Help with BLI E7 (Partial Solution update)

[mecgp7]

I purchased a BLI E7 because I had to have the paint scheme. I run DC and this loco can run on both DC and DCC right out of the box. The problem is that I want it to run DC without the bells and whistles aka the sound and momentum features. The loco does not operate to my liking as it is slow to respond due to the sound start up process. It also does not perform well on the run. Any electrical interruption and it stops and starts the process all over again. Speed control is an issue to as I have trouble keeping it at a constant speed.

Basically, the loco is too advanced for me now and I am wondering if I can dumb it down. I'd like to have it run like any of my other DC locos and I don't care if I lose the sound. I have inquired about this before, but I didn't get too far. I have a DCC test track if anything needs to be changed using it.

If anyone can help, I'd sure appreciate it. For now all I have is an expensive shelf Queen.
Many thanks in advance,
Clint

[peteski]

The sound decoder will always need a high starting DC voltage.  You basically want to remove the decoder and hard-wire the motor (and headlights) to the truck pickups.  That should not be difficult. If the headlight LED is soldered on the decoder board you might have to do a bit of improvising to have a working headlight in DC.  The DC headlight LED will need a current limiting resistor and a diode for protection.

[C855B]

Good luck with this. I have a BLI E8 here sitting on the desk with the shell off; I think this E8 is contemporary to your E7 and likely has the same chassis. (I also have earlier E8s from the first run, when they offered a DC version.)

From what I can see, they deleted the 8-pin "NMRA" connector at the back of the chassis that was on the convertible versions. That would've made it a piece of cake. But now there appears to be no easy way to do what you want (decoder-ectomy?) without digging into the wiring harness, tracing leads, and then cutting and splicing. This would essentially make the conversion permanent, or highly inconvenient to restore.

This particular BLI sound decoder is operationally weak, as you have discovered. I will eventually replace mine with a non-sound decoder, but the stack of "to-do" projects on the workbench is completely out of control and when this is going to happen will be anybody's guess. I have a PA and PB in the same boat that needs this done, too. [sigh]

[mecgp7]

In my opinion, the loco can't be much good even to DCC operators unless it operates differently in DCC. How does one keep it from coming to a complete stop every time it loses conductivity. My DC locos glide right through it. Did the earlier DC versions have this issue? Would I be able to swap out the chassis? Kind of a drastic move, but the unit is useless to me now.

[C855B]

No similar issues with the older DC version, they run like any other flywheel-equipped loco. I converted mine to conventional (non-sound) DCC, and they still run fine. The problem is entirely the poor ride-through characteristics of the BLI sound decoder.

Your problem with the chassis swap idea is finding one of the older ones. The BLI DC versions were rare as hen's teeth. In your (and my) case, the path of least resistance appears to be taking on the wiring modifications to remove the decoder. Let me mull over taking this on in the next day or so. My original intent with the one I have was to sell it on eBay since I bought it as part of an A-B set where just I needed the B. This was (and is) the only way to acquire a dummy B to match the other four powered units I had from the first run.

[peteski]

If keeping DCC, these locos seem like good candidates for keep-alice capacitor circuit.

As far as poor contact goes (and decoder resets), I've heard that they have very finicky contacts. Combine that with not 100% perfect trackwork (very few modelers have 100% perfect trackwork), and you have a loco stalling repeatedly (especially at slow speeds). The slow decoder reinitialization makes things even worse.

[C855B]

"...finicky contacts. ..."? Probably a misdiagnosis of the OMG decoder restart issue. BLI hard-wires to the trucks, no frame contacts like we're used to with most of the other makers. It is possible... haven't verified... there may be an issue with truck range-of-movement that plays into loss of contact at the track. As far as a keep-alive cap goes, very little room. It seems like they've used every cubic millimeter. Probably could do something like sacrifice a speaker (there are two) if you had to, and then you'd have to know where the cap(s) would attach to the board.

[peteski]

"...finicky contacts. ..."? Probably a misdiagnosis of the OMG decoder restart issue. BLI hard-wires to the trucks, no frame contacts like we're used to with most of the other makers. It is possible... haven't verified... there may be an issue with truck range-of-movement that plays into loss of contact at the track. As far as a keep-alive cap goes, very little room. It seems like they've used every cubic millimeter. Probably could do something like sacrifice a speaker (there are two) if you had to, and then you'd have to know where the cap(s) would attach to the board.

I seem to recall an earlier thread here with several people complaining about the poor running qualities of the BLI 6-axle diesels. I don't recall the specifics but it was finicky contact. Maybe a coating on the wheel treads, or wheel to pickups.  Maybe it was a model from an earlier run?

These are large models as far as their internal volume goes. There is no way to mill out some of the metal frame to make room for keep-alive caps?

[mecgp7]

When all else fails, read the manual . In the manual it shows how the DC start-up process can be essentially turned off. There are a few other CVs that can be adjusted for DC. So I need DCC to control some of the DC functions. Fortunately I have a Digitrax system and test track for testing decoder equipped locos. I'll give it a shot and report on the results.

[mecgp7]

So I played with the DCC system and managed to make an improvement in the loco's DC operation. By changing CV248, the start up delay, I was able to get the loco to start and move almost instantly. The factory setting was 20 and I changed it to 1. Now the loco runs like a normal DC loco except that I have to use the upper half of the throttle and I need to start it at almost full throttle to get it to start. Once it gets up to the desired speed (which it does slowly), I back off the throttle. It then responds almost as a normal DC loco.
There are two other CVs that affect DC operation, CV251 and CV252. 251 is the enhanced DC motor control Vmax and controls the voltage at which 100% of track power is sent to the motor. 252 is enhanced DC motor control Vmin which controls the voltage at which the motor will start moving (lower value=lower start voltage). I played with these and only managed to make the loco N inoperable. I figured lowering each would enhance control, but obviously I am doing something wrong. All I know is that the value of 251 must be higher than 252.

[Mike C]

Maybe try leaving CV251 alone and lower CV252 ?  I've got two of their M1's that gave me nightmares trying to get the sound and performance that I wanted . ( not that they were bad , just not what I wanted )  I eventually sent them to Woodone and he replaced the decoders with the new Tsunami 2 decoders . I'm much more familiar with Soundtraxx decoders and the locos run even better with them .

[mecgp7]

I did try that, but my limited abilities in DCC may have interfered. I also found that I could not check the DC operation of the loco on the Digitrax DC power source. Any changes that I made to the DC function would only work when I put the loco on my DC layout.
I don't understand why lowering both 251 and 252 would work, but it didn't. I will re-run the CVs and try lowering 252 again.

[davefoxx]

One of the best ways to fix the intermittent electrical contact problems is to replace the traction-tired axle with a regular wheelset.  These can be purchased from BLI (I hope you still can, since I haven't done mine yet).  That traction-tired axle essentially reduces the rear truck to pick up by probably just two wheels, since the traction tires are insulation and the middle axle probably doesn't have good contact due to the thickness of the traction tires on the rear axle.  I also found that regauging my wheelsets helped a lot (for some reason), which is why I haven't gotten around to replacing the wheelset with traction tires.  That, and I'm lazy.

Hope this helps,
DFF

[dougnelson]

I used to run my BLI Precision E7s in DC with only fair results.  I had purchased an A and B units, both powered, but I discovered in DC they did not run in sync, so I returned the B unit for a dummy (which BLI no longer makes).  With the coming of the Bachmann K4 and the BLI PAs, M1, and Centipedes, I added DCC to my layout and I have to say, all these engines run better in DCC despite being advertised as DC compatible.  For me, adding DCC could not have been more simple.  I had dual-cab blocked DC operation and I swapped out one of the DC cabs for the DCC system, still retaining one DC cab to run all my non-DCC locos.  My control panel, that previously switched each block between the two DC cabs, now toggles each block between DC or DCC.  I easily run DC or DCC locomotives (but not on the same track).

I know that may not be your solution, but consider before cutting out the decoders and burning the bridge to DCC. 

[peteski]

I used to run my BLI Precision E7s in DC with only fair results.  .

That is true. DCC decoders were made for DCC and are best operated on DCC.  The analog compatibility mode is just a function to make them operable on DC. But they will never run as well on DC as decoderless DC locos.  This is especially true for sound decoders where the sound circuitry needs a fairly high voltage to even initialize.  This is nothing new and there is no good way to change that. Not even mentioned is the fact that running decoders in DC does not allow using all of the decoder's capabilities (especially the sound decoders).

A full-function DCC systems can be purchased from several manufacturers like NCE, Digitrax or MRC.  It often makes sense to buy one of those to see the difference.   I know some people here (like @Joetrain59 ) took that road and I don't think the have regretted it. Right Joe?