Pro, I have to throttle up pretty high for the engine to start moving.  I've played with the start voltages ever since I got the HHPs.  There's really no improvement.

[richg]

I'm curious.  Would cutting the capacitors also improve the motor's response to the throttle.  On my NCE powerhouse Pro, I have to throttle up pretty high for the engine to start moving.  I've played with the start voltages ever since I got the HHPs.  There's really no improvement.

Cutting the capacitors is primarily because of decoders that have the BEMF capability.

Do a search for

bachmann capacitors dcc bemf

The Bachmann on board factory equipped locos are low end decoders the do not have BEMF capability.
The locos that have sound are the Tsunami and run fine.

There may be other issues if the loco does not run like you expect it to. Might be the gearing.

Rich

[mlrr]

I was referring to my older locos of the same model type with the older PC board.  They have Digitrax decoders.

[richg]

I was referring to my older locos of the same model type with the older PC board.  They have Digitrax decoders.

Which model Digitrax decoder? Try to give more details with an issue like this.

Rich

[Jim Banner]

mirr, you have  basically answered your own question.  Diigitrax decoders and the capacitors still in place.  Digitrax and all other "silent" decoders send high frequency pulses to the motors.  The motors appear silent because these pulses are above the frequencies that can be heard by humans (dogs and bats may have trouble with them.)  The trouble starts when the motor has anti RFI capacitors connected across it.  These capacitors are virtually a short circuit at high frequencies.  So the decoder senses an overload condition and reduces or turns off its output to protect itself.  For more information, see the Digitrax Website or the Digitrax Yahoo! group.

Jim   

[mlrr]

Thanks Jim!

Just an update, I operated one of my HHPs with semi-hardwired decoder last weekend with a five-car Amfleet I consist and it easily made it up to 125 MPH with my NCE throttle set at 123/126 throttle.  No additional modifications were necessary .

[CAB_IV]

wow, i didn't even geta notification from bachmann!

Anyway, the semi hardwiring solution is so simple that i to wonder why i hadn't thought of it.    Maybe this year i'll be able to get this HHP-8 out there for show season.