Proto F7 to slow at full throttle

[rrinker]

Reset. WHen in doubt, reset! Factory default values for NMRA compliant decoders will have no settings which can possible affect speed. Simple, basic settigns that shoudl work on any system. If that doesn't fix the problem, then it's time to look elsewhere.

                          --Randy

 

[Hamltnblue]

Thanks for giving us feedback on what worked.  Too many times people ask for info and after fixing the problem don't return to close the forum and let everyone know the fix. Enjoy.

[Railcon44]

Problem solved, yeah! I reset the engine back to factory default and tested it and came up with 74smph. Thats good enough for me. I want to thank everyone that put there heads together and gave me lots of different areas to look at to solve the problem. THANKS

[ATLANTIC CENTRAL]

Texas Zepher

ATLANTIC CENTRAL

rrinker

Run the loco at what you THINK is 50mph - then actually time it - it's probably going WAY faster than that. Meaure and time 15mph - typical max speed in yard limits - you'll think the loco is hardly moving.

the OP said his DCC versions would only go 64 SMPH, my DC versions go 82 SMPH?

I measured mine right at 70mph using one of the little speed tunnel measuring devices.

DC or DCC?

[Texas Zepher]

ATLANTIC CENTRAL

rrinker

Run the loco at what you THINK is 50mph - then actually time it - it's probably going WAY faster than that. Meaure and time 15mph - typical max speed in yard limits - you'll think the loco is hardly moving.

the OP said his DCC versions would only go 64 SMPH, my DC versions go 82 SMPH?

I measured mine right at 70mph using one of the little speed tunnel measuring devices.

[Hamltnblue]

Your 14.5v track voltage is good.  I agree with it probably being the decoder.  Can't hurt to try resetting the decoder to factory to make sure it doesn't have any changed settings causing the problem.

[Railcon44]

My DT400 is plugged into the DCS100 and the mode switch is set to Ho, i never change that, i only look at it to make sure it hasn't been tamper with. I was just reading the manual and it says the voltage that is displayed on the DT400 screen is just the voltage that is available to the throttle. This voltage display will only change if the DT 400 is plugged into a LocoNet and than you might see the value between 9& 15 volts. I just want to let you guys know that i'm not sitting here waiting for an answer. I got the Digitrax books out and doing alot of reading. Railcon44

[Grampys Trains]

Hi Railcon44: According to the maual, when you are plugged into Loconet, the value will be between 9 & 15 volts. If you have radio, and insert a battery, the value will be the battery power available. DJ

[CSX Robert]

Railcon44

If the voltage on the throttle is only 9 volts when turned on, should that be reading the voltage that is going to the track?

Usually not. If you have the throttle plugged straight into the command station, the the voltage reading will be the railsync voltage, which is not the same as the track voltage. If the throttle is plugged into a UP5, then the voltage depends on where the UP5 is getting it's power. The UP5 can be powered in three ways: from railsync, an external power supply, or from the track power connections on the back of the unit. There is a set of steering diodes in the UP5 to direct power from these three inputs to the throttle jacks. The voltage reported by the DT400 will be whatever the highest of these three voltages is minus the voltage drop through the diodes.

[ATLANTIC CENTRAL]

Railcon44, One of these DCC guys will have to answer that, I use DC.

Randy, I agree, if I did use DCC, the factory boards would have to go. Actually, some of them do go now. I buy bluelline and other BLI/PCM locos (only at REALLY low prices) and remove the sound boards and rewire them completely. And, Bachmann's cheap built in dual mode decoders is stuff like the GE 70 toner, all bypassed and lighting rewired.

Sheldon

 

[rrinker]

 Makes me wonder what their circuit board looks like. The complex ones in the older E's and PA's I ALWAYS bypass when installign a decoder. A good decoder does a better Mars light effect then their silly 2 filament bulb, and bypassing the board eliminates any oddness in the way they wire it - extra diode drops to the motor, that sort of thing. No speed problems on those. I haven't seen a new one yet, if they use the same sort of circuit board as the older releases or if this is something all new.

Just one more reason I strip factory boards. Worst was a P2K SD7, those didn;t have DCC sockets, you were supposed to sodler the wires in certain holes and cut a couple of traces. I drew out the circuit and there's just no way it would have worked properly after cutting where they marked with an x.

            --Randy

[Railcon44]

Okay this is what i got. I have a Digitrax Super chief with the DCS 100 command station booster and a DT400 throttle. Now that we are talking voltage, i have noticed that on the throttle when i turn it on that it sometimes says 9 volt and the next time i turn it on it says 7 volts. I have checked the actual voltage at the track and that shows 14.5 volts. Should this be? All my engines are DCC with sound that came from the manufacture except for 3 that i installed myself and they have Digitrx decoders in them. My F7's came from the manufacture with DCC and sound already installed. I have 46 engines in all. My layout is 14x12 with 2 main lines. Number 1 main has 30 degree curves and number 2 main has 28 degree. I have made sure that all the track is clean and the engines are clean as well as all the cars. But this voltage problem that has come up here, i'm kind of wondering about. If the voltage on the throttle is only 9 volts when turned on, should that be reading the voltage that is going to the track?

[ATLANTIC CENTRAL]

rrinker

 He's using Digitrax, maybe he has the track settign on N scale instead of HO, that's 12V to the track (DCC signal peak) so after rectifiers and the drive transistors the motor is probably seeing 10 volts peak.

 Or he has a power supply with too low an output - the Digitrax power supply is 15VAC, if the command station is fed only 12V AC it's going to be hard pressed to put out 15 to the track (close - because of RMS from filtering), or if it's a 12-14V DC supply going in, it won't even reach 12 volts out.

 Or the previously mention speed table or non-zero entry in CV5, setting a less than full top speed.

 Personally, I don't do passenger trains so I'm perfectly happy with the top speed of my freight locos when run on 12V DCC. My switchers I block down even more with CV5.

                                                     --Randy

 

OK, that still makes it a DCC/decoder (note the slash - translation = one or the other) issue.

NOT a mechanical/electrical problem with the speed capibility of the motor or the gear ratio.

Walthers has taken some heat for the 14:1 gear ratio, mostly from people using DCC. Maybe this is the whole problem.

Sheldon

[rrinker]

 He's using Digitrax, maybe he has the track settign on N scale instead of HO, that's 12V to the track (DCC signal peak) so after rectifiers and the drive transistors the motor is probably seeing 10 volts peak.

 Or he has a power supply with too low an output - the Digitrax power supply is 15VAC, if the command station is fed only 12V AC it's going to be hard pressed to put out 15 to the track (close - because of RMS from filtering), or if it's a 12-14V DC supply going in, it won't even reach 12 volts out.

 Or the previously mention speed table or non-zero entry in CV5, setting a less than full top speed.

 Personally, I don't do passenger trains so I'm perfectly happy with the top speed of my freight locos when run on 12V DCC. My switchers I block down even more with CV5.

                                                     --Randy

 

[ATLANTIC CENTRAL]

rrinker

 I suspect more so that it's not a decoder issue, it's a perception issue. Run the loco at what you THINK is 50mph - then actually time it - it's probably going WAY faster than that. Meaure and time 15mph - typical max speed in yard limits - you'll think the loco is hardly moving.

Randy, maybe, but the OP said his DCC versions would only go 64 SMPH, my DC versions go 82 SMPH?

Sheldon

[rrinker]

 So long as CV5 is set to 0 or 255, and there is no speed table in use, a typical system putting 15 volts to the track will deliver right about that same 13.5 to the motor after the rectifier and the loss in the H bridge driver circuit. SO - reset the decoder to factory default and check the speed again.

 I suspect more so that it's not a decoder issue, it's a perception issue. Run the loco at what you THINK is 50mph - then actually time it - it's probably going WAY faster than that. Meaure and time 15mph - typical max speed in yard limits - you'll think the loco is hardly moving.

                                          --Randy

 

[ATLANTIC CENTRAL]

OK, I got curious, so I measured the top speed of my DC versions of the new Proto F7's. I have two ABA sets.

My throttles put out a maximum voltage of 13.5, pulse widith modulated DC.

Averaging about 8 passes through my "measured" level straightaway, I got a top speed of 82 scale MPH, or about in the middle of the gear options on the prototype.

So, I would have to conclude, 14:1 gears and all, that this complaint and those from others, and possibly similar complaints about newer Proto E units, is a DCC/decoder issue, not actually a motor speed issue.

My older Proto E-8's go 90 SMPH on my 13.5 volts.

Sheldon

[cudaken]

Proto E-7s are just slow. I have one with QSI sound and top speed is about 60 to 62 MPH. My Proto E-6's on the other hand. I have a powered E-6 B with a Digitrax DH 123 speed matched to the E-7. E-6 CV 6 had to be sat at 121 and CV 5 sat at 211 so they will run with out fighting each other. 

 

             Cuda Ken

[Railcon44]

I really appreciate all the help you guys have giving me, thank you. All 3 of my F7's have dcc and sound just the way they came from Proto. I haven't tried to do to much to them, just change their addresses and tone down the sound. What i been doing if i want the passenger train to be faster than the freights is put the 2 Athearn FP45's i just got, they also have dcc and sound on the passenger train. The Athearns are not all that smooth when they start pulling, but i think with a little tinkering i might beable to help that problem. Railcon44

[Steve_F]

F7’s at 60mph top speed sounds about right to me. That’s what I program my top speeds to any way, most of the time they will run at about half that or less anyway.

[Phoebe Vet]

FYI:

I have had a Proto F3 AB set with Digitrax DZ123PS  Decoders I recently bought another identical set except that that decoder has been discontinued so I installed DZ125PS decoders in the new ones.

When I began to speed match them, the difference in speeds was major.  I swapped one set of decoders between an original engine and the new engine, and the performance difference moved with the decoder.  Now all 4 engines have DZ125s in them and the performance is identical with no adjusting required.

The moral of this story?  Maybe it's the decoder.  Not defective, just different.

[Railcon44]

I tested one F7 and got a speed 59 smph than tested all 3 units mu together and got a speed of 64 smph and seem to make no difference when attaching 10 passenger cars to them. My track radius is 30 degrees on main 1 and 28 degrees on main 2

[ATLANTIC CENTRAL]

EMD F7's where available with 8 different gearing options. They produced top speeds of 55, 65(this was the standard equipment), 71, 77, 83, 89, 95, 102 MPH.

Many railroads used them for passenger service and had them geared accordingly for their needs.

Sheldon

[Hamltnblue]

I Got 29.65 Smph using the above example.

1800 ft/hr times 87 equals 156600 scale feet per hour

There are 5280 feet in a mile

156600 / 5280 equals 29.65mph.  basically 30Smph.

[Texas Zepher]

Railcon44

I have a Proto F7 and when i run it at full throttle it seems slow to me.

Walther's have standardized on a 14:1 gear ration in the new Proto's.  This means the top speed is about 70 smph.  For a freighter this would be just fine.  For a passenger loco (like the ones they produced for the Empire Builder) it is too slow.   The only way I know to fix it is to re-motor with a high-rev unit or change the gearing.  I have yet to attempt either.

[JoeinPA]

 Hi Railcon44:

Since you mentioned that you are using a DT400 can I assume that your loco is equipped with a decoder?  If so, it may be that CV5 has been set too low.  Give it a check and adjust it to a larger value if needed.  If it is set to a high enough value and you still are running too slow then David's advice is the proper place to start your diagnosis.

Joe

[tstage]

Douglas,

Has it always run slow?  What "seems" slow and what actual sMPH (scale MPH) is may be two different things?  Have you actually calculated how fast your locomotive is going scale-wise?  It may be faster than you think.

I would first figure rate/hour per the distance formula (distance = rate x time, or rate = distance/time for rate) then divide by 87.1 (HO) or 160 (N) to get the actual sMPH of your locomotive.

_______________________________________________________________________________________

Example: It takes 6 seconds (time) for your locomotive to travel 3 feet (distance) in HO scale and you want to figure out how fast (rate) that is prototypically:

If rate = distance/time, then rate = 3'/6 sec. or 0.5'/sec.

Multiplying 0.5/sec. by 3,600 (to convert seconds to hours - i.e. 60 seconds x 60 minutes), rate = 1,800'/hr.

[Edit: Dividing 1,800'/hr x 5,280 (to convert feet to miles), rate = 0.34 MPH]

Dividing 1,800/hr. Multiplying 0.34 MPH by 87.1 (to convert to scale MPH or sMPH in HO), rate = 20.67 29.61 sMPH

_______________________________________________________________________________________ 

Douglas, I also did a search on Google ("top speed of an EMD F7") and found out that F7s only had a top speed of 65 MPH.  Here's the site where I found that info.

So, given the above: An HO F7 running at prototypical top speed would be traveling at ~1.57 ~1.1 feet/sec.

Hope that helps...

Tom

[Edit: Sorry for the miscalculations, everyone.   Hamltnblue, thanks for the correction.]

[Railcon44]

I have a Proto F7 and when i run it at full throttle it seems slow to me. I use a DT400 throttle by digitrax. Is there a way to boost the top end or are they just slow? Railcon44